Isolation and molecular characterization of Mycobacterium tuberculosis from humans and cattle in Namwala District, Zambia

Genotyping of Mycobacterium tuberculosis complex isolated from humans and animals in northeastern Iran

The objective of this study was to genotype Mycobacterium tuberculosis complex isolated from humans and cattle in northern Iran. Over the course of one year, a total of 120 human and 21 cattle isolates were tested using region of difference (RD)-based polymerase chain reaction (PCR) and mycobacterial interspersed repetitive unites-variable number tandem repeats (MIRU-VNTR). In M. tuberculosis, out of 120 isolates investigated, the most common genotype detected was NEW-1 (53.3%), followed by CAS/ Delhi (24.1%), Haarlem (5%), Beijing (4.16%), Uganda I (4.16%), S (3.3%), Ural (0.83%), TUR (0.83%), Uganda II (0.83%), Lam (0.83%) and Cameroon (0.83%). The HGDI rate was 0.9981 and the clustering rate was 10.83. Of the isolates, QUB26 had the highest allele diversity (h: 0.76), while the loci Mtub29 and MIRU24 had the lowest (h: 0). In M. Bovis, out of 123 collected tissue samples, 21 (17%) grew on culture media. The HGDI rate was 0.71 and clustering rate was 85.7%. The locus ETRC had the highest allele diversity (h: 0.45). The findings of this study suggest that there is high genetic diversity among M. tuberculosis isolates in Khorasan Razavi Province, which is consistent with similar results from other studies in other provinces in Iran and neighboring countries. This indicates that the prevalent genotypes in this study are spreading in the Middle East region. Furthermore, considering that M. Bovis isolates were identified in two clusters, it seems that all of them have a common origin and are circulating among the livestock farms in the province.

Genetic Diversity and Transmission of Multidrug Resistant Mycobacterium tuberculosis strains in Lusaka, Zambia

OBJECTIVE

Zambia is among the 30 high tuberculosis burden countries in the world. Despite increasing reports of multidrug resistant tuberculosis (MDR-TB) in routine surveillance, information on the transmission of MDR Mycobacterium tuberculosis strains is largely unknown. This study elucidated genetic diversity and transmission of MDR M. tuberculosis strains in Lusaka, Zambia.

METHODS

Eighty-five MDR M. tuberculosis samples collected from the year 2013 to 2017 at the University Teaching Hospital were used. Drug-resistance associated gene sequencing, spoligotyping, 24-loci mycobacterial interspersed repetitive units-variable number of tandem repeats, and multiplex PCR for RD-Rio sub-lineage identification were applied.

RESULTS

Clades identified were LAM (48%), CAS (29%), T (14%), X (6%) and Harlem (2%). Strains belonging to SITs 21/CAS1-Kili and 20/LAM1 formed the largest clonal complexes. Combined spoligotyping and 24 loci-MIRU-VNTR revealed 47 genotypic patterns with clustering rate of 63%. Ninety five percent of LAM strains belonged to RD-Rio sub-lineage.

CONCLUSION

The high clustering rate suggested that a large proportion of MDR-TB was due to recent transmission rather than independent acquisition of MDR. This spread was attributed to clonal expansion of SIT21/CAS1-Kili and SIT20/LAM1 strains. Therefore, TB control programs recommending genotyping coupled with conventional epidemiological methods can guide measures for stopping the spread of MDR-TB.

Role of abattoir monitoring in determining the prevalence of bovine tuberculosis: A systematic review and meta-analysis

Bovine tuberculosis (bTB) is one of the major zoonotic concerns of the world, as milk and meat from cattle are major products for human consumption. Bovine tuberculosis not only affects the health of cattle and poses an imminent zoonotic threat, but also causes significant economic loss in both developed and developing countries. This systematic review reports the prevalence of Mycobacterium tuberculosis complex (MTBC) organisms in slaughtered cattle showing tuberculosis-like lesion (TBL) with available literature worldwide. Appropriate keywords were used to search various databases to collect articles pertaining to slaughterhouse studies. Bovine TB prevalence, based on the prevalence of MTBC organisms in slaughtered cattle showing TBL by culture, microscopy, PCR and spoligotyping, was assessed in each study using a random-effects model and standardized mean with 95% confidence interval (CI). Heterogeneity was assessed by the I² statistic. Publication bias was evaluated using funnel plots. Out of 72 hits, 37 studies were selected based on title and abstract. Ten articles were excluded due to lack of desired data, and 27 studies were included in the final analysis. From the selected articles, it was found that 426 [95% CI: 302-560] per 1,000 slaughtered cattle with TBL were positive for the presence of MTBC organisms. The sensitivity analysis showed that no individual study alone influenced the estimation of pooled prevalence. The prevalence of MTBC organisms in slaughtered cattle showing TBL by culture, microscopy, PCR and spoligotyping was 474[95% CI: 342-610], 385 [95% CI: 269-515], 218 [95% CI: 132-338], 326 [95% CI: 229-442], respectively, per 1,000 slaughtered cattle. Most of the slaughtered cattle were from the same locality as the slaughterhouse. The results obtained in this study suggest that abattoir monitoring can give an estimate of the prevalence of bTB in that locality. This study also emphasizes the need to test cattle and animal handlers who were in contact with bTB-positive cattle.

