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BMC Microbiology May 2003Mycobacterium avium subspecies avium (M. avium) is frequently encountered in the environment, but also causes infections in animals and immunocompromised patients. In...
BACKGROUND
Mycobacterium avium subspecies avium (M. avium) is frequently encountered in the environment, but also causes infections in animals and immunocompromised patients. In contrast, Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) is a slow-growing organism that is the causative agent of Johne's disease in cattle and chronic granulomatous infections in a variety of other ruminant hosts. Yet we show that despite their divergent phenotypes and the diseases they present, the genomes of M. avium and M. paratuberculosis share greater than 97% nucleotide identity over large (25 kb) genomic regions analyzed in this study.
RESULTS
To characterize genome similarity between these two subspecies as well as attempt to understand their different growth rates, we designed oligonucleotide primers from M. avium sequence to amplify 15 minimally overlapping fragments of M. paratuberculosis genomic DNA encompassing the chromosomal origin of replication. These strategies resulted in the successful amplification and sequencing of a contiguous 11-kb fragment containing the putative Mycobacterium paratuberculosis origin of replication (oriC). This fragment contained 11 predicted open reading frames that showed a conserved gene order in the oriC locus when compared with several other Gram-positive bacteria. In addition, a GC skew analysis identified the origin of chromosomal replication which lies between the genes dnaA and dnaN. The presence of multiple DnaA boxes and the ATP-binding site in dnaA were also found in M. paratuberculosis. The strong nucleotide identity of M. avium and M. paratuberculosis in the region surrounding the origin of chromosomal replication led us to compare other areas of these genomes. A DNA homology matrix of 2 million nucleotides from each genome revealed strong synteny with only a few sequences present in one genome but absent in the other. Finally, the 16s rRNA gene from these two subspecies is 100% identical.
CONCLUSIONS
We present for the first time, a description of the oriC region in M. paratuberculosis. In addition, genomic comparisons between these two mycobacterial subspecies suggest that differences in the oriC region may not be significant enough to account for the diverse bacterial replication rates. Finally, the few genetic differences present outside the origin of chromosomal replication in each genome may be responsible for the diverse growth rates or phenotypes observed between the avium and paratuberculosis subspecies.
Topics: Bacterial Proteins; Base Sequence; Cell Division; Conserved Sequence; DNA Replication; Gene Order; Genome, Bacterial; Gram-Positive Bacteria; Molecular Sequence Data; Mycobacterium; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Open Reading Frames; Sequence Homology, Nucleic Acid
PubMed: 12740027
DOI: 10.1186/1471-2180-3-10 -
Frontiers in Cellular and Infection... 2023is an intracellular, facultative bacterium known to colonize and infect the human host through ingestion or respiratory inhalation. The majority of pulmonary infections...
INTRODUCTION
is an intracellular, facultative bacterium known to colonize and infect the human host through ingestion or respiratory inhalation. The majority of pulmonary infections occur in association with pre- existing lung diseases, such as bronchiectasis, cystic fibrosis, or chronic obstructive pulmonary disease. is also acquired by the gastrointestinal route in immunocompromised individuals such as human immunodeficiency virus HIV-1 patients leading to disseminated disease. A hallmark of pulmonary infections is the ability of pathogen to form biofilms. In addition, M. avium can reside within granulomas of low oxygen and limited nutrient conditions while establishing a persistent niche through metabolic adaptations.
METHODS
Bacterial metabolic pathways used by within the host environment, however, are poorly understood. In this study, we analyzed proteome with a focus on core metabolic pathways expressed in the anaerobic, biofilm and aerobic conditions and that can be used by the pathogen to transition from one environment to another.
