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1
Fol, Marek, Piotr Koziński, Jakub Kulesza, Piotr Białecki e Magdalena Druszczyńska. "Dual Nature of Relationship between Mycobacteria and Cancer". International Journal of Molecular Sciences 22, n. 15 (3 agosto 2021): 8332. http://dx.doi.org/10.3390/ijms22158332.
Testo completoAbstract (sommario):
Although the therapeutic effect of mycobacteria as antitumor agents has been known for decades, recent epidemiological and experimental studies have revealed that mycobacterium-related chronic inflammation may be a possible mechanism of cancer pathogenesis. Mycobacterium tuberculosis and non-tuberculous Mycobacterium avium complex infections have been implicated as potentially contributing to the etiology of lung cancer, whereas Mycobacterium ulcerans has been correlated with skin carcinogenesis. The risk of tumor development with chronic mycobacterial infections is thought to be a result of many host effector mechanisms acting at different stages of oncogenesis. In this paper, we focus on the nature of the relationship between mycobacteria and cancer, describing the clinical significance of mycobacteria-based cancer therapy as well as epidemiological evidence on the contribution of chronic mycobacterial infections to the increased lung cancer risk.
2
Slany, Michal, Petr Jezek, Vera Fiserova, Monika Bodnarova, Jiri Stork, Marta Havelkova, Frantisek Kalat e Ivo Pavlik. "Mycobacterium marinum infections in humans and tracing of its possible environmental sources". Canadian Journal of Microbiology 58, n. 1 (gennaio 2012): 39–44. http://dx.doi.org/10.1139/w11-104.
Testo completoAbstract (sommario):
The low frequency of nontuberculous mycobacterial infections, nonspecific symptoms for individual mycobacteria, and the lack of specific identification methods could alter correct diagnosis. This study presents a combined microbiology and molecular-based approach for Mycobacterium marinum detection in four aquarists with cutaneous mycobacterial infection. Simultaneously, ecology screening for M. marinum presence in the aquarists’ fish tanks was performed. A total of 38 mycobacterial isolates originated from four human patients (n = 20), aquarium animals (n = 8), and an aquarium environment (n = 10). Isolate identification was carried out using 16S rRNA sequence analysis. A microbiology-based approach, followed by 16S rRNA sequence analysis, was successfully used for detection of M. marinum in all four patients. Animal and environmental samples were simultaneously examined, and a total of seven mycobacterial species were isolated: Mycobacterium chelonae , Mycobacterium fortuitum , Mycobacterium gordonae , Mycobacterium kansasii , Mycobacterium mantenii , Mycobacterium marinum , and Mycobacterium peregrinum . The presence of M. marinum was proven in the aquarium environments of two patients. Although M. marinum is described as being present in water, it was detected only in fish.
3
Chilima, Benson Z., Ian M. Clark, Sian Floyd, Paul E. M. Fine e Penny R. Hirsch. "Distribution of Environmental Mycobacteria in Karonga District, Northern Malawi". Applied and Environmental Microbiology 72, n. 4 (aprile 2006): 2343–50. http://dx.doi.org/10.1128/aem.72.4.2343-2350.2006.
Testo completoAbstract (sommario):
ABSTRACT The genus Mycobacterium includes many species that are commonly found in the environment (in soil and water or associated with plants and animals), as well as species that are responsible for two major human diseases, tuberculosis (Mycobacterium tuberculosis) and leprosy (Mycobacterium leprae). The distribution of environmental mycobacteria was investigated in the context of a long-term study of leprosy, tuberculosis, Mycobacterium bovis BCG vaccination, and the responses of individuals to various mycobacterial antigens in Karonga District, northern Malawi, where epidemiological studies had indicated previously that people may be exposed to different mycobacterial species in the northern and southern parts of the district. A total of 148 soil samples and 24 water samples were collected from various locations and examined to determine the presence of mycobacteria. The detection method involved semiselective culturing and acid-fast staining, following decontamination of samples to enrich mycobacteria and reduce the numbers of other microorganisms, or PCR with primers specific for the mycobacterial 16S rRNA gene, using DNA extracted directly from soil and water samples. Mycobacteria were detected in the majority of the samples, and subsequent sequence analysis of PCR products amplified directly from soil DNA indicated that most of the products were related to known environmental mycobacteria. For both methods the rates of recovery were consistently higher for dry season samples than for wet season samples. All isolates cultured from soil appeared to be strains of Mycobacterium fortuitum. This study revealed a complex pattern for the environmental mycobacterial flora but identified no clear differences between the northern and southern parts of Karonga District.
4
Inoue, Hiroyuki, Naoki Washida, Kohkichi Morimoto, Keisuke Shinozuka, Takahiro Kasai, Kiyotaka Uchiyama, Hirobumi Tokuyama, Shu Wakino e Hiroshi Itoh. "Non-Tuberculous Mycobacterial Infections Related to Peritoneal Dialysis". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 38, n. 2 (1 marzo 2017): 147–49. http://dx.doi.org/10.3747/pdi.2017.00172.
Testo completoAbstract (sommario):
Most infections related to peritoneal dialysis (PD) are caused by common bacteria, and non-tuberculous mycobacteria are rare. The clinical characteristics and prognosis of PD patients with non-tuberculous mycobacterial infections were investigated at our hospital. Non-tuberculous mycobacteria were detected in 11 patients (exit-site infection, tunnel infection, and peritonitis in 3, 5, and 3 patients, respectively). Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus were identified in 4, 2, and 2 patients, respectively. Most patients with peritonitis or tunnel infection required catheter removal. During the study period (2007 – 2017), peritonitis occurred in 44 patients, including 3 patients (6.8%) with non-tuberculous mycobacterial peritonitis. When non-tuberculous mycobacterial infection occurs, multi-agent antibiotic therapy, unroofing surgery, and/or catheter replacement should be performed to prevent peritonitis.
5
Torkko, Pirjo, Marja-Leena Katila e Merja Kontro. "Gas-chromatographic lipid profiles in identification of currently known slowly growing environmental mycobacteria". Journal of Medical Microbiology 52, n. 4 (1 aprile 2003): 315–23. http://dx.doi.org/10.1099/jmm.0.05113-0.
Testo completoAbstract (sommario):
Cellular fatty acid analysis by GLC is widely used in the species identification of mycobacteria. Combining mycolic acid cleavage products with shorter cellular fatty acids increases the informative value of the analysis. A key has been created to aid in the identification of all currently known slowly growing environmental species. In this scheme, the species are classified into six categories, each characterized by a combination of fatty markers shared by those species. Within each category, individual species may be distinguished by the presence or absence of specific marker substances, such as methyl-branched fatty acids or secondary alcohols. This study also describes earlier unpublished GLC profiles of 14 rare, slowly growing, environmental mycobacteria, Mycobacterium asiaticum, Mycobacterium botniense, Mycobacterium branderi, Mycobacterium conspicuum, Mycobacterium cookii, Mycobacterium doricum, Mycobacterium heckeshornense, Mycobacterium heidelbergense, Mycobacterium hiberniae, Mycobacterium kubicae, Mycobacterium lentiflavum, Mycobacterium scrofulaceum, Mycobacterium triplex and Mycobacterium tusciae. Though no single identification technique alone, even sequencing of an entire single gene such as 16S rRNA, can identify all mycobacterial species accurately, GLC has proven to be both reliable and reproducible in the identification of slowly growing mycobacteria. In cases of earlier unknown species, it generates useful information that allows their further classification and may lead to the description of novel species.
6
Lutsenko, A. V., A. L. Yasenyavskaya e M. A. Samotrueva. "Mycobacterial infections: features of microbiological diagnosis". Сибирский научный медицинский журнал 43, n. 6 (10 gennaio 2024): 34–44. http://dx.doi.org/10.18699/ssmj20230604.
Testo completoAbstract (sommario):
To date, more than 200 species of mycobacteria have been identified, in addition to the well-known Mycobacterium leprae and Mycobacterium tuberculosis. Among microorganisms belonging to the genus Mycobacterium, there are obligate pathogenic, opportunistic and saprophytic strains. The incidence of non-tuberculous or atypical mycobacteria, which cause opportunistic infections in humans and animals, is steadily increasing. Non-tuberculous mycobacteria are increasingly recognized as a source of healthcare-associated infections.Aim of the study was to analyze the literature on current methods of microbiological diagnosis of mycobacterial infections.Material and methods. A search and analysis of scientific literature in the Web of Science, PubMed, eLIBRARY.RU, Europe PMC databases was performed using the following key words: mycobacteriosis, non-tuberculous mycobacteria, mycobacterial infections, MALDITOF MS, atypical mycobacteria. Results and discussion. The review summarizes and presents the classification, morphological, cultural, genetic and ecological features of mycobacterial strains. Modern approaches in the diagnosis of mycobacterial diseases and identification of pathogens are analyzed; their advantages and disadvantages are indicated.Conclusions. Mycobacterial infections are often considered as diseases associated with the provision of medical care, requiring a detailed assessment of the situation with the definition of criteria for microbiological monitoring of objects of a medical organization, etc. The analyzed literature data demonstrate a variety of methods for laboratory diagnosis of mycobacterial infections with the need for further improvement of methodological approaches.
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Zavgorodniy, A. I., S. A. Pozmogova e M. V. Kalashnyk. "Domestic parrots as a potential source of Mycobacteriosis". Journal for Veterinary Medicine, Biotechnology and Biosafety 6, n. 2 (28 febbraio 2020): 5–8. http://dx.doi.org/10.36016/jvmbbs-2020-6-2-1.
