Multidrug-resistant strains of Mycobacterium complex species in Egyptian farm animals, veterinarians, and farm and abattoir workers

Abstract

Background and Aim: Mycobacterium tuberculosis complex (MTBC) is a group of mycobacteria that are important human pathogens. Mycobacterium tuberculosis and Mycobacterium bovis cause serious chronic life-threatening disease and also significant economic losses in both production and remedication. Recently, emergence of multidrug-resistant tuberculosis (MDR-TB) complex has generated global recognition of the need for rapid and sensitive diagnosis and development of new treatments. The current study illustrates the isolation/identification of MTBC strains in specimens obtained from cows and humans by conventional and real-time polymerase chain reaction (RT-PCR) techniques. Further, the study assesses sensitivity to antituberculosis drugs in isolated MDR strains. Materials and Methods: A total of 1464 samples from cattle (1285 raw milk and 179 lymph node), and 149 human sputum samples, were collected from farms and abattoirs in Delta Egypt. Conventional methods (culture and Ziehl–Neelsen staining) were implemented as were RT-PCR using MTBC universal DNA. The effect of some antituberculosis drugs on obtained isolates was assayed using drug susceptibility proportion and qualitative suspension techniques. Results: The MBTC detection rate using the culture method was higher than for Ziehl–Neelsen staining; raw cow milk (2.56 vs. 1.63%), lymph nodes (51.59 vs. 48.04%), and human sputum (5.36 vs. 4.02%). A total of 135 isolates were obtained. Application of RT-PCR detected 138 isolates from the same set of samples. MBTC isolates were resistant to first-line antituberculosis drugs, such as pyrazinamide, isoniazid, rifampicin, and ethambutol by 78.5, 59.3, 40.7, and 31.8%, respectively, and could be highly resistant to kanamycin (82.3%) and amikacin (80.7%). However, isolates remained sensitive to