-
PloS One 2022Little is known about the role that B cells play in immune responses to infection with the intracellular pathogen, Mycobacterium avium subsp. paratuberculosis (MAP)....
Little is known about the role that B cells play in immune responses to infection with the intracellular pathogen, Mycobacterium avium subsp. paratuberculosis (MAP). Traditionally, the role of B cells has been constrained to their function as antibody-producing cells, however, antibodies are not thought to play a protective role in mycobacterial infections. The present study was designed to characterize B cell subpopulations as well as activation/maturation states in cattle with paratuberculosis. Peripheral blood mononuclear cells (PBMCs) were isolated from noninfected control cows (n = 8); as well cattle naturally infected with MAP in the subclinical (n = 8) and clinical (n = 7) stage of infection and stimulated with MAP antigen for 6 days. MAP infection resulted in greater numbers of total B cells for clinical cows compared to control noninfected cows. The major subpopulation in freshly isolated PBMCs in clinical cows was B-1a B cells, but this shifted to a composite of both B-1a and B-2 B cells upon stimulation of PBMCs with either MAP antigen or pokeweed mitogen, with higher numbers of B-2 B cells. Early B cells were observed to predominate the population of B cells in PBMCs, with lesser populations of germinal B cells, memory B cells and plasma cells. These subpopulations were elevated in clinical cows upon stimulation of PBMCs with MAP antigen, except for plasma cells which were lower compared to control noninfected cows. Increased numbers of B cells in clinical cows aligned with higher expression of B cell markers such as MAPK1/3, BTG1, Bcl2, CD79A and SWAP70, depending upon in vitro stimulation with either mitogen or antigen. This would indicate that the B cells were capable of activation but were anti-apoptotic in nature. The shift to B-2 B cells in the periphery of clinical cows seems to be indicative of an expansion of memory B cells, rather than plasma cells. This may be a last attempt by the host to control the rampant inflammatory state associated with advanced clinical disease.
Topics: Animals; Cattle; Female; Leukocytes, Mononuclear; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Proto-Oncogene Proteins c-bcl-2
PubMed: 36477266
DOI: 10.1371/journal.pone.0278313 -
PloS One 2021Bovine paratuberculosis (PTB) is a chronic inflammatory disease caused by Mycobacterium avium susbp. paratuberculosis (MAP). Genome-wide association studies (GWAS) have...
Identification of loci associated with susceptibility to Mycobacterium avium subsp. paratuberculosis infection in Holstein cattle using combinations of diagnostic tests and imputed whole-genome sequence data.
Bovine paratuberculosis (PTB) is a chronic inflammatory disease caused by Mycobacterium avium susbp. paratuberculosis (MAP). Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) significantly associated with susceptibility to bovine PTB. The main objective of this study was to identify quantitative trait loci (QTLs) associated with MAP infection in Spanish Holstein cows (N = 983) using combinations of diagnostic tests and imputed whole-genome sequence (WGS) data. The infection status of these animals was defined by three diagnostic methods including ELISA for MAP-antibodies detection, and tissue culture and PCR for MAP detection. The 983 cows included in this study were genotyped with the Bovine MD SNP50 Bead Chip, and the corresponding genotypes were imputed to WGS using the 1,000 Bull genomes reference population. In total, 33.77 million SNP variants per animal were identified across the genome. Linear mixed models were used to calculate the heritability (h2) estimates for each diagnostic test and test combinations. Next, we performed a case-control GWAS using the imputed WGS datasets and the phenotypes and combinations of phenotypes with h2 estimates > 0.080. After performing the GWAS, the test combinations that showed SNPs with a significant association (PFDR ≤ 0.05), were the ELISA-tissue PCR-tissue culture, ELISA-tissue culture, and ELISA-tissue PCR. A total of twelve quantitative trait loci (QTLs) highly associated with MAP infection status were identified on the Bos taurus autosomes (BTA) 4, BTA5, BTA11, BTA12, BTA14, BTA23, BTA24, and BTA28, and some of these QTLs were linked to immune-modulating genes. The identified QTLs on BTA23 spanning from 18.81 to 22.95 Mb of the Bos taurus genome overlapped with several QTLs previously found to be associated with PTB susceptibility, bovine tuberculosis susceptibility, and clinical mastitis. The results from this study provide more clues regarding the molecular mechanisms underlying susceptibility to PTB infection in cattle and might be used to develop national genetic evaluations for PTB in Spain.
Topics: Animals; Case-Control Studies; Cattle; Cattle Diseases; Diagnostic Tests, Routine; Enzyme-Linked Immunosorbent Assay; Female; Genetic Predisposition to Disease; Genome-Wide Association Study; Genotype; Linear Models; Male; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Oligonucleotide Array Sequence Analysis; Paratuberculosis; Phenotype; Polymorphism, Single Nucleotide; Quantitative Trait Loci; Spain; Tuberculosis; Whole Genome Sequencing
PubMed: 34449805
DOI: 10.1371/journal.pone.0256091 -
Journal of Bacteriology Apr 2008Mycobacterium avium comprises organisms that share the same species designation despite considerable genomic and phenotypic variability. To determine the degree and...