RESULTS
Overall, 3,715 common proteins were identified between all studied conditions and proteins with increased synthesis over the of the level of expression in aerobic condition were selected for analysis of in specific metabolic pathways. The data obtained from the proteome of biofilm phenotype demonstrates in enrichment of metabolic pathways involved in the fatty acid metabolism and biosynthesis of aromatic amino acid and cofactors. Here, we also highlight the importance of chloroalkene degradation pathway and anaerobic fermentationthat enhance during the transition of from aerobic to anaerobic condition. It was also found that the production of fumarate and succinate by MAV_0927, a conserved hypothetical protein, is essential for M. avium survival and for withstanding the stress condition in biofilm. In addition, the participation of regulatory genes/proteins such as the TetR family MAV_5151 appear to be necessary for survival under biofilm and anaerobic conditions.
CONCLUSION
Collectively, our data reveal important core metabolic pathways that utilize under different stress conditions that allow the pathogen to survive in diverse host environments.
Topics: Humans; Mycobacterium avium; Proteome; Mycobacterium; Metabolic Networks and Pathways
PubMed: 37124045
DOI: 10.3389/fcimb.2023.1092317 -
Clinical Microbiology and Infection :... Oct 2003Mycobacterium intracellulare and Mycobacterium avium (MAC) require specialized culture and identification procedures. To simplify the diagnosis, we inoculated reference...
Mycobacterium intracellulare and Mycobacterium avium (MAC) require specialized culture and identification procedures. To simplify the diagnosis, we inoculated reference strains, and 85 M. avium and 12 M. intracellulare clinical isolates, on egg-based and sheep blood agar. After 5 days of culture, there were significantly more colonies on sheep blood than on egg-based agar for M. avium (ratio: 250.5 +/- 209) but not for M. intracellulare (ratio: 0.44 +/-0.11). Using a ratio > or = 20, the sensitivity of the identification of an MAC isolate as M. avium was 97.65%, the specificity was 100%, and the positive predictive value was 100%. Differential growth on egg-based and blood agar is an aid to the identification of MAC isolates.
Topics: Agar; Colony Count, Microbial; Culture Media; DNA Probes; DNA, Bacterial; Humans; Mycobacterium avium; Mycobacterium avium Complex; Mycobacterium avium-intracellulare Infection; Nucleic Acid Hybridization; RNA, Ribosomal, 16S
PubMed: 14616746
DOI: 10.1046/j.1469-0691.2003.00706.x -
Acta Microbiologica Et Immunologica... Aug 2018The aim of this study was to determine the effect of mycobacterial proteins on mycobacterial biofilm formation and growth processes. We separated growth-affecting...
The aim of this study was to determine the effect of mycobacterial proteins on mycobacterial biofilm formation and growth processes. We separated growth-affecting proteins (GEPs) from wild type of Mycobacterium bovis and ATCC strain of Mycobacterium avium subsp. avium. Our results showed that these mycobacteria-secreted GEPs are involved in biofilm formation, growth stimulatory, and inhibitory processes. Our findings suggest that GEP stimulated M. avium subsp. avium growth in vitro. Stimulation process was observed in mycobacteria affected with GEP extracted from M. avium subsp. avium. We found that both GEPs inhibited the growth of the M. bovis. Optical density measurement and visual analysis confirm that GEP plays an important role in biofilm formation process. Most of M. bovis GEP are associated with the type VII secretion and general secretion pathways. Our results contribute to a better understanding of the mechanisms underlying mycobacterial biofilm formation and growth-affecting processes and better characterization of mycobacterial proteins and their functions. It is noteworthy that this finding represents the first demonstration of GEP-mediated growth effects on a solid and liquid medium.
Topics: Bacterial Proteins; Biofilms; Humans; Mycobacterium avium; Mycobacterium bovis
PubMed: 30024267
DOI: 10.1556/030.65.2018.033 -
Microbial Pathogenesis Apr 2012Previous research has demonstrated that inactivation of the Mycobacterium avium gene, PPE25-MAV (MAV_2928), leads to a significant attenuation of virulence in both...