Testo completoAbstract (sommario):
The article presents the results of bacteriological examination of five samples of feces from grey parrots (Psittacus) (n = 3), cockatoo (Cacatua) (n = 1), yellow-crowned amazon (Amazona) (n = 1). Five cultures of mycobacteria were bacteriologically isolated from the five samples. According to biochemical and cultural-morphological characteristics, mycobacterial cultures are classified as Mycobacterium scrofulaceum (n = 1) and Mycobacterium genavense (n = 4). Isolated cultures of mycobacteria are important in human pathology. Infected exotic poultry pose a potential risk of mycobacterial infection in their owners, so it is necessary to conduct research on biological material
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Chin, Kai Ling. "Molecular Characterization of Mycobacterium species Isolates from Patients with Pulmonary Tuberculosis in Sabah, Malaysia". Medicine & Health 17, n. 1 (29 giugno 2022): 198–210. http://dx.doi.org/10.17576/mh.2022.1701.15.
Testo completoAbstract (sommario):
Tuberculosis (TB) is one of the deadliest diseases worldwide, caused by members of Mycobacterium tuberculosis complex (MTBC), commonly by Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis. In Malaysia, Sabah is one of the states of public health concern with the highest TB cases. Clinical presentations of TB and non-tuberculous mycobacteria (NTM) lung disease are similar, and mycobacteria appear to be identical under standard diagnosis with sputum smear microscopy, causing difficulty to diagnose TB. Identification of Mycobacterium species is essential for effective management of mycobacterial diseases treatment and their control strategy. Thus, this study aimed to identify the Mycobacterium species from suspected TB patients in Sabah using molecular methods. Sputum samples (n=595) were screened with GeneXpert MTB/RIF (Xpert), and positive TB samples (n=67) were processed and cultured in BACTEC MGIT. Forty-five isolates were successfully recovered in MGIT and characterisation of the mycobacterial isolates using PCR and/or sequencing with rpoB, RD9, hsp65, and 16S rRNA genes confirmed the presence of Mtb in 41 samples, and four non-mycobacteria, i.e. Microbacterium laevaniformans, Streptomyces sp., Streptomyces misionensis and Gordonia sp. These non-mycobacteria isolates showed negative results when tested directly with Xpert. In conclusion, Mtb is the predominant species of MTBC circulating in Sabah. The presence of non-mycobacteria in this study was due to bacterial contamination in MGIT, not bacterial cross-reactivity in Xpert, implying the high sensitivity and specificity of Xpert for diagnosis of TB.
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Falkinham, Joseph O., Cheryl D. Norton e Mark W. LeChevallier. "Factors Influencing Numbers of Mycobacterium avium, Mycobacterium intracellulare, and Other Mycobacteria in Drinking Water Distribution Systems". Applied and Environmental Microbiology 67, n. 3 (1 marzo 2001): 1225–31. http://dx.doi.org/10.1128/aem.67.3.1225-1231.2001.
Testo completoAbstract (sommario):
ABSTRACT Eight water distribution systems were sampled over an 18-month period (528 water and 55 biofilm samples) to measure the frequency of recovery and number of mycobacteria, particularly Mycobacterium avium and Mycobacterium intracellulare, in raw source waters before and after treatment and within the distribution system. The systems were chosen to assess the influence of source water, treatment, and assimilable organic carbon levels on mycobacterial numbers. Overall, mycobacterial recovery from the systems was low (15% of samples). Numbers of mycobacteria ranged from 10 to 700,000 CFU liter−1. The number of M. avium in raw waters was correlated with turbidity. Water treatment substantially reduced the number of mycobacteria in raw waters by 2 to 4 log units. Mycobacterial numbers were substantially higher in the distribution system samples (average, 25,000-fold) than in those collected immediately downstream from the treatment facilities, indicating that mycobacteria grow in the distribution system. The increase in mycobacterial numbers was correlated with assimilable organic carbon and biodegradable organic carbon levels (r 2 = 0.65, P = 0.03). Although M. intracellulare was seldom recovered from water samples, it was frequently recovered (six of eight systems) in high numbers from biofilms (average, 600 CFU/cm2). Evidently, the ecological niches of M. avium and M. intracellulare are distinct.
10
Harth, Günter, Saša Masleša-Galić e Marcus A. Horwitz. "A two-plasmid system for stable, selective-pressure-independent expression of multiple extracellular proteins in mycobacteria". Microbiology 150, n. 7 (1 luglio 2004): 2143–51. http://dx.doi.org/10.1099/mic.0.27113-0.
Testo completoAbstract (sommario):
Recombinant mycobacteria expressing Mycobacterium tuberculosis extracellular proteins are leading candidates for new vaccines against tuberculosis and other mycobacterial diseases, and important tools both in antimycobacterial drug development and basic research in mycobacterial pathogenesis. Recombinant mycobacteria that stably overexpress and secrete major extracellular proteins of M. tuberculosis in native form on plasmids pSMT3 and pNBV1 were previously constructed by the authors. To enhance the versatility of this plasmid-based approach for mycobacterial protein expression, the Escherichia coli/mycobacteria shuttle plasmid pGB9 was modified to accommodate mycobacterial genes expressed from their endogenous promoters. Previous studies showed that the modified plasmid, designated pGB9.2, derived from the cryptic Mycobacterium fortuitum plasmid pMF1, was present at a low copy number in both E. coli and mycobacteria, and expression of recombinant M. tuberculosis proteins was found to be at levels paralleling its copy number, that is, approximating their endogenous levels. Plasmid pGB9.2 was compatible with the shuttle vectors pSMT3 and pNBV1 and in combination with them it simultaneously expressed the M. tuberculosis 30 kDa extracellular protein FbpB. Plasmid pGB9.2 was stably maintained in the absence of selective pressure in three mycobacterial species: Mycobacterium bovis BCG, M. tuberculosis and M. smegmatis. Plasmid pGB9.2 was found to be self-transmissible between both fast- and slow-growing mycobacteria, but not from mycobacteria to E. coli or between E. coli strains. The combination of two compatible plasmids in one BCG strain allows expression of recombinant mycobacterial proteins at different levels, a potentially important factor in optimizing vaccine potency.
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Mohamed, Amr M., Peter C. Iwen, Stefano Tarantolo e Steven H. Hinrichs. "Mycobacterium nebraskense sp. nov., a novel slowly growing scotochromogenic species". International Journal of Systematic and Evolutionary Microbiology 54, n. 6 (1 novembre 2004): 2057–60. http://dx.doi.org/10.1099/ijs.0.63126-0.
Testo completoAbstract (sommario):
The characterization of a novel slowly growing, scotochromogenic Mycobacterium species is reported. This previously undescribed mycobacterial species was isolated from five different patients with symptomatic pulmonary infections. All isolates were acid-fast-positive and the mycolic acid profiles were unique and supported placement into the genus Mycobacterium. Phenotypic characteristics of each strain included optimal growth after 3 weeks at a temperature range of 30–35 °C, yellow pigmentation after incubation in the dark and production of a heat-stable catalase. The 16S rRNA gene and internal transcribed spacer 1 sequences were identical for all five strains, but distinct from all known mycobacterial species. Phylogenetic analysis based on the 16S rRNA gene sequence placed the novel species within the slowly growing mycobacteria group in close proximity to Mycobacterium malmoense, Mycobacterium avium, Mycobacterium kansasii and Mycobacterium scrofulaceum. These data support the conclusion that the related five described organisms represent a novel Mycobacterium species, for which the name Mycobacterium nebraskense sp. nov. is proposed, with the type strain UNMC-MY1349T (=ATCC BAA-837T=DSM 44803T).
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Roth, Andreas, Udo Reischl, Anna Streubel, Ludmila Naumann, Reiner M. Kroppenstedt, Marion Habicht, Marga Fischer e Harald Mauch. "Novel Diagnostic Algorithm for Identification of Mycobacteria Using Genus-Specific Amplification of the 16S-23S rRNA Gene Spacer and Restriction Endonucleases". Journal of Clinical Microbiology 38, n. 3 (2000): 1094–104. http://dx.doi.org/10.1128/jcm.38.3.1094-1104.2000.
Testo completoAbstract (sommario):
A novel genus-specific PCR for mycobacteria with simple identification to the species level by restriction fragment length polymorphism (RFLP) was established using the 16S-23S ribosomal RNA gene (rDNA) spacer as a target. Panspecificity of primers was demonstrated on the genus level by testing 811 bacterial strains (122 species in 37 genera from 286 reference strains and 525 clinical isolates). All mycobacterial isolates (678 strains among 48 defined species and 5 indeterminate taxons) were amplified by the new primers. Among nonmycobacterial isolates, only Gordonia terrae was amplified. The RFLP scheme devised involves estimation of variable PCR product sizes together with HaeIII and CfoI restriction analysis. It yielded 58 HaeIII patterns, of which 49 (84%) were unique on the species level. Hence,HaeIII digestion together with CfoI results was sufficient for correct identification of 39 of 54 mycobacterial taxons and one of three or four of seven RFLP genotypes found inMycobacterium intracellulare and Mycobacterium kansasii, respectively. Following a clearly laid out diagnostic algorithm, the remaining unidentified organisms fell into five clusters of closely related species (i.e., the Mycobacterium aviumcomplex or Mycobacterium chelonae-Mycobacterium abscessus) that were successfully separated using additional enzymes (TaqI, MspI, DdeI, orAvaII). Thus, next to slowly growing mycobacteria, all rapidly growing species studied, including M. abscessus,M. chelonae, Mycobacterium farcinogenes,Mycobacterium fortuitum, Mycobacterium peregrinum, and Mycobacterium senegalense (with a very high 16S rDNA sequence similarity) were correctly identified. A high intraspecies sequence stability and the good discriminative power of patterns indicate that this method is very suitable for rapid and cost-effective identification of a wide variety of mycobacterial species without the need for sequencing. Phylogenetically, spacer sequence data stand in good agreement with 16S rDNA sequencing results, as was shown by including strains with unsettled taxonomy. Since this approach recognized significant subspecific genotypes while identification of a broad spectrum of mycobacteria rested on identification of one specific RFLP pattern within a species, this method can be used by both reference (or research) and routine laboratories.
