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Euro Surveillance : Bulletin Europeen... 2016Mycobacterium avium represents a health concern for both humans and pigs. The characterisation of its subspecies is an important step improving the understanding of the...
Mycobacterium avium represents a health concern for both humans and pigs. The characterisation of its subspecies is an important step improving the understanding of the epidemiology and the control of this pathogen. Ninety-two human M. avium strains were selected for a retrospective study. Subspecies determination by rpoB sequencing and IS1245/IS901 analysis showed that 98.9% of Belgian human M. avium strains belong to the subspecies hominissuis (MAH). Some of these MAH strains present particular IS1245/IS901 profiles (absence of IS1245 and false IS901 detection provoked by the presence of ISMav6). In addition, 54 MAH strains isolated from submandibular lymph nodes of Belgian pigs with lymphadenitis were included in this study. Genotyping of human and porcine isolates was performed using multispacer sequence typing (MST). In total, 49 different MST types were identified among pig (n = 11) and human (n = 43) MA isolates, with only five shared by both hosts. Among these MST types, 34 were newly identified. Our findings demonstrate the extensive genetic diversity among MAH isolates. Some genotypes were more prevalent in human or pigs but no correlation was observed between MST type and place of residence or the farm of origin for human and porcine isolates respectively, suggesting an environmental source of infection.
Topics: Animals; Belgium; Genetic Variation; Genotype; Humans; Minisatellite Repeats; Mycobacterium avium; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Retrospective Studies; Sequence Analysis, DNA; Swine; Swine Diseases; Tuberculosis
PubMed: 26835872
DOI: 10.2807/1560-7917.ES.2016.21.3.30111 -
Revue Scientifique Et Technique... Apr 2016The species Mycobacterium bovis and Mycobacterium avium subspecies paratuberculosis are the causal agents, respectively, of tuberculosis and paratuberculosis in animals....
The species Mycobacterium bovis and Mycobacterium avium subspecies paratuberculosis are the causal agents, respectively, of tuberculosis and paratuberculosis in animals. Both mycobacteria, especially M. bovis, are also important to public health because they can infect humans. In recent years, this and the impact of tuberculosis and paratuberculosis on animal production have led to significant advances in knowledge about both pathogens and their host interactions. This article describes the contribution of genomics and functional genomics to studies of the evolution, virulence, epidemiology and diagnosis of both these pathogenic mycobacteria.
Topics: Animals; Evolution, Molecular; Genomics; High-Throughput Nucleotide Sequencing; Molecular Epidemiology; Mycobacterium avium; Mycobacterium bovis; Tuberculosis; Virulence
PubMed: 27217180
DOI: 10.20506/rst.35.1.2429 -
Journal of the American Veterinary... Dec 2019
Topics: Alligators and Crocodiles; Animals; Citrobacter; Dermatitis; Male; Mycobacterium avium
PubMed: 31793839
DOI: 10.2460/javma.255.12.1349 -
BMC Microbiology Apr 2021Mycobacterium avium subsp. paratuberculosis (Map) causes Johne's disease (JD), a chronic enteritis widespread in ruminants, resulting in substantial economic losses,...
BACKGROUND
Mycobacterium avium subsp. paratuberculosis (Map) causes Johne's disease (JD), a chronic enteritis widespread in ruminants, resulting in substantial economic losses, especially to the dairy industry. Understanding the genetic diversity of Map in Australia will assist epidemiological studies for tracking disease transmission and identify subtype characteristics for use in development of improved diagnostic typing methods. Here we investigated the phylogenetic relationships of 351 Map isolates and compared different subtyping methods to assess their suitability for use in diagnostics and accuracy.
