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Чемич, Оксана Миколаївна, Оксана Николаевна Чемич, Oksana Mykolaivna Chemych, Я. Л. Кравцова i А. А. Олефір. "Structure of opportunistic infections in patients with HIV- infection". Thesis, Sumy State University, 2018. http://essuir.sumdu.edu.ua/handle/123456789/74893.
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Діагностика першої та другої стадій ВІЛ-інфекції низька. Опортуністичні інфекції та супутні захворювання посилюють перебіг ВІЛ-інфекції. Найбільш поширеною опортуністичною інфекцією є кандидоз ротоглотки. У структурі супутньої патології переважають хронічні вірусні гепатити С і метаболічна кардіоміопатія.Диагностика первой и второй стадии ВИЧ-инфекции невысока. Оппортунистические инфекции и сопутствующие заболевания обостряют течение ВИЧ-инфекции. Наиболее распространенной оппортунистической инфекцией является кандидоз ротоглотки. Хронический вирусный гепатит С и метаболическая кардиомиопатия преобладают в структуре сопутствующей патологии.
Diagnosis of the first and second stages of HIV-infection is low. Opportunistic infections and concomitant illnesses aggravate the course of HIV-infection. The most common opportunistic infection is oropharyngeal candidiasis. Chronic viral hepatitis C and metabolic cardiomyopathy are predominate in the structure of concomitant pathology.
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Chung, Moonsik. "Infection /". Link to online version, 2006. https://ritdml.rit.edu/dspace/handle/1850/2291.
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Thesis (M.F.A.)--Rochester Institute of Technology, 2006.Typescript. Film produced by Damul Films. Director, Moonsik Chung. Cast: Jonathan Flanigan, Ashley St. John-Yantz, Greg Petralis, Jesse Knight. Co-writer, Oreathia C. Smith.
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Corvellec-Rudelli, Anne. "Les infections néo-natales". Bordeaux 2, 1989. http://www.theses.fr/1989BOR23061.
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Richard, Patrick. "L'infection en réanimation : étude prospective". Montpellier 1, 1990. http://www.theses.fr/1990MON11221.
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Nguyen, Patrick Bouaziz Hervé. "Etude de l'intérêt et influence de la décontamination digestive sélective chez le patient polytraumatisé ventilé en réanimation chirurgicale". [S.l.] : [s.n.], 2001. http://www.scd.uhp-nancy.fr/docnum/SCDMED_T_2001_NGUYEN_PATRICK.pdf.
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Walzl, Gerhard. "The influence of infection history on the immunopathology of unrelated infections". Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405807.
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Bettridge, Judy. "The epidemiology and ecology of infectious diseases in Ethiopian village chickens and the role of co-infection in infection risk". Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/2004959/.
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The scavenging village chicken is important to millions of smallholders in Ethiopia, as in other less-economically developed countries, for its contribution to the economic, nutritional and social well-being of farmers, especially women and children. Infectious diseases are frequently cited as the greatest constraint to village chicken production, and in Ethiopia, most mortality is attributed to seasonal outbreaks of Newcastle disease (ND). This study conducted four cross-sectional surveys over an 18-month period in two geographically distinct regions of Ethiopia, to examine a range of bacterial, viral and parasitic infections in randomly-selected village chickens, and to look at their 6-month survival rate. The two chicken populations of the different regions were found to be different in terms of their population dynamics and phenotypic characteristics, and these may be driven by farmer demands, which are dictated by the local economic and cultural value placed on specific qualities in the chickens. Over the course of the study, no large outbreaks were observed in the eight villages which took part in the study, and only 9 out of 1280 birds (0.7%) were found to be serologically positive for ND. However, even in the absence of large outbreaks, around 20% of the birds in the study were reported to have died of disease within the 6-month follow-up period, and a further 13% lost to predation. Both location and seasonal variation influenced a bird’s fate, as did farmer decisions, such as choosing birds with specific characteristics to sell or eat. Rather than large outbreaks, the rainy season appeared to be associated with increased small-scale losses, and a variety of signs were described, suggesting several pathogens may be involved. No single infection measured at the time of sampling was a good predictor of subsequent death from disease; instead different pathogens appeared to be important in each region, and reduced the probability of survival through a variety of mechanisms. Positive correlations between Pasteurella and Salmonella, and between Marek’s disease and parasitic diseases were identified, but fewer birds than expected were identified with pathogens from both these groups, perhaps suggesting a decreased chance of survival for co-infected birds. Strong seasonal variation in prevalence was not observed for any of the infections in the study, suggesting that seasonal rises in disease mortality are unlikely to be attributable to a single infection, but other factors may play a role, including an increased probability of co-infection. This makes it difficult to prioritise control strategies for individual diseases; instead development programmes may find broad-based strategies, such as improving hygiene and chick management may be more beneficial to minimise the small-scale losses. Programmes also need to be tailored to local needs rather than assuming a blanket strategy will work equally well for all farmers or regions. Any development strategies to control single diseases should consider potential impacts on non-target infections, due to the existence of multiple interactions between pathogens in this system.
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Berthelot, Philippe. "Exploration endoscopique et instrumentation thérapeutique comme sources d'infection respiratoire nosocomiale". Saint-Etienne, 1993. http://www.theses.fr/1993STET6411.
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Phan, Quang Tien. "Innate immune response to tissue-specific infection : notochord infection in the zebrafish embryo". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT082/document.
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Lors des infections bactériennes, selon les tissus infectés, et selon la nature des pathogènes, l’organisme répond en mobilisant différents acteurs. Nous avons décidé d’utiliser le modèle du zebrafish ou Danio rério pour étudier la réponse immunitaire innée dans les situations d’infection bactérienne où les phagocytes professionnels ne peuvent pas venir au contact direct des bactéries. Pour cela, j’ai développé un modèle d’infection de la notochorde del’embryon de zebrafish. Lors de l’injection des bactéries dans ce compartiment, les bactéries se retrouvent protégées par une épaisse gaine de collagènes que les phagocytes ne peuvent pas pénétrer. Alors que les mycobactéries,protégées par la gaine de collagène ne sont pas détectées par les phagocytes, les bactéries E. coli sont immédiatement détectées ce qui déclenche une importante inflammation locale autour de la notochorde. Alors que les bactéries E. coli, bien qu’inaccessibles à la phagocytose sont éliminées dans les première 24 heures qui suivent l’injection, l’inflammation dure plusieurs jours.J’ai étudié les mécanismes qui conduisent à cette inflammation persistante et ses conséquences à long terme sur le développement du poisson. J’ai montré le rôle central de la cytokine IL1b dans ce processus, et j’ai développé une lignée transgénique qui permet d’étudier l’induction de cette cytokine in vivo chez le poisson.J’ai ensuite étudié le rôle des deux principales populations de phagocytes dans l’élimination des bactéries E coli. J’ai montré que les macrophages ne sont pas impliqués dans la disparition des bactéries alors que les neutrophiles, bien qu’incapable de pénétrer à l’intérieur de la gaine de collagène sont nécessaires à l’élimination des bactéries.J’ai ensuite montré que la myelopéroxidase et le monoxyde d’azote ne sont pas impliqués dans l’élimination des bactéries alors que les espèces réactives de l’oxygène produites par les neutrophiles sont nécessaires pour éradiquer l’infectionIn bacterial infections, according to the infected tissue and the nature of pathogens, the body responds by mobilizing various actors. I decided to use zebrafish or Danio rerio model to study the innate immune response to bacterial infection in the situations that professional phagocytes cannot come in direct contact with the bacteria. For this, I developed a model of infection in the notochord of zebrafish embryo. Upon injection of bacteria in this compartment, the microbes find themselves protected by the thick collagensheath where the phagocytes cannot penetrate. While mycobacteria are not detected by phagocytes; E. coli bacteria are sensed and a significant local inflammation around the notochord is mounted. The E. coli, although inaccessible to phagocytosis are eliminated within the first 24 hours after injection, the inflammation lasts several days.I studied the mechanisms that lead to this persistent inflammation and its long term consequences on the development of the fish. I showed the central role of the cytokine IL1B in this process, and I developed a transgenic line that allows studying in vivo the induction of this cytokine in fish.I then studied the roles of the two main populations of phagocytes in the elimination of E. coli. I revealed that macrophages are not involved in the removal of bacteria but neutrophils, although unable to penetrate inside the collagen casing, are necessary for the bacterial elimination. I also confirmed that myeloperoxidase and nitrogen monoxide are not involved in the removal of bacteria, rather the reactive oxygen species produced by neutrophils are needed to eradicate the infection
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Tscherning, Charlotte. "Déterminants biologiques et génétiques du VIH-1 et rôle du placenta dans la transmission materno-foetale". Lyon 1, 1998. http://www.theses.fr/1998LYO1T187.
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Eouzan, Eric. "La primo-infection herpétique génitale, à propos de 9 observations". Bordeaux 2, 1997. http://www.theses.fr/1997BOR2M075.
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Rashleigh-Rolls, Rebecca M. "Hospital acquired infections : outbreaks and infection control interventions, a national descriptive survey". Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/101494/1/Rebecca_Rashleigh-Rolls_Thesis.pdf.