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Thomas, Dia-Jeanette. "Mycobacterial Diseases in HIV-Positive Patients". Journal of Pharmacy Practice 19, n. 1 (febbraio 2006): 10–16. http://dx.doi.org/10.1177/0897190005284100.
Testo completoAbstract (sommario):
Mycobacterial infections comprise the largest group of opportunistic infections in the HIV-infected population. The incidence of these and other opportunistic infections has declined significantly since the introduction of highly active antiretroviral therapy. Mortality from these illnesses has decreased as optimal combinations of antibiotics were discovered. Despite these facts, mycobacterial infections still pose a major threat to AIDS patients, particularly in underserved populations. The most common mycobacterial infections found in HIV-infected individuals are Mycobacterium tuberculosis, Mycobacterium avium intracellulare, and Mycobacterium kansasii, although other nontuberculous mycobacteria have been isolated. While established guidelines have made the task of preventing and treating opportunistic infections easier, resistance, toxicity, adherence, and drug interactions remain barriers to providing optimal therapy.
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De Groote, Mary Ann, Norman R. Pace, Kayte Fulton e Joseph O. Falkinham. "Relationships between Mycobacterium Isolates from Patients with Pulmonary Mycobacterial Infection and Potting Soils". Applied and Environmental Microbiology 72, n. 12 (20 ottobre 2006): 7602–6. http://dx.doi.org/10.1128/aem.00930-06.
Testo completoAbstract (sommario):
ABSTRACT High numbers of mycobacteria, including known pathogenic species such as Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chelonae, were recovered from aerosols produced by pouring commercial potting soil products and potting soil samples provided by patients with pulmonary mycobacterial infections. The dominant mycobacteria in the soil samples corresponded to the dominant species implicated clinically. Profiles of large restriction fragments obtained by pulsed-field gel electrophoresis demonstrated a closely related pair of M. avium isolates recovered from a patient and from that patient's own potting soil. Thus, potting soils are potential sources of infection by environmental mycobacteria. Use of dust-excluding masks should be considered during potting or other activities that generate aerosol with soil.
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Julien, Coulibaly Kalpy, Vakou N’dri Sabine, Kouakou Luc Venance, Ouattara Yakoura Karidja, Yao Kouamé Eric, Gnali Gbohounou Fabrice, Dosso Mireille e Djaman Allico Joseph. "Phylogenetic Profile of Nonulcerans and Nontuberculous Environmental Mycobacteria Isolated in Côte d’Ivoire". International Journal of Mycobacteriology 13, n. 2 (aprile 2024): 158–64. http://dx.doi.org/10.4103/ijmy.ijmy_96_24.
Testo completoAbstract (sommario):
Background: Environmental mycobacteria are involved in several infections ranging from lung to skin infections. In Côte d’Ivoire, apart from Mycobacterium ulcerans and Mycobacterium tuberculosis, little information exists on other species. The culture of these species, a real challenge, especially in developing countries like Cote d’Ivoire, limits their identification. However, there are reports in literature of infections caused by these mycobacteria, and few species have never been described in human or animal infections. These are difficult cases to treat because of their resistance to most antituberculosis antibiotics. The aim of our work was to study the diversity of potentially pathogenic mycobacterial species in wastewater drainage channels in different townships and in two hospital effluents in the city of Abidjan. Methods: Wastewater samples were cultured, followed by conventional polymerase chain reaction (PCR) targeting mycobacterial 16S ribonucleic acid (16S RNA) using PA/MSHA primers. 16 S RNA identified were sequenced by Sanger techniques. Sequences obtained were analyzed, and a phylogenic tree was built. Results: Fast-growing mycobacteria, including Mycobacterium fortuitum, Mycobacterium phocaicum, Mycobacterium sp., and others presence, were confirmed both by culture and molecular techniques. M. fortuitum strain was the same in effluents of the Treichville University Hospital and in the wastewater of the township of Koumassi. New species never isolated in Côte d’Ivoire, such as M. phocaicum, have been identified in wastewater of the township of Yopougon. Conclusion: This study showed that the sewer network in the city of Abidjan is colonized by both potentially pathogenic mycobacteria and saprophytic environmental mycobacteria.
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To, Kimberly, Ruoqiong Cao, Aram Yegiazaryan, James Owens e Vishwanath Venketaraman. "General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus". Journal of Clinical Medicine 9, n. 8 (6 agosto 2020): 2541. http://dx.doi.org/10.3390/jcm9082541.
Testo completoAbstract (sommario):
Nontuberculous mycobacteria (NTM) are emerging human pathogens, causing a wide range of clinical diseases affecting individuals who are immunocompromised and who have underlying health conditions. NTM are ubiquitous in the environment, with certain species causing opportunistic infection in humans, including Mycobacterium avium and Mycobacterium abscessus. The incidence and prevalence of NTM infections are rising globally, especially in developed countries with declining incidence rates of M. tuberculosis infection. Mycobacterium avium, a slow-growing mycobacterium, is associated with Mycobacterium avium complex (MAC) infections that can cause chronic pulmonary disease, disseminated disease, as well as lymphadenitis. M. abscessus infections are considered one of the most antibiotic-resistant mycobacteria and are associated with pulmonary disease, especially cystic fibrosis, as well as contaminated traumatic skin wounds, postsurgical soft tissue infections, and healthcare-associated infections (HAI). Clinical manifestations of diseases depend on the interaction of the host’s immune response and the specific mycobacterial species. This review will give a general overview of the general characteristics, vulnerable populations most at risk, pathogenesis, treatment, and prevention for infections caused by Mycobacterium avium, in the context of MAC, and M. abscessus.
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Marmiesse, Magali, Priscille Brodin, Carmen Buchrieser, Christina Gutierrez, Nathalie Simoes, Veronique Vincent, Philippe Glaser, Stewart T. Cole e Roland Brosch. "Macro-array and bioinformatic analyses reveal mycobacterial ‘core’ genes, variation in the ESAT-6 gene family and new phylogenetic markers for the Mycobacterium tuberculosis complex". Microbiology 150, n. 2 (1 febbraio 2004): 483–96. http://dx.doi.org/10.1099/mic.0.26662-0.
Testo completoAbstract (sommario):
To better understand the biology and the virulence determinants of the two major mycobacterial human pathogens Mycobacterium tuberculosis and Mycobacterium leprae, their genome sequences have been determined recently. In silico comparisons revealed that among the 1439 genes common to both M. tuberculosis and M. leprae, 219 genes code for proteins that show no similarity with proteins from other organisms. Therefore, the latter ‘core’ genes could be specific for mycobacteria or even for the intracellular mycobacterial pathogens. To obtain more information as to whether these genes really were mycobacteria-specific, they were included in a focused macro-array, which also contained genes from previously defined regions of difference (RD) known to be absent from Mycobacterium bovis BCG relative to M. tuberculosis. Hybridization of DNA from 40 strains of the M. tuberculosis complex and in silico comparison of these genes with the near-complete genome sequences from Mycobacterium avium, Mycobacterium marinum and Mycobacterium smegmatis were undertaken to answer this question. The results showed that among the 219 conserved genes, very few were not present in all the strains tested. Some of these missing genes code for proteins of the ESAT-6 family, a group of highly immunogenic small proteins whose presence and number is variable among the genomically highly conserved members of the M. tuberculosis complex. Indeed, the results suggest that, with few exceptions, the ‘core’ genes conserved among M. tuberculosis H37Rv and M. leprae are also highly conserved among other mycobacterial strains, which makes them interesting potential targets for developing new specific anti-mycobacterial drugs. In contrast, the genes from RD regions showed great variability among certain members of the M. tuberculosis complex, and some new specific deletions in Mycobacterium canettii, Mycobacterium microti and seal isolates were identified and further characterized during this study. Together with the distribution of a particular 6 or 7 bp micro-deletion in the gene encoding the polyketide synthase pks15/1, these results confirm and further extend the revised phylogenetic model for the M. tuberculosis complex recently presented.
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Qadri, S. M. Hussain, e Kevin K. Smith. "Nonspecificity of the Anda A60-tb ELISA test for serodiagnosis of mycobacterial disease". Canadian Journal of Microbiology 38, n. 8 (1 agosto 1992): 804–6. http://dx.doi.org/10.1139/m92-131.
Testo completoAbstract (sommario):
The conventional methods for the laboratory diagnosis of tuberculosis and other mycobacterial diseases are time consuming and beyond the scope of most of the small and medium-sized hospital facilities. Therefore, there has been considerable interest in the development of a serological method for the detection of antibodies against mycobacteria. We recently evaluated a commercially available ELISA test (Anda Biologicals, Strasbourg, France) that measures antibody levels to A60 antigen, a membrane glycoprotein that is found in most mycobacteria. Of the 123 patients with positive pulmonary cultures for Mycobacterium tuberculosis, 82% had detectable antibodies against the kit antigen. Of the 68 patients with extrapulmonary tuberculosis, 59% yielded positive results. Specimens from 2 of the 12 patients that grew Mycobacterium avium–intracellulare complex, and one each with Mycobacterium fortuitum and Mycobacterium chelonei, were considered significant on the basis of medical history and repeated isolation of the bacterium from clinical specimens, and these patients yielded positive serology. Of the healthy, normal PPD positive and PPD negative controls, 24% gave false positive results. Key words: Anda A60-tb ELISA, serodiagnosis of mycobacteria, mycobacterium.
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Mah, Nancy, Carolina Perez-Iratxeta e Miguel A. Andrade-Navarro. "Outer membrane pore protein prediction in mycobacteria using genomic comparison". Microbiology 156, n. 8 (1 agosto 2010): 2506–15. http://dx.doi.org/10.1099/mic.0.040089-0.