RESULTS
SNP-based phylogenetic analysis of 228 Australian isolates and 123 publicly available international isolates grouped Type S and Type C strains into two distinct lineages. Type C strains were highly monomorphic with only 20 SNP differences separating them. Type S strains, when aligned separately to the Telford strain, fell into two distinct clades: The first clade contained seven international isolates while the second clade contained one international isolate from Scotland and all 59 Australian isolates. The Australian Type B strain clustered with US bison strains. IS1311 PCR and Restriction Enzyme Analysis (REA) intermittently generated incorrect results when compared to Long Sequence Polymorphism (LSP) analysis, whole genome SNP-based phylogenetic analysis, IS1311 sequence alignment and average nucleotide identity (ANI). These alternative methods generated consistent Map typing results. A published SNP based assay for genotyping Map was found to be unsuitable for differentiating between Australian and international strain types of Map.
CONCLUSION
This is the first phylogenetic analysis of Australian Map isolates. The Type C lineage was highly monomorphic, and the Type S lineage clustered all Australian isolates into one clade with a single Scottish sheep strain. The Australian isolate classified as Type B by IS1311 PCR and REA is likely to be descended from bison and most closely related to US bison strains. Limitations of the current typing methods were identified in this study.
Topics: Animals; Australia; Genetic Variation; Genome, Bacterial; Genotype; Mycobacterium avium subsp. paratuberculosis; Paratuberculosis; Phylogeny; Polymerase Chain Reaction; Polymorphism, Single Nucleotide
PubMed: 33789575
DOI: 10.1186/s12866-021-02140-2 -
Microbial Pathogenesis Nov 2014Mycobacterium avium causes disseminated disease in patients with AIDS and other immunosuppressive conditions and pulmonary infections in individuals with chronic lung...
Mycobacterium avium causes disseminated disease in patients with AIDS and other immunosuppressive conditions and pulmonary infections in individuals with chronic lung diseases. Much still need to be learn about the mechanisms of M. avium pathogenesis. Using a mouse model of disseminated M. avium disease, we applied an in vivo expression technology system and identified M. avium genes up-regulated in different organs of mice during early stage of infection. The M. avium oppA gene, involved in an active transport of oligopeptides across the cell membrane, was found highly expressed in lung, liver and spleen of mice. Mutation in the transport domain of the oppA gene resulted in bacterial attenuation in both macrophages and in mice. Using protein-protein interaction assay, it was determined that two hypothetical small proteins, MAV_2941 (73aa) and MAV_4320 (45aa), interact with OppA. MAV_2941 was shown to be secreted by the bacterium into the macrophage cytoplasm. Mutations in MAV_2941 was associated with significant impairment of growth in macrophages. Understanding the mechanisms involved in the functions of MAV_2941 and MAV_4320 is warranted.
Topics: Animal Structures; Animals; Bacterial Proteins; Carrier Proteins; Disease Models, Animal; Gene Expression Profiling; Genes, Bacterial; Lipoproteins; Macrophages; Mice; Mutant Proteins; Mycobacterium avium; Oligopeptides; Tuberculosis; Virulence; Virulence Factors
PubMed: 25245008
DOI: 10.1016/j.micpath.2014.09.010 -
Clinical Microbiology Reviews Apr 2007The past several years have witnessed an upsurge of genomic data pertaining to the Mycobacterium avium complex (MAC). Despite clear advances, problems with the detection... (Review)
Review
The past several years have witnessed an upsurge of genomic data pertaining to the Mycobacterium avium complex (MAC). Despite clear advances, problems with the detection of MAC persist, spanning the tests that can be used, samples required for their validation, and the use of appropriate nomenclature. Additionally, the amount of genomic variability documented to date greatly outstrips the functional understanding of epidemiologically different subsets of the organism. In this review, we discuss how postgenomic insights into the MAC have helped to clarify the relationships between MAC organisms, highlighting the distinction between environmental and pathogenic subsets of M. avium. We discuss the availability of various genetic targets for accurate classification of organisms and how these results provide a framework for future studies of MAC variability. The results of postgenomic M. avium study provide optimism that a functional understanding of these organisms will soon emerge, with genomically defined subsets that are epidemiologically distinct and possess different survival mechanisms for their various niches. Although the status quo has largely been to study different M. avium subsets in isolation, it is expected that attention to the similarities and differences between M. avium organisms will provide greater insight into their fundamental differences, including their propensity to cause disease.
