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Flock, Margareta. "Development of a vaccine against strangles /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-500-3/.
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Unnikrishnan, Meera. "Streptococcal superantigens in Group A streptococcal infections." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248185.
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Smith, Jennifer Marie. "Characterization of host-bacteria interactions contributing to group B streptococcus colonization." Huntington, WV : [Marshall University Libraries], 2002. http://www.marshall.edu/etd/descript.asp?ref=64.
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Ihendyane, Nahla. "Pathogenesis and immunotherapy of streptococcal septicemia and shock /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-599-9/.
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Darenberg, Jessica. "Streptococcus pyogenes infections and toxic shock syndrome : molecular epidemiology and immunotherapy /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-676-X/.
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Law, Vicky Wai-Kee. "Oral colonization of mutans streptococci in young children : a longitudinal study /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19176.pdf.
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Westling, Katarina. "Viridans group streptococci septicaemia and endocarditis : molecular diagnostics, antibiotic susceptibility and clinical aspects /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-364-7/.
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Power, Daniel Aaron, and n/a. "Non-culture based studies of the human upper respiratory tract microbiota and preliminary considerations of the influence of bacteriocin producing commensal and pathogenic oral streptococci." University of Otago. Department of Microbiology & Immunology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070620.160726.
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The upper respiratory tract (URT) of humans is complex and interconnected region and comprises several major ecosystems including the oral cavity, oropharynx, nasal cavity, sinuses, nasopharynx and middle ear. Most of the anatomical locations within the URT are colonised with a normal bacterial microbiota, within which are often organisms having the potential to cause disease. The diseases of the URT are both varied and frequent in their occurrence, and conditions such as otitis media, rhinosinusitis and pharyngitis are sources of morbidity and mortality in adults and children in both developing and developed countries.
The study of diseases of the URT has traditionally been based on application of culture-based methods in which the infection-implicated organisms are first grown in vitro and then studied further. Ongoing advances in DNA-based techniques have led to the development of new molecular tools for the study of infectious diseases. One such technique is PCR-denaturing gradient gel electrophoresis (PCR-DGGE). This is a PCR-based tool that allows the investigation of microbial communities independent of culture. Although this technique has been applied extensively in the study of the gastrointestinal tract, the vagina and endodontic infections in humans, there have been few reports of its application to URT infections. PCR-DGGE was applied in the present study to investigate (a) the bacteria present in the middle ear of children suffering from otitis media with effusion (OME), (b) the microbiota associated with the sinuses in patients with chronic rhinosinusitis (CRS) and (c) perioperative changes in the bacterial population of the middle meatus of patients undergoing nasal or sinus surgery. The analysis of the middle ear fluid samples indicated an increased role in OME for the newly-discovered pathogen Alloiococcus otitidis and also the possible involvement of certain coryneform bacteria and coagulase-negative staphylococci in the aetiology of this condition. PCR-DGGE analysis of patients with CRS revealed a polymicrobial disease with considerable variability in the predominant species detected when multiple, serial samples were evaluated. The perioperative audit showed that when good clinical practice is adhered to, there was no apparent introduction of potentially-harmful organisms into the middle meatus.
Streptococcus salivarius is a common, commensal inhabitant of the oral cavity of humans and has also been shown to inhabit the nasopharynx of infants. S. salivarius is also a well known producer of bacteriocins with activity directed against Streptococcus pyogenes. One such strain, S. salivarius K12, is now marketed in New Zealand as the probiotic, K12 Throat Guard[TM]. In the present study, S. salivarius K12 was compared with two additional strongly-inhibitory S. salivarius (strains T18A and T30A) for activity against the common causative pathogens of otitis media. A paediatric formulation of strain K12 was also tested in a pilot clinical trial for its ability to colonise the URT of young children. Although the levels of colonisation of these subjects was not as high as typically obtained with use of the K12 Throat Guard[TM] formulation, it was considered that further development of the paediatric formulation is warranted, particularly with respect to use of a different pre-treatment regimen. In other studies, the molecular basis for the unusual in vitro inhibitory activity of S. salivarius strain T30A was investigated. Although this still remains unresolved, other observations made during the course of this study have led to the introduction of a schema for the division of inhibitory S. salivarius into three groups based on (a) their sensitivity to the lantibiotic salivaricin A and (b) the structure of their salivaricin A genetic locus. This grouping is analogous to the "rock-paper-scissors" system previously described for colicin-producing strains of E. coli.
Streptococcus pneumoniae is a major human pathogen responsible for a variety of diseases in humans. There have been very few reports of bacteriocin production by S. pneumoniae when compared to other streptococcal species. In the present study a putative cluster of bacteriocins encoded by the blp locus has been investigated. The distribution of the individual blp determinants within this locus was evaluated in a collection of S. pneumoniae strains using PCR. The blp genes were detected in 92% of 57 tested strains and a variant form (termed the B-form) of the cluster was identified that appeared to have arisen due to a genetic recombination event. In this case an approximately 250 bp portion of the blpMNO cluster appears to have recombined into blpK of the blpIJK cluster. Attempts were made to express the putative bacteriocin peptide genes in an Escherichia coli expression system. Failure to achieve expression was taken to indicate that these bacteriocin-like peptides may be toxic for the host producer cells under these test conditions. Future attempts to achieve expression of the Blp peptides, could explore the use of different fusion proteins, a Gram-positive expression host or a cell-free protein expression system.
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Wright, Lynda J. "Identification and characterisation of components expressed by gram-positive bacterial pathogens during human infection." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/10312/.
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Gram-positive pathogens are responsible for a wide range of global diseases, including nosocomial infections. The increasing incidence of antibiotic-resistant strains warrants the development of novel therapeutic strategies to combat these organisms.
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Sanderson-Smith, Martina Louise. "Investigation of the role of the plasminogen-binding group A streptococcal M-like protein (PAM) in the pathogenesis of Streptococcus pyogenes." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070821.125843/index.html.
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Leung, Chin-pang, and 梁展鵬. "Characterization of group a streptococcus in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B3196963X.
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Stofile, P. Z. "Prevalence of Group B streptococcus and staphylococcus aureus colonization in the anogenital tract of pregnant women in the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/5983.