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This study investigated hospital-acquired infection (HAI) across Australian public hospitals from January 2005 - December 2011. Specifically, outbreaks of HAI and infection control interventions (aimed at reducing HAI rates) were investigated. Outbreaks of HAI, with the most frequent pathogens being Norovirus and Vancomycin-resistant Enterococcus, occurred in the majority of hospitals. Further, a wide variety of infection control interventions were applied during the time-frame yet there was no standardised implementation approach. Rates of HAI appeared to be affected by the implementation of particular infection control interventions, either by reducing or increasing mean infection rates.
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Cordel, Nadège. "Infections ano-génitales par les papillomavirus humains oncogènes chez les femmes en Guadeloupe". Thesis, Antilles, 2017. http://www.theses.fr/2017ANTI0120/document.
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Les cancers viro-induits dont le chef de file est le cancer du col utérin lié aupapillomavirus humain (HPV) représentent une cause importante de mortalité dans la Caraïbe. Ilsont récemment été désignés comme objectif de santé publique par les registres des cancers antillais.Pour autant, les données virologiques disponibles sont rares et concernent principalement lesantilles anglophones. Des études de répartition génotypique menées à Tobago, en Jamaïque et à laBarbade montrent, en population générale, une forte prévalence des infections par les HPV à hautrisque oncogène (HRHPV) et une prédominance de génotypes différents de ceux qui prévalent dansles pays du nord (i.e.: HPV16, HPV18) notamment les génotypes HPV45 et HPV58. Ces donnéessoulèvent la question de l’existence d’un profil de distribution génotypique particulier dans laCaraïbe et la nécessité, le cas échéant, d’adapter la stratégie de prévention vaccinale des infectionspar les HPV à haut risque oncogène car les vaccins actuels ne ciblent que les génotypes 16 et 18 .Objectifs : L’objectif principal du travail était de décrire la distribution génotypique (estimation dela prévalence des différents génotypes) des HPV oncogènes impliqués dans les infections de lasphère ano-génitale des femmes, en Guadeloupe. L’objectif secondaire était de préciser les facteursdémographiques, sociaux et cliniques associés à la présence d’une infection ano-génitale à HPVoncogène.Patients et méthodes : Trois études ont été envisagées : i) une étude rétrospective, en populationgénérale, à partir des données cytologiques et virologiques du cabinet de pathologie de Guadeloupedont l’activité est la plus intense dans le domaine ciblé, ii) deux études prospectives conduites chezdes femmes immunodéprimées, soit par une transplantation rénale, soit par une maladie systémiqueauto-immune. Cette population de femmes a été choisie car elle est caractérisée par une prévalenceélevée d’infections ano-génitales à HPV oncogènes et une fréquence importante de complicationscarcinologiques HPV-induites, documentée dans la littérature.8prévalence des HPV à haut risque oncogène de type ni 16 ni 18 comme en atteste la distributiongénotypique observée en population générale et en population immunodéprimée (i.e. prévalenceforte du type HPV52 et à moindre degré des types HPV39 et HPV51 chez les patientestransplantées et des types HPV31, HPV58, HPV39, HPV45 chez les patientes présentant unemaladie systémique auto-immune). Ces résultats confortent les données des études précédemmentconduites dans l’arc antillais et constituent un argument pour élargir la protection vaccinale anti-HPV aux types non 16 non 18, dans le but d’ optimiser la prévention primaire du cancer du colutérin, aux Antilles.Le vaccin anti-HPV nonavalent, de commercialisation récente, semble représenter une optionintéressante. En effet, les 5 types supplémentaires de HRHPV qu’il cible par rapport aux vaccins de1ère génération (i.e.: HPV31, HPV33, HPV45, HPV52, HPV58) correspondent aux types despapillomavirus humains à haut risque oncogène ni 16 ni 18 qui circulent activement dans laCaraïbe, y compris deux types impliqués dans les cancers invasifs du col utérin aux antillesfrançaises: HPV33 et HPV45.Les facteurs de risque d’infection par les HPV oncogènes identifiés dans notre travailcorrespondent aux facteurs largement documentés dans la littérature comme le début précoce desrapports sexuels ou le statut de célibataire. Une étude de plus grande envergure est nécessaire pourinvestiguer l’association avec la sclérodermie systémiqueOf the virus-related cancers, cervical cancer linked to the human papillomavirus(HPV), is one of the leading causes of mortality in the Caribbean. These cancers have recently beenidentified as an important public health problem by Caribbean cancer registries. However,virological data available are limited and related primarily to the English-speaking Caribbean.Genotypic distribution studies in Tobago, Jamaica and Barbados show a high HPV prevalence ofhigh-risk HPV types (HR HPV) infections in the general population and a predominance ofgenotypes different from those of northern countries (i.e.: HPV16 and HPV18) in particular typesHPV45 and HPV58. These data raise the question of the existence of a specific genotypicdistribution profile in the Caribbean and the need, if required, to adapt vaccine prevention strategyagainst HRHPV infections because current vaccines only target genotypes 16 and 18.Objectives: The main objective of this study was to describe the distribution of carcinogenic HPVtypes involved in anogenital infections of women in Guadeloupe. The second objective was toidentify the demographic, social and clinical factors associated with the presence of oncogenic HPVinfection of the anogenital area.Patients and methods: Three studies were conducted: (i) a retrospective study concerning thegeneral population based on cytological and virological data from the Guadeloupe pathologylaboratory whose activity is the most intense in the targeted field; (ii) two prospective studies inwomen immunocompromised (i.e.: kidney transplant recipients, autoimmune systemic disease).This population of women was chosen because it is characterized by a high prevalence of HPVanogenital infections with frequent HPV-induced mucosal cancer complications reported in theliterature.Our 3 studies show a high prevalence of anogenital infections with carcinogenic HPVin women on the island of Guadeloupe. This high prevalence appears to be directly linked to theprevalence of high-risk, oncogenic HPVs of type non 16 and non 18, as evidenced by the genotypicdistribution observed in the general population and the immunocompromised population (i.e. HPV52 , HPV39, HPV51 in kidney transplant recipients and HPV31, HPV58, HPV39, HPV45 inpatients with autoimmune systemic disease). These results are in accordance with data from studiespreviously carried-out in Caribbean. They constitute an argument for extending the protectionagainst non-16 and non-18 HPV types infections with the aim of optimizing the basic prevention ofcervical cancer in the caribbean countries. The nonavalent new HPV vaccine seems to constitute aninteresting option. The 5 additional types of HR HPV that it targets compared to first generationvaccines (i.e.: HPV31, HPV33, HPV45, HPV52, HPV58) correspond to high risk HPV types nor16nor18 that are actively marketed in the Caribbean, including two types involved in invasive cervical11cancer in the French West Indies: HPV33 and HPV45.Risk factors for HPV infection identified in our study correspond to factors widely documented inthe literature such as early onset of sexual intercourse or unmarried status. A larger study is neededto investigate the association with systemic sclerosis
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Mourgues, Jean-Marcel. "Les infections nosocomiales : étude rétrospective dans un service de médecine interne d'un centre hospitalier général d'Aquitaine". Bordeaux 2, 1989. http://www.theses.fr/1989BOR25269.
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Poueyts, Sabine. "Etude des hémocultures positives recencées à l'hopital de Bayonne sur une période de six mois". Bordeaux 2, 1989. http://www.theses.fr/1989BOR25165.
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Rubenovitch, Josh. "Les infections nosocomiales : à propos des infections liées aux catheters". Montpellier 1, 1995. http://www.theses.fr/1995MON11168.
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Gauthier, Simon. "Infection focale : rôle des parodontopathogènes dans les infections de la cavité amniotique". Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28303/28303.pdf.
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Egan, Jonathon Todd. "Chiropractic Student Infection Control Practices and Methicillin-Resistant Staphylococcus aureus Skin Infections". ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2027.
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Chiropractic training involves many hours of skin contact, and chiropractors have manual contact with millions of patients annually, but chiropractic has only had professional clinical hygiene guidance since 2010. Methicillin-resistant Staphylococcus aureus (MRSA) is the most common cause of cultured skin and soft tissue infection (SSTI) in the United States. Using the epidemiologic triad of person, place, and time as a framework, this quantitative, cross-sectional study obtained the first assessment of MRSA SSTI incidence among chiropractic students and its association with infection control behaviors (hand and table hygiene, sharing gowns, and sharing lotion) and initiation of patient care. The study obtained surveys from 312 students attending half (9/18) of U.S. chiropractic campuses. Associations were assessed by Ï?2 and Fisher's exact test. Stratum specific effects were assessed. Two logistic regression models were produced. The results were that attendance at Campus 6 was associated with postmatriculation MRSA SSTI in univariate analysis, p = 0.010. There was an interaction between campus attended, sharing lotion, and postmatriculation MRSA SSTI, with the Mantel-Haenszel pooled estimate varying significantly from unity, Ï?2 (1) = 6.75, p = 0.009. No other association between any assessed factor and MRSA SSTI was detected. Logistic regression models were significant (p < 0.05), but the composing variables were not. For social change, chiropractic colleges should instruct students and chiropractic associations could encourage members not to share massage lotions and emollients during the practice of manual therapy to help prevent MRSA SSTI.