Topics: Bacterial Proteins; Chaperonin 60; Chaperonins; DNA Transposable Elements; Genetic Variation; Genome, Bacterial; Genomics; Humans; Mycobacterium avium; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Serotyping
PubMed: 17428883
DOI: 10.1128/CMR.00036-06 -
PloS One 2015Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to...
Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to treat. In recent years, extracellular DNA (eDNA) has been found to be a major component of bacterial biofilms, including many pathogens involved in biofilm-associated infections. To date, eDNA has not been described as a component of mycobacterial biofilms. In this study, we identified and characterized eDNA in a high biofilm-producing strain of Mycobacterium avium subsp. hominissuis (MAH). In addition, we surveyed for presence of eDNA in various MAH strains and other nontuberculous mycobacteria. Biofilms of MAH A5 (high biofilm-producing strain) and MAH 104 (reference strain) were established at 22°C and 37°C on abiotic surfaces. Acellular biofilm matrix and supernatant from MAH A5 7 day-old biofilms both possess abundant eDNA, however very little eDNA was found in MAH 104 biofilms. A survey of MAH clinical isolates and other clinically relevant nontuberculous mycobacterial species revealed many species and strains that also produce eDNA. RAPD analysis demonstrated that eDNA resembles genomic DNA. Treatment with DNase I reduced the biomass of MAH A5 biofilms when added upon biofilm formation or to an already established biofilm both on abiotic surfaces and on top of human pharyngeal epithelial cells. Furthermore, co-treatment of an established biofilm with DNase 1 and either moxifloxacin or clarithromycin significantly increased the susceptibility of the bacteria within the biofilm to these clinically used antimicrobials. Collectively, our results describe an additional matrix component of mycobacterial biofilms and a potential new target to help treat biofilm-associated nontuberculous mycobacterial infections.
Topics: Anti-Bacterial Agents; Biofilms; Cell Line; Clarithromycin; DNA, Bacterial; Deoxyribonuclease I; Drug Resistance, Bacterial; Epithelial Cells; Fluoroquinolones; Humans; Moxifloxacin; Mycobacterium avium
PubMed: 26010725
DOI: 10.1371/journal.pone.0128772 -
Antimicrobial Agents and Chemotherapy Dec 1986We determined the MICs of ethambutol for both Mycobacterium avium and Mycobacterium tuberculosis strains by using broth dilution (7H12 broth, radiometric method) and... (Comparative Study)
Comparative Study
We determined the MICs of ethambutol for both Mycobacterium avium and Mycobacterium tuberculosis strains by using broth dilution (7H12 broth, radiometric method) and agar dilution (7H11 agar) methods. We found the MICs to be much lower in liquid than in solid medium. The broth-determined MICs for susceptible M. tuberculosis and most of the M. avium strains were comparable to the levels in blood of patients, being lower than the peak levels. We propose that the MICs, determined radiometrically in in 7H12 broth, be considered as tentative criteria for susceptibility testing of M. avium isolates in future clinical trials. The use of these values instead of critical concentrations should also be considered as an alternative to the conventional susceptibility testing method in chemotherapy of tuberculosis. Ethambutol produced bactericidal effects against both M. tuberculosis and M. avium, and the MIC/MBC ratios were in the same range for both species when MICs and MBCs were tested in 7H12 broth by conventional sampling and plating.
Topics: Culture Media; Ethambutol; Humans; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium tuberculosis
PubMed: 3101588
DOI: 10.1128/AAC.30.6.927 -
Applied and Environmental Microbiology Nov 2005Surveys for Mycobacterium avium subsp. paratuberculosis infection in free-ranging mammals and birds were conducted on nine dairy and beef cattle farms in Wisconsin and...