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Neonatal sickness and death is increasingly becoming a public health problem worldwide. The colonization of Group B Streptococcus and Staphylococcus in the rectovaginal area is among the sources of infections in neonates which can result in illness and mortality. The over exposure of humans to antibiotics is the possible cause of resistance in bacteria. These resistant strains can be passed onto offspring, leading to resistant infections and increasing the morbidity of neonates because of treatment failures. Many people, including healthcare personnel are not aware of the effect of these bacteria, and informing clinics and hospitals can help create awareness and monitoring the levels of resistance among bacteria can assist in preventing the transference of the bacteria. In this study we investigated the prevalence of group B Streptococcus (GBS) and Staphylococcus aureus in the anogenital tract of pregnant women in the Eastern Cape Province, South Africa. A total of 49 isolates from 25 (30.5 percent) pregnant women colonized with GBS were isolated from vaginal and rectal swabs of 82 pregnant women at 25-37 gestation who participated in this study. These isolates were obtained using standard microbiological methods and confirmed by polymerase chain reaction (PCR) technique aimed at the ScpB gene. The isolates were further screened for the presence of 9 serogroups (Ia, Ib, II, III, IV, V, VI, VII, VII) and serogroups Ib 2 (4.8 percent), II 20 (40.8 percent) and IV 5 (10.2 percent) and 22 non-typable (44.9 percent) were identified. Susceptibility profiling of the isolates to 12 antibiotics (tetracycline, clindamycin, erythromycin, gentamycin, naladixic acid, norfloxacin, chloramphenicol, cefuroxime, cefotaxime, imipenem, penicillin and vancomycin) was tested in vitro by the standardized disc diffusion method. All the confirmed GBS isolates (49) were resistant to erythromycin, tetracycline and clindamycin. A higher percentage of the isolates were resistant to gentamycin 44 (90 percent), nalidixic acid 41 (84 percent), penicillin 41 (84 percent), chloramphenicol 38 (78 percent), cefuroxime 36 (74 percent), imipenem 36 (74 percent), cefotaxime 35 (71 percent), norfloxacin 32 (65 percent) and vancomycin 31 (78 percent). Multiple antimicrobial resistance patterns ranged from 9‒11 and indices ranged from 0.7‒0.9, respectively. Among the antimicrobial resistance determinants examined, genes encoding for resistance to erythromycin ermB 25 (51 percent), tetracycline tetM 32 (65 percent) and penicillin bla-Z 4 (8 percent) only were identified. On the other hand, screening for S. aureus yielded a total of 7 isolates from 4 study participants as confirmed by PCR based on staphylococcal, nuc gene. The isolates were further screened for the presence of six virulence genes (Hla, Hlb, LUKM, LUKED, PVL, Eta and Etb) and antibiotic susceptibility pattern by the disc diffusion method using 12 (penicillin, vancomycin, tetracycline, rifampicin, imipenem, gentamycin, chloramphenicol, norfloxacin, oxacillin, erythromycin and sulfamethoxazole-trimethoprim) antibiotics that are adopted in the treatment of infections caused by the organism. PVL 6 (85.7 percent) and eta 1 (14.3 percent) were the two virulence genes detected. The following percentages of antibiotics resistance among the isolates were observed; penicillin G 7 (100 percent), clindamycin 7 (100 percent), vancomycin 5 (100 percent), rifampicin 5 (71 percent), oxacillin 5 (71 percent), erythromycin 5 (71 percent) gentamycin 3 (43 percent), norfloxacin 3 (43 percent), sulfamethoxazole-trimethoprim 3 (43 percent), chloramphenicol 2 (29 percent), imipenem 1 (14 percent). Multiple antimicrobial resistance patterns ranged from 7‒8 and indices ranged from 0.6‒0.7, respectively. Genetic profiling of the resistance genes identified erythromycin ermB 5(71.4 percent), tetracycline tetM 5(71.4 percent) and penicillin bla-Z 1(14.3 percent) only. The findings from the study have revealed GBS and S. aureus colonization of pregnant women in the Eastern Cape Province, and these have great public health implications especially for the neonates who are mostly likely to be infected during birth. The unidentifiable multidrug resistant serogroups of GBS as well as resistant S. aureus limit the choice of drugs in the management of infections caused by these pathogens more so if transmitted to infants. Therefore asymptomatic pregnant women needed to be properly educated about the bacteria as well as the precautions that need to be taken.
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Rox, Katharina [Verfasser], and Rolf [Akademischer Betreuer] Müller. "Natural compounds as pathoblockers of streptococcal infections / Katharina Rox ; Betreuer: Rolf Müller." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2015. http://d-nb.info/1165573938/34.
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Kong, Fanrong. "Integrated study of group B streptococcus and human ureaplasmas : the paradigm shifts." Thesis, The University of Sydney, 2004. http://hdl.handle.net/2123/592.
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Group B streptococcus (GBS, S. agalactiae) and human ureaplasmas (U. parvumand U. urealyticum) are two clinically and phylogenetically related, potential perinatal pathogens. Their relationships between genotypes and pathogenesis of GBS and ureaplasma infection were still not well understood, one of the reason is that both of them are still short of a very practical genotyping system. In the study, to solve the above problem we developed genotyping systems for the organisms (the second section). For human ureaplasmas, based on four genes/gene clusters (rRNAgene clusters, the elongation factor Tu genes, urease gene complexes and multiplebanded antigen genes), we designed many primer pairs suitable for developing species identification assays for the two newly established human ureaplasma species (U. parvum and U. urealyticum). Further, based on the heterogeneity of ureaplasma multiple banded antigen gene (which contains species- and serovar-specific regions), we developed genotyping methods for each ureaplasma species.For GBS, based on three sets of molecular markers (capsular polysaccharidesynthesis gene clusters, surface protein antigen genes and mobile genetic elements),we developed a genotyping system. The primary evaluation of the genotyping systems showed that the genotyping systems were practical alternative assays for the conventional serotyping and they will be useful to further explore the relationships between genotypes and pathogenesis of GBS and ureaplasma infection. In the study, we introduced novel data and tools into GBS and ureaplasma studies especially from genomic- and bioinformatics-based molecular microbiology(the third section). For two newly established human ureaplasma species, based on the U. parvum serovar-3 genome, and using the above four important genes/geneclusters, we exposed some interesting problems in the understanding of newureaplasma taxonomy especially in the post genomic era. For GBS, we studied the two published full genomes and exposed some new problems or possible future new research fields. In particular we found the two finished and one ongoing GBS genomes were all non-typical and suggest that future genomic project had better have genetic population structure viewpoint. Finally, we suggested that integrated studies of the two potential or conditional perinatal pathogens, from the viewpoint of evolution, would provide a new understanding angle of the pathogenesis of the two organisms. Studies suggested that during coevolution, human ureaplasmas(especially U. parvum) became friendlier than their ancestors to their human host (by losing most of its virulence genes); however, GBS tried to increase its invasive abilities (by getting more virulence genes) to fight against the human host attack.
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Kong, Fanrong. "Integrated study of group B streptococcus and human ureaplasmas � the paradigm shifts." University of Sydney. Medicine, 2004. http://hdl.handle.net/2123/592.
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Group B streptococcus (GBS, S. agalactiae) and human ureaplasmas (U. parvumand U. urealyticum) are two clinically and phylogenetically related, potential perinatal pathogens. Their relationships between genotypes and pathogenesis of GBS and ureaplasma infection were still not well understood, one of the reason is that both of them are still short of a very practical genotyping system. In the study, to solve the above problem we developed genotyping systems for the organisms (the second section). For human ureaplasmas, based on four genes/gene clusters (rRNAgene clusters, the elongation factor Tu genes, urease gene complexes and multiplebanded antigen genes), we designed many primer pairs suitable for developing species identification assays for the two newly established human ureaplasma species (U. parvum and U. urealyticum). Further, based on the heterogeneity of ureaplasma multiple banded antigen gene (which contains species- and serovar-specific regions), we developed genotyping methods for each ureaplasma species.For GBS, based on three sets of molecular markers (capsular polysaccharidesynthesis gene clusters, surface protein antigen genes and mobile genetic elements),we developed a genotyping system. The primary evaluation of the genotyping systems showed that the genotyping systems were practical alternative assays for the conventional serotyping and they will be useful to further explore the relationships between genotypes and pathogenesis of GBS and ureaplasma infection. In the study, we introduced novel data and tools into GBS and ureaplasma studies especially from genomic- and bioinformatics-based molecular microbiology(the third section). For two newly established human ureaplasma species, based on the U. parvum serovar-3 genome, and using the above four important genes/geneclusters, we exposed some interesting problems in the understanding of newureaplasma taxonomy especially in the post genomic era. For GBS, we studied the two published full genomes and exposed some new problems or possible future new research fields. In particular we found the two finished and one ongoing GBS genomes were all non-typical and suggest that future genomic project had better have genetic population structure viewpoint. Finally, we suggested that integrated studies of the two potential or conditional perinatal pathogens, from the viewpoint of evolution, would provide a new understanding angle of the pathogenesis of the two organisms. Studies suggested that during coevolution, human ureaplasmas(especially U. parvum) became friendlier than their ancestors to their human host (by losing most of its virulence genes); however, GBS tried to increase its invasive abilities (by getting more virulence genes) to fight against the human host attack.