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Douglas-Jones, Martin. "An explorative study of the factors possibly contributing to the burden of maxillofacial infection presenting at the Tygerberg Oral Health Centre". University of Western Cape, 2020. http://hdl.handle.net/11394/7605.
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Magister Scientiae Dentium - MSc(Dent)Over the last few decades, and throughout the world, there would seem to have been an increase in the number and severity of infections affecting the maxillofacial region. In the South African setting this seems to be especially evident in the state health system. Maxillofacial infection of odontogenic origin is largely preventable. If treated appropriately and early in the pathological process, the progression of the disease process is generally prevented and complications avoided. Management of maxillofacial infections once established has serious implications for patients and an already stressed health system. The reasons for this perceived increase in infections are likely multifactorial and it is hoped that this study may aid in understanding factors contributing to this burden.
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Gohin, Jean-Christophe. "Infections cutanées, sous cutanées et articulaires à mycobactéries atypiques : à propos de six cas". Montpellier 1, 1997. http://www.theses.fr/1997MON11038.
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Barrieshee, Ahmed. "Hepatitis c virus infection / re-infection in illicit drug users". Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/15249.
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Introduction: Over 300,000 Canadians have chronic Hepatitis C virus (HCV) infection, over half being current or former Injection drug users (IDUs). The possibility of re-infection is often cited as a reason for not initiating treatment in this group of patients, although recent observational data suggest that the rate of re-infection may be reduced following spontaneous or treatment-induced virologic clearance, such data are often retrospective and incomplete.
Methods: In a prospective study to evaluate the incidence of HCV viremia, we indentified a cohort of IDUs at risk of new infection, who were receiving care at the Pender Community Health Centre on Vancouver’s Downtown East Side. Potential subjects were identified as either: never been infected with HCV (non-infected arm), spontaneously cleared the virus (spontaneous arm), or achieved a sustained virologic response after treatment (SVR arm). A questionnaire to identify demographics, health status, risk behavior and drug use was administered at baseline and every 6 months, along with blood tests to identify their HCV status.
Results: 518 subjects were screened, 245 (47%) were excluded because of being viremic and 69 (13 %) met the criteria for inclusion in the study: 18 in the non-infected, 29 in the spontaneous and 22 in the SVR arm respectively. There were no significant differences among the 3 groups with respect to age, ethnicity, source of income, unstable housing, and being on opioid maintenance program. Over follow-up, 20% of the non-infected group became viremic, as compared to 0% of the other two groups (p=0.04). Injecting drugs in the past 30 days (p=0.004), sharing non-injection equipments (p=0.015), heroin, amphetamines, and combined drugs use was significantly higher in the non-infected compared to SVR arm (p=0.02, 0.04 and 0.02 respectively). There were no significant differences in drug use and risk behavior between non-infected and spontaneous arms.
Conclusion: We have demonstrated in a prospective cohort with systematic follow-up that HCV infection is more likely to occur in those who have never been previously infected, and that this susceptibility to infection cannot be completely explained by an increase in risk behavior, at least as compared to individuals who have cleared their viremia spontaneously.
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Gagné, Stéphanie. "Étude des mécanismes de virulence du pathogène nosocomial Acinetobacter baumannii". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1045/document.
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Acinetobacter baumannii est un pathogène nosocomial qui induit principalement des infections du système respiratoire ou urinaire, et des septicémies chez les patients immunodéprimés. L'émergence de souches multi résistantes aux antibiotiques et l'augmentation de nombreuses d'infections par A. baumannii fait de ce pathogène un enjeu majeur de santé publique. De plus aujourd'hui émerge des souches hypervirulentes. Nous nous sommes intéressés à différentes souches afin de caractériser le phénotype hypervirulent de ces souches. L'étude du système de sécrétion de type VI montre la complexité des mécanismes de virulence d'A. baumannii et sa régulation dépendante des souches. Dans un second temps l'étude des souches cliniques hypervirulentes et nous avons mis en évidence deux nouveaux potentiels mécanismes de virulence : une phase de réplication intracellulaire et une limitation de la réponse immunitaire. Ces mécanismes peuvent expliquer la virulence accrue de ces souches chez l'homme. L'étude nous montre également qu'A. baumannii est un pathogène complexe et qu'on son étude à l'heure actuelle nécessité l'emploi de souche représentative des souches infectant les patientsA. baumannii is an hospital acquired pathogen which causes mainly ventilator associated infection, urinary tract infection and bacteraemia. Last years Multi Drug Resistant strains increase and nosocomial infection cause by A. baumannii also which led him as a serious health care problem. We compare different strains in propose to find phenotype that can explain hypervirulent strain emergence. We studied type six secretion and showed that the complexity of A. baumannii virulence mechanism. Indeed type six secretion system regulation is strain dependant. Secondary we study hypervirulent strain and showed that intracellular stage exists and there is intracellular replication. Also hypervirulent strain induces less immune response. Those two mechanisms can explain A. baumannii hypervirulent phenotype
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Khoury, Pascale. "Infection chez l'hémodialysé chronique : expérience d'un centre en Guyane". Montpellier 1, 1993. http://www.theses.fr/1993MON11163.
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Plummer, Kathleen Hope. "Cancer and Infection". Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5293.
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E. coli is the most frequently isolated Gram negative pathogen from bacteremia in cancer patients and is repeatedly recovered from many other extraintestinal illnesses. These infections are commonly endogenous in nature and interfere with the treatment of cancer resulting in increased healthcare costs, morbidity, and mortality rates. Cancer and the treatments related to cancer cause alterations in the microbiome of the gut and other organs. Despite this point, there is a serious lack of knowledge about the genetic types of E. coli infecting cancer patients. This gap results in vague prevention strategies and limited treatment options for cancer patients. Multi Locus Sequence Typing (MLST) was used to successfully genotype 105 sequentially collected E. coli isolates from patients admitted to H. Lee Moffitt Cancer Center (HLMCC, Tampa, FL) with confirmed extraintestinal infections between 2010 and 2012. In total, 24 distinct genotypes (STs) have been identified in this dataset using EcMLST (STEC Reference Center). Of these, ST34 constituted 39% of the isolates and may represent a disseminating clone at HLMCC. Furthermore, 17 isolates not found in the EcMLST database have been identified. Importantly, phylogenetic analysis of DNA sequence data for MLMCC E. coli revealed only 22% of HLMCC E. coli clustered with ECOR reference strains commonly attributed to the B2 phylogroup of extraintestinal pathogenic E. coli (ExPEC). Four HLMCC E. coli belonging to ST171 and attributed to life-threatening blood infections clustered with Shiga toxin (Stx) producing E. coli (STEC) strain TW06296. HLMCC E. coli belonging to ST34 clustered with enteroaggregative E. coli (EAEC) strain TW10263. Importantly, these non-B2 phylogroup strains demonstrated more pathogenic potential than HLMCC E. coli clustered with B2 ExPEC,which included a higher incidence of bacteremia and sepsis, as well as resistance to first-line antibiotics. Upon further investigation, ST34 may equate to ST131 by another MLST database. These findings suggest that isolates previously characterized as commensal and intestinal pathogenic E. coli have an increased ability to cause infection outside of the gastrointestinal tract in cancer patients and that selective pressures are contributing to increased antibiotic resistance. These findings may change the approach to clinical management of E. coli infections at cancer centers.
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Kolotylo, T. R. "Peculiarities of HIV infection with active tuberculosis in association with other opportunistic infections". Thesis, БДМУ, 2020. http://dspace.bsmu.edu.ua:8080/xmlui/handle/123456789/18222.
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Islam, Zeenath Ul. "Statistical modelling and analysis of the infection dynamics of PRRSV in vivo infections". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29513.