Surveys for Mycobacterium avium subsp. paratuberculosis infection in free-ranging mammals and birds were conducted on nine dairy and beef cattle farms in Wisconsin and Georgia. Specimens were collected from 774 animals representing 25 mammalian and 22 avian species. Specimens of ileum, liver, intestinal lymph nodes, and feces were harvested from the larger mammals; a liver specimen and the gastrointestinal tract were harvested from birds and small mammals. Cultures were performed by using radiometric culture and acid-fast isolates were identified by 16S/IS900/IS1311 PCR and mycobactin dependency characteristics. M. avium subsp. paratuberculosis was cultured from tissues and feces from 39 samples from 30 animals representing nine mammalian and three avian species. The prevalence of infected wild animals by premises ranged from 2.7 to 8.3% in Wisconsin and from 0 to 6.0% in Georgia. Shedding was documented in seven (0.9%) animals: three raccoons, two armadillos, one opossum, and one feral cat. The use of two highly polymorphic short sequence repeat loci for analysis of 29 of the 39 strains identified 10 alleles. One allelic pattern broadly shared in domestic ruminants ("7,5") appeared in approximately one-third of the wildlife M. avium subsp. paratuberculosis isolates studied. Given the few cases of shedding by free-ranging animals compared to the volume of contaminated manure produced by infected domestic ruminant livestock, contamination of the farm environment by infected wildlife was negligible. Wildlife may, however, have epidemiological significance for farms where M. avium subsp. paratuberculosis recently has been eliminated or on farms free of M. avium subsp. paratuberculosis but located in the geographic vicinity of farms with infected livestock.
Topics: Animal Husbandry; Animals; Animals, Domestic; Animals, Wild; Bird Diseases; Birds; Cattle; Cattle Diseases; Ecosystem; Mammals; Mycobacterium avium subsp. paratuberculosis; Organ Specificity; Paratuberculosis; Species Specificity
PubMed: 16269731
DOI: 10.1128/AEM.71.11.6963-6967.2005 -
Proceedings of the National Academy of... Jun 2007The ability to infect macrophages is a common characteristic shared among many mycobacterial species. Mycobacterium avium, Mycobacterium tuberculosis, and Mycobacterium...
The ability to infect macrophages is a common characteristic shared among many mycobacterial species. Mycobacterium avium, Mycobacterium tuberculosis, and Mycobacterium kansasii enter macrophages, using the complement receptors CR1, CR3, CR4, and the mannose receptor. To identify M. avium genes and host cell pathways involved in the bacterial uptake by macrophages, we screened a M. avium transposon mutant library for the inability to enter macrophages. Uptake-impaired clones were selected. Sequence of six M. avium clones identified one gene involved in glycopeptidolipid biosynthesis, one gene encoding the conserved membrane protein homologue to the M. avium subsp. paratuberculosis MAP2446c gene and four others belonging to the same region of the chromosome. Analysis of the chromosome region revealed a pathogenicity island inserted between two tRNA sequences with 58% of G+C content versus 69% in the M. avium genome. The region is unique for M. avium and is not present in M. tuberculosis or M. paratuberculosis. Although the mutants did not differ from the WT bacterium regarding the binding to macrophage cell membrane, analysis of macrophage proteins after 1 h infection revealed a deficiency in the mutant to phosphorylate certain proteins on uptake. To understand M. avium interaction with two evolutionarily distinct hosts, the mutants were evaluated for Acanthamoeba castellanii invasion. The defect in the ability of the mutants to invade both cells was highly similar, suggesting that M. avium might have evolved mechanisms that are used to enter amoebas and human macrophages.
Topics: Amoeba; Animals; Cell Line; Genes, Bacterial; Genome, Bacterial; Genomic Islands; Humans; Macrophages; Mutation; Mycobacterium avium; Phosphorylation; Tuberculosis
PubMed: 17578930
DOI: 10.1073/pnas.0610746104