Mycobacterium avium comprises organisms that share the same species designation despite considerable genomic and phenotypic variability. To determine the degree and nature of variability between subspecies and strains of M. avium, we used multilocus sequencing analysis, studying 56 genetically diverse strains of M. avium that included all described subspecies. In total, 8,064 bp of sequence from 10 gene loci were studied, with 205 (2.5%) representing variable positions. The majority (149/205) of these variations were found among M. avium subsp. hominissuis organisms. Recombination was also evident in this subspecies. In contrast, there was comparatively little variability and no evidence of recombination within the pathogenic subspecies, M. avium subsp. paratuberculosis, M. avium subsp. avium, and M. avium subsp. silvaticum. Phylogenetic analysis showed that M. avium subsp. avium and M. avium subsp. silvaticum strains clustered together on one branch, while a distinct branch defined M. avium subsp. paratuberculosis organisms. Despite the independent origin of these pathogenic subspecies, an analysis of their rates of nonsynonymous (dN) to synonymous (dS) substitutions showed increased dN/dS ratios for both: 0.67 for M. avium subsp. paratuberculosis and 0.50 for M. avium subsp. avium/M. avium subsp. silvaticum, while the value was 0.08 for M. avium subsp. hominissuis organisms. In conclusion, M. avium subsp. hominissuis represents a diverse group of organisms from which two pathogenic clones (M. avium subsp. paratuberculosis and M. avium subsp. avium/M. avium subsp. silvaticum) have evolved independently.
Topics: Bacterial Proteins; DNA, Bacterial; DNA-Binding Proteins; Evolution, Molecular; Molecular Sequence Data; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Phylogeny; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Sequence Analysis, DNA; Superoxide Dismutase
PubMed: 18245284
DOI: 10.1128/JB.01691-07 -
Antimicrobial Agents and Chemotherapy May 1990A new quinolone, Win 57273 [1-cyclopropyl-7-(2,6-dimethyl-4-pyridinyl)-6-fluoro-1,4-dihydro-4-oxo-3 - quinolonecarboxylic acid], synthesized by Sterling Research Group,... (Comparative Study)
Comparative Study
A new quinolone, Win 57273 [1-cyclopropyl-7-(2,6-dimethyl-4-pyridinyl)-6-fluoro-1,4-dihydro-4-oxo-3 - quinolonecarboxylic acid], synthesized by Sterling Research Group, was tested in vitro against Mycobacterium tuberculosis and Mycobacterium avium strains. The broth-determined MICs of this agent ranged from 1.0 to 4.0 micrograms/ml for M. tuberculosis strains and from 0.25 to 8.0 micrograms/ml for M. avium strains. A distinctive feature of this agent, in comparison with ofloxacin and ciprofloxacin, is its substantially greater activity at the low pHs. For M. avium strains, the MICs of Win 57273 were 2.0 micrograms/ml or less for 54.5% of strains at pH 6.8 and 85.5% of strains at pH 5.0. Win 57273 was more active than ciprofloxacin against M. avium strains, and this difference was very substantial for all M. avium strains at pH 5.0. Taking into account that the predominant locations of these organisms in vivo are within the phagosomes and phagolysosomes of macrophages, i.e., in acidic environments at pH 5.0 or lower, the greater activity of Win 57273 at low pH makes this quinolone especially promising for M. avium infection. The bactericidal activity of Win 57273 for M. avium strains was the same as that of ciprofloxacin, with MBCs from 4.0 to 16.0 micrograms/ml.
Topics: Anti-Infective Agents; Ciprofloxacin; Culture Media; Fluoroquinolones; Hydrogen-Ion Concentration; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium tuberculosis; Ofloxacin; Quinolones
PubMed: 2113793
DOI: 10.1128/AAC.34.5.770 -
BMC Microbiology Aug 2009Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all... (Comparative Study)
Comparative Study
BACKGROUND
Mycobacterium avium includes the subspecies avium, silvaticum, paratuberculosis and hominissuis, and M. avium subspecies has been isolated from various environments all over the world including from biofilms in water distribution systems. The aim of this study was to examine isolates of M. avium subsp. avium and M. avium subsp. hominissuis of different origin for biofilm formation and to look for correlations between biofilm formation and RFLP-types, and to standardise the method to test for biofilm formation. In order to determine the best screening method, a panel of 14 isolates of M. avium subsp. avium and M. avium subsp. hominissuis, were tested for their ability to form biofilm in microtiter plates under different conditions. Subsequently, 83 additional isolates from humans, swine and birds were tested for biofilm formation. The isolates were tested for the presence of selected genes involved in the synthesis of glycopeptidolipids (GPLs) in the cell wall of M. avium, which is believed to be important for biofilm formation. Colony morphology and hsp65 sequvar were also determined.