Previous research has demonstrated that inactivation of the Mycobacterium avium gene, PPE25-MAV (MAV_2928), leads to a significant attenuation of virulence in both in vitro and in vivo models. PPE25-MAV encodes for a PPE family protein, a family from which many members have been implicated in both bacterial virulence and host immune recognition. Recent research has shown that many PPE family proteins are exported by a specialized Type VII secretion system in mycobacteria. In this context, the mechanisms of PPE25-MAV in M. avium pathogenesis were investigated. A mycobacterial 2-hybrid system was used to perform a directed search for M. avium proteins that interact directly with PPE25-MAV. An interaction was observed between PPE25-MAV and the ESAT-6 family protein, MAV_2921, and was further defined by 2-hybrid analysis of truncated PPE25-MAV, and confirmed by co-immunoprecipitation. Localization of the PPE25-MAV protein was analyzed in Mycobacterium smegmatis expressing the recombinant protein and a significant percentage of PPE25-MAV was shown to be exposed at the bacterial surface by surface biotinylation and trypsin protection assays. Finally, transcriptional analysis of PPE25-MAV and its associated operon suggested that nutrient limitation, a condition which occurs in the phagosome, plays a role in regulating expression of the PPE25-MAV gene.
Topics: Amino Acid Motifs; Bacterial Proteins; Cell Membrane; Mycobacterium avium; Protein Binding; Protein Transport
PubMed: 22265661
DOI: 10.1016/j.micpath.2012.01.004 -
Journal of Clinical Microbiology Dec 2014
Comparative Study
Topics: Amikacin; Antitubercular Agents; Clarithromycin; Humans; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium avium Complex
PubMed: 25274991
DOI: 10.1128/JCM.02127-14 -
The Journal of Veterinary Medical... Dec 2019A cat was referred because of diffuse parenchymal lung disease. Close examinations revealed a swollen abdominal lymph node and multiple nodules of the liver....
A cat was referred because of diffuse parenchymal lung disease. Close examinations revealed a swollen abdominal lymph node and multiple nodules of the liver. Mycobacterium avium subspecies hominissuis infection was confirmed by culture and single nucleotide polymorphism analysis of samples recovered from the liver and bronchoalveolar lavage. After administration of combination antibiotics for 6 months, culture results were negative. Though atonic seizures were observed during the treatment, it disappeared after isoniazid discontinuation and pyridoxal phosphate administration. On day 771 of illness, no clinical signs, lung diseases, or obvious swelling of lymph nodes was observed. This is the first report to confirm Mycobacterium avium subspecies hominissuis infection in cats through gene analysis and to completely cure it with combination antibiotics.
Topics: Animals; Anti-Bacterial Agents; Cat Diseases; Cats; Drug Therapy, Combination; Isoniazid; Liver; Lung Diseases; Male; Mycobacterium avium; Polymorphism, Single Nucleotide; Pyridoxal Phosphate; Seizures; Tuberculosis
PubMed: 31666444
DOI: 10.1292/jvms.19-0492 -
BMC Veterinary Research Sep 2011Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of paratuberculosis. The aim of our study was to combine Mini-and Microsatellite loci analysis...
BACKGROUND
Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of paratuberculosis. The aim of our study was to combine Mini-and Microsatellite loci analysis in order to explore the effectiveness of this sub-typing method in a group of Map isolates. For this purpose, 84 Italian Type C Map isolates, each from a different cattle herd, were submitted to MIRU-Variable-Number Tandem-Repeats (VNTRs) typing and Short Sequence repeats (SSRs) sequencing. Moreover, the method was used to analyse the variability inside 10 herds (from three to 50 isolates per herd).
RESULTS
The molecular sub-typing, carried out using three SSR and 10 MIRU-VNTR loci, differentiated the 84 isolates into 33 clusters, reaching a Simpson's Discriminatory Index (SID) value of 0.952 (0.933 to 0.972, 95% confidence intervals). Among all considered loci, six (SSR2, MIRU2, SSR1, SSR8, VNTR3527 and VNTR1067) showed relevant allelic variability. Thirty-eight% of the isolates were clustered into four genotypes, differing from each other for the SSR2 locus. The other isolates, characterised by differences in two or more loci, were spread among the rest of the clusters. The intra-herd analysis revealed more than one genotype in most herds with a similar distribution of clusters.
