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BMC Microbiology Oct 2021In Ethiopia, the distribution of bovine tuberculosis (BTB) has long been known and documented as a major problem of animal health. However, the burden of circulating M....
BACKGROUND
In Ethiopia, the distribution of bovine tuberculosis (BTB) has long been known and documented as a major problem of animal health. However, the burden of circulating M. bovis strains is poorly understood in the country. Therefore; this study aimed to identify and characterize the mycobacterial isolates responsible for BTB in Northwest Ethiopia.
METHODS
A cross-sectional study was conducted on tuberculous lesions that had been collected from slaughtered cattle between September 2018 to June 2019. Collected lesions were cultured and tested for tuberculous bacilli. The MPT64 assay and Genotype line probe assay (LPA) were used for identification of mycobacterial isolates, and region of deletion 4 (RD4) typing and spoligotyping were used to characterize the M. bovis strains.
RESULTS
Of the total 1458 examined slaughtered cattle, only 62 (4.3, 95%CI; 0.0328-0.0542) had tuberculous lesions. The highest number of gross tuberculous lesions were observed from the lymph nodes of the thoracic cavity; at the mediastinal (40.3%, 25/62) and bronchial (22.6%, 14/62) lymph nodes. Of the 62 collected tuberculous lesions; 18 (29.0%) were culture positive for mycobacterium isolates, and only five isolates were confirmed for M. tuberculosis complex (MTBc) by the MPT64 assay and LPA. All the five MTBc isolates were positive for RD4 typing of M. bovis with a PCR product size of 446 bp, and no isolate was noticed to have M. tuberculosis. The detected M. bovis strains displayed five spoligotypes; with the common SB1176 and SB0133 M. bovis strains, although the two spoligotypes had not been previously reported.
CONCLUSION
The present study shows that BTB in North Gondar, Ethiopia, is caused by M. bovis strains SB1176 and SB0033, with low frequency. Thus, the finding highlights the importance of continuous surveillance for mycobacterial strains in cattle populations.
Topics: Abattoirs; Animals; Bacterial Typing Techniques; Cattle; DNA, Bacterial; Ethiopia; Genotype; Male; Mycobacterium; Mycobacterium bovis; Tuberculosis, Bovine
PubMed: 34666679
DOI: 10.1186/s12866-021-02349-1 -
Journal of Infection in Developing... May 2021Zoonotic tuberculosis is a disease of public health importance worldwide, especially in developing countries. The present study aimed to investigate the role played by...
INTRODUCTION
Zoonotic tuberculosis is a disease of public health importance worldwide, especially in developing countries. The present study aimed to investigate the role played by Mycobacterium bovis and other mycobacteria as etiologic agents of bubaline tuberculosis (TB) in the Brazilian Amazon region.
METHODOLOGY
Granulomatous lesions suggestive of TB obtained from 109 buffaloes (n =109) during sanitary inspection at slaughter were subjected to histopathological evaluation, immunohistochemical (IHC) detection of Mycobacterium antigens, and to molecular tests (PCR) to detect hsp65, IS6110 and RD4 genes, which are specific to Mycobacterium spp., Mycobacterium tuberculosis Complex (MTBC) and M. bovis, respectively.
RESULTS
PCR results indicated Mycobacterium infection in 87.2% of the cases, of which 69.5% were positive for M. bovis, 27.4% belonged to MTBC, and 3.1% were probably non-TB mycobacteria. There was good agreement between the genus-specific molecular technique and the histopathological analysis. This high frequency of TB cases caused by non-M. bovis suggests a diversified scenario of mycobacteria associated with bubaline TB in the Brazilian Amazon region.
CONCLUSIONS
The results reinforce the need of discussing the inclusion of more accurate techniques in examinations carried out by Inspection Services in Brazil.
Topics: Abattoirs; Animals; Brazil; Buffaloes; Humans; Mycobacterium bovis; Tuberculosis; Zoonoses
PubMed: 34106899
DOI: 10.3855/jidc.13558 -
Microbes and Infection Nov 2017Mycobacterium tuberculosis is one of the most successful pathogens known, having infected more than a third of the global population. An important strategy for...