Testo completoAbstract (sommario):
Proteins responsible for outer membrane transport across the unique membrane structure of Mycobacterium spp. are attractive drug targets in the treatment of human diseases caused by the mycobacterial pathogens, Mycobacterium tuberculosis, M. bovis, M. leprae and M. ulcerans. In contrast with Escherichia coli, relatively few outer-membrane proteins (OMPs) have been identified in Mycobacterium spp., largely due to the difficulties in isolating mycobacterial membrane proteins and our incomplete understanding of secretion mechanisms and cell wall structure in these organisms. To further expand our knowledge of these elusive proteins in mycobacteria, we have improved upon our previous method of OMP prediction in mycobacteria by taking advantage of genomic data from seven mycobacteria species. Our improved algorithm suggests 4333 sequences as putative OMPs in seven species with varying degrees of confidence. The most virulent pathogenic mycobacterial species are slightly enriched in these selected sequences. We present examples of predicted OMPs involved in horizontal transfer and paralogy expansion. Analysis of local secondary structure content allowed identification of small domains predicted to perform as OMPs; some examples show their involvement in events of tandem duplication and domain rearrangements. We discuss the taxonomic distribution of these discovered families and architectures, often specific to mycobacteria or the wider taxonomic class of Actinobacteria. Our results suggest that OMP functionality in mycobacteria is richer than expected and provide a resource to guide future research of these understudied proteins.
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Park, Sae W., Eun H. Hwang, Hyuck Park, Jeong A. Kim, Jinho Heo, Key H. Lee, Taeksun Song et al. "Growth of Mycobacteria on Carbon Monoxide and Methanol". Journal of Bacteriology 185, n. 1 (1 gennaio 2003): 142–47. http://dx.doi.org/10.1128/jb.185.1.142-147.2003.
Testo completoAbstract (sommario):
ABSTRACT Several mycobacterial strains, such as Mycobacterium flavescens, Mycobacterium gastri, Mycobacterium neoaurum, Mycobacterium parafortuitum, Mycobacterium peregrinum, Mycobacterium phlei, Mycobacterium smegmatis, Mycobacterium tuberculosis, and Mycobacterium vaccae, were found to grow on carbon monoxide (CO) as the sole source of carbon and energy. These bacteria, except for M. tuberculosis, also utilized methanol as the sole carbon and energy source. A CO dehydrogenase (CO-DH) assay, staining by activity of CO-DH, and Western blot analysis using an antibody raised against CO-DH of Mycobacterium sp. strain JC1 (formerly Acinetobacter sp. strain JC1 [J. W. Cho, H. S. Yim, and Y. M. Kim, Kor. J. Microbiol. 23:1-8, 1985]) revealed that CO-DH is present in extracts of the bacteria prepared from cells grown on CO. Ribulose bisphosphate carboxylase/oxygenase (RubisCO) activity was also detected in extracts prepared from all cells, except M. tuberculosis, grown on CO. The mycobacteria grown on methanol, except for M. gastri, which showed hexulose phosphate synthase activity, did not exhibit activities of classic methanol dehydrogenase, hydroxypyruvate reductase, or hexulose phosphate synthase but exhibited N,N-dimethyl-4-nitrosoaniline-dependent methanol dehydrogenase and RuBisCO activities. Cells grown on methanol were also found to have dihydroxyacetone synthase. Double immunodiffusion revealed that the antigenic sites of CO-DHs, RuBisCOs, and dihydroxyacetone synthases in all mycobacteria tested are identical with those of the Mycobacterium sp. strain JC1 enzymes.
21
Cayer, Marie-Pierre, Marc Veillette, Pascal Pageau, Richard Hamelin, Marie-Josée Bergeron, Anne Mériaux, Yvon Cormier e Caroline Duchaine. "Identification of mycobacteria in peat moss processing plants: application of molecular biology approaches". Canadian Journal of Microbiology 53, n. 1 (1 gennaio 2007): 92–99. http://dx.doi.org/10.1139/w06-105.
Testo completoAbstract (sommario):
Peat moss processing plant workers are exposed to high concentrations of bioaerosols. Although mycobacteria have been cultured from peat moss, no study has examined the workers' exposure to mycobacterial bioaerosols. We evaluated the presence of mycobacteria in air samples from peat moss processing plants using molecular biology approaches (cloning-sequencing and polymerase chain reaction (PCR)) and the workers exposure using immunoglobulin G (IgG) complexes to mycobacteria. In addition, species detected in air samples and in peat moss were compared. Two peat moss processing plants were chosen among 14 previously studied. A total of 49 clones were sequenced. Real-time PCR was also performed on the same air samples to evaluate the airborne concentration of mycobacteria and estimate exposure levels. Several Mycobacterium species were present in the air samples (M. malmoense, M. smegmatis, M. graceum, M. bohemicum, and M. interjectum). Mycobacterium avium was recovered by culture in peat moss but not in the air using the molecular approach. Total airborne Mycobacterium concentration was estimated at 8.2 × 108/m3. Workers had IgG against the mycobacterial mix and M. avium, suggesting significant exposure. The findings from air samples, supported by IgG measurements, demonstrate that peat moss processing plant workers are exposed to mycobacteria in addition to other biological agents.Key words: exposure, peat moss, airborne mycobacteria.
22
Aboagye, Samuel Yaw, Emelia Danso, Kobina Assan Ampah, Zuliehatu Nakobu, Prince Asare, Isaac Darko Otchere, Katharina Röltgen, Dzidzo Yirenya-Tawiah e Dorothy Yeboah-Manu. "Isolation of Nontuberculous Mycobacteria from the Environment of Ghanian Communities Where Buruli Ulcer Is Endemic". Applied and Environmental Microbiology 82, n. 14 (6 maggio 2016): 4320–29. http://dx.doi.org/10.1128/aem.01002-16.
Testo completoAbstract (sommario):
ABSTRACTThis study aimed to isolate nontuberculous mycobacterial species from environmental samples obtained from some selected communities in Ghana. To optimize decontamination, spiked environmental samples were used to evaluate four decontamination solutions and supplemented media, after which the best decontamination solution and media were used for the actual analysis. The isolates obtained were identified on the basis of specific genetic sequences, including heat shock protein 65, IS2404, IS2606,rpoB, and the ketoreductase gene, as needed. Among the methods evaluated, decontamination with 1 M NaOH followed by 5% oxalic acid gave the highest rate of recovery of mycobacteria (50.0%) and the lowest rate of contamination (15.6%). The cultivation medium that supported the highest rate of recovery of mycobacteria was polymyxin B-amphotericin B-nalidixic acid-trimethoprim-azlocillin–supplemented medium (34.4%), followed by isoniazid-supplemented medium (28.1%). Among the 139 samples cultivated in the main analysis, 58 (41.7%) yielded mycobacterial growth, 70 (50.4%) had no growth, and 11 (7.9%) had all inoculated tubes contaminated. A total of 25 different mycobacterial species were identified. Fifteen species (60%) were slowly growing (e.g.,Mycobacterium ulcerans,Mycobacterium avium,Mycobacterium mantenii, andMycobacterium malmoense), and 10 (40%) were rapidly growing (e.g.,Mycobacterium chelonae,Mycobacterium fortuitum, andMycobacterium abscessus). The occurrence of mycobacterial species in the various environmental samples analyzed was as follows: soil, 16 species (43.2%); vegetation, 14 species (38.0%); water, 3 species (8.0%); moss, 2 species (5.4%); snail, 1 species (2.7%); fungi, 1 species (2.7%). This study is the first to report on the isolation ofM. ulceransand other medically relevant nontuberculous mycobacteria from different environmental sources in Ghana.IMPORTANCEDiseases caused by mycobacterial species other than those that cause tuberculosis and leprosy are increasing. Control is difficult because the current understanding of how the organisms are spread and where they live in the environment is limited, although this information is needed to design preventive measures. Growing these organisms from the environment is also difficult, because the culture medium becomes overgrown with other bacteria that also live in the environment, such as in soil and water. We aimed to improve the methods for growing these organisms from environmental sources, such as soil and water samples, for better understanding of important mycobacterial ecology.
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Wang, Chun Fang, Hua Rui Qi, Xiu Yun Jiang, Hong Xia Ma, Ai Dong Qian e Chun Feng Wang. "Isolated Strains of Nontuberculous Mycobacterium Interfere with Immune Responses Associated with Mycobacterium Bovis BCG Vaccination". Advanced Materials Research 884-885 (gennaio 2014): 450–54. http://dx.doi.org/10.4028/www.scientific.net/amr.884-885.450.
Testo completoAbstract (sommario):
Prior exposure of a vaccine to certain species of environmental mycobacteria can prime the immune system against common mycobacterial antigens, which can in turn reduce the subsequent efficacy of live attenuated mycobacterial vaccines (such as Mycobacterium bovis BCG), in both human and livestock vaccination programs. In this study, five strains of nontubeculous mycobacterium, all isolated from lymphonodi mandibulares and lymphonodi mesenterici samples of swine and cattle, were investigated to determine their growth characteristics and effects on the immune system in murine models. Markedly, different effects on the immune system were observed. The different results may be linked to the inherent growth characteristics of the five strains, The implications of these findings for BCG vaccination protocols are discussed.
24
Clark, J. E., e E. L. C. Ong. "A UK centre's experience of mycobacterial infections in HIV-infected patients". International Journal of STD & AIDS 9, n. 10 (1 ottobre 1998): 613–15. http://dx.doi.org/10.1258/0956462981921062.
Testo completoAbstract (sommario):
A descriptive retrospective review of 26 patients with mycobacterial infection; 7 Mycobacterium tuberculosis (MTB), 17 Mycobacterium avium complex (MAC), one M. xenopei and one M. kansasii . Diagnosis of non-tuberculous mycobacteria (NTM) was made mainly from blood in 68%, with biopsy material initially useful in 68%. All MTB were fully sensitive. No patients received MAC chemoprophylaxis, yet resistance to rifabutin, ciprofloxacin and ethambutol was noted. It is important to examine the UK experience of mycobacterial infection; individual centres may find it useful to review infecting organisms and resistance patterns.