Characterization of Mycobacterium tuberculosis genotypes and their correlation to multidrug resistance in Lusaka, Zambia

OBJECTIVES

The burden of multidrug-resistant tuberculosis (MDR-TB) has been reported to be increasing in Zambia. The reasons for the increase are still unclear. This study determined the diversity of Mycobacterium tuberculosis genotypes among isolates in Lusaka, the capital city, and investigated their association with MDR-TB.

METHODS

Spoligotyping, large sequence polymorphism (LSP) analysis, and sequencing of MDR associated genes were performed on a total of 274 M. tuberculosis clinical isolates stored at the University Teaching Hospital from 2013 to 2017. Of these, 134 were MDR-TB while 126 were pan-susceptible.

RESULTS

Spoligotyping showed the LAM family as the most predominant genotype (149/274, 54.4%) followed by the CAS family (44/274, 16.1%), T family (39/274, 14.2%), and minor proportions of X, S, Harleem, EAI and Beijing spoligofamilies were identified. Three M. bovis isolates were also observed. Among those, CAS1-Kili (SIT 21) and LAM1 (SIT 20) subfamilies showed a propensity for MDR-TB with p = 0.0001 and p = 0.001, respectively.

CONCLUSIONS

This phenomenon might explain the future increase in the MDR-TB burden caused by specific lineages in Zambia. Therefore, it is recommended that the National TB control program in the country complements conventional control strategies with molecular analysis for monitoring and surveillance of MDR-TB epidemiology.

Seroprevalence and molecular characterization of Mycobacterium bovis infection in camels (Camelus dromedarius) in the Delta region, Egypt

AIM

This study aimed to determine the prevalence rates of Mycobacterium infection in camel sera collected before slaughter and gross lesion tissue collected postmortem (PM) using enzyme-linked immunosorbent assay (ELISA), bacteriological culture, and polymerase chain reaction (PCR). In addition, serum samples from humans who had occupational contact with camels were tested by ELISA and sputum sample by culture.

MATERIALS AND METHODS

ELISA was performed on serum samples antemortem. In addition, bacteriological culture and PCR were conducted after PM. Tuberculosis infection was identified in humans who had contact with camels using ELISA for serum samples and culture for sputum samples.

RESULTS

Tuberculous lesions were detected in 184 of 10,903 camels (1.7%). The ELISA results revealed that of the 184 examined camel serum samples, 124 (67.39%) were positive and all 20 camel serum samples that had no associated tuberculous lesions were negative. Moreover, only one of 48 (2.08%) human serum samples was positive by ELISA. Mycobacterial culture revealed 112 isolates from the 184 examined camel samples (60.87%), while human sputum sample cultures were all negative. PCR analysis identified the mpb70 gene in three of seven randomly tested samples.

CONCLUSION

Gene sequencing was performed on two samples and the sequences were submitted to the National Center for Biotechnology Information GenBank (accession numbers MF990289 and MG59479). A phylogenetic tree was constructed based on the partial DNA sequences of the mpb70 gene; the similarity between the isolates was 98.1%. The similarities between the two isolates and the standard strains of Mycobacterium bovis in GenBank were 98.1% and 100%, respectively. Further investigation on the antemortem detection of M. bovis infection in camels is needed to decrease public risk.

Survey of bovine tuberculosis in Nigerian beef cattle

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobacterium tuberculosis complex (MTBC) that primarily affects cattle, but also other domestic and wild mammals. In Nigeria, abattoir monitoring of gross bTB lesions is the only control method being applied in all animals. This study aims to investigate tubercle bacilli infection in slaughtered cattle found with visible tuberculosis-like lesions. Lesions suggesting bTB were detected in 226 cattle during abattoir monitoring in Zamfara State, Nigeria. Tissue samples collected from the affected carcasses were subjected to Ziehl-Neelsen stain (ZN). Of the 226 carcasses with lesions, 37 (16.4%) were positive by the Ziehl-Neelsen stain (ZN), and MTBC was detected from 34 (91.9%) of the 37 ZN-positive samples. Molecular typing by region of difference (RD) deletion analysis revealed the genotype of Mycobacterium bovis, Mycobacterium caprae and Mycobacterium tuberculosis. Infection was most significantly associated with age of the animals (OR = 3.49; CI: 1.29-9.47 [p = 0.002]). The findings indicate a serious threat for health as well as for TB control in Nigeria.

Mycobacterium tuberculosis Complex Members Adapted to Wild and Domestic Animals

The Mycobacterium tuberculosis complex (MTBC) is composed of several highly genetically related species that can be broadly classified into those that are human-host adapted and those that possess the ability to propagate and transmit in a variety of wild and domesticated animals. Since the initial description of the bovine tubercle bacillus, now known as Mycobacterium bovis, by Theobald Smith in the late 1800's, isolates originating from a wide range of animal hosts have been identified and characterized as M. microti, M. pinnipedii, the Dassie bacillus, M. mungi, M. caprae, M. orygis and M. suricattae. This chapter outlines the events resulting in the identification of each of these animal-adapted species, their close genetic relationships, and how genome-based phylogenetic analyses of species-specific variation amongst MTBC members is beginning to unravel the events that resulted in the evolution of the MTBC and the observed host tropism between the human- and animal-adapted member species.