Mycobacterium tuberculosis is one of the most successful pathogens known, having infected more than a third of the global population. An important strategy for intracellular survival of pathogenic mycobacteria relies on their capacity to resist delivery to lysosomes, instead surviving within macrophage phagosomes. Several factors of both mycobacterial and host origin have been implicated in this process. However, whether or not this strategy is employed in vivo is not clear. Here we show that in vivo, following intravenous infection, M. tuberculosis and Mycobacterium bovis BCG initially survived by resisting lysosomal transfer. However, after prolonged infection the bacteria were transferred to lysosomes yet continued to proliferate. A M. bovis BCG mutant lacking protein kinase G (PknG), that cannot avoid lysosomal transfer and is readily cleared in vitro, was found to survive and proliferate in vivo. The ability to survive and proliferate in lysosomal organelles in vivo was found to be due to an altered host environment rather than changes in the inherent ability of the bacteria to arrest phagosome maturation. Thus, within an infected host, both M. tuberculosis and M. bovis BCG adapts to infection-specific host responses. These results are important to understand the pathology of tuberculosis and may have implications for the development of effective strategies to combat tuberculosis.
Topics: Animals; Cattle; Host-Pathogen Interactions; Lysosomes; Mice; Mice, Inbred DBA; Mice, Knockout; Mycobacterium bovis; Mycobacterium tuberculosis; Oligonucleotide Array Sequence Analysis; Phagosomes; Tuberculosis; Tuberculosis, Bovine
PubMed: 28689009
DOI: 10.1016/j.micinf.2017.06.008 -
PloS One 2017Mycobacterium bovis, the causative agent of the bovine tuberculosis (bTB), mainly affects cattle, its natural reservoir, but also a wide range of domestic and wild...
Mycobacterium bovis, the causative agent of the bovine tuberculosis (bTB), mainly affects cattle, its natural reservoir, but also a wide range of domestic and wild mammals. Besides direct transmission via contaminated aerosols, indirect transmission of the M. bovis between wildlife and livestock might occur by inhalation or ingestion of environmental substrates contaminated through infected animal shedding. We monitored the survival of M. bovis in two soil samples chosen for their contrasted physical and-chemical properties (i.e. pH, clay content). The population of M. bovis spiked in sterile soils was enumerated by a culture-based method after 14, 30, 60, 90, 120 and 150 days of incubation at 4°C and 22°C. A qPCR based assay targeting the IS1561' locus was also performed to monitor M. bovis in both sterile and biotic spiked soils. The analysis of survival profiles using culture-based method showed that M. bovis survived longer at lower temperature (4°C versus 22°C) whereas the impact of soil characteristics on M. bovis persistence was not obvious. Furthermore, qPCR-based assay detected M. bovis for a longer period of time than the culture based method with higher gene copy numbers observed in sterile soils than in biotic ones. Impact of soil type on M. bovis persistence need to be deepened in order to fill the gap of knowledge concerning indirect transmission of the disease.
Topics: Microbial Viability; Mycobacterium bovis; Soil; Temperature; Time Factors
PubMed: 28448585
DOI: 10.1371/journal.pone.0176315 -
Microbiology (Reading, England) Aug 2020Biofilm-associated infections are difficult to eradicate because of their ability to tolerate antibiotics and evade host immune responses. Amoebae and/or their secreted...
Biofilm-associated infections are difficult to eradicate because of their ability to tolerate antibiotics and evade host immune responses. Amoebae and/or their secreted products may provide alternative strategies to inhibit and disperse biofilms on biotic and abiotic surfaces. We evaluated the potential of five predatory amoebae - , , , and - and their cell-free secretions to disrupt biofilms formed by methicillin-resistant (MRSA) and . The biofilm biomass produced by MRSA and was significantly reduced when co-incubated with , and , and their corresponding cell-free supernatants (CFS). spp. generally produced CFS that mediated biofilm dispersal rather than directly killing the bacteria; however, CFS demonstrated active killing of MRSA planktonic cells when the bacteria were present at low concentrations. The active component(s) of the CFS is resistant to freezing, but can be inactivated to differing degrees by mechanical disruption and exposure to heat. and its CFS also reduced preformed biofilms, whereas only decreased biofilm biomass when amoebae were added. These results highlight the potential of using select amoebae species or their CFS to disrupt preformed bacterial biofilms.