25
Beatty, Wandy L., e David G. Russell. "Identification of Mycobacterial Surface Proteins Released into Subcellular Compartments of Infected Macrophages". Infection and Immunity 68, n. 12 (1 dicembre 2000): 6997–7002. http://dx.doi.org/10.1128/iai.68.12.6997-7002.2000.
Testo completoAbstract (sommario):
ABSTRACT Considerable effort has focused on the identification of proteins secreted from Mycobacterium spp. that contribute to the development of protective immunity. Little is known, however, about the release of mycobacterial proteins from the bacterial phagosome and the potential role of these molecules in chronically infected macrophages. In the present study, the release of mycobacterial surface proteins from the bacterial phagosome into subcellular compartments of infected macrophages was analyzed. Mycobacterium bovis BCG was surface labeled with fluorescein-tagged succinimidyl ester, an amine-reactive probe. The fluorescein tag was then used as a marker for the release of bacterial proteins in infected macrophages. Fractionation studies revealed bacterial proteins within subcellular compartments distinct from mycobacteria and mycobacterial phagosomes. To identify these proteins, subcellular fractions free of bacteria were probed with mycobacterium-specific antibodies. The fibronectin attachment protein and proteins of the antigen 85-kDa complex were identified among the mycobacterial proteins released from the bacterial phagosome.
26
Falkinham, Joseph O. "The Changing Pattern of Nontuberculous Mycobacterial Disease". Canadian Journal of Infectious Diseases 14, n. 5 (2003): 281–86. http://dx.doi.org/10.1155/2003/323058.
Testo completoAbstract (sommario):
Nontuberculous mycobacteria are human opportunistic pathogens whose source of infection is the environment. These include both slow-growing (eg,Mycobacterium kansasii and Mycobacterium avium) and rapid-growing (eg,Mycobacterium abscessusandMycobacterium fortuitum) species. Transmission is through ingestion or inhalation of water, particulate matter or aerosols, or through trauma. The historic presentation of pulmonary disease in older individuals with predisposing lung conditions and in children has been changing. Pulmonary disease in elderly individuals who lack the classic predisposing lung conditions is increasing. Pulmonary disease and hypersensitivity pneumonitis have been linked with occupational or home exposures to nontuberculous mycobacteria. There has been a shift fromMycobacterium scrofulaceumtoM aviumin children with cervical lymphadenitis. Further, individuals who are immunosuppressed due to therapy or HIV-infection are at a greatly increased risk for nontuberculous mycobacterial infection. The changing pattern of nontuberculous mycobacterial disease is due in part to the ability of these pathogens to survive and proliferate in habitats that they share with humans, such as drinking water. The advent of an aging population and an increase in the proportion of immunosuppressed individuals suggest that the prevalence of nontuberculous mycobacterial disease will increase.
27
Pagán-Ramos, E., J. Song, M. McFalone, M. H. Mudd e V. Deretic. "Oxidative Stress Response and Characterization of theoxyR-ahpC and furA-katG Loci inMycobacterium marinum". Journal of Bacteriology 180, n. 18 (15 settembre 1998): 4856–64. http://dx.doi.org/10.1128/jb.180.18.4856-4864.1998.
Testo completoAbstract (sommario):
ABSTRACT Oxidative stress response in pathogenic mycobacteria is believed to be of significance for host-pathogen interactions at various stages of infection. It also plays a role in determining the intrinsic susceptibility to isoniazid in mycobacterial species. In this work, we characterized the oxyR-ahpC and furA-katG loci in the nontuberculous pathogen Mycobacterium marinum. In contrast to Mycobacterium smegmatis and likeMycobacterium tuberculosis and Mycobacterium leprae, M. marinum was shown to possess a closely linked and divergently oriented equivalents of the regulator of peroxide stress response oxyR and its subordinate geneahpC, encoding a homolog of alkyl hydroperoxide reductase. Purified mycobacterial OxyR was found to bind to theoxyR-ahpC promoter region from M. marinum and additional mycobacterial species. Mobility shift DNA binding analyses using OxyR binding sites from several mycobacteria and a panel of in vitro-generated mutants validated the proposed consensus mycobacterial recognition sequence. M. marinum AhpC levels detected by immunoblotting, were increased upon treatment with H2O2, in keeping with the presence of a functional OxyR and its binding site within the promoter region ofahpC. In contrast, OxyR did not bind to the sequences upstream of the katG structural gene, and katGexpression did not follow the pattern seen with ahpC. Instead, a new open reading frame encoding a homolog of the ferric uptake regulator Fur was identified immediately upstream ofkatG in M. marinum. The furA-katGlinkage and arrangement are ubiquitous in mycobacteria, suggesting the presence of additional regulators of oxidative stress response and potentially explaining the observed differences in ahpC andkatG expression. Collectively, these findings broaden our understanding of oxidative stress response in mycobacteria. They also suggest that M. marinum will be useful as a model system for studying the role of oxidative stress response in mycobacterial physiology, intracellular survival, and other host-pathogen interactions associated with mycobacterial diseases.
28
Seagar, A. Louise, Carmel Prendergast, F. Xavier Emmanuel, Alan Rayner, Susan Thomson e Ian F. Laurenson. "Evaluation of the GenoType Mycobacteria Direct assay for the simultaneous detection of the Mycobacterium tuberculosis complex and four atypical mycobacterial species in smear-positive respiratory specimens". Journal of Medical Microbiology 57, n. 5 (1 maggio 2008): 605–11. http://dx.doi.org/10.1099/jmm.0.47484-0.
Testo completoAbstract (sommario):
A novel, commercially available reverse hybridization assay [GenoType Mycobacteria Direct (GTMD), version 2.0; Hain Lifescience] was evaluated for the direct detection of five clinically relevant mycobacterial species [Mycobacterium tuberculosis complex (MTBC), Mycobacterium avium, Mycobacterium malmoense, Mycobacterium kansasii and Mycobacterium intracellulare] from 54 smear-positive respiratory specimens and the findings were compared with culture results. Three approaches were used for specimen preparation using either whole or ‘split’ sample volumes and N-acetyl-l-cysteine/3 % NaOH or 4 % NaOH as decontamination chemicals. Forty-three out of 52 samples in which RNA amplification was successful gave GTMD results that concurred with the identification of the cultured isolate. All cases of MTBC were detected. Twenty-two samples contained M. tuberculosis complex, seven had M. kansasii, four had M. malmoense, seven contained atypical mycobacteria other than those detectable using the GTMD assay and three specimens contained no viable mycobacteria. The assay is easy to use and can be completed in one working day. Results interpretation is facilitated by the inclusion of an internal amplification control with each sample to allow identification of specimens containing amplification inhibitors. A positive GTMD result will quickly identify patients with MTBC infection or provide specific identification of four other atypical mycobacteria from the same specimen. This allows more rapid drug susceptibility testing, treatment, and public health and infection control decisions.
29
Malik, Richard, Carolyn O'Brien e Janet Fyfe. "Infections of cats attributable to slow growing or ‘non-culturable’ mycobacteria". Microbiology Australia 30, n. 2 (2009): 92. http://dx.doi.org/10.1071/ma09092.
Testo completoAbstract (sommario):
Cats are susceptible to a range of different mycobacterial infections. Tuberculosis has not been seen in domestic species living in Australia (including the cat) for decades. Mycobacterial infections most commonly develop in cats subsequent to penetrating injuries (typically inflicted by other cats) that become contaminated with soil or dirt. Most of these infections are caused by rapidly growing mycobacteria, especially Mycobacterium smegmatis and related species, although occasionally other species such as Mycobacterium avium and Mycobacterium ulcerans are involved. In this report we briefly review infections caused by some novel mycobacterial species, which are either impossible or very difficult to grow in vitro using the usual range of liquid and solid media available in reference laboratories. Our understanding of these infections, sometimes referred to as ?feline leprosy-like syndromes?, has increased greatly since the application of molecular techniques and the systematic investigation of affected cats.
30
Sharma, Megha, Bharti Malhotra, Jitendra Tiwari e Shipra Bhargava. "Profile of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug-Resistant Tuberculosis". Journal of Laboratory Physicians 12, n. 03 (23 novembre 2020): 203–11. http://dx.doi.org/10.1055/s-0040-1721160.
Testo completoAbstract (sommario):
Abstract Objective Infections due to nontuberculous mycobacteria (NTM) is increasing globally and may present as drug-resistant tuberculosis (DRTB). In India, data on NTM prevalence and species diversity is limited. Present study was conducted to detect the prevalence and profile of NTM among patients suspected of DRTB using paraffin slide culture (PSC)and mycobacteria growth indicator tube (MGIT) culture methods for isolation of NTM. Material and Method A total of 2,938 samples suspected of TB/DRTB were cultured on PSC and MGIT960. Species identification of mycobacterial isolate was done by sequencing of 16s ribosomal RNA gene. Result Among 2938 samples, 35 (1.19%) were found positive for NTM by PSC and 9 (0.30%) were found positive by MGIT. The diversity of NTM species was high (13 species). Out of 35 NTM isolates by PSC, maximum 34.29% (12) isolates were found to be Mycobacterium fortuitum, followed by 11.43% (4) Mycobacterium abscessus and Mycobacterium chelonae, and 42.85% (15) were other species viz. 8.57% (3) were Mycobacterium intracellulare and Mycobacterium kansasii, 5.71% (2) were Mycobacterium peregrinum, and 2.85% (1) were Mycobacterium flavescens, Mycobacterium farcinogenes, Mycobacterium moriokanese, Mycobacterium wolinskyi, Mycobacterium simiae, Mycobacterium goodii, and Mycobacterium terrae each. Coinfection of Mycobacterium tuberculosis(MTB) and NTM was found in 60% (21) samples. Conclusion Prevalence of NTM was low among multidrug resistant tuberculosis/TB suspected patients, similar to other studies done in India. PSC was found better than MGIT for the isolation of NTM, though poor separation of NTM and MTB on subculture may have led to false negativity in cases of coinfection. About 13 species were isolated; M. fortuitum was the most common of all. Since coinfection of NTM and TB can also occur, samples of patients suspected of NTM should be cultured on PSC even if positive for MTB.