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Mills, Jamie-Lee S. "Modelling natural immunity to streptococcal mucosal infections and novel approaches to vaccine delivery." Thesis, Griffith University, 2022. http://hdl.handle.net/10072/414917.
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Streptococcus pyogenes causes significant global morbidity and mortally through a range of pathologies. The most common sites of infection are the upper respiratory tract and the skin, resulting in pharyngitis and impetigo respectively. Non-invasive infections are usually self-limiting; however, they have the potential to progress to life threatening invasive diseases such as toxic-shock syndrome and necrotizing fasciitis with a high rate of mortality. Furthermore, S. pyogenes infections can give rise to auto-immune sequelae of ARF/RHD and ASPGN that result in approximately 500 000 deaths each year. Despite global efforts that span decades, no human vaccine is approved for use. The major hurdles in vaccine development are the broad serotypic and antigenic diversity of S. pyogenes, the risk for potential auto-immune disease due to the molecular mimicry of the S. pyogenes M-protein (a prime vaccine target) and human cardiac myosin, and the ability of S. pyogenes to infect different body sites that require different protective immune mechanisms.
Previous research has shown that exposure to S. pyogenes can result in protective antibodies, though immunity is slow to develop and its role in preventing subsequent infections is poorly understood. In addition, there is a need to understand the mechanism of cross-compartment immunity to aid in guiding vaccine development to protect from multiple serotypes and also at various infection sites. To understand the mechanisms involved in site-specific and cross-compartment immunity, repeated mucosal exposures to S. pyogenes non-lethal infections in mice were performed to mimic endemic settings. Repeated homologous mucosal infections resulted in significant site-specific protection that endured for at least 9 weeks. Mice developed type-specific serum antibodies and antibody secreting cells (ASCs) that increased with increasing number of infections. These data indicate that the longevity of the antibody response is governed by the number of prior mucosal infections; however, no direct correlation with protection was established. Mucosal protection indicated a role for cell-mediated immunity. Repeated acute mucosal infections resulted in significant neutrophil recruitment to the local site of inflammation that correlated with protection.
Cytokine analysis suggested a role for IL-17A in mucosal protection, particularly for enduring protection. To assess the importance of IL-17, IL-17 knockout (IL-17-/-) mice were given repeated homologous mucosal infections. Unlike wild type BALB/c mice, IL-17-/- mice failed to generate mucosal protection with repeated exposures. Furthermore, IL-17-/- mice had significantly reduced M-protein type-specific salivary IgG, IgG and IgA-secreting cells in bone marrow, and neutrophil influx to the lung, correlating with lack of protection.
Mice required only one prior mucosal infection to develop significant and long-lasting protection against a homologous mucosal challenge. However, when cross-compartment protection at the skin was assessed, mice required a minimum of four repeated mucosal infections to generate significant protection. These data suggest that developing a protective immune response by repeated exposures is unlikely in a real-world setting. The literature indicates that multiple different S. pyogenes types move through communities, and people rarely encounter the same strain again within a short period of time. Realising these constraints in developing naturally acquired immunity to S. pyogenes, the next question was then asked: ‘could vaccine mediated immunity be boosted and broadened via natural exposures to S. pyogenes?’
Vaccine candidates based on the conserved C-terminal region of S. pyogenes M-protein (p145) have made considerable progress. The C-terminal region of the M protein is conserved across the majority of S. pyogenes strains, therefore forgoing the issue of serotype diversity. Two vaccine epitopes at the forefront of development, J8 and p*17, when conjugated to the carrier protein, diphtheria toxoid (DT), create J8-DT and p*17-DT.
p*17-DT delivered intramuscularly with the adjuvant, alum, (p*17-DT/Alum) has shown promising immunogenicity and protection against several S. pyogenes isolates; however, it does not protect mice against intranasal challenge with a hypervirulent covR/S mutant strain. To test the hypothesis that infection will boost vaccine-mediated immunity, mice received two vaccinations with p*17-DT/Alum, followed by repeated mucosal infections every three weeks with heterologous isolates. Mice that received vaccinations followed by sequential infections showed increasing protection against NALT (nasal associated lymphoid tissue) bacterial load with each subsequent infection when compared to naïve mice. Bacterial load in the NALT was significantly reduced in these mice following a covR/S mutant challenge. Antigen-specific ASCs were assessed as a determinant of humoral immunity. Although no increase in serum antibody levels or antibody avidity were observed between mice that received vaccination alone or when followed by repeated infections, the mice that received vaccination and sequential infections had significantly increased IgG secreting cells in the spleen. The ASCs, in combination with lung specific CD4+ T-cell responses may be contributing to increased protection seen in mice that were boosted with repeated heterologous infections. Although promising, the results were scattered, which may be attributed to the differences in sequence homology of p145 as well as characteristics of different isolates. These data suggest that vaccine-mediated immunity has the potential to be boosted with repeated exposures to S. pyogenes. However, it was demonstrated that there is room for improvement in vaccination strategy and alternative approaches should be explored. Therefore, the next aim was to assess if new delivery methods could be used to increase vaccine-mediated immunogenicity and protection.
Different methods of vaccine delivery can invoke varied immune responses. Skin-based immunisation routes have gained attention due to targeting of the epidermis and dermis layers rich in immune cells. Several advantages are associated with cutaneous routes, particularly when using high density/micro array patches (MAPs and HD-MAPs). These include dose sparing, enhanced thermostability, ease of administration, reduced generation of sharp-waste and risk of needle-stick injuries, good tolerability and enhanced acceptability in patients. HD-MAPs, developed by Vaxxas Pty Ltd, are at an advanced stage of development and have shown promising clinical trials results. The aim of his final study was to determine if the M-protein-based vaccine candidate J8-DT would have comparable immunogenicity and protection if delivered on the adjuvant free HD-MAP in comparison to intramuscular delivery.
The effect of dose sparing and the number of vaccinations on the antibody response profile of vaccinated mice were assessed. A reduction in the number of vaccinations (from three to two) with J8-DT/HD-MAP induced comparable antibody responses to three vaccinations with intramuscular J8-DT/Alum. J8-DT/HD-MAP vaccination led to a significant reduction in the number of S. pyogenes colony forming units in skin (92.9%) and blood (100%) compared to intramuscular vaccination with unadjuvanted J8-DT when assessed following skin challenge. J8-DT/HD-MAP induced a shift in the antibody isotype profile, with a bias towards Th1-related isotypes, compared to J8-DT/Alum (Th2 bias). Based on the results of this study, the use of J8-DT/HD-MAP should be considered in future clinical development and control programs against S. pyogenes.
The studies in this thesis demonstrate the constraints in developing naturally acquired immunity and highlight the importance for developing an effective vaccine against S. pyogenes.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Institute for Glycomics
Science, Environment, Engineering and Technology
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Jarvis, Christopher D. "Mouse Antibody Response to Group A Streptococcal Carbohydrate: A Thesis." eScholarship@UMMS, 1989. https://escholarship.umassmed.edu/gsbs_diss/227.
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In an attempt to more fully understand the generation of antibody diversity to carbohydrate antigens, we produced and characterized a panel of hybridoma cell lines specific for group A streptococcal carbohydrate from mice injected with the intact bacteria (minus the hyaluronic acid capsule and cell wall protein antigens). We have analyzed the use of heavy and light chain variable region genes in the early (day 7) and late response (hyperimmune) and have determined the nucleotide sequence of the dominant VH gene used in several of our hybridomas. Our data allowed us to assess the extent to which the recombination of various V, D, and J gene segments and somatic mutation contribute to antibody diversification in this system. In this report we confirm that a minimum of two VH and four VK gene segments are used to encode this response. We extend this analysis to show that multiple D and J gene segments are used and that a significant amount of junctional variability is tolerated in CDR 3. Our results also suggest that there is a positive selection for somatic mutation in CDR 1 during the hyperimmune response to group A streptococcal carbohydrate.