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Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically significant viral diseases facing the global swine industry. Viraemia profiles of PRRS virus challenged pigs reflect the severity and progression of infection within the host and provide crucial information for subsequent control measures. In this thesis we analyse the largest longitudinal PRRS viraemia dataset from an in-vivo experiment, and corresponding immune measures in the form of cytokine data and neutralising antibodies. In the PRRS Host Genetic Consortium (PHGC) trials, pigs were challenged with one of two PRRSV isolates (NVSL and KS06, respectively). In Chapter 2 we derive a statistical description of the temporal changes in viraemia and determine the influence of diverse factors (e.g. PRRSV strain, pig genetic background, resistance genotype, etc.) on viraemia profiles. The well-established methodology of linear mixed modelling with a repeated measures model and fitting a linearized Wood’s function, a gamma-type function, is applied to the viraemia dataset. The virus isolate had a significant impact on the viraemia profiles which was captured by statistically significant differences in model parameters via both statistical methods. The more virulent NVSL isolate had higher early viraemia predictions and a faster rate of decline than KS06. In line with previous studies the WUR “resistance” genotype, associated with lower AUC viraemia found in previous studies, also resulted in lower viraemia predictions in the statistical models. The typical time trends of the viraemia profiles were a rise to a peak followed by a period of decline with dynamics and magnitude influenced by the virus isolate. Both uni and bimodal viraemia profiles were observed. The Wood’s model appeared a suitable candidate model for the data associated with uni-modal profiles and captured the time trends concisely in only three model parameters which also had a biological relevance. Overall the best fitting Wood’s model (y=atbe-ct) was when there was a random effect in Wood’s parameters b and c. Bimodal profiles significantly reduced the model fit, particularly in the later phase of infection resulting in large model residuals. However bimodal profiles did not impact upon the significance of the differences between the LSM repeated measures estimates nor the LSM linearized Wood’s model parameter estimates. The longitudinal viraemia measures from the PRRSV challenge experiment revealed substantial differences in the viraemia profiles between hosts infected with the same PRRSV challenge dose, pointing to considerable variation in the host response to PRRSV infections. In Chapter 3 we provide a suitable mathematical description of all viraemia profiles with biologically meaningful parameters for quantitative analysis of profile characteristics. The Wood’s function and a biphasic extended Wood’s function were fit to the individual profiles using Bayesian inference with a likelihood framework in Chapter 3. Using maximum likelihood inference and numerous fit criteria, we established that the broad spectrum of viraemia trends could be adequately represented by either uni-or biphasic Wood’s functions. Three viraemic categories emerged: cleared (uni-modal and below detection within 42 days post infection(dpi)), persistent (transient experimental persistence over 42 dpi) and rebound (biphasic within 42 dpi). The convenient biological interpretation of the model parameters estimates, allowed us not only to quantify inter-host variation, but also to establish common viraemia curve characteristics and their predictability. The convenient biological interpretation of the model parameters estimates, allowed us not only to quantify inter-host variation, but also to establish common viraemia curve characteristics and their predictability, which were utilized in subsequent quantitative genetic analyses to identify genomic regions associated with these new resistance traits. The Bayesian approach for curve fitting in Chapter 3 led to better model fits than the classical linear mixed models approach of Chapter 2. Furthermore in Chapter 4 we explored the association between the observed PRRS viraemia profile characteristics and the corresponding measures of the immune response in the form of: neutralising antibody (nAb) cross protection data and longitudinal cytokine profiles. Statistical analysis of the profile characteristics revealed that persistent profiles were distinguishable already within the first 21 dpi, whereas it is not possible to predict the onset of viraemia rebound. Analysis of the neutralizing antibody (nAb) data indicated that there was a ubiquitous strong response to the homologous PRRSV challenge, but high variability in the range of cross-protection of the nAbs. Persistent pigs were found to have a significantly higher nAb cross-protectivity than pigs that either cleared viraemia or experienced rebound within 42 dpi. We determined the typical features and time trends of each cytokine profile, examined the associations between cytokines, and characterised the cytokine response. A stronger association was found in the direction of cytokines driving the ensuing viraemia characteristics as opposed to vice versa. It was found that viraemia class differences were best captured in the anti-viral cytokine IFNA and also the chemokine CCL2, furthermore these key cytokines were the most strongly associated with viraemia measures. The breadth of the cytokine responsiveness was associated with viral profile class and genetic background but not the WUR genotype. The statistical categorization of pigs from each PHGC trial through model fitting provides a critical basis for the generation of new desirable host phenotypes, and of potential use in the genetic selection of pigs with favourable infection traits. Our study provides novel insights into the nature and degree of variation of hosts’ responses to infection as well as new informative traits for subsequent genetic and modelling studies.
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Akinlotan, Morenikeji D. "Within-host dynamics of Chlamydia trachomatis infection: Repeat infections and the immune response". Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/119362/1/Morenikeji%20Akinlotan%20Thesis.pdf.
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Chlamydia trachomatis is the most common bacterial sexually transmitted infection worldwide. The control of its incidence is a major public health challenge. It is one of the major preventable causes of disability and mortality. Genital Chlamydia infection is asymptomatic and thus commonly undiagnosed and untreated. In this study, we use ordinary differential equation models to provide qualitative insights into the within-host dynamics of Chlamydia infections, the associated host immune response, and the in vivo control or treatment of the infection. The thesis examines optimal control treatment strategies for acute and chronic genital chlamydial infections, including an investigation of efficacious anti-Chlamydia vaccination strategies. Qualitative results of the presented models provide frameworks for the design of new and improved treatment strategies for genital chlamydial infections.
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Bernit-Roubira, Marie-Noe͏̈lle. "Clostridium difficile et infection par le V. I. H". Montpellier 1, 1993. http://www.theses.fr/1993MON11115.
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Atwine, Daniel. "Improving TB management and control through innovative shorter anti-tuberculosis regimens". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT041/document.
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Le traitement actuel de la tuberculose chimio-sensible est de 6 mois, ce qui est beaucoup trop long et entraine des défauts d’adhésion au traitement, des échecs thérapeutiques par sélection de bactéries résistantes. Puisque dans le futur proche, aucun nouveau traitement ne permettra de raccourcir la durée de traitement, d’autres voies doivent être recherchées, entre autres l’augmentation de la posologie de rifampicine (R) au-delà des 10 mg/kg actuellement recommandés qui pourrait permettre un traitement de 3-4 mois.Notre travail, réalisé dans le cadre d’essais cliniques, a consisté d’une part à étudier la tolérance d’une dose élevée de R au sein du traitement antituberculeux standard chez des patients tuberculeux séronégatifs ou séropositifs pour le VIH, et d’autre part l’interaction entre une double dose de R (20mg/kg) et le traitement antirétroviral, en particulier l’efavirenz (EFV). Enfin un autre axe de recherche a consisté à étudier si la négativation des cultures de crachat à 2 mois pouvait être un marqueur de l’efficacité du traitement antituberculeux dans les essais cliniques. Afin de répondre à ces objectifs, les études suivantes ont été réalisées.Une étude ouverte, de Phase II, randomisée, contrôlée (RIFATOX) a été mise en place (Bolivie, Pérou and Ouganda). Trois cent patients tuberculeux, séronégatifs pour le VIH ont été randomisés entre 3 schémas thérapeutiques se différenciant par la posologie de la R durant les 16 premières semaines : R à 10, 15 ou 20 mg/kg. La fonction hépatique et la réponse bactériologiques ont été monitorées. La toxicité hépatique n’était pas plus importante à dose élevée de R. En utilisant les résultats des patients ougandais, nous avons montré que la négativation des cultures à deux mois était influencée par le type de milieu de culture utilisé, avec négativation plus importante en milieu solide qu’en milieu liquide pour les traitements avec dose élevée de R. Ces résultats nous amènent à recommander que le même milieu de culture soit utilisé dans tous les sites lors d’essais multicentriques visant à étudier l’efficacité de traitement antituberculeux.Une étude bibliographique « systématique » a été réalisée afin de colliger les informations existantes sur l’efficacité, la tolérance et les interactions pharmacocinétiques de l’EFV associé au traitement antituberculeux à posologie standard dans les pays à forte endémie. Vingt-deux articles publiés entre 2006 et 2016 ont été sélectionnés. Aucune relation entre des concentrations élevées d’EFV et la survenue d’effets indésirables neurologiques ou hépatiques n’a pu être mise en évidence.Au vu de ces informations, un essai pharmacocinétique de phase 2, ouvert (ANRS12292 RIFAVIRENZ trial) a randomisé 97 patients tuberculeux vivant avec le VIH et naïfs de traitement antirétroviral entre 3 bras de traitement : R20mg/kg+EFV 600mg, R20mg/kg +EFV 800 mg et R10mg/kg+EFV600mg (bras contrôle). R était associé au traitement antituberculeux à posologie standard et EFV associé à deux analogues nucléosidiques (tenofovir+lamivudine) a été initié 2-4 semaines après le traitement antituberculeux. Après 8 semaines de suivi, tous les patients ont reçu les traitements à posologie standard. Des prélèvements sanguins ont été réalisés pour étudier la pharmacocinétique de l’EFV associé à R ou administré seul (4 semaines après arrêt du traitement antituberculeux). Malgré une légère diminution des concentrations d’EFV dans le bras R20 mg/kg+EFV 600mg, les concentrations sont restées dans la zone des concentrations thérapeutiques. Quelque soit le bras de traitement, le traitement a été bien toléré. Cependant s’il n’y avait pas de différence sur l’efficacité virologique mesurée à 12 semaines, elle était diminuée à 24 semaines dans le bras R20 mg/kg+EFV 600mg. La pertinence clinique de ce résultat est en cours d’évaluation pour que des patients tuberculeux vivant avec le VIH puissent être inclus dans de futurs essais de phase 3The recommended 6-month treatment for drug-susceptible tuberculosis (DS-TB) is too long, hence threatening patient adherence, with resulting treatment failure and drug-resistance. Consequently, this complicates efforts towards achieving the TB control and elimination goal. Currently, no new drug is expected in the short term for reducing treatment duration. We hypothesized that optimization of the current treatment regimen with use of high-dose rifampicin (R), above the 10mg/kg current dose, might result in a shorter TB treatment duration (3-4 months). Clinical trials were conducted to investigate two research areas: first, Safety of high-dose R in HIV-negative TB and in HIV-TB coinfected patients; secondly, drug-drug interaction between high-dose R and antiretroviral drugs. A 3rd research area addressed the use of 2 months sputum culture conversion as surrogate marker for treatment efficacy in TB trials.A Phase II, open-label randomized controlled trial (RIFATOX) was conducted with sites in Bolivia, Peru and Uganda. Three hundred HIV-negative smear-positive TB patients were randomised between three regimens differing only by R dose during the first 16 weeks of the standard 24 weeks treatment: R at 10 mg/kg and two high-R doses (15mg/kg or 20mg/kg). Liver function and bacteriological response were monitored. There was no significant increase in hepatotoxicity with high-dose R. Using data from the cohort of patients from the Ugandan site only, we showed that month-2 culture conversion, a commonly used surrogate marker in phase 2 trials was influenced by the culture method used with significantly higher conversion rates noted with solid versus liquid media within patients on high-R dose regimens. We therefore recommend use the same culture method across sites within multi-centric TB trials.We conducted a systematic review to gather existing information on the pharmacokinetics, adverse effects and efficacy of efavirenz (EFV), the most commonly used antiretroviral drug, co-administered with R-based TB regimens among high TB/HIV-burden countries. Twenty-two articles published between 2006 and 2016 were analyzed. With the use of 600mg EFV daily, plasma concentrations on average were above the minimum therapeutic concentrations during R co-administration with good safety and efficacy. No clear relationship between supratherapeutic EFV concentrations and occurrence of neurological and hepatic adverse events was observed.Then, we conducted a phase-2, randomized, open-label pharmacokinetic trial (ANRS12292 RIFAVIRENZ trial) among 97 DS-TB patients and antiretroviral therapy (ART)-naïve Ugandan patients. These were randomized between 3 drug regimens: 2 using R (20mg/Kg) with ART initiation 2-4 weeks later with EFV600mg/day or 800mg/day) and a control regimen using R10mg/kg and EFV600mg/day. At 8 weeks, all patients were switched to standard R and EFV doses. All patients had intensive pharmacokinetic sampling 4 weeks after EFV-R co-administration, and 4 weeks after R discontinuation. Despite a trend of lower EFV concentration when the R dose was doubled, concentrations remained within the therapeutic window. Treatment with high-dose R was well tolerated. Virological efficacy was high during the first 12 weeks on ART but reduced in the R arms after 24 weeks. We conclude that, use of high-dose R at 20mg/Kg is safe and could be evaluated in larger trials towards shortening of treatment for DS-TB patients. Due to late virological failures in patients on R 20 mg/kg and standard EFV dose, comprehensive efforts through additional research are needed to fast-track the inclusion of TB-HIV co-infected patients in phase 3 trials
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Chêne, Geneviève. "Les infections urinaires nosocomiales dans un service de soins intensifs : épidémiologie,coût, prévention". Bordeaux 2, 1990. http://www.theses.fr/1990BOR23021.