31
Suffys, Philip, Adalgiza da Silva Rocha, Adeilton Brandão, Bart Vanderborght, Wouter Mijs, Geert Jannes, Fernanda C. Q. Mello et al. "Detection of mixed infections with Mycobacterium lentiflavum and Mycobacterium avium by molecular genotyping methods". Journal of Medical Microbiology 55, n. 1 (1 gennaio 2006): 127–31. http://dx.doi.org/10.1099/jmm.0.46218-0.
Testo completoAbstract (sommario):
Three mycobacterial isolates, one from the blood of an HIV-infected patient and two consecutive isolates from a woman with unknown HIV status, had been identified as belonging to the Mycobacterium avium complex by conventional procedures. In both patients, using genetic analysis procedures such as PCR–restriction enzyme analysis (PRA) of the hsp65 gene, a commercially available reverse hybridization-based assay (INNO-LiPA mycobacteria) and/or sequencing analysis of the 16S–23S internal transcribed spacer (ITS), the presence of Mycobacterium lentiflavum was also demonstrated. At the time of detection, both cases were also infected with M. avium, suggesting an underestimation of infection with M. lentiflavum and co-infection with different Mycobacterium species.
32
Galassi, L., R. Donato, E. Tortoli, D. Burrini, D. Santianni e R. Dei. "Nontuberculous mycobacteria in hospital water systems: application of HPLC for identification of environmental mycobacteria". Journal of Water and Health 1, n. 3 (1 settembre 2003): 133–39. http://dx.doi.org/10.2166/wh.2003.0016.
Testo completoAbstract (sommario):
Nontuberculous mycobacteria (NTM), ubiquitous in water environments, are increasingly recognized as nosocomial pathogens. Our study reports a one-year survey of the water system of two hospitals, A and B, in a small town near Florence, Italy. NTM were found throughout the study period in both settings, but B showed a significantly higher mycobacterial load. Mycobacterium gordonae and Mycobacterium fortuitum were the most frequent species isolated. Identification was carried out by conventional techniques and by high performance liquid chromatography (HPLC) analysis of cell wall mycolic acids. HPLC profiling could be used as a first-choice method for identification of environmental mycobacteria.
33
Bao, Yanqing, Lin Wang e Jianjun Sun. "A Small Protein but with Diverse Roles: A Review of EsxA in Mycobacterium–Host Interaction". Cells 10, n. 7 (30 giugno 2021): 1645. http://dx.doi.org/10.3390/cells10071645.
Testo completoAbstract (sommario):
As a major effector of the ESX-1 secretion system, EsxA is essential for the virulence of pathogenic mycobacteria, such as Mycobacterium tuberculosis (Mtb) and Mycobacterium marinum (Mm). EsxA possesses an acidic pH-dependent membrane permeabilizing activity and plays an essential role by mediating mycobacterial escape from the phagosome and translocation to the cytosol for intracellular replication. Moreover, EsxA regulates host immune responses as a potent T-cell antigen and a strong immunoregulator. EsxA interacts with multiple cellular proteins and stimulates several signal pathways, such as necrosis, apoptosis, autophagy, and antigen presentation. Interestingly, there is a co-dependency in the expression and secretion of EsxA and other mycobacterial factors, which greatly increases the complexity of dissecting the precise roles of EsxA and other factors in mycobacterium–host interaction. In this review, we summarize the current understandings of the roles and functions of EsxA in mycobacterial infection and discuss the challenges and future directions.
34
Bashyam, Murali D., e Anil K. Tyagi. "Identification and Analysis of “Extended −10” Promoters from Mycobacteria". Journal of Bacteriology 180, n. 9 (1 maggio 1998): 2568–73. http://dx.doi.org/10.1128/jb.180.9.2568-2573.1998.
Testo completoAbstract (sommario):
ABSTRACT Earlier studies from our laboratory on randomly isolated transcriptional signals of mycobacteria had revealed that the −10 region of mycobacterial promoters and the corresponding binding domain in the major sigma factor are highly similar to their Escherichia coli counterparts. In contrast, the sequences in −35 regions of mycobacterial promoters and the corresponding binding domain in the major sigma factor are vastly different from their E. colicounterparts (M. D. Bashyam, D. Kaushal, S. K. Dasgupta, and A. K. Tyagi, J. Bacteriol. 178:4847–4853, 1996). We have now analyzed the role of the TGN motif present immediately upstream of the −10 region of mycobacterial promoters. Sequence analysis and site-specific mutagenesis of a Mycobacterium tuberculosispromoter and a Mycobacterium smegmatis promoter reveal that the TGN motif is an important determinant of transcriptional strength in mycobacteria. We show that mutation in the TGN motif can drastically reduce the transcriptional strength of a mycobacterial promoter. The influence of the TGN motif on transcriptional strength is also modulated by the sequences in the −35 region. Comparative assessment of these extended −10 promoters in mycobacteria and E. coli suggests that functioning of the TGN motif in promoters of these two species is similar.
35
DIDKOWSKA, ANNA, PIOTR ŻMUDA, BLANKA ORŁOWSKA e KRZYSZTOF ANUSZ. "Mycobacterial infections in cats (Felis catus) as a potential threat to humans – a review 2014–2023". Medycyna Weterynaryjna 79, n. 12 (2023): 6842–2023. http://dx.doi.org/10.21521/mw.6842.
Testo completoAbstract (sommario):
Mycobacteria infections in cats include tuberculosis (caused by Mycobacterium bovis and Mycobacterium microti) and mycobacteriosis caused by non-tuberculous mycobacteria (NTM). The aim of the paper is to present the latest reports on mycobacterial infections in cats and place emphasis on their impact on the health of their owners. The reviewers looked for papers about mycobacterial infections in cats in PubMed and Google Scholar from any date from January 2014 to June 2023. The search used the following keywords: cat, feline, tuberculosis, and mycobacteria. Papers were evaluated for their value to science and their applicability. Papers published in recent years have shown that mycobacterial infections in cats should still be considered in a differential diagnosis when many clinical signs present and they are mainly skin and ocular symptoms. An epidemiological investigation of these infections is highly important because cases were reported also in low-risk regions. Mycobacterial infections pose a risk to humans. The degree of risk depends on many factors, such as the species of mycobacteria, the closeness of animal-owner contact, and the immune status of the owner. The greatest risk are still believed to be M. bovis infections; however, NTM infections should also raise a concern, especially in high-risk groups.
36
Thomson, Rachel, Robyn Carter, Chris Gilpin, Chris Coulter e Megan Hargreaves. "Comparison of Methods for Processing Drinking Water Samples for the Isolation of Mycobacterium avium and Mycobacterium intracellulare". Applied and Environmental Microbiology 74, n. 10 (21 marzo 2008): 3094–98. http://dx.doi.org/10.1128/aem.02009-07.
Testo completoAbstract (sommario):
ABSTRACT Several protocols for isolation of mycobacteria from water exist, but there is no established standard method. This study compared methods of processing potable water samples for the isolation of Mycobacterium avium and Mycobacterium intracellulare using spiked sterilized water and tap water decontaminated using 0.005% cetylpyridinium chloride (CPC). Samples were concentrated by centrifugation or filtration and inoculated onto Middlebrook 7H10 and 7H11 plates and Lowenstein-Jensen slants and into mycobacterial growth indicator tubes with or without polymyxin, azlocillin, nalidixic acid, trimethoprim, and amphotericin B. The solid media were incubated at 32°C, at 35°C, and at 35°C with CO2 and read weekly. The results suggest that filtration of water for the isolation of mycobacteria is a more sensitive method for concentration than centrifugation. The addition of sodium thiosulfate may not be necessary and may reduce the yield. Middlebrook M7H10 and 7H11 were equally sensitive culture media. CPC decontamination, while effective for reducing growth of contaminants, also significantly reduces mycobacterial numbers. There was no difference at 3 weeks between the different incubation temperatures.
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Mignard, Sophie, e Jean-Pierre Flandrois. "Identification of Mycobacterium using the EF-Tu encoding (tuf) gene and the tmRNA encoding (ssrA) gene". Journal of Medical Microbiology 56, n. 8 (1 agosto 2007): 1033–41. http://dx.doi.org/10.1099/jmm.0.47105-0.
Testo completoAbstract (sommario):
The partial nucleotide sequences encoding the elongation factor Tu (tuf gene) (652 bp) and transfer-mRNA (tmRNA or ssrA gene) (340 bp) were determined to assess the suitability of these two genes as phylogenetic markers for the classification of mycobacteria, and thus as alternative target molecules for identifying mycobacteria. A total of 125 reference strains of the genus Mycobacterium and 74 clinical isolates were amplified by PCR and sequenced. Phylogenies of the two genes constructed by the neighbour-joining method were created and compared to a concatenated tree of 16S rDNA, hsp65, sodA and rpoB genes. The phylogenetic trees revealed the overall natural relationships among Mycobacterium species. The tmRNA phylogeny was similar to that of 16S rDNA, with low resolving power. The tuf gene provided better resolution of each mycobacterial species, with a phylogeny close to that of hsp65. However, none of these methods differentiated between the members of the Mycobacterium tuberculosis complex or the subspecies of the Mycobacterium avium complex. The correct identification of clinical isolates confirms the interest of these genes, especially tuf. It is suggested from these findings that tmRNA might be useful as another housekeeping gene in a polyphyletic approach to Mycobacterium species, but not as a first-line marker of species. tuf gene analysis suggests that this gene could be used effectively for phylogenetic analysis and to identify mycobacteria.