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McKay, Fiona Catherine. "Is plasminogen deployed as a virulence factor by Northern Territory group A streptococcal isolates during invasive disease?" Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060712.140148/index.html.
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Nooh, Mohammed Mostafa. "Biochemical and immunological mechanisms underlying differential interaction of superantigens with host immunogenetic factors in streptococcal sepsis." View the abstract Download the full-text PDF version, 2008. http://etd.utmem.edu/ABSTRACTS/2008-027-Nooh-index.html.
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Thesis (Ph.D )--University of Tennessee Health Science Center, 2008.Title from title page screen (viewed on Sept. 17 2008). Research advisor: Malak Y. Kotb, Ph.D. Document formatted into pages (xvii, 189 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 161-189).
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Effertz, Bernard Stephen. "The humoral immune response to streptococcal cell wall-induced arthritis in the rat." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184877.
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I investigated the humoral immune response to streptococcal cell walls (SCW) in arthritis susceptible Lewis and resistant Fisher rats. All rats were given a single intraperitoneal injection of either SCW or saline (controls). Rats were sacrificed, three rats per time point, over an eleven week period and serum was collected for ELISA. SCW injected Lewis rats produced anti-SCW antibody, whereas control rats did not. Anti-SCW antibody was significantly elevated over controls between days 14-28 (post injection). Both saline and SCW injected Fisher rats produced anti-SCW antibody, but with different kinetics. Anti-SCW antibody increased by day 7 and remained elevated over controls till day 21, after which there was no difference. ELISA were designed to determine the SCW epitope(s) recognized by anti-SCW antibody. Formamide extracts of SCW, peptidoglycan and polysaccharide, were investigated along with the terminal epitope of polysaccharide, N-acetyl-D-glucosamine, and the peptidoglycan precursor peptide. The data revealed that anti-SCW antibody was directed against a combined SCW epitope, given the lack of significant binding to any of the SCW epitopes tested. Isotype analysis of anti-SCW antibody revealed that the Lewis response was composed primarily of IgG2a whereas the Fisher response was composed primarily of IgM. Binding of rat IgG isotypes to whole streptococcus, SCW, peptidoglycan, and polysaccharide was investigated, given the possibility of background binding by the streptococcal Fc-receptor. Streptococcal binding of rat IgG was specific for IgG2c and the polysaccharide portion of SCW was necessary for binding. Passive immunization of naive Lewis rats with antibody from rats with active arthritis was ineffective at transferring the disease. However, subcutaneous injection of affinity purified anti-SCW antibody or IgG into Lewis rats, followed twenty-four hours later by a single intraperitoneal injection of SCW, suppressed the acute phase and inhibited the chronic disease. IgM rheumatoid factor (RF) was present in the serum of both saline and SCW injected Lewis and Fisher rats. However, SCW injection only induced a significant increase in IgM RF (between days 3-7) in Lewis rats. Passive immunization of Fisher rats with affinity purified IgM RF (from Lewis serum), three days post SCW injection, was ineffective at inducing arthritis.
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Ozberk, Victoria. "Design and evaluation of novel liposome-based peptide vaccines for improved efficacy against group A streptococcal infections of the mucosa and skin." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/380063.
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Streptococcus pyogenes (group A streptococcus, GAS) is an important human pathogen that is responsible for a range of diseases. Non-invasive diseases include pharyngitis, scarlet fever and pyoderma/impetigo. GAS is also capable of causing invasive diseases such as streptococcal toxic shock syndrome and necrotizing fasciitis. There is a high chance of mortality associated with GAS invasive diseases, with approximately 8-23% of patients dying within 7 days of infection. Consecutive GAS infections may give rise to auto-immune complications, including acute rheumatic fever (ARF) and rheumatic heart disease (RHD). Approximately 2-3% of patients who acquire streptococcal pharyngitis develop ARF. Skin-associated GAS strains have also been linked to cases of ARF. A vaccine that can stop the progression of disease from the primary sites of infection (URT and skin) is desperately needed.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Institute for Glycomics
Science, Environment, Engineering and Technology
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Cole, Jason Nicklaus. "Characterisation of cell wall proteins, virulence factor maturation and invasive disease trigger of Group A streptococcus." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20070130.144214/index.html.
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Seanego, Christinah Tshephisho. "Phytochemical analysis and bioactivity of Garcinia Kola (Heckel) seeds on selected bacterial pathogens." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/420.
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Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.
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Schirm, Sibylle, Peter Ahnert, Sandra Wienhold, Holger Müller-Redetzky, Geraldine Nouailles-Kursar, Markus Löffler, Martin Witzenrath, and Markus Scholz. "A biomathematical model of pneumococcal lung infection and antibiotic treatment in mice." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-204153.
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Pneumonia is considered to be one of the leading causes of death worldwide. The outcome depends on both, proper antibiotic treatment and the effectivity of the immune response of the host. However, due to the complexity of the immunologic cascade initiated during infection,
the latter cannot be predicted easily. We construct a biomathematical model of the murine immune response during infection with pneumococcus aiming at predicting the outcome of antibiotic treatment. The model consists of a number of non-linear ordinary differential
equations describing dynamics of pneumococcal population, the inflammatory cytokine IL-6, neutrophils and macrophages fighting the infection and destruction of alveolar tissue due to pneumococcus. Equations were derived by translating known biological mechanisms
and assuming certain response kinetics. Antibiotic therapy is modelled by a transient depletion of bacteria. Unknown model parameters were determined by fitting the predictions of the model to data sets derived from mice experiments of pneumococcal lung infection with and without antibiotic treatment. Time series of pneumococcal population, debris, neutrophils, activated epithelial cells, macrophages, monocytes and IL-6 serum concentrations were available for this purpose. The antibiotics Ampicillin and Moxifloxacin were considered. Parameter fittings resulted in a good agreement of model and data for all experimental scenarios. Identifiability of parameters is also estimated. The model can be used to predict the performance of alternative schedules of antibiotic treatment. We conclude that we established a biomathematical model of pneumococcal lung infection in mice allowing predictions regarding the outcome of different schedules of antibiotic treatment. We aim at translating the model to the human situation in the near future.
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Woods, Robin. "The infectious nature of dental caries and mutans streptococci in an Australian rural school community." Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/4822.
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Deicke, Christin [Verfasser], and Manfred [Akademischer Betreuer] Rohde. "The role of coagulation factor XIII in the early innate immune response against streptococcal infections / Christin Deicke ; Betreuer: Manfred Rohde." Braunschweig : Technische Universität Braunschweig, 2015. http://d-nb.info/1175818925/34.
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Walker, Kate. "Trends in birthweight and infant weights : relationships between early undernutrition, skin lesions, streptococcal infections and renal disease in an Aboriginal community /." Connect to thesis, 1996. http://repository.unimelb.edu.au/10187/2406.
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Undernutrition in prevalent in Aboriginal communities, in utero, infancy and childhood. It influences childhood morbidity and mortality and growth patterns. Undernutrition and poor socio-economic status also contribute to endemic and epidemic infectious disease, including scabies and streptococcal infection. It has been suggested that early undernutrition, and streptococcal and scabies infection are risk factors for renal disease, which is at epidemic levels and increasing. This thesis examines the prevalence of undernutrition in newborns and infants in an Aboriginal community over time, and its impact on childhood growth and child and adult renal markers. The association between skin lesions, streptococcal serology, post-streptococcal glomerulonephritis (PSGN) and renal markers as evaluated through a community wide screening program in 1992-1995 is also examined. Birthweights have increased since the 1960s, but they are still much lower than the non-Aboriginal values. Weights in infancy have decreased since the 1960s. At screening in childhood stunting was common, reflecting the presence of long-term poor nutrition in infancy. In both adults and children, birth weight and infant weights were negatively associated with albuminuria measured by the albumin to creatine ratio (ACR).