Characterization of non-tuberculous mycobacterium from humans and water in an Agropastoral area in Zambia

Background

The non-tuberculous mycobacteria include those mycobacterium species that are not members of the Mycobacterium tuberculosis complex, the causative agent of pulmonary tuberculosis and Mycobacterium leprae. In Zambia, Non-tuberculous Mycobacteria are gaining recognition as pathogens of public health significance. However, there is scanty information on the isolation and speciation of these organisms for better patient management, consequently reducing the burden of these infections. Given the above information, the thrust of this study was to isolate and characterize NTM from humans and water in Namwala district of Zambia.

Method

This was a cross-sectional study were 153 individuals with suspected TB were sampled from four health facilities in Namwala district, sputum samples were also collected. Additionally, 149 water samples were collected from different water drinking sources such as Tap water, Borehole water, rivers, wells and streams. Standard TB culture methods were employed to isolate Non-tuberculous Mycobacteria and later 16S–23S internal transcribed spacer region Sequencing was employed to characterize NTM.

Results

Seven (7, 4.6%) NTM species were identified from humans with M. arupense (3, 42.9%) being the most common organism, while twenty three (23, 15.4%) NTM were identified from water with the common species being Mycobacterium gordonae (5, 21.7%). Mycobacterium avium and Mycobacterium fortuitum were both identified from human and water samples.

Conclusion

This study has shown the isolation of NTM species from humans and water. The isolation of NTM from drinking water sources could signify a public health risk to humans.

Updated Reference Genome Sequence and Annotation of Mycobacterium bovis AF2122/97

We report here an update to the reference genome sequence of the bovine tuberculosis bacillus Mycobacterium bovis AF2122/97, generated using an integrative multiomics approach. The update includes 42 new coding sequences (CDSs), 14 modified annotations, 26 single-nucleotide polymorphism (SNP) corrections, and disclosure that the RD900 locus, previously described as absent from the genome, is in fact present.

Abattoir-based estimates of mycobacterial infections in Cameroon

Mycobacteria cause major diseases including human tuberculosis, bovine tuberculosis and Johne’s disease. In livestock, the dominant species is M. bovis causing bovine tuberculosis (bTB), a disease of global zoonotic importance. In this study, we estimated the prevalence of Mycobacteria in slaughter cattle in Cameroon. A total of 2,346 cattle were examined in a cross-sectional study at four abattoirs in Cameroon. Up to three lesions per animal were collected for further study and a retropharyngeal lymph node was collected from a random sample of non-lesioned animals. Samples were cultured on Lowenstein Jensen media and the BACTEC MGIT 960 system, and identified using the Hain^® Genotype kits. A total of 207/2,346 cattle were identified with bTB-like lesions, representing 4.0% (45/1,129), 11.3% (106/935), 23.8% (38/160) and 14.8% (18/122) of the cattle in the Bamenda, Ngaoundere, Garoua and Maroua abattoirs respectively. The minimum estimated prevalence of M. bovis was 2.8% (1.9–3.9), 7.7% (6.1–9.6), 21.3% (15.2–28.4) and 13.1% (7.7–20.4) in the four abattoirs respectively. One M. tuberculosis and three M. bovis strains were recovered from non-lesioned animals. The high prevalence of M. bovis is of public health concern and limits the potential control options in this setting without a viable vaccine as an alternative.

Isolation and characterization of non tuberculous mycobacteria from humans and animals in Namwala District of Zambia

BACKGROUND

The genus Mycobacterium contains more than 100 species, most of which are classified as non-tuberculous mycobacteria (NTM). In Zambia, the NTM are slowly becoming recognized as pathogens of major public health significance with the advent of Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS). This study aimed at reporting the isolated NTM and ascertains their zoonotic potential and diagnostic significance in Zambia.

METHOD

A total of 100 sputum samples were collected from three health facilities from suspected pulmonary tuberculosis human patients. In addition, 67 lymph node tissue samples from cattle and 14 from Kafue lechwe (Kobus leche kafuensis) showing tuberculosis-like lesions were collected. The samples were appropriately decontaminated and cultured on Middlebrook 7H10 and Stone brink. The isolates were then identified accordingly using the 16S ribosomal RNA analysis method.

RESULTS

A total of 8 NTM were isolated from human sputum, 12 from cattle and 1 from the Kafue lechwe. The identified NTM included M. intracellulae, M. abscess, M. chimaera, M. bolleti, M. fortuitum and M. stomatopae sp. Nov.

CONCLUSION

The isolation of NTM from humans and animals at the interface in Namwala district has highlighted the clinical significance and diagnostic challenge. The epidemiological investigation of NTM in the study area is therefore recommended. This should include sampling from environmental sources such as water and soil.