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Groulard, Alain. "Apport de la technique de sondage vésical clos dans la prévention des infections urinaires nosocomiales". Paris 5, 1994. http://www.theses.fr/1994PA05P142.
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Raj, G. Dhinakar. "Studies on pathogenicity and immunopathogenesis of infectious bronchitis virus infection in chickens". Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321164.
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Beshara, Ranin. "Impact d’une infection par le virus grippal de type A sur la myélopoïèse". Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S016/document.
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L’infection par le virus de la grippe, ou le Myxovirus influenzae de type A (IAV), constitue l'une des causes les plus importantes de maladies des voies respiratoires dans le monde. Elle conduit également à des épidémies récurrentes avec des taux élevés de morbidité et de mortalité. Des surinfections bactériennes, principalement causées par Streptococcus pneumoniae (pneumonie), sont souvent associées à la grippe et contribuent de manière significative à l’excès de mortalité. La perturbation de l'intégrité des tissus pulmonaires et la diminution de l'immunité antibactérienne au cours de l'infection par IAV sont à l’origine de la colonisation et à la dissémination des bactéries.L'infection grippale entraîne une altération profonde du compartiment de cellules myéloïdes pulmonaires caractérisée par une altération numérique ou fonctionnelle des cellules sentinelles - les macrophages alvéolaires et les cellules dendritiques conventionnelles (cDC) - et par un recrutement de cellules myéloïdes inflammatoires -les neutrophiles, les monocytes inflammatoires ou encore les cellules dendritiques inflammatoires.Les cellules myéloïdes sont originaires de la moelle osseuse (MO). Lors d’infections, la myélopoïèse peut être profondément affectée afin de maintenir la production et la mobilisation de cellules myéloïdes inflammatoires au niveau du site d’infection. A l’heure actuelle, les conséquences de l’infection grippale sur la myélopoïèse restent encore mal connues.Dans notre projet, nous rapportons que l'infection grippale conduit à une diminution transitoire du nombre de cDC (cDC1 et cDC2) dans les poumons qui coïncide avec une chute dans la MO, du nombre de progéniteurs/précurseurs impliqués dans la génération des cDC (CDP, pre-cDC et plus particulièrement les pre-cDC1). Cette diminution de la "DCpoïèse" est associée à une accélération de la génération des monocytes, i.e. monopoïèse. La différenciation altérée des cDC est indépendante des cytokines pro-inflammatoires et n'est pas due à un dysfonctionnement intrinsèque des précurseurs de cDC. De façon intéressante, nous rapportons que ces altérations au niveau de la MO sont associées à une diminution de la production de Flt3-L ou Fms-like tyrosine kinase 3 ligand, un facteur crucial pour la différenciation des DC. La supplémentation en Flt3-L au cours de la grippe rétablit la différenciation des progéniteurs de cDC dans la MO et restaure le compartiment des cDC pulmonaires. De façon intéressante, cette restauration s’accompagne d’une protection partielle contre l’infection pneumococcique secondaire caractérisée par une réduction de la charge bactérienne, une amélioration de la pathologie pulmonaire et une survie prolongéeInfluenza type A virus (IAV) infection, is one of the most important causes of respiratory diseases worldwide. It also leads to recurrent epidemics with high rates of morbidity and mortality. Secondary bacterial infections, mainly caused by Streptococcus pneumoniae (pneumonia), are often associated with influenza and contribute significantly to excess mortality. Disruption of lung tissue integrity and impaired antibacterial immunity during IAV infection participate in bacterial pulmonary colonization and dissemination out of the lungs.Influenza infection leads to a profound alteration in the pulmonary myeloid cell compartment characterized by numeric or functional alteration of sentinel cells (alveolar macrophages and conventional dendritic cells (cDC)) and recruitment of inflammatory myeloid cells (neutrophils, inflammatory monocytes and inflammatory dendritic cells).Myeloid cells originate from the bone marrow (BM). During infections, myelopoiesis may be profoundly affected in order to maintain the production and mobilization of inflammatory myeloid cells to the site of infection. At present, the consequences of influenza infection on myelopoiesis remain poorly understood.In our project, we report that influenza infection leads to a transient decrease in the number of Cdc (cDC1 and cDC2) in the lungs, and severely impairs the number of BM progenitors committed to the DC lineage (CDP, pre-cDC and, most importantly, the cDC1-biased pre-DC lineage). This reduction was associated with an increase in the production of monocytes in the BM (monopoiesis). The altered cDC differentiation was independent of pro-inflammatory cytokines and was not due to an intrinsic dysfunction of cDC precursors. Defective DC genesis during influenza was associated with a decrease in the production of the key cDC differentiation factor, Fms-like tyrosine kinase 3 ligand (Flt3-L). Importantly, Flt3-L overexpression during influenza restores the differentiation of BM progenitors into cDC - a phenomenon associated with repopulation of cDC in the lungs. The restoration of pulmonary cDC associates with a partial protection against secondary pneumococcal infection characterized by reduced bacterial loads, improved pathological outcomes and prolonged survival
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Timsit, Jean-François. "Estimation de la mortalité attribuable aux infections nosocomiales en réanimation : prise en compte de l'évolution de la gravité des patients en réanimation". Nancy 1, 2003. http://docnum.univ-lorraine.fr/public/SCD_T_2003_0243_TIMSIT.pdf.
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Diallo, Bruno Salla. "Études des acinetobacter : à propos de 98 souches isolées en milieu hospitalier". Bordeaux 2, 1990. http://www.theses.fr/1990BOR23091.
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Barthel, Vincent. "Sensibilité à la péfloxacine de souches isolées dans les infections urinaires communautaires". Paris 5, 1989. http://www.theses.fr/1989PA05P160.
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Grislin, Isabelle. "Incidence et facteurs de risque des infections nosocomiales en réanimation polyvalente : étude prospective sur six mois". Montpellier 1, 1993. http://www.theses.fr/1993MON11122.
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Spenillo, Jocelyn K. "Nurse’s Perceptions of Visitor’s Adherence to Transmission-Based Precautions". Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/honors/316.