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Chella, Krishnan Karthickeyan. "Host-Pathogen Interactions Promoting Pathogen Survival and Potentiating Disease Severity & Morbidity in Invasive Group A Streptococcal Necrotizing Soft Tissue Infections." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1446546952.
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Koskenkorva, T. (Timo). "Outcome after tonsillectomy in adult patients with recurrent pharyngitis." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207995.
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Abstract Recurrent pharyngitis causes doctor visits, antibiotics use and absences from school or work and thus worsens patients’ quality of life (QOL). Even though tonsillectomy is often performed for recurrent pharyngitis, there is limited evidence of the tonsillectomy benefit concerning both researcher- and patient-recorded outcomes. The intent of this work was to find out if tonsillectomy reduces numbers of pharyngitis episodes or symptom days, if tonsillectomy improves patients’ QOL and if there are any clinical factors predicting QOL benefit after tonsillectomy. Seventy adult patients with recurrent streptococcal pharyngitis (2001–2005) and 86 patients with recurrent pharyngitis of any origin (2007–2010) were enrolled for two randomised controlled trials. Patients with recurrent pharyngitis of any origin were followed up either before (control group, n=40) or after (tonsillectomy group, n=46) tonsillectomy. At five months of follow-up, 17 (43%) patients in the control group and 2 (4%) patients in the tonsillectomy group consulted a physician for pharyngitis. Thirty-two (80%) patients in the control group and 18 (39%) patients in the tonsillectomy group experienced any kind of pharyngitis episode. Only one episode was considered severe. The numbers of days with throat pain and fever were significantly lower in the tonsillectomy group. QOL of 142 responders measured by Glasgow Benefit Inventory (GBI) six months after tonsillectomy showed improvement: median GBI total score was +27. However, GBI total scores varied considerably between the patients (range −19 to +69). Only one patient reported declined QOL. The number of prior pharyngitis episodes, frequent throat pain, untreated dental caries and chronically infected tonsils were the best clinical factors predicting QOL improvement. The precision of these predictions was still quite low. The results of this work suggest that tonsillectomy reduces numbers of acute pharyngitis episodes and symptoms. Although most of the episodes are not severe, tonsillectomy still generally improves patients’ QOL. The distribution of QOL benefit is broad, however. Throat-related morbidity before tonsillectomy is the only clinical factor that was associated with patient satisfactionTiivistelmä Toistuvat nielutulehdukset aiheuttavat paljon lääkärikäyntejä, antibioottihoitoja sekä poissaoloja töistä tai opinnoista ja huonontavat potilaiden elämänlaatua. Toistuvien nielutulehdusten vuoksi päädytään usein nielurisaleikkaukseen, vaikka tutkimusnäyttö leikkauksen hyödystä on vähäistä. Tämän väitöskirjatyön tavoitteena oli tutkia, vähentääkö nielurisaleikkaus nielutulehdusten määrää tai oireita sekä selvittää leikkauksenjälkeistä elämänlaatua ja siihen liittyviä ennustekijöitä. Tutkimusaineisto koostui kahta eri satunnaistettua kliinistä koetta varten rekrytoiduista potilaista: 70 potilasta, joiden toistuvien nielutulehdusten aiheuttaja oli A-ryhmän streptokokki (2001–2005) ja 86 potilasta, joiden toistuvien nielutulehdusten etiologialle ei asetettu vaatimuksia (2007–2010). Potilaat, joilla nielutulehdusten etiologia oli avoin, satunnaistettiin kahteen ryhmään: kontrolliryhmää (n=40) seurattiin ennen nielurisaleikkausta ja leikkausryhmää (n=46) sen jälkeen, molempia 5 kuukauden ajan. Seurannassa 17 (43 %) kontrolliryhmän potilasta ja 2 (4 %) leikkausryhmän potilasta hakeutui lääkäriin nielutulehduksen vuoksi. Kontrolliryhmän potilaista 32 (80 %) ja leikkausryhmän potilaista 18 (39 %) sairasti nielutulehduksen vähintään kerran. Vain yksi episodi luokiteltiin vaikeaksi. Nielukipu- ja kuumepäiviä oli merkittävästi vähemmän leikkausryhmässä. Nielurisaleikkauksen vaikutusta elämänlaatuun tutkittiin Glasgow Benefit Inventory (GBI) -kyselyllä kuusi kuukautta leikkauksen jälkeen. Yhteensä 142 potilasta vastasi kyselyyn. GBI:n mediaanitulos +27 osoitti leikkauksen parantavan elämänlaatua. GBI-tulokset kuitenkin vaihtelivat huomattavasti potilaiden välillä (−19 – +67), vaikkakin vain yksi potilas raportoi elämänlaatunsa heikentyneen. Aiempien nielutulehdusten määrä, usein toistuva nielukipu, hoitamaton karies ja kroonisesti tulehtuneet nielurisat ennustivat parhaiten potilastyytyväisyyttä leikkauksen jälkeen, mutta näidenkin tekijöiden ennustearvo oli melko heikko. Tulosten perusteella nielurisaleikkaus vähentää akuutteja nielutulehduksia sekä oirepäiviä. Vaikka sairastamisjaksot ovat harvoin vaikeaoireisia, leikkaus parantaa useimmiten elämänlaatua, mutta hyödyn määrä vaihtelee merkittävästi potilaiden välillä. Ainoastaan leikkausta edeltävä nielun oireilun määrä ennustaa leikkaushyötyä jossain määrin
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Cardoso, Debora Morais. "Impacto do uso de técnicas microbiológicas para o estreptococo beta hemolítico do grupo A no diagnóstico e tratamento das faringotonsilites." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/5/5141/tde-04082015-094743/.
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INTRODUÇÃO: A Faringotonsilite é doença comum nos consultórios e prontosocorros de pediatria. OBJETIVOS: Avaliar o impacto da realização rotineira da prova rápida para pesquisa de estreptococo do grupo A (PRE) no diagnóstico e tratamento da faringotonsilite aguda em crianças e adolescentes atendidos em um Hospital Geral. MÉTODOS: Trata-se de um estudo prospectivo, observacional, de protocolo de atendimento, instituído no Pronto-Socorro do Hospital Universitário da Universidade de São Paulo para o atendimento de crianças e adolescentes com diagnóstico de faringotonsilite aguda. RESULTADOS: Foram estudadas 1039 crianças e adolescentes. Com base no quadro clínico, antibiótico seria prescrito em 530 pacientes (51%), e com o uso da PRE e/ou cultura de orofaringe foi prescrito em 268 (25,8%) pacientes. Das 509 crianças que não receberiam antibiótico pelo quadro clínico, 157 tiveram PRE e/ou cultura de orofaringe positiva. O diagnóstico baseado no quadro clínico apresentou sensibilidade de 63,06% (IC-95%:62,95-63,17%); especificidade de 57,33% (IC-95%:57,25-57,41%); valor preditivo positivo de 50,57% (IC-95%:50,47-50,66%) e valor preditivo negativo de 69,16% (IC-95%: 50,47-50,66%). CONCLUSÕES: Neste estudo o diagnóstico clínico da faringotonsilite estreptocócica mostrou baixa sensibilidade e especificidade. O uso rotineiro da prova rápida para pesquisa de estreptococo permitiu uma redução do uso de antibiótico e a identificação de crianças e adolescentes com faringotonsilite estreptocócicas que não receberiam antibiótico e estariam sob o risco das complicações da infecção estreptocócicaBACKGROUND: Sore throat is a common disease in the pediatric emergency room. OBJECTIVES: The objective of this study was to evaluate the impact of routine performance of rapid antigen detection test (RADT) in the diagnosis and treatment of acute pharyngitis in children treated at an academic hospital. METHODS: This is a prospective, observational, protocol compliance, established at the Emergency of Hospital Universitário - Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. RESULTS: We studied 1039 children and adolescents. Based on clinical findings, antibiotic would be prescribed in 530 patients (51%) and using the RADT or sore throat culture was prescribed in 268 patients. Of the 509 children who did not receive antibiotics for the clinical, 157 had positive RADT or sore throat culture. The diagnosis based on clinical sensitivity was 63,06% (IC 95% 62,95- 63,17%), specificity 57,3% (IC 95% 57,25-57,41%), positive predictive value of 50,57% (IC 95% 50,47-50,66%) and negative predictive value of 69,16% (IC 95% 50,47-50,66%). CONCLUSIONS: In this study the clinical diagnosis of streptococcal pharyngitis had low sensitivity and specificity. The routine use of rapid test for streptococcal research led to a reduction of antibiotic use and the identification of a risk group for complication of streptococcal infection
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Skull, Susan. "Effectiveness of influenza and pneumococcal vaccination against hospitalisation for community-acquired pneumonia among persons >65 years /." Connect to thesis, 2007. http://repository.unimelb.edu.au/10187/1998.