RESULTS
Nine isolates from swine produced biofilm. There was a significant higher frequency of porcine isolates forming biofilm compared to human isolates. All isolates were previously characterised by IS1311- and IS1245-RFLP typing. The ability to form biofilm did not correlate with the RFLP-type, hsp65 sequevar, colony morphology or the presence of gene sequences related to GPL synthesis.
CONCLUSION
The observed differences in biofilm forming abilities between porcine and human isolates raises questions regarding the importance of biofilm formation for infectious potential. The optimised method worked well for screening of multiple isolates.
Topics: Animals; Bacterial Proteins; Bacterial Typing Techniques; Biofilms; Birds; Chaperonin 60; Chaperonins; Glycoconjugates; Humans; Mycobacterium avium; Polymorphism, Restriction Fragment Length; Swine
PubMed: 19660141
DOI: 10.1186/1471-2180-9-159 -
Scientific Data Dec 2018Infection with Mycobacterium avium is a significant cause of morbidity and its treatment requires the use of multiple antibiotics for more than 12 months. In the current...
Infection with Mycobacterium avium is a significant cause of morbidity and its treatment requires the use of multiple antibiotics for more than 12 months. In the current work, we provide the genome sequence, gene annotations, gene ontology annotations, and protein homology data for M. avium strain 109 (MAC109), which has been used extensively in preclinical studies. The de novo assembled genome consists of a circular chromosome of length 5,188,883 bp and two circular plasmids of sizes 147,100 bp and 16,516 bp. We have named the plasmids pMAC109a and pMAC109b, respectively. Based on its genome, we confirm that MAC109 should be classified as Mycobacterium avium subsp. hominissuis. Using genome annotation software, we identified 4,841 coding sequences and annotated these with Gene Ontology (GO) terms. Additionally, we wrote software to generate a database of homologous proteins among MAC109 and eight other commonly used mycobacterial laboratory strains. The resulting database may be useful for translating genetic data between various strains of mycobacteria, and the software may be applied readily to other organisms.
Topics: Databases, Factual; Genome, Bacterial; Mycobacterium avium; Phylogeny; Sequence Analysis, DNA
PubMed: 30512015
DOI: 10.1038/sdata.2018.277 -
Antimicrobial Agents and Chemotherapy Dec 1993We compared MICs and MBCs of various free- and liposome-incorporated antimicrobial agents against several patient isolates of Mycobacterium avium-M. intracellulare... (Comparative Study)
Comparative Study
We compared MICs and MBCs of various free- and liposome-incorporated antimicrobial agents against several patient isolates of Mycobacterium avium-M. intracellulare complex and certain American Type Culture Collection strains of M. avium, M. intracellulare, and Mycobacterium tuberculosis. Seven of 19 agents were selected for incorporation into liposomes. The MICs of these agents for 50 and 90% of isolates tested (MIC50s and MIC90s, respectively) ranged from 0.5 to 62 micrograms/ml. Members of the M. avium-M. intracellulare complex were resistant to killing by most of the other agents tested in the free form. However, clofazimine, resorcinomycin A, and PD 117558 showed complete killing of bacteria at concentrations ranging from 8 to 31 micrograms/ml, represented as MBC90s. Among the liposome-incorporated agents, clofazimine and resorcinomycin A had the highest killing effects (MBC90s, 8 and 16 micrograms/ml, respectively). Furthermore, both free and liposome-incorporated clofazimine had equivalent growth-inhibitory and killing effects on all American Type Culture Collection strains of M. avium, M. intracellulare, and M. tuberculosis tested. These results show that the antibacterial activities of certain drugs, particularly those of clofazimine and resorcinomycin, were maintained after the drugs were incorporated into liposomes.
Topics: Anti-Bacterial Agents; Cerulenin; Drug Carriers; Humans; Liposomes; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium avium Complex; Rifampin
PubMed: 8109920
DOI: 10.1128/AAC.37.12.2584 -
Journal of Clinical Microbiology May 2005A liquid culture followed by molecular confirmation was evaluated for potential to improve sensitivity and reduce time to diagnosis of Mycobacterium avium subsp....