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Issa, Rahizan, Hatijah Abdul, Siti Hasmah Hashim, Valentinus H. Seradja, Nurul ‘Aishah Shaili e Nurul Akma Mohd Hassan. "High resolution melting analysis for the differentiation of Mycobacterium species". Journal of Medical Microbiology 63, n. 10 (1 ottobre 2014): 1284–87. http://dx.doi.org/10.1099/jmm.0.072611-0.
Testo completoAbstract (sommario):
A quantitative real-time PCR (qPCR) followed by high resolution melting (HRM) analysis was developed for the differentiation of Mycobacterium species. Rapid differentiation of Mycobacterium species is necessary for the effective diagnosis and management of tuberculosis. In this study, the 16S rRNA gene was tested as the target since this has been identified as a suitable target for the identification of mycobacteria species. During the temperature gradient and primer optimization process, the melting peak (Tm) analysis was determined at a concentration of 50 ng DNA template and 0.3, 0.4 and 0.5 µM primer. The qPCR assay for the detection of other mycobacterial species was done at the Tm and primer concentration of 62 °C and 0.4 µM, respectively. The HRM analysis generated cluster patterns that were specific and sensitive to distinguished small sequence differences of the Mycobacterium species. This study suggests that the 16S rRNA-based real-time PCR followed by HRM analysis produced unique cluster patterns for species of Mycobacterium and could differentiate the closely related mycobacteria species.
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Gupta, Sandeep K., e Ben Z. Katz. "Intrathoracic Disease Associated With Mycobacterium avium-intracellulare Complex in Otherwise Healthy Children: Diagnostic and Therapeutic Considerations". Pediatrics 94, n. 5 (1 novembre 1994): 741–42. http://dx.doi.org/10.1542/peds.94.5.741.
Testo completoAbstract (sommario):
Mycobacterium tuberculosis (MTB) is a well described human pathogen.1 Less commonly, atypical or nontuberculous mycobacteria (NTM) can cause disease in humans. Recent studies report that NTM account for one-third of all pathogenic mycobacterial isolates in the United States.2 Mycobacterium avium-intracellulare complex (MAI) is the most common NTM causing human disease.2 It is also the most common mycobacterial cause of cervical lymphadenitis in children in areas with low endemic rates of MTB infection.3 MAI/NTM infection other than cervical adenitis is unusual in children, except in those that are immunosuppressed.4 Rarely, MAI presents as mediastinal or endobronchial disease in otherwise healthy children.
40
Agustí, Gemma, Oihane Astola, Elisabeth Rodríguez-Güell, Esther Julián e Marina Luquin. "Surface Spreading Motility Shown by a Group of Phylogenetically Related, Rapidly Growing Pigmented Mycobacteria Suggests that Motility Is a Common Property of Mycobacterial Species but Is Restricted to Smooth Colonies". Journal of Bacteriology 190, n. 20 (8 agosto 2008): 6894–902. http://dx.doi.org/10.1128/jb.00572-08.
Testo completoAbstract (sommario):
ABSTRACT Motility in mycobacteria was described for the first time in 1999. It was reported that Mycobacterium smegmatis and Mycobacterium avium could spread on the surface of solid growth medium by a sliding mechanism and that the presence of cell wall glycopeptidolipids was essential for motility. We recently reported that Mycobacterium vaccae can also spread on growth medium surfaces; however, only smooth colonies presented this property. Smooth colonies of M. vaccae do not produce glycopeptidolipids but contain a saturated polyester that is absent in rough colonies. Here, we demonstrate that Mycobacterium chubuense, Mycobacterium gilvum, Mycobacterium obuense, and Mycobacterium parafortuitum, which are phylogenetically related to M. vaccae, are also motile. Such motility is restricted to smooth colonies, since natural rough mutants are nonmotile. Thin-layer chromatography analysis of the content of cell wall lipids confirmed the absence of glycopeptidolipids. However, compounds like the above-mentioned M. vaccae polyester were detected in all the strains but only in smooth colonies. Scanning electron microscopy showed great differences in the arrangement of the cells between smooth and rough colonies. The data obtained suggest that motility is a common property of environmental mycobacteria, and this capacity correlates with the smooth colonial morphotype. The species studied in this work do not contain glycopeptidolipids, so cell wall compounds or extracellular materials other than glycopeptidolipids are implicated in mycobacterial motility. Furthermore, both smooth motile and rough nonmotile variants formed biofilms on glass and polystyrene surfaces.
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Pandey, N., K. Singh, F. Ahmad e R. Sharma. "Characterization of biofilm formation by Mycobacterium smegmatis during different environmental stress conditions: An in-vitro study". Journal of Environmental Biology 43, n. 6 (15 novembre 2022): 771–78. http://dx.doi.org/10.22438/jeb/43/6/mrn-4081.
Testo completoAbstract (sommario):
Aim: In-vitro characterisation of biofilm produced by Mycobacterium smegmatis (M. smegmatis), a surrogate model for biofilm production by Mycobacteria, and to evaluate the impact of different environmental stress on mycobacterial growth and biofilm formation. Methodology: M. smegmatis biofilms were studied using tissue culture plate and tube adherence methods. Confocal Laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to study the 3D structure and surface morphology, respectively. Additionally, the effect of different environmental stress, such as the absence of essential ions, exposure to harsh environmental conditions, such as acidic environment or oxidative stress, on mycobacterial biofilm formation and mycobacterial growth was assessed. Results: All the exposures, except for carbon supplemented media had a detrimental effect on the number of viable counts and on biofilm formation by mycobacteria (p<0.001). Growth in low pH and oxidative stress was found to be maximum showing reduction by 98% when compared with control. Interpretation: Our findings present various environmental conditions that profoundly affect biofilm formation and thus, may find practical implications in future as effective mycobacterial control strategies having attributes of mycobacterial growth as well as biofilm inhibition. Key words: Biofilm, Environmental stress, Multi-drug resistance, Mycobacterium
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Davis, William C., Gaber S. Abdellrazeq, Asmaa H. Mahmoud, Kun-Taek Park, Mahmoud M. Elnaggar, Gaetano Donofrio, Victoria Hulubei e Lindsay M. Fry. "Advances in Understanding of the Immune Response to Mycobacterial Pathogens and Vaccines through Use of Cattle and Mycobacterium avium subsp. paratuberculosis as a Prototypic Mycobacterial Pathogen". Vaccines 9, n. 10 (26 settembre 2021): 1085. http://dx.doi.org/10.3390/vaccines9101085.
Testo completoAbstract (sommario):
Lack of understanding of the immune response to mycobacterial pathogens has impeded progress in development of vaccines. Infection leads to development of an immune response that controls infection but is unable to eliminate the pathogen, resulting in a persistent infection. Although this puzzle remains to be solved, progress has been made using cattle as a model species to study the immune response to a prototypic mycobacterium, Mycobacterium a. paratuberculosis (Map). As chronicled in the review, incremental advances in characterizing the immune response to mycobacteria during the last 30 years with increases in information on the evolution of mycobacteria and relA, a gene regulating the stringent response, have brought us closer to an answer. We provide a brief overview of how mycobacterial pathogens were introduced into cattle during the transition of humankind to nomadic pastoralists who domesticated animals for food and farming. We summarize what is known about speciation of mycobacteria since the discovery of Mybacterium tuberculsis Mtb, M. bovis Mbv, and Map as zoonotic pathogens and discuss the challenges inherent in the development of vaccines to mycobacteria. We then describe how cattle were used to characterize the immune response to a prototypic mycobacterial pathogen and development of novel candidate vaccines.
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Ganesan, S., A. Thirlwall, C. Brewis, H. R. Grant e V. M. Novelli. "Dual infection with atypical mycobacteria and Mycobacterium tuberculosis causing cervical lymphadenopathy in a child". Journal of Laryngology & Otology 114, n. 8 (agosto 2000): 649–51. http://dx.doi.org/10.1258/0022215001906426.
Testo completoAbstract (sommario):
The most common presentation of mycobacterial infection encountered in otolaryngological practice is cervical lymphadenitis. We report a child with an unusual cause of cervical lymphadenopathy, i.e. dual tuberculous infections. This had clinical ramifications as, initially Mycobacterium avium-intracellulare was grown in culture and was resistant to standard anti-tuberculous agents, and hence treated with excision of the lymph node. However, the cultures from the excised lymph node grew out Mycobacterium tuberculosis that was sensitive to standard anti-tuberculous drugs. To our knowledge, no such presentation has been reported previously. We also review the literature on cervical lymphadenitis due to atypical mycobacteria and Mycobacterium tuberculosis , with particular emphasis on clinical presentation, diagnosis and management.
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Soini, Hanna, e James M. Musser. "Molecular Diagnosis of Mycobacteria". Clinical Chemistry 47, n. 5 (1 maggio 2001): 809–14. http://dx.doi.org/10.1093/clinchem/47.5.809.
Testo completoAbstract (sommario):
Abstract Tuberculosis is one of the leading infectious diseases in the world and is responsible for more than 2 million deaths and 8 million new cases annually. Because of the slow growth rate of the causative agent Mycobacterium tuberculosis, isolation, identification, and drug susceptibility testing of this organism and other clinically important mycobacteria can take several weeks or longer. During the past several years, many molecular methods have been developed for direct detection, species identification, and drug susceptibility testing of mycobacteria. These methods can potentially reduce the diagnostic time from weeks to days. Currently, two nucleic acid amplification methods, the Enhanced Mycobacterium tuberculosis Direct Test (Gen-Probe) and the Amplicor Mycobacterium tuberculosis Test (Roche Diagnostic Systems), have been approved by the Food and Drug Administration for direct detection of M. tuberculosis from clinical specimens. PCR-based sequencing has become commonly used to identify many mycobacterial species. DNA probes have been widely used for species determination of the most commonly encountered mycobacteria. High-density oligonucleotide arrays (DNA microarrays) also have been applied to simultaneous species identification and detection of mutations that confer rifampin resistance in mycobacteria.