Topics: Amoebida; Antibiosis; Biofilms; Cell Survival; Culture Media, Conditioned; Methicillin-Resistant Staphylococcus aureus; Mycobacterium bovis; Species Specificity
PubMed: 32459167
DOI: 10.1099/mic.0.000933 -
PLoS Neglected Tropical Diseases Jan 2018Bovine tuberculosis is a zoonotic disease with largely unknown impact in Africa, with risk factors such as HIV and direct contact with animals or consumption of...
Bovine tuberculosis is a zoonotic disease with largely unknown impact in Africa, with risk factors such as HIV and direct contact with animals or consumption of Mycobacterium bovis infected animal products. In order to understand and quantify this risk and design intervention strategies, good epidemiological studies are needed. Such studies can include molecular typing of M. bovis isolates. The aim of this study was to apply these tools to provide novel information concerning the distribution of bovine tuberculosis in cattle in Mozambique and thereby provide relevant information to guide policy development and strategies to contain the disease in livestock, and reduce the risk associated with transmission to humans. A collection of 178 M. bovis isolates was obtained from cattle in Mozambique. Using spoligotyping and regions of difference analysis, we classified the isolates into clonal complexes, thus reporting the first characterisation of M. bovis strains in this region. Data from MIRU-VNTR typing was used to compare isolates from a number of African countries, revealing a deeply geographically structured diversity of M. bovis. Eastern Africa appears to show high diversity, suggesting deep evolution in that region. The diversity of M. bovis in Africa does not seem to be a function of recent importation of animals, but is probably maintained within each particular region by constant reinfection from reservoir animals. Understanding the transmission routes of M. bovis in Mozambique and elsewhere is essential in order to focus public health and veterinary resources to contain bovine tuberculosis.
Topics: Animals; Cattle; Disease Transmission, Infectious; Genetic Variation; Genotype; Molecular Epidemiology; Molecular Typing; Mozambique; Mycobacterium bovis; Tuberculosis, Bovine; Zoonoses
PubMed: 29346413
DOI: 10.1371/journal.pntd.0006147 -
Tuberculosis (Edinburgh, Scotland) Jan 2022Bovine tuberculosis, caused by Mycobacterium bovis (M. bovis), is a globally distributed chronic disease of animals. The bacteria can be transmitted to humans via the... (Meta-Analysis)
Meta-Analysis
Bovine tuberculosis, caused by Mycobacterium bovis (M. bovis), is a globally distributed chronic disease of animals. The bacteria can be transmitted to humans via the consumption of unpasteurised (raw) milk, thus representing an important public health risk. To investigate the risk of zoonotic transmission of M. bovis via raw milk, this study systematically reviewed published studies to estimate the prevalence of M. bovis in on-farm bulk-tank milk (BTM) and individual cow's milk (IM) by meta-analysis. In total, 1,339 articles were identified through seven electronic databases and initially screened using titles and abstracts. The quality of 108 potentially relevant articles was assessed using full texts, and 67 articles comprising 83 studies (76 IM and 7 BTM), were included in the meta-analysis. The prevalence of M. bovis in IM and BTM was summarised according to the diagnostic test used, and the tuberculin skin test (TST) infection status of the individual cows (for IM) or herds (for BTM). Heterogeneity was quantified using the I-squared statistic. Prediction intervals (95% PIs) were also estimated. For IM, the overall prevalence was summarised at 5% (95%CI: 3%-7%). In TST positive cows, prevalence was summarised at 8% (95%CI: 4%-13%). For BTM, the overall prevalence independent of individual herd TST infection status was summarised at 5% (95%CI: 0%-21%). There was considerable heterogeneity evident among the included studies, while PIs were also wide. Inconsistency in the quality of reporting was also observed resulting in missing information, such as the TST infection status of the individual animal/herd. No study reported the number of M. bovis bacteria in test-positive milk samples. Several studies reported the detection of M. tuberculosis and M. africanum in milk. Despite international efforts to control tuberculosis, this study highlights the risk of zoonotic transmission of M. bovis via unpasteurised milk and dairy products made using raw milk.