A liquid culture followed by molecular confirmation was evaluated for potential to improve sensitivity and reduce time to diagnosis of Mycobacterium avium subsp. paratuberculosis infection. Fecal samples from 240 animals from Ohio farms were assessed for presence of M. avium subsp. paratuberculosis using four different protocols: (i) sedimentation processing followed by inoculation on Herrold's Egg Yolk media (HEYM) slants (monitored biweekly up to 16 weeks), (ii) double centrifugation processing followed by inoculation on HEYM slants (monitored biweekly up to 16 weeks), (iii) liquid-solid double culture method using modified 7H9 broth (8 weeks) followed by subculture on HEYM slants (monitored up to 8 weeks), and (iv) liquid culture using modified 7H9 broth (8 weeks) followed by molecular assays for the presence of two M. avium subsp. paratuberculosis-specific targets. The number of positive samples detected by each protocol was 37, 53, 65, and 76, respectively. Twenty-seven samples were positive by all four methods. Based on samples positive by at least one method (n = 81), the sensitivities for sedimentation processing, double centrifugation processing, liquid-solid double culture, and liquid culture followed by molecular confirmation were 46%, 65%, 80%, and 94%, respectively. Fingerprinting of the positive samples using two polymorphic (G and GGT) short sequence repeat regions identified varying levels of within-farm and between-farm diversity. Our data indicate that liquid culture followed by molecular confirmation can significantly improve sensitivity and reduce time-to-diagnosis (from 16 to 8 weeks) of M. avium subsp. paratuberculosis infection and can also be efficiently employed for the systematic differentiation of M. avium subsp. paratuberculosis strains to understand the epidemiology of Johne's disease.
Topics: Bacterial Typing Techniques; Feces; Humans; Mycobacterium Infections; Mycobacterium avium; Mycobacterium avium subsp. paratuberculosis; Ohio; Paratuberculosis
PubMed: 15872229
DOI: 10.1128/JCM.43.5.2111-2117.2005 -
Journal of Clinical Microbiology Aug 1999Mycobacterium avium complex (MAC) is composed of environmental mycobacteria found widely in soil, water, and aerosols that can cause disease in animals and humans,...
Mycobacterium avium complex (MAC) is composed of environmental mycobacteria found widely in soil, water, and aerosols that can cause disease in animals and humans, especially disseminated infections in AIDS patients. MAC consists of two closely related species, M. avium and M. intracellulare, and may also include other, less-defined groups. The precise differentiation of MAC species is a fundamental step in epidemiological studies and for the evaluation of possible reservoirs for MAC infection in humans and animals. In this study, which included 111 pig and 26 clinical MAC isolates, two novel allelic M. avium PCR-restriction enzyme analysis (PRA) variants were identified, differing from the M. avium PRA prototype in the HaeIII digestion pattern. Mutations in HaeIII sites were confirmed by DNA sequencing. Identification of these isolates as M. avium was confirmed by PCR with DT1-DT6 and IS1245 primers, nucleic acid hybridization with the AccuProbe system, 16S ribosomal DNA sequencing, and biochemical tests. The characterization of M. avium PRA variants can be useful in the elucidation of factors involved in mycobacterial virulence and routes of infection and also has diagnostic significance, since they can be misidentified as M. simiae II and M. kansasii I if the PRA method is used in the clinical laboratory for identification of mycobacteria.
Topics: Alleles; Animals; Base Sequence; Brazil; Genome, Bacterial; Heat-Shock Proteins; Humans; Molecular Sequence Data; Mycobacterium avium; Sequence Alignment; Swine; Tuberculosis
PubMed: 10405407
DOI: 10.1128/JCM.37.8.2592-2597.1999 -
Applied and Environmental Microbiology Jun 2006Mycobacterium avium and Mycobacterium intracellulare were grown in suspension and in biofilms, and their susceptibilities to chlorine were measured. M. avium and M....
Mycobacterium avium and Mycobacterium intracellulare were grown in suspension and in biofilms, and their susceptibilities to chlorine were measured. M. avium and M. intracellulare readily adhered within 2 h, and numbers increased 10-fold in 30 days at room temperature in biofilms on both polystyrene flasks and glass beads. The chlorine resistance of M. avium and M. intracellulare cells grown and exposed to chlorine in biofilms was significantly higher than that of cells grown in suspension. Survival curves showed no evidence of a resistant, persisting population after 6 h of exposure to 1 mug chlorine/ml. The chlorine susceptibility of cells grown in biofilms and exposed in suspension (cells detached from bead surfaces) was also significantly higher than that of cells grown and exposed in suspension (planktonic cells), although it was lower than that of cells grown and exposed in biofilms. The higher resistance of the detached biofilm-grown cells was reversed upon their growth in suspension. There was a strong correlation between the chlorine susceptibility of cells of both M. avium and M. intracellulare and cell surface hydrophobicity measured by contact angle for both biofilm- and suspension-grown cells.
Topics: Biofilms; Chlorine; Microbial Sensitivity Tests; Mycobacterium avium; Mycobacterium avium Complex
PubMed: 16751509
DOI: 10.1128/AEM.02573-05