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Although there are well-documented benefits from influenza vaccine and 23-valent pneumococcal polysaccharide vaccine (23vPPV) against invasive pneumococcal disease and laboratory confirmed influenza, their effectiveness against pneumonia remains controversial for community-based persons aged >=65years. At the time of this research, within Australia, only the government of Victoria publicly funded these vaccines for elderly persons. With continued growth of the elderly population, the subsequent adoption of an Australia-wide program, and increasing uptake of similar programs in other countries, there is a need for data clarifying the impact of vaccination on pneumonia. This research estimates incremental vaccine effectiveness of 23vPPV over and above influenza vaccine against hospitalisation with community-acquired pneumonia (CAP) in the elderly.
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Garcia, Febres Julio Carib. "A comparative investigation of Streptococcus agalactiae isolates from fish and cattle." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Dissertations/GARCIA_JULIO_46.pdf.
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Dossou-Gbete, Lucien. "Les infections a streptococcus anginosus." Université Louis Pasteur (Strasbourg) (1971-2008), 1991. http://www.theses.fr/1991STR1M147.
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Perry, Frances. "Oxidative responses of neutrophils to Streptococcus pneumoniae." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335509.
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Eriksson, Björn K. G. "Invasive group A streptococcal infection : host and pathogen interactions /." Stockholm, 1999. http://diss.kib.ki.se/1999/91-628-3609-9/.
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Ekdahl, Karl. "Immunological aspects on pneumococcal infections with special reference to bacteremic pneumococcal infections and recurrent pneumonia /." Lund : Dept. of Infectious Diseases, University of Lund, 1995. http://catalog.hathitrust.org/api/volumes/oclc/39177549.html.
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Gillespie, S. H. "Species specific diagnosis of Streptococcus pneumoniae infection." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261768.
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Malak, H. "Pneumolysin-macrophage interactions in Streptococcus pneumoniae infection." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3001781/.
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Gomes, Machado Marina. "The role of acetate in macrophage`s response against Streptococcus pneumoniae." Thesis, Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/LIBRE/EDBSL/2022/2022ULILS001.pdf.
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Les acides gras à chaîne courte (AGCC) sont des métabolites produits principalement par le microbiote intestinal. Ils jouent un rôle important dans la régulation des réponses immunitaires et inflammatoires. L'acétate, le principal AGCC, est décrit pour disséminer dans l’organisme et réguler la fonction d’organes distaux tels que les poumons. Des travaux récents indiquent une fonction dans le contrôle des agents pathogènes, notamment d’origine bactérienne. Notre groupe a précédemment démontré que l'acétate augmente l’élimination de Streptococcus pneumoniae dans le cadre d'une infection secondaire post-virale. Cette protection est médiée par les macrophages alvéolaires, la première ligne de défense pulmonaire. Ainsi, notre objectif était d'évaluer l'effet de l'acétate sur l’activité bactéricide des macrophages alvéolaires et d’identifier les mécanismes impliqués dans cette réponse. Nous montrons ici que la supplémentation en acétate dans l'eau de boisson module la sécrétion de protéines de défense par les cellules pulmonaires murines et conduit à une réduction de la charge de S. pneumoniae. Nous montrons par analyse transcriptomique (RNAseq) que l’acétate induit une signature spécifique de défense de l’hôte au sein des macrophages alvéolaires conditionnés en présence de S. pneumoniae. Cet effet s’accompagne par l’augmentation de l’activité bactéricide des macrophages mediée pour l'oxyde nitrique (NO). L’augmentation de NO induit par acétate dépendait de l'augmentation des niveaux d'IL-1β. De manière surprenante, la production d'IL-1β déclenchée par l'acétate est indépendante de son récepteur de surface (Free-Fatty Acid Receptor 2) et des enzymes responsables de son métabolisme (Acetyl-CoA Synthetases 1/2). En contrepartie, l'acétate a modulé le profil glycolytique des macrophages induisant l’activation de HIF-1α, qui aboutit à la transcription de l’IL-1β. De plus, l'augmentation de la sécrétion de l’IL-1β déclenchée par l'acétate reposait sur l'activation de l'inflammasome NLRP3. En conclusion, nous avons identifié un nouveau mécanisme conduisant à l’élimination des bactéries par les macrophages alvéolaires traité avec l’acétate. L'acétate augmente la production et la sécrétion d'IL-1β selon un mécanisme dépendant de l'axe glycolyse/HIF-1α et de NLRP3, respectivement. Par conséquent, des niveaux plus élevés d'IL-1β conduit à une augmentation de la production de NO et une meilleure activité bactéricide des macrophagesShort chain fatty acids (SCFAs) are metabolites produced mainly by the gut microbiota with a known role in immune regulation. Acetate, the major SCFA, is described to disseminate to distal organs such as the lungs. Moreover, the literature supports that acetate modulates inflammation and improves bacterial clearance. Our group has previously demonstrated that acetate improves Streptococcus pneumoniae clearance in the context of a secondary post-viral infection. This protection is mediated by alveolar macrophages, the first line of pulmonary immune defense. Thus, our aim was to evaluate the effect of acetate on the killing ability of alveolar macrophages and to delineate the mechanisms involved in this response. Here we show that acetate supplementation in drinking water modulated the secretion of host defense proteins by murine pulmonary cells and led to reduced S. pneumoniae loads in the lungs. To understand the mechanisms of bacterial clearance, alveolar macrophages were used. Transcriptomic analysis (RNAseq) revealed that acetate induced a specific signature of host defense in S. pneumoniae conditioned macrophages. This associates with the improved killing ability of acetate treated macrophages mediated by nitric oxide (NO) production. Increased NO concentration triggered by acetate was dependent on augmentation of IL-1β levels. Surprisingly, IL-1β production led by acetate was neither dependent on its cell surface receptor (Free-Fatty Acid Receptor 2), nor on the enzymes responsible for its metabolism (Acetyl-CoA Synthetase 1 and 2). Alternatively, acetate enhanced the glycolytic profile of macrophages resulting in greater HIF-1α activity which culminated in higher transcription of IL-1β. Moreover, the increased secretion of IL-1β triggered by acetate relied on NLRP3 inflammasome activation. In conclusion, we unravel a new mechanism of bacterial killing by acetate-activated macrophages. We show that acetate increased IL-1β production and secretion in a mechanism dependent on the axis glycolysis/HIF-1α and NLRP3, respectively. Consequently, higher levels of IL-1β resulted in augmented NO production and improved killing ability of alveolar macrophages
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Salloum, Mazen. "Les infections à "Streptococus agalactiae" chez l'adulte : emergence et impact de la lysogénie." Thesis, Tours, 2010. http://www.theses.fr/2010TOUR3144/document.