Topics: Animals; Cattle; Dairying; Female; Milk; Mycobacterium bovis; Prevalence
PubMed: 35091379
DOI: 10.1016/j.tube.2022.102166 -
The Onderstepoort Journal of Veterinary... Feb 2020All effects taken together, bovine tuberculosis (bTB) has a long-term detrimental effect on bovine herds and many wildlife species in South Africa. The disease is not... (Review)
Review
All effects taken together, bovine tuberculosis (bTB) has a long-term detrimental effect on bovine herds and many wildlife species in South Africa. The disease is not only found in domestic cattle but also in African buffaloes and has to date been diagnosed in 21 wildlife species, including several rare and endangered species, thus having a potentially serious effect on conservation and biodiversity. In cattle, bTB is mostly characterised by sporadic outbreaks, but bovine herds chronically infected with the clinical disease are not uncommon. Presently, the recognised bTB control strategy in South Africa is based on 'test and slaughter', using the intradermal tuberculin test, followed by the slaughter of animals that have tested positive. Affected herds are placed under veterinary quarantine with movement restrictions until the outbreak is eradicated; this can take several years or last indefinitely if the outbreak cannot be eradicated. The same measures apply to infected buffalo populations, often with no prospect of ever being eradicated. This strategy is neither practical nor viable in the context of a communal farming system and becomes unethical when dealing with valuable wildlife reservoir hosts. Transmission of bTB between wildlife and cattle has been demonstrated and emphasises the need for an effective, affordable and culturally acceptable control strategy to curb the spread of bTB in South Africa. In countries with similar challenges, vaccination has been used and found to be promising for treating wild and domestic reservoir species and may hence be of value as a complementary tool for bTB control in South Africa.
Topics: Animals; Buffaloes; Cattle; Disease Outbreaks; Mycobacterium bovis; South Africa; Tuberculosis, Bovine
PubMed: 32129639
DOI: 10.4102/ojvr.v87i1.1690 -
Frontiers in Cellular and Infection... 2023(Mtb) is an intracellular bacterium that causes a highly contagious and potentially lethal tuberculosis (TB) in humans. It can maintain a dormant TB infection within...
(Mtb) is an intracellular bacterium that causes a highly contagious and potentially lethal tuberculosis (TB) in humans. It can maintain a dormant TB infection within the host. DosR (dormancy survival regulator) (Rv3133c) has been recognized as one of the key transcriptional proteins regulating bacterial dormancy and participating in various metabolic processes. In this study, we extensively investigate the still not well-comprehended role and mechanism of DosR in () Bacillus Calmette-Guérin (BCG) through a combined omics analysis. Our study finds that deleting DosR significantly affects the transcriptional levels of 104 genes and 179 proteins. Targeted metabolomics data for amino acids indicate that DosR knockout significantly upregulates L-Aspartic acid and serine synthesis, while downregulating seven other amino acids, including L-histidine and lysine. This suggests that DosR regulates amino acid synthesis and metabolism. Taken together, these findings provide molecular and metabolic bases for DosR effects, suggesting that DosR may be a novel regulatory target.
Topics: Humans; Mycobacterium bovis; Bacterial Proteins; Multiomics; Tuberculosis; Mycobacterium tuberculosis; Lysine; BCG Vaccine
PubMed: 38076461
DOI: 10.3389/fcimb.2023.1292864 -
Frontiers in Immunology 2023Despite the widespread use of standardised drug regimens, advanced diagnostics, and Bacille-Calmette-Guérin (BCG) vaccines, the global tuberculosis (TB) epidemic... (Review)
Review
Despite the widespread use of standardised drug regimens, advanced diagnostics, and Bacille-Calmette-Guérin (BCG) vaccines, the global tuberculosis (TB) epidemic remains uncontrollable. To address this challenge, improved vaccines are urgently required that can elicit persistent immunologic memory, the hallmark of successful vaccines. Nonetheless, the processes underlying the induction and maintenance of immunologic memory are not entirely understood. Clarifying how memory T cells (Tm cells) are created and survive long term may be a crucial step towards the development of effective T cell-targeted vaccines. Here, we review research findings on the memory T cell response, which involves mobilization of several distinct Tm cell subsets that are required for efficient host suppression of (Mtb) activity. We also summaries current knowledge related to the T cell response-based host barrier against Mtb infection and discuss advantages and disadvantages of novel TB vaccine candidates.
Topics: Humans; Memory T Cells; Tuberculosis; BCG Vaccine; Mycobacterium tuberculosis; Mycobacterium bovis
PubMed: 37063832
DOI: 10.3389/fimmu.2023.1100741