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Olsen, Randall J., Patricia L. Cernoch e Geoffrey A. Land. "Mycobacterial Synovitis Caused by Slow-Growing Nonchromogenic Species: Eighteen Cases and a Review of the Literature". Archives of Pathology & Laboratory Medicine 130, n. 6 (1 giugno 2006): 783–91. http://dx.doi.org/10.5858/2006-130-783-mscbsn.
Testo completoAbstract (sommario):
Abstract Context.—Slow-growing nonchromogenic mycobacterial species are an infrequent cause of soft tissue infection. Because these organisms are rare, they are not often initially considered in the differential diagnosis of synovitis. Objective.—To evaluate the clinical and pathologic characteristics of patients with synovitis resulting from slow-growing nonchromogenic mycobacterial species. Design.—A 20-year retrospective review of records from The Methodist Hospital Microbiology Laboratory identified 18 culture-positive cases of synovitis that resulted from slow-growing nonchromogenic mycobacteria, including 14 caused by Mycobacterium avium complex, 1 caused by Mycobacterium malmoense, 1 caused by Mycobacterium haemophilum, and 2 caused by Mycobacterium nonchromogenicum isolates. In addition, a comprehensive literature search revealed an additional 48 cases of synovitis caused by slow-growing nonchromogenic mycobacteria. Results.—The historic literature described the majority of the 48 patients as previously healthy, elderly individuals with a several-month history of monoarticular pain and swelling in the small joints of the upper extremity. In contrast, the current series demonstrated the probable role of multiple chronic coexisting medical conditions in promoting disease susceptibility. These patients were also unique in their significantly younger age distribution and diversity of infection sites. Histologic examination and direct acid-fast bacteria stains generally did not aid the diagnosis. Amputation was performed in 2 patients because of delayed identification of disease. Conclusions.—The current series demonstrates that difficult identification and infrequent occurrence cause these organisms to be overlooked by physicians and laboratory personnel. A heightened clinical suspicion for slow-growing nonchromogenic mycobacterial species is necessary when routine culture and histopathologic findings do not readily isolate an organism, or when the patient does not respond to antibiotic and anti-inflammatory treatment.
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Shrivastava, Kamal, Chanchal Kumar, Anupriya Singh, Anshika Narang, Astha Giri, Naresh Kumar Sharma, Shraddha Gupta et al. "An Overview of Pulmonary Infections Due to Rapidly Growing Mycobacteria in South Asia and Impressions from a Subtropical Region". International Journal of Mycobacteriology 9, n. 1 (2020): 62–70. http://dx.doi.org/10.4103/ijmy.ijmy_179_19.
Testo completoAbstract (sommario):
Background: Rapidly growing mycobacteria (RGM) comprise nearly half of the validated species of nontuberculous mycobacteria (NTM) and have been reported to have a higher incidence in Asia as compared to Europe and America. There is limited information on RGM infections from South Asia. Hence, the present study aimed to ascertain the incidence of pulmonary infections due to RGM in Delhi and to review the status of available information on the prevalence of RGM in South Asia, a region endemic for tuberculosis. Methods: We analyzed 933 mycobacterial isolates obtained from pulmonary samples in Delhi and performed species identification by polymerase chain reaction (PCR)-restriction analysis (restriction fragment length polymorphism) and line probe assay. Drug susceptibility testing (DST) was performed by broth microdilution method. We also reviewed reports available on pulmonary infections in South Asia, attributed to RGM. Results: Of the 933 mycobacterial isolates studied, NTM were identified in 152 (16.3%). Of these, 65/152 (42.8%) were RGM comprising Mycobacterium fortuitum (34/65; 52.3%), Mycobacterium abscessus (25/65; 38.5%), Mycobacterium chelonae (3/65; 4.61%), Mycobacterium mucogenicum (2/65; 3.1%), and Mycobacterium smegmatis (1/65; 1.5%). On applying the American Thoracic Society/Infectious Diseases Society of America guidelines, 11/25 (44%) M. abscessus, 3/3 (100%) M. chelonae, and both isolates of M. mucogenicum were found to be clinically relevant. DST revealed that maximum susceptibility of the RGM was seen to linezolid, clarithromycin, and amikacin. Conclusions: Of the RGM isolated in the present study, 16/65 (24.6%) were found to be clinically relevant. Hence, it is important to recognize these organisms as potential pathogens to identify patients with RGM disease to initiate appropriate therapy.
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Fusco da Costa, Ana R., Tarcisio Fedrizzi, Maria L. Lopes, Monica Pecorari, Wana L. Oliveira da Costa, Elisabetta Giacobazzi, Jeann R. da Costa Bahia et al. "Characterization of 17 strains belonging to the Mycobacterium simiae complex and description of Mycobacterium paraense sp. nov." International Journal of Systematic and Evolutionary Microbiology 65, Pt_2 (1 febbraio 2015): 656–62. http://dx.doi.org/10.1099/ijs.0.068395-0.
Testo completoAbstract (sommario):
Fourteen mycobacterial strains isolated from pulmonary samples of independent patients in the state of Pará (Brazil), and three strains isolated in Italy, were characterized using a polyphasic approach. Thorough genetic investigation, including whole-genome sequencing, demonstrated that the strains belong to the M. simiae complex, being most closely related to Mycobacterium interjectum . For 14 of the strains, evidence emerged supporting their inclusion in a previously unreported species of the genus Mycobacterium , for which the name Mycobacterium paraense sp. nov. is proposed (type strain, IEC26T = DSM 46749T = CCUG 66121T). The novel species is characterized by slow growth, unpigmented or pale yellow scotochromogenic colonies, and a HPLC mycolic acid profile different from other known mycobacteria. In different genetic regions, high sequence microheterogeneity was detected.
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Poupin, P., J. J. Godon, E. Zumstein e N. Truffaut. "Degradation of morpholine, piperidine, and pyrrolidine by mycobacteria: evidences for the involvement of a cytochrome P450". Canadian Journal of Microbiology 45, n. 3 (1 marzo 1999): 209–16. http://dx.doi.org/10.1139/w99-002.
Testo completoAbstract (sommario):
Nine bacterial strains that grew on morpholine and pyrrolidine as sole carbon, nitrogen, and energy sources were isolated from three different environments with no known morpholine contamination. One of these strains could also degrade piperidine. These bacteria were identified as Mycobacterium strains. A phylogenetic analysis based on the partial 16S rDNA sequences indicated that the isolated strains clustered within the fast growing group of mycobacteria. When the above-mentioned cyclic amines were used as growth substrates, the synthesis of a soluble cytochrome P450 was induced in all these bacteria. Other laboratory strains, Mycobacterium fortuitum and Mycobacterium smegmatis mc2155, were tested for their abilities to degrade morpholine. Neither of them degraded morpholine but could use pyrrolidine and piperidine. The growth of M. fortuitum and M. smegmatis mc2155 on these compounds involved a soluble cytochrome P450, suggesting that mycobacterial strains are naturally able to use pyrrolidine and have developed a similar enzymatic pathway to metabolize this amine.Key words: mycobacteria, morpholine, piperidine, pyrrolidine, cytochrome P450.
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Muñoz-Muñoz, Lara, Carolyn Shoen, Gaye Sweet, Asunción Vitoria, Tim J. Bull, Michael Cynamon, Charles J. Thompson e Santiago Ramón-García. "Repurposing Avermectins and Milbemycins against Mycobacteroides abscessus and Other Nontuberculous Mycobacteria". Antibiotics 10, n. 4 (3 aprile 2021): 381. http://dx.doi.org/10.3390/antibiotics10040381.
Testo completoAbstract (sommario):
Infections caused by nontuberculous mycobacteria (NTM) are increasing worldwide, resulting in a new global health concern. NTM treatment is complex and requires combinations of several drugs for lengthy periods. In spite of this, NTM disease is often associated with poor treatment outcomes. The anti-parasitic family of macrocyclic lactones (ML) (divided in two subfamilies: avermectins and milbemycins) was previously described as having activity against mycobacteria, including Mycobacterium tuberculosis, Mycobacterium ulcerans, and Mycobacterium marinum, among others. Here, we aimed to characterize the in vitro anti-mycobacterial activity of ML against a wide range of NTM species, including Mycobacteroides abscessus. For this, Minimum Inhibitory Concentration (MIC) values of eight ML were determined against 80 strains belonging to nine different NTM species. Macrocyclic lactones showed variable ranges of anti-mycobacterial activity that were compound and species-dependent. Milbemycin oxime was the most active compound, displaying broad-spectrum activity with MIC lower than 8 mg/L. Time kill assays confirmed MIC data and showed bactericidal and sterilizing activity of some compounds. Macrocyclic lactones are available in many formulations and have been extensively used in veterinary and human medicine with suitable pharmacokinetics and safety properties. This information could be exploited to explore repurposing of anti-helminthics for NTM therapy.
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KRYSZTOPA-GRZYBOWSKA, KATARZYNA, SYLWIA BRZEZIŃSKA, EWA AUGUSTYNOWICZ-KOPEĆ, EWA AUGUSTYNOWICZ e ANNA LUTYŃSKA. "PCR-Based Genomic Deletion Analysis of RD-Regions in the Identification of Mycobacteria Isolated from Adverse Events Following BCG Vaccination or TB Suspected Cases". Polish Journal of Microbiology 63, n. 3 (2014): 359–62. http://dx.doi.org/10.33073/pjm-2014-048.
Testo completoAbstract (sommario):
Early identification of mycobacterial species is crucial for early diagnosis. PCR-multiplex method performed on randomly chosen 54 mycobacteria isolates originating from clinical samples was found to be an inexpensive, quick and reliable alternative for commercially available diagnostics tests. Although the results of gene probes identification performed by NTLDR were generally consistent with multiplex PCR, two mixed Mycobacterium bovis BCG/Mycobacterium tuberculosis infections and a single misdiagnosis of M. tuberculosis with M. bovis were found. The routine application of multiplex-PCR has the potential to make diagnostics surveillance studies feasible.