CONCLUSIONS
Our results revealed the advantage of using both Mini-and Microsatellite approaches for successfully discriminating among Map Type C isolates from the same geographic area, host species and herd. These data suggest that the combination of loci here proposed could be a useful molecular tool for regional epidemiological studies.
Topics: Alleles; Animals; Cattle; Cattle Diseases; DNA, Bacterial; Italy; Microsatellite Repeats; Minisatellite Repeats; Mycobacterium avium subsp. paratuberculosis; Paratuberculosis; Polymerase Chain Reaction
PubMed: 21929793
DOI: 10.1186/1746-6148-7-54 -
Journal of Clinical Microbiology May 1995The occurrence of two markers, a newly identified 40-kDa protein (p40) and the insertion sequence IS901-IS902, in strains of Mycobacterium avium subspp. was evaluated....
The occurrence of two markers, a newly identified 40-kDa protein (p40) and the insertion sequence IS901-IS902, in strains of Mycobacterium avium subspp. was evaluated. Analysis of 184 type and field strains of the M. avium complex from human, animal, and environmental sources by PCR specific to IS901 and by a monoclonal antibody specific to p40 demonstrated the presence of the two molecular markers in all of the M. avium subsp. silvaticum strains examined and also in a number of M. avium subsp. avium strains (the latter isolated mainly from pigs). The appearance of the two markers was completely concurrent in all strains. Further, the marker-positive M. avium subsp. avium strains were mainly serotype 2, whereas M. avium complex strains of serotypes 4, 6, 8, 9, and 10 were marker negative. The M. avium subsp. avium type strains ATCC 25291 and approximately 50% of the M. avium subsp. avium field strains isolated from animals contained the markers, while only one strain of human origin was found to be marker positive. Therefore, IS901 and p40 appear to have substantial potential to differentiate among isolates of the M. avium complex. This observation raises new issues regarding classification of strains, since the presence of the markers was found to be inconsistent with the present taxonomic grouping of M. avium subspp.
Topics: Animals; Antibodies, Monoclonal; Bacterial Proteins; Base Sequence; DNA Primers; DNA Transposable Elements; DNA, Bacterial; Enzyme-Linked Immunosorbent Assay; Genes, Bacterial; Genetic Markers; Humans; Molecular Sequence Data; Mycobacterium avium; Mycobacterium avium Complex; Polymerase Chain Reaction; Serotyping; Species Specificity
PubMed: 7615703
DOI: 10.1128/jcm.33.5.1049-1053.1995 -
The Journal of Infectious Diseases Mar 2010Iron is an essential nutrient for microbes, and many pathogenic bacteria depend on siderophores to obtain iron. The mammalian innate immunity protein lipocalin 2 (Lcn2;...
Iron is an essential nutrient for microbes, and many pathogenic bacteria depend on siderophores to obtain iron. The mammalian innate immunity protein lipocalin 2 (Lcn2; also known as neutrophil gelatinase-associated lipocalin, 24p3, or siderocalin) binds the siderophore carboxymycobactin, an essential component of the iron acquisition apparatus of mycobacteria. Here we show that Lcn2 suppressed growth of Mycobacterium avium in culture, and M. avium induced Lcn2 production from mouse macrophages. Lcn2 also had elevated levels and initially limited the growth of M. avium in the blood of infected mice but did not impede growth in tissues and during long-term infections. M. avium is an intracellular pathogen. Subcellular imaging of infected macrophages revealed that Lcn2 trafficked to lysosomes separate from M. avium, whereas transferrin was efficiently transported to the mycobacteria. Thus, mycobacteria seem to reside in the Rab11(+) endocytic recycling pathway, thereby retaining access to nutrition and avoiding endocytosed immunoproteins like Lcn2.
Topics: Acute-Phase Proteins; Animals; Blood; Colony Count, Microbial; Lipocalin-2; Lipocalins; Liver; Lysosomes; Macrophages; Mice; Mice, Inbred C57BL; Mycobacterium avium; Oncogene Proteins; Spleen; Transferrin; Tuberculosis; rab GTP-Binding Proteins
PubMed: 20121435
DOI: 10.1086/650493