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Transmissions based precautions are measures implemented in various clinical health care settings as a means to prevent the transmission of infectious diseases and decrease instances of healthcare acquired infections (HAI). HAI’s result in increased cost to hospitals, longer hospitalization for patients, increased patient suffering, and fatal patient outcomes. While staff member adherence to transmissions based precautions are mandated through various organizations and hospital policies, a review of literature indicates little research has been conducted regarding visitor compliance with transmission-based precautions. The potential implications in healthcare from visitor non-adherence acquired infections are unknown; revealing a gap in literature and supporting the need for further research to describe the phenomenon. Through utilization of a descriptive online survey instrument, the purpose of this descriptive study is to gain insight into why nurses believe visitors may or may not be compliant with transmission-based precautions. To collect the data, an online descriptive survey instrument was developed and distributed via email to all graduate students’ enrolled East Tennessee State University’s College of Nursing. Only ten participants met the eligibility requirements to participate in this study. Data was analyzed though a predictive analytics software and grouping responses into themes. Responses suggest that nurses feel visitors are not complying with transmission-based precautions because of a lack in education, not perceiving the infection as a threat, prior exposure to loved one at home, and inconvenience.
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Derry, Melanie C. "Role of annexins in cytomegalovirus infection I Annexin 2 tetramer enhances infection II Annexins 5 and 1 inhibit infection". Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/29098.
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Cytomegalovirus (CMV), a widespread pathogen, causes significant pathology in immunocompromised individuals, and chronic infection has been linked to heart disease. Since CMV infection can be controlled, but not prevented, therapeutics aimed at the virus-cell interaction would be beneficial, but CMV-host cell interactions are not well understood. Cell-free experiments have suggested a function for annexin 2 (AnxA2), which exists in heterotetrameric (p36 2p112, AnxA2t) or monomeric (p36) form, but a role for AnxA2 in productive infection of cells is controversial. In the first part of this study we followed the effect on various stages of infection of endogenous AnxA2, using inhibitory antibodies, and purified AnxA2. Anti-p11 or anti-p36 antibodies inhibited CMV production by up to 95%,immediate-early (IE72) expression by 90% and plaque formation by 50%, but 35S-CMV-cell binding was unaffected. Confirming the role of endogenous AnxA2, AnxA2t and p11, but not p36, enhanced virus production 7-fold and IE72 expression 3-fold. Interestingly, purified proteins did not alter plaque formation, whereas AnxA2t, but not p36, enhanced 35S-CMV-cell binding 3-fold, suggesting biochemical differences between endogenous and purified AnxA2. IE72 expression was enhanced 3-fold in the p36-null cell line HepG2 following p36 transfection. Co-immunodepletion, chemical crosslinking, and ligand blots suggested an interaction between p11 and the viral fusogen glycoprotein B. In the second part of this study, we investigated whether purified AnxA5 and AnxA1, which interact with AnxA2, affect CMV infection by altering AnxA2 function. AnxA1 or AnxA5 inhibited CMV production by up to 80%, IE72 expression by 60% and plaque formation by 50%. However, 35S-CMV-cell binding was unaffected. Combined AnxA5 and AnxA1 were not additive at saturating concentrations, indicating that they inhibit by a similar pathway. Inhibition was reversed by preincubation with purified AnxA2t, and by anti-AnxA2 mAbs that alone had no effect on infection. Attenuation by AnxA1 or AnxA5 was not additive with inhibitory anti-AnxA2 antibodies, implying that a common pathway, i.e. AnxA2t, was impeded. AnxA1 or AnxA5 inhibited IE72 gene expression by 80% in p36-transfected but not native HepG2. These data demonstrate that (1) AnxA2t enhances CMV infection, and (2) purified AnxA5 and AnxA1 inhibit CMV infection by disrupting AnxA2t activity.
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Moussa, Souradjou. "Infection cutanée à mycobactérium malmoense : à propos d'un cas". Bordeaux 2, 1993. http://www.theses.fr/1993BOR2M016.
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England, Kirsty Anne. "Paediatric HCV and HIV infection : mode of acquisition, progression and co-infection". Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/1444156/.
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In this thesis a diverse range of topics related to paediatric HIV and HCV infection are investigated information is provided on the more specific areas of coinfection, disease monitoring methodologies and the impact of mode of acquisition of infection. Four unique epidemiological cohorts of vertically and parenterally HIV, HCV and HIV/IICV coinfcctcd children are analysed. ALT reference ranges adjusted for age and sex in children under five years of age show that ALT levels greater than 60U/1 in boys and 55U/1 in girls should be regarded as elevated in the first 18 months of life while thereafter the upper limits of normal ALT levels are lower 40U/1 in boys and 35U/1 in girls. There are no differences found between vertically and parenterally HCV-only infected groups in their genotype profile, proportion with consistent viraemia, consistently elevated ALT levels or evidence of two or more markers of disease progression. Parenterally HIV infected children are described for the first time and only 12% found to progress to moderate/severe clinical symptoms or immunosuppression during follow-up. The lack of treatment in this group (11% treated) suggests a more favourable disease progression in parenterally than vertically HIV infected children. The possible detrimental effects of ART on ALT levels in HIV/HCV coinfected children are demonstrated along with the possible need for differential management of children infected via different routes given the faster progression to immunosuppression in parenterally coinfected children. The survey of current practices and policies for care of HIV/HCV coinfected children reveals that in general the management practices vary widely in terms of testing high risk groups for coinfection, which laboratory tests to carry out in comparison to those performed on HIV- only and HCV-only infected children and the opinions on optimal treatment for this group emphasise the importance of research in this area to inform clinical guidelines.
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Opadotun, Olukemi. "Infection control practices for the prevention of surgical site infections in the operating room". Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1017195.
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Infections are a major cause of morbidity and mortality during the post-operative phase of patients’ recovery. Wound infections are the second most commonly encountered type of nosocomial infection. Because wound infections can be introduced by not applying infection control measures and sterile technique principles in the operating room, the implementation of infection control principles is an imperative. The aim of this study was to explore and describe infection control practices related to the prevention of Surgical site infections in the operating rooms in a public health care sector in the Nelson Mandela Bay Municipality. The findings were compared with practices, as indicated in an evidence-based guideline. The research design was quantitative, explorative, descriptive, comparative-descriptive and contextual in nature. The research sample consisted of all the professional nurses, in the operating room. The data were collected by means of a self-administered questionnaire. Descriptive statistics was used to present the data in the form of tables and graphs. Based on the analysis of the data, some recommendations were made for the implementation of infection control practices, in order to prevent Surgical site infections in the operating room.
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Karrer, Urs. "Mouse cytomegalovirus infection as a model for persistent viral infections in mice and humans". Thesis, Open University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422034.
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Martin, Matthew David. "Time-dependent alterations in memory CD8 T cell function after infection". Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3138.
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CD8 T cells play a critical role in the clearance of pathogenic bacteria, viruses, and protozoan parasites. Upon encountering their cognate antigen through either infection or vaccination, naïve CD8 T cells undergo robust proliferative expansion, which is followed by contraction and the formation of a memory population. Memory CD8 T cells are long-lived, and because they persist in increased numbers and possess enhanced functional abilities compared to naïve CD8 T cells, they are able to provide the host with increased protection following re-infection. Because of these properties, vaccines designed to elicit memory CD8 T cells have the potential to reduce health care burdens related to infection with pathogens including human immuno deficiency virus (HIV), malaria, influenza, and hepatitis virus. However, stimulating protective CD8 T cell responses against these pathogens through vaccination has proven challenging. Therefore, a better understanding of the properties of memory CD8 T cells generated following vaccination, and the characteristics of memory CD8 T cells best suited for providing protection against diverse pathogens is needed.
While memory CD8 T cells can be maintained for as long as the life of the host, evidence suggests that their properties change with time after infection. Because CD8 T cell-mediated protection is based upon both the numbers and quality or functional abilities of memory cells present at the time of re-infection, changes in memory CD8 T cell function over time could impact their ability to provide protection upon re-infection. Therefore, a better understanding of how memory CD8 T cells change with time after infection is needed. As part of the studies presented in this thesis, I found that the phenotype and function of memory CD8 T cells including localization, interleukin (IL)-2 cytokine production, responsiveness to homeostatic cytokines, metabolic capabilities, and proliferation and secondary memory generation potential change with time after infection. Interestingly functional changes could not be completely explained by changes in subset composition that occur with time, as changes over time were also seen in defined CD62Lhi subsets. Importantly, functional changes of memory CD8 T cells that occurred with time led to an increased ability to provide protection against a chronic viral infection. These data improve our knowledge of the capabilities of memory CD8 T cells generated following infection, and suggests that the outcome of vaccination strategies designed to elicit protective memory CD8 T cells using single or prime-boost immunizations will depend upon the timing between antigen encounters.
Following re-infection, memory CD8 T cells become activated and produce effector cytokines and cytolytic molecules that aid the host in clearing invading microbes. Activation can be triggered not only through cognate antigen recognition, but also by antigen-independent cytokine driven signals. However, our knowledge of how antigen-dependent and –independent signals contribute to CD8 T cell activation and protection following infection is incomplete. In the second part of my thesis, I show that the ability of memory CD8 T cells to become activated in response to inflammation decreases with time after infection, that antigen and inflammation act synergistically to induce activation of memory CD8 T cells, that the presence of cognate antigen enhances activation of memory CD8 T cells that contribute to clearance of infection, and that bystander memory CD8 T cell responses following unrelated bacterial infection do not provide the host with a protective benefit.
Together, the data in this thesis further our understanding of memory CD8 T cells generated following infection and/or vaccination, and the properties of memory CD8 T cells important for providing protection upon re-infection with invading pathogens.
