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 at 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

Review on Bovine Tuberculosis: An Emerging Disease Associated with Multidrug-Resistant Mycobacterium Species

Bovine tuberculosis is a serious infectious disease affecting a wide range of domesticated and wild animals, representing a worldwide economic and public health burden. The disease is caused by Mycobacteriumbovis and infrequently by other pathogenic mycobacteria. The problem of bovine tuberculosis is complicated when the infection is associated with multidrug and extensively drug resistant M. bovis. Many techniques are used for early diagnosis of bovine tuberculosis, either being antemortem or postmortem, each with its diagnostic merits as well as limitations. Antemortem techniques depend either on cellular or on humoral immune responses, while postmortem diagnosis depends on adequate visual inspection, palpation, and subsequent diagnostic procedures such as bacterial isolation, characteristic histopathology, and PCR to reach the final diagnosis. Recently, sequencing and bioinformatics tools have gained increasing importance for the diagnosis of bovine tuberculosis, including, but not limited to typing, detection of mutations, phylogenetic analysis, molecular epidemiology, and interactions occurring within the causative mycobacteria. Consequently, the current review includes consideration of bovine tuberculosis as a disease, conventional and recent diagnostic methods, and the emergence of MDR-Mycobacterium species

New Insights into Listeria monocytogenes Antimicrobial Resistance, Virulence Attributes and Their Prospective Correlation

Listeriosis is one of the most common foodborne diseases caused by Listeria monocytogenes (L. monocytogenes). A poor prognosis has been recorded for the invasive listeriosis, especially neurolisteriosis. In several countries throughout the world, foodborne infections with L. monocytogenes exceeded the legal safety limits in animal sourced foods. Therefore, we decided to investigate the variability, virulence and antimicrobial resistance profiles of this pathogen. Both phenotypic and genotypic methods were used for identifying L. monocytogenes isolates and confirming their virulence profiles. The antimicrobial resistances and their correlation analysis with the existence of virulence genes were detected. Additionally, sequencing and phylogenetic analysis based on L. monocytogenes inlA and inlB genes were undertaken. The prevalence rate (11.9%) and the resistance profiles of L. monocytogenes were shocking. The multi-drug resistance (MDR) phenotypes were common among our isolates (64.9%). Fortunately, the resistance phenotypes were always associated with low virulence arrays and the MDR strains possessed low virulence fitness. Herein, the high genotypic and phenotypic diversity of L. monocytogenes isolates and their weak clonality and adaptability highlighted the difficulty in controlling and managing this pathogen. Therefore, it is important to add more restriction guidelines from national authorities on the consumption of ready to eat foods