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Streptococcus Agalactiae est depuis les années 1990, responsable d'infections invasives émergentes chez l'adulte. Nous montrons queles souches responsables de ces infections appartiennent majoritairement aux sérotypes V et Ia et aux deux clones phylogénétiquement éloignés, CC1 et CC23. L'étude du contenu prophagique montre une lysogénie fréquente suggérant l'importance de la lysogénie dans la spécialisation de ces souches particulièrement aptes à infecter l'adulte. Dans un deuxième temps, nous avons isolé sept phages tempérés de souches associées à des infections cutanées et ostéo-articulaires. Ces phages appartiennent à la famille des SIPHOVIRIDAE. L’analyse par restriction enzymatique de l’ADN phagique et l’amplification par PCR de fragments d’ADN prophagique a montré la diversité de ces phages et leurdifférence des phages isolés de souches associées aux infections materno-foetales. Les phagesisolés de souches lysogènes de CC1 ont présenté un spectre lytique étendu aux souches de tous les clones intra-speciesStreptococcus agalactiae has emerged since 1990 in infections in nonpregnant adults, We showed that the strains isolated from adult infections were mainly of serotypes V and Ia., and mainly belonged to the two phylogenetically distant clones, CC1 and CC23. The prophagic content study showed a frequent lysogeny, suggesting a role of lysegeny in the specialization of these strains able to infect adult. Also, we isolated seven phages from strains associated with cutaneous and osteoarticular infections in adult. Ces phages classified among SIPHOVIRIDAE. Restriction analysis of phagic DNA and PCR for prophagic DNA showed genetiacally diverse phages, distinct from the phages isolated from strains responsible for materno-foetal infections. Phages isolated from lysogenic strains of CC1 had a wide lytic spectrum and were able to lyse strains belonging to all clones intra-species
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McNamee, Lynnelle Ann. "Effects of a primary influenza infection on susceptibility to a secondary Streptococcus pneumoniae infection." Diss., Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/mcnamee/McNameeL1206.pdf.
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Crowley, Ian F. "Intranasal Vaccination to Boost Equine Immunity to Uterine Streptococcal Infection." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/CrowleyIF2007.pdf.
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Nghia, Ho Dang Trung. "Epidemiology of Streptococcus suis infection in Viet Nam." Thesis, Open University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543864.
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Wilson, R. J. "Natural adaptive immunity to Streptococcus pneumoniae lung infection." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1417184/.
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Streptococcus pneumoniae is an important respiratory pathogen and a leading cause of community-acquired pneumonia. As well as invasive disease S. pneumoniae also colonises the nasopharynx. Colonisation with S. pneumoniae is nearly universal in infants, dropping to 10% in adulthood. This frequent exposure has potential for developing and boosting natural adaptive immune responses. However naturally-acquired immune responses that protect against subsequent lung infection with S. pneumoniae are not fully understood. This thesis investigates the targets and function of naturally-acquired IgG to S. pneumoniae in humans and additionally the mechanisms of protection from lung infection following experimental colonisation in mice. The target and function of naturally-acquired IgG in human sera and pooled intravenous immunoglobulin (IVIG) preparations was assessed. IVIG, pooled from >1000 adult donors provides a tool to investigate the natural antibody responses to S. pneumoniae within a population. Data indicate that naturally-acquired human IgG predominantly binds to non-capsular antigens on the surface of S. pneumoniae and can target surface exposed protein antigens. In vitro assays indicate that antibodies to non-capsular targets may be functional, enhancing phagocytosis and killing of S. pneumoniae. In vivo human IgG protected against lung infection. Cellular depletion demonstrated that protection within the lung required neutrophils and clearance of S. pneumoniae from the blood required macrophages. A model of lung infection in the absence of bacteraemia using S. pneumoniae strain EF3030 was developed. This model allowed assessment of the immune responses to S. pneumoniae colonisation of the nasopharynx that protect against re-infection specifically within the lung. Prior nasal colonisation with S. pneumoniae EF3030 was protective against subsequent lung infection. Cellular depletion strategies and challenge in antibody-deficient mice demonstrated that protection against lung infection required the development of both humoral and cell-mediated immunity.
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King, Quinton Oliver. "Contributions of pneomococcal virulence factors to secondary Streptococcus pneumoniae infection following influenza infection." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/king/KingQ0809.pdf.
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Influenza infection increases susceptibility to secondary infection with Streptococcus pneumoniae resulting in significantly increased morbidity and mortality. Whereas viral contributions to this synergism have been explored, little is known concerning contributions of the bacterium, specifically those provided through bacterial virulence factors. To assess the contributions of the known pneumococcal virulence factors hyaluronidase (Hyl), neuraminidase (NanA) and pneumococcal surface protein A (PspA) to secondary S. pneumoniae infection following influenza infection, mutants lacking these proteins were administered with wildtype pneumococci in a competitive growth model. Whereas mutants lacking the Hyl and NanA proteins did not exhibit attenuation, mutants lacking PspA were severely attenuated in mice without influenza infection and significantly more so in mice with a prior influenza infection. Additionally, mice received intranasal immunization with recombinant PspA protein and subsequently received primary and secondary challenges with serotypes 2, 3 and 4 pneumococci. Immunization with PspA significantly reduced bacterial burdens of all three challenge serotypes in primary and secondary pneumococcal infection and significantly reduced lung damage markers in mice receiving secondary pneumococcal challenges. In addition to known virulence factors, two surface-exposed proteins, Spr0075 and Spr1345, were assessed for virulence contributions to primary and secondary pneumococcal infections. Mutants lacking Spr0075 or Spr1345 were found to be severely attenuated in both primary and secondary pneumococcal challenges. Whereas immunization with either recombinant Spr0075 or Spr1345 significantly reduced primary pneumococcal burdens, only immunization with Spr0075 significantly reduced secondary pneumococcal burdens. Together these results indicate virulence contributions to both primary and secondary pneumococcal challenges for the PspA, Spr0075 and Spr1345 proteins. However, whereas immunization with PspA and Spr0075 significantly reduced both primary and secondary pneumococcal burdens, immunization with Spr1345 did not significantly impact secondary pneumococcal burdens. This result illustrates that a virulence contribution and/or an ability to protect against primary infection does not necessarily translate into a protein's capacity to protect against secondary infection. The results presented here are the first experimental evidence demonstrating virulence roles for the Spr0075 and Spr1345 proteins and are the first reports of immunization with pneumococcal proteins, specifically PspA and Spr0075, providing protection against secondary pneumococcal infection following influenza.
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Polidori, Fabiani Isabelle. "Les infections a streptococcus pneumoniae chez les sujets seropositifs vih." Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX20047.
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Wongsathein, Dilok. "Factors affecting experimental Streptococcus agalactiae infection in tilapia, Oreochromis niloticus." Thesis, University of Stirling, 2012. http://hdl.handle.net/1893/10375.