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Guan, Suhua. "Experimental evolution of nodule intracellular infection in legume symbionts". Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1738/.
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Les rhizobia, symbiotes de légumineuses phylogénétiquement variés, pourraient avoir évolués selon un scenario évolutif en deux étapes : le transfert horizontal de fonctions symbiotiques clés suivi de l'activation de ce potentiel symbiotique par la reprogrammation du génome receveur et la pression de sélection de la plante. Alors que les bactéries nodulantes sont sélectionnées à l'entrée des racines par la plante, les mécanismes de sélection des propriétés symbiotiques plus tardives comme l'infection intracellulaire restent inconnus. Pour répondre à cette question, nous avons profité de travaux préalables ayant converti la bactérie pathogène de plantes Ralstonia solanacearum portant le plasmide symbiotique du rhizobium Cupriavidus taiwanensis en bactéries nodulantes qui infectent les nodules de façon extracellulaire uniquement. Cette souche nodulante non infectieuse a été évoluée expérimentalement en symbiote intracellulaire par des cycles sériés de co-cultures plantes-bactéries. Les mutations adaptatives qui ont permis la transition d'un statut extracellulaire à intracellulaire ont été identifiées. Nos résultats ont montré que ces mutations ont été sélectionnées pour leur effet sur la compétitivité pour la nodulation. De plus, nous avons montré que la mutation ayant initialement permis à la souche ancestrale de noduler, i. E. L'inactivation du système de sécrétion de type III de R. Solanacearum, est également requise pour permettre l'infection intracellulaire. Toutes les mutations adaptatives pour la nodulation et pour l'infection intracellulaire que nous avons identifiées jusqu'ici, impactent en fait les deux processus, suggérant un contrôle similaire de l'invasion bactérienne aux deux niveaux d'entrées, précoce (poil absorbant racinaire) et tardif (cellule du nodule)Rhizobia, which are phylogenetically disparate legume symbionts, may have evolved in a two-step evolutionary scenario: horizontal transfer of key symbiotic functions followed by activation of the newly acquired symbiotic potential through reprogramming of the recipient genome under plant selection pressure. While the plant traps nodulating bacteria, how late event of intracellular infection is selected remains unknown. To address this question, we took advantage of the previous conversion of the plant pathogen Ralstonia solanacearum chimera carrying the symbiotic plasmid of the rhizobium Cupriavidus taiwanensis into a legume-nodulating bacterium that only extracellularly invades nodules. This non-infective nodulating strain was experimentally evolved into intracellular endosymbionts using serial cycles of legume-bacterium co-cultures. The adaptive mutations that drove the transition from extracellular to intracellular status were identified. Our results showed that these mutations were selected for their effect on nodulation competitiveness. Moreover, we showed that the mutation that initially allowed the ancestral strain to nodulate, i. E. Inactivation of the R. Solanacearum type three secretion system, was also required to permit intracellular infection. All key adaptive mutations for nodulation and infection identified so far in this evolution experiment, were actually found to impact on both processes, suggesting a similar control for bacterial invasion at the early (root hair) and late (nodule cell) entry levels
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Batra, A. "The role of the PI3K/AKT signalling pathway during avian infectious bronchitis infection". Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3004963/.
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Infectious bronchitis is a highly contagious respiratory disease that results in reduced egg production and can be fatal in young birds. It has recently been identified as the most economically detrimental disease to the poultry industry. It is caused by the gammacoronavirus infectious bronchitis virus (IBV), which is endemic in most countries worldwide. All viruses modulate cellular processes to establish themselves within the cell. The cellular PI3K/AKT signalling pathway is often modified by viruses and plays a crucial role in the regulation of many cellular processes. In this project the activation of the PI3K/AKT signalling pathway and downstream processes such as apoptosis, translation and macropinocytosis were investigated during IBV infection. Techniques such as western blotting, immunofluorescence, flow cytometry and protein expression were used to determine the effect of IBV infection on modulation of the signalling pathway, as well as the downstream cellular effects of the modulation. This study demonstrates that IBV requires an active PI3K/AKT pathway for efficient replication, and that infection with IBV induces phosphorylation of AKT in a PI3K-dependent manner in mammalian and avian cells. This activation occurs late during infection in mammalian cells. However, in avian cells activation occurs in a biphasic manner at both an early and late time point during infection. To summarise the findings, a model is presented to describe the role of the PI3K/AKT signalling pathway during IBV infection. This study highlights the importance of the PI3K/AKT signalling pathway during IBV infection and may be applied to other human and livestock coronaviruses for development of therapeutics or novel vaccines.
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Shen, Hong. "Hepatitis C infection models". Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05T016.
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L'hépatite C (VHC) est l'une des causes principales de maladies du foie dans le monde, qui représentent un risque élevé d'évoluer vers la cirrhose et le carcinome hépatocellulaire. Actuellement, le traitement standard de l’infection par le VHC est l'interféron pégylé-(peg-IFN) et la ribavirine. Bien que le taux de la réponse virale soutenue (RVS) au traitement se soit améliorée au cours de ces années, cette thérapie n'est pas efficace chez tous les patients. En outre, plusieurs effets secondaires toxiques, de complications et le coût élevé limitent la compliance du patient et l'efficacité du traitement. Il n'existe pas de modèle simple d'infection par le VHC et il est nécessaire de développer des modèles in vitro et in vivo utiles pour étudier la physiopathologie de l'infection par le VHC, y compris les événements précoces de l'infection aiguë (l'entrée du virus, des mécanismes immunologiques et génétiques prédictifs) ainsi que l'évaluation de la puissance des médicaments antiviraux contre le VHC. Nous rapportons ici, nos efforts visant à développer des modèles appropriés de l'infection par le VHC. Dans un premier temps, nous avons établi un modèle de petit animal pour étudier l'infection par le VHC. Tupaia est un petit animal, apparenté aux primates et peu couteux. Dans notre travail, nous avons étudié la susceptibilité du tupaia à l'infection par VHC. Douze tupaias adultes ont été inoculés avec le VHC provenant de sérum de patient et d'ARN du VHC (génotype 1a). Trois jeunes tupaias ont été artificiellement nourris pendant un mois et ensuite inoculés par le VHC provenant de sérum du patient. L'ARN du VHC, les anticorps anti-VHC et l’évolution des quasi-espèces du VHC ont été déterminées chez l'animal avant et après l'inoculation. L'infection transitoire et intermittente s'est produite chez deux des 3 jeunes tupaias et l’infection chronique par le VHC s’est produite chez quatre tupaias sur 12 tupaias adultes. Le tupaia devrait représenter un modèle utile pour l'étude de l’infection chronique par le VHC. Dans une deuxième étape, un système de culture in vitro d'hépatocytes primaires de Tupaia a été établi, dans lequel l'infection par le VHC ne pouvait être bloquée ni par le CD81 soluble ni par des anticorps dirigés contre le CD81. Pour comprendre ces résultats, nous avons cloné, séquencé la grande boucle extracellulaire (LEL) du CD81 chez le Tupaia et analysé l'interaction de la protéine d’enveloppe E2 du VHC avec la LEL du CD81 chez le Tupaia par un test « enzyme-linked immunosorbent assay » (EIA). Nous avons constaté que chez le Tupaia, la séquence d'acides aminés du LEL de CD81 qui se lie au VHC présentait en 6 résidus d'acides aminés différents par rapport à la séquence humaine et la capacité de LEL de CD81 à se lier à la proteine d’enveloppe E2 du VHC a également diminuée. La structure différente de CD81 chez l’homme et chez le tupaia pourrait expliquer l'altération de l'interaction entre CD81 et la proteine E2 du VHC. Ce résultat démontre un rôle important de LEL du CD81 pour l'entrée du VHC. Dans une troisième étape, nous avons développé un modèle ex vivo de culture de tranches de foie humain et leur infection par le VHC. Le développement de lignées cellulaires provenant d’hepatocarcinome, permissives à la réplication du VHC, a fourni d'importants nouveaux outils virologiques pour étudier les mécanismes de l'infection par le VHC, mais ce modèle expérimental reste relativement éloigné des conditions physiologiques et pathologiques. Nous rapportons ici le développement d'un nouveau modèle ex vivo utilisant la culture de tranches de foie humain adulte, démontrant, pour la première fois, la capacité d’isolats primaires ainsi que JFH -1, H77/C3, Con1/C3 (HCVcc), de répliquer et de produire de novo des particules virales infectieuses ayant un titre viral élevé…Hepatitis C virus (HCV) is one of the major causes of liver disease all over the world which has a high risk to progress to cirrhosis and hepatocellular carcinoma. Currently, the licensed standard treatment of HCV infection is Pegylated-interferon (peg-IFN) and ribavirin. Although the sustained viral response (SVR) rate of treatment has improved during these years, this therapy is not effective in all patients. In addition, several toxic side effects, complication and high cost limit the patient compliance and the efficacy of the treatment. There is no easy model of HCV infection and it is necessary to develop useful in vitro and in vivo models to study the pathobiology of HCV infection, including early events of acute infection (viral entry, immunological mechanisms, and genetic predictors) as well as the evaluation of the potency of the HCV antiviral drugs. We report here in our efforts in developing suitable models of HCV infection. In a first step, we preliminary established a small animal model to study HCV infection. Tupaia is a small, closed related to primate and cost-effective animal. In our work, we investigated the susceptibly of tupaia to HCV infection. Twelve adult tupaias were inoculated with native HCV from patient serum and full-length HCV RNA (Genotype 1a). Three young tupaias were artificially breeded for a month and then inoculated by native HCV from patient serum. HCV RNA, anti-HCV and HCV quasi species evolution were determined in the animal before and after inoculation. Transient and intermittent infection occurred in two among 3 young tupaias and HCV chronic infection occurred in four among 12 adult tupaias. Tupaia should represent a useful model for study HCV chronic infection. In a second step, an in vitro culture system of primary tupaia hepatocytes has been established in which HCV infection could be blocked neither by the soluble CD81 nor by antibodies against CD81. To understand these results, we cloned, sequenced the large extracellular loop (LEL) of tupaia CD81 and analyzed the interaction of HCV E2 with the tupaia CD81 LEL by enzyme-linked immunosorbent assay (EIA). We found that in the tupaia the amino acids sequence of HCV CD81 LEL presented in 6 different amino acid residues compared with human CD81 LEL sequence and the CD81 LEL ability to bind to HCV E2 was also decreased. The different structure of CD81 between human and tupaia could explain the alteration of the interaction between HCV E2 and CD81. This result demonstrated an important role of CD81 LEL for HCV entry. In a third step, we developed an ex vivo model of human liver slices culture and their infection with HCV. The development of human cultured HCV-replication-permissive hepatocarcinoma cell lines has provided important new virological tools to study the mechanisms of HCV infection; however this experimental model remains distantly related to physiological and pathological conditions. Here, we report the development of a new ex vivo model using human adult liver slices culture, demonstrating, for the first time, the ability of primary isolates to undergo de novo viral replication with the production of high titer infectious virus, as well as JFH-1, H77/C3, Con1/C3 (HCVcc). This experimental model was validated by demonstrating the HCV neutralization or HCV inhibition, in a dose-dependent manner, either by CD81 or E2 specific antibodies or convalescent serum from a recovered HCV patient, or by anti-viral drugs. This new ex vivo model represents a powerful tool for studying the viral life cycle, dynamics of virus spread in the liver and also for evaluating the efficacy of the new antiviral drugs. In the last step, we evaluated the efficacy of the new antiviral drugs with our ex vivo model of human adult liver slices. HCV NS3/4A protease is essential for viral replication and has been one of the most important target for developing specific antiviral drug
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Irwin, Nicola Jayne. "Infection-responsive urinary biomaterials". Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602549.
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The catheterised urinary tract constitutes an ideal niche for bacterial colonisation, with an estimated 80% of all nosocomial urinary infections attributed to the presence of an indwelling catheter. The present thesis describes the rational design and development of three novel drug delivery systems for application as infection-resistant catheter coatings, which respond to the alkaline conditions generated at the onset of urinary catheter infections by urease-producing pathogens, particularly Proteus mirabilis, via the release of drugs. Upon probing P. mirabilis biofilms with a pH microelectrode, values up to pH 10.12 were recorded directly within the biofilm micro environment. In addition to exploiting this pH elevation to act as a trigger for drug release, the effect of pH on quinolone antibacterial activity is reported herein. Specifically, bactericidal potency of the fluoroquinolone agents: norfloxacin and ciprofloxacin, against P. mirabilis was observed to increase with elevated pH, whereas high concentrations of nalidixic acid demonstrated bactericidal activity selectively in alkaline environments, in contrast to the characteristic 'paradoxical' survival of bacteria observed with high concentrations of this agent in acidic and neutral media. In the first drug delivery system developed herein, the inherent pH -dependent physicochemical properties of nalidixic acid were exploited by a novel, surface particulate localisation method to achieve up to 50-fold faster drug release at pH 9 , than at normal physiological urine pH values ranging from pH 5 to pH 7. In contrast to physical drug loading, the final two systems focused on chemical conjugation of nalidixic acid and surfactant moieties via labile ester bonds to hydrogel backbones. Release of the covalently attached agents was successfully delayed at pH 7 compared to the significantly faster rates of ester hydrolysis and subsequent release at pH 10. Comparative differences in the resistances to bacterial adherence relative to the control hydrogel were demonstrated depending on the specific conjugated agent.
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Morgan, M. "Bell's palsy and infection". Thesis, University of Aberdeen, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593159.
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Despite various pointers to an infectious aetiology, the cause of Bell's palsy remains obscure. We examined paired sera from 62 patients with facial palsy and 50 age and sex matched contemporaneous controls. Significantly more patients than controls had IgM antibodies by ELISA to varicella zoster virus (56.4% vs 20%, p=0.0001) and herpes simplex virus (41.9% vs 18%, p=0.006). Additionally, significantly more patients than controls were positive for CF antibody to varicella zoster virus (14.5% vs 0%, p=0.004) but not to herpes simplex or cytomegalovirus. Significantly more controls than patients (54% vs 25.8%, p=0.002) had no evidence of antigenic stimulation by any member of the herpesvirus group. No significant difference between patients and controls in seropositivity by IgM ELISA to cytomegalovirus, Epstein-Barr virus and IFA for human herpes virus 6 was found. Furthermore, there was no significant difference between the two groups as to evidence of recent infection by the following agents: rubella virus and Borrelia burgdorferi by IgM ELISA, influenza A, influenza B, adenovirus, respiratory syncytial virus, mumps and measles viruses, Mycoplasma pneumoniae, Coxiella burnetii and chlamydia spp. by complement fixation test. The first reported case of clinically and serologically proven Mycoplasma pneumoniae pneumonia associated with Bell's palsy is described. The rate of complete recovery at 6-8 weeks after onset was not significantly different in patients who were given steroids compared to those who were not. Ear related symptoms were the most common, occurring in 12 of 65 cases, but only three (4.6%) had clinical shingles (vesicles in ear).
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Cheng, Chi-chung Vincent, i 鄭智聰. "Proactive infection control measures". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48540596.
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Infection control is an often neglected clinical subject in Hong Kong until the outbreak of severe acute respiratory syndrome (SARS) in 2003. A total of eight healthcare workers, including four medical doctors, succumbed as a result of nosocomial acquisition of SARS-coronavirus (SARS-CoV) at the time. Since then, the importance of infection control practice was much better appreciated by the frontline healthcare workers, as it can be a matter of life-or-death. My thesis summarized our research on the proactive infection control measures to prevent nosocomial transmission of respiratory and gastrointestinal viruses, to control emerging and endemic antibiotic-resistant bacteria, and on the management of unprecedented infection outbreaks in the hospital.
Promotion of hand hygiene is the cornerstone of proactive infection control measures. By adopting the concept and practice of directly-observed hand hygiene, we demonstrated successful control of outbreaks and prevention for both respiratory and gastroenteritis viruses. Introduction of electronic devices for continuous monitoring of hand hygiene compliance in high risk clinical areas provides an opportunity for immediate feedback and timely education to frontline staffs.
The global dissemination of multiple drug resistant organisms (MDROs) such as methicillin-resistant Staphylococcus aureus (MRSA), community-associated MRSA (CA-MRSA), vancomycin-resistant enterococcus (VRE), hypervirulent clone of Clostridium difficile, extended-spectrum beta-lactamase (ESBL) producing organisms, and the recently described carbapenem-resistant enterobacteriaceae (CRE), pose a great challenge to the infection control professionals. In Hong Kong, MRSA has been endemic for more than two decades. Although we proved that the appropriate use of single room isolation and hand hygiene can significantly reduce the incidence of nosocomial MRSA in the adult intensive care unit, the isolation facilities remain limited in the general medical and surgical units. Innovations are much in need to manage this old and persistent problem. Therefore, we demonstrated that use of antibiotics, in particular beta-lactams and fluoroquinolones, could increase the risk of environmental contamination by increasing microbial density of MRSA in the anterior nares by 2-3 log10 in as little as 1 week. We also found that some MRSA strains such as spa types t1081 and t037 were more transmissible. Based on these findings, we prioritized our isolation facilities for those patients who are heavily colonized or infected with highly transmissible spa-type t1081, especially when they are receiving antibiotic therapy. Along with our enhancement of hand hygiene practices and antibiotic stewardship program, the incidence of MRSA bacteremia per 1000-patient-days was the lowest among the seven hospital clusters in Hong Kong. We believe that our experience in the control of the MRSA can be extended to contain the spread of CA-MRSA and other MDROs.
Besides the prevailing infectious diseases with high endemicity, we have to be vigilant against other potential outbreaks due to uncommon micro-organisms such as the polymicrobial outbreak in patients undergoing intermittent peritoneal dialysis caused by hospital renovation, the unprecedented outbreak of intestinal mucormycosis caused by Rhizopus microsporous among the patients with hematological malignancy, and the nosocomial outbreak of legionellosis in our locality. Extensive outbreak investigations were performed, which demonstrated that environmental factors were also important in causing nosocomial outbreaks.published_or_final_version
Microbiology
Master
Doctor of Medicine