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Streptococcus agalactiae infection is one of the major disease problems affecting farmed tilapia (Oreochromis niloticus) worldwide. Tilapia are highly susceptible to this disease which results in mortality of up to 70% over a period of around 7 days and significant economic losses for farmers. Affected tilapia commonly present with an irregular behaviour associated with meningoencephalitis and septicaemia. Currently, factors affecting the virulence and transmission of S. agalactiae in fish including tilapia are poorly understood. Reports from natural outbreaks of S. agalactiae infection on tilapia farms have suggested larvae and juvenile or fish smaller than 20 g are not susceptible. In addition, there is variability in individual response to experimental inflammatory challenge associated with coping styles (bold, shy) in common carp (Cyprinus carpio). The central hypotheses of this thesis were that weight, age and coping style might affect the development and progression of this bacterial disease. This study investigated these three factors with experimental S. agalactiae infection in Nile tilapia. A range of bacterial isolates recovered from farmed tilapia, presenting with clinical sign of streptococcosis during natural disease outbreaks were identified and characterised as S. agalactiae by standard conventional methods, biochemical characteristic tests, Lancefield serogrouping and species-specific PCR assay. These isolates were Gram-positive cocci, either β- or non-haemolytic (γ), non-motile, oxidase negative and all of serogroup B. In addition, they were able to grow on Edwards medium (modified) agar as blue colonies and growth was observed in broth from 22 to 37 oC and with 0.5-5% NaCl. The biochemical profiles showed some differences in reactions while all the PCR samples showed similarities to the S. agalactiae type strain. These data confirmed that these strains were identified as group B S. agalactiae. A challenge model for S. agalactiae in Nile tilapia was developed and the LD50 estimated prior to performing subsequent experimental challenge studies. Two exposure routes, immersion and intraperitoneal injection (i.p.), were tested with various concentrations of S. agalactiae. Only i.p. injection produced significant mortalities (9 × 108 CFU/ml = 48% mortality, 9 × 107 = 48% and 8 × 106 = 26%). Streptococcus agalactiae was recovered and identified from all the dead and moribund fish during these experiments, where affected fish showed similar clinical signs and pathology to those reported from natural S. agalactiae infections. The study results showed that an experimental i.p. challenge model for S. agalactiae infection had successfully infected healthy Nile tilapia. In the immersion challenges, only 1 fish died despite testing a range of bacterial concentrations, exposure times, stocking density, water system and bacterial preparations. The experimental studies were conducted to investigate the association between weight or age of fish and susceptibility to S. agalactiae infection in Nile tilapia. This was performed under experimental conditions including control groups and a single population of 8 months old fish from one set of parents divided into 7 weight categories. These fish received a single i.p. injection of 6 × 107 CFU/ml of S. agalactiae. Controls and fish of 4 or 8 months old with a mean weight of 5 g received an i.p. injection of 7 × 107 CFU/ml of S. agalactiae. Clinical signs, lesions and histopathological changes in the affected fish were consistent with those reported in natural infection. Streptococcus agalactiae was recovered and identified from all moribund or dead fish. The mortality in the study of different weights varied from 0 to 33% between the groups but the association with weight was weak (R2 = 0.02). In the study of different ages the 4 months old fish group had a total mortality of 24%, and the 8 months old fish group a total mortality of 4%. This study produced no evidence for an association between the weight and susceptibility to S. agalactiae infection but suggested an association between the age or growth rate of fish and this disease. Different coping styles and susceptibility to S. agalactiae infection in Nile tilapia was examined. Fish were screened and scored depending on their risk-taking behavioural responses to a range of different environmental conditions. Individual differences in behavioural responses were evident but only consistent across behavioural trials for some individuals. A selection of fish with consistent responses across trials was exposed to the 6 × 107 CFU/ml of S. agalactiae by i.p. injection. Fewer bold than shy fish died suggesting that the bold fish might be less susceptible to the infection than shy fish. In conclusion, this study characterised a number of S. agalactiae isolates and developed an experimental bacterial challenge model. Subsequent experiments suggested that age (or growth rate) and coping style in fish but not the fish weight may affect susceptibility to S. agalactiae infection in Nile tilapia.
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De, Negri Rafaela. "EQUINE SERUM ANTIBODY RESPONSES TO STREPTOCOCCUS EQUI AND STREPTOCOCCUS ZOOEPIDEMICUS." UKnowledge, 2013. http://uknowledge.uky.edu/gluck_etds/13.
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Streptococcus zooepidemicus (Sz) and Streptococcus equi (Se) share 98% DNA sequence homology, but display different pathogenic properties. Infection by one organism does not cross-protect against the other. To better understand pathogenic differences between these organisms and gain information about which proteins are expressed in horses infected experimentally with Se, intrauterine Sz or naturally with respiratory Sz we compared antibody specificities of convalescent sera using ELISA. These comparisons were based on sets of 8 and 14 immunoreactive recombinant proteins of Se strain CF32 and Sz strain NC78, respectively. Sera from donkeys that were previously naturally affected with strangles and later developed Sz pneumonia secondary to an experimental influenza challenge were also included.
Serum antibody responses were quantitatively and qualitatively much greater following recovery from strangles than following respiratory Sz infection. Increased reactions to Se proteins IdeE2, Se75.3, Se46.8, Se18.9 and Se42.0 were observed for the majority of strangles sera but not for sera from respiratory Sz infection cases. Reactions of sera from Sz respiratory disease to Sz proteins varied greatly and were mostly to HylC and ScpC. Interestingly, sera of donkey recovered from Sz bronchopneumonia did not show increased antibody reaction to any of the proteins even though these donkeys had also recovered from clinical strangles 6 months previously. Only 1/5 mare with Sz placentitis presented increased serum antibody responses to MAP. In conclusion, adaptive immune responses to Se of horses with strangles are stronger and involve a greater number of proteins than adaptive immune responses to Sz infection of the lower respiratory tract.
In an effort to develop an improved vaccine against Se, modified live strain of EHV-1, RacH was constructed to express three recombinant antigens of Se SeM, IdeE and Se18.9. Two groups of 10 and 2 ponies were vaccinated intramuscularly or intranasally, respectively. Another group (n=6) vaccinated with empty RacH served as controls. Sera from 2/3 ponies from each vaccination groups and 1/2 serum from IN vaccinated ponies showed increased serum neutralizing antibodies to EHV-1. ELISA detected no significant increase in antibodies to proteins. Only one IM and IN vaccinated pony showed serum bactericidal activity post vaccination.
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Lawrence, Elliot Roger. "DNA based methods for serotype discrimination of Streptococcus pneumoniae." Thesis, Queen Mary, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248010.
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Fashola, Bola. "The Effect of Sodium Chloride on Beta-Hemolytic Streptococci." TopSCHOLAR®, 1987. https://digitalcommons.wku.edu/theses/2321.
Full textAbstract:
The drug of choice for the treatment of Stieptococcal pharyngitis is penicillin G. However, a common home remedy prescribes the use of salt-water solutions for gargling.
Members of Beta -hemolytic streptococcal groups A, B, and C were isolated from the upper -respiratory tracts of patients diagnosed as having streptococcal pharyngitis. These cultures we:e obtained from HCA Greenview Hospital (Bowling Green, Kentucky) and used to study the effects of sodium chloride on the isolates.
The minimum inhibitory concentration of sodium chloride was determined for each of eight hospital isolates. Croup A streptococci were inhibited at a concentration of 7.2% sodium chloride while Group C streptococci were inhibited at a 7.0% concentration. Group P streptococci were more resistant, and inhibition of growth occurred at 12.0% sodium chloride concentrations.
Scanning electron microscopic studies showed no significant differences in the external structure of cells treated with sodium chloride when compared to non-treated cells. Despite the lack of changes in the external structure of treated cells, fine structural alterations were observed with transmission electron microscopic studies.
Treatment of the cells with sodium chloride resulted in a condensation of nucleoid deoxyribonucleic acid (DNA) and some loss of ribosomes. These changes were followed by a dissolution of the cytoplasmic cell contents resulting in an intact cell wall with capsule.
Other parameters such as the rate of growth, minimum bactericidal concentrations, DNA content and protein content of cells treated with sodium chloride were examined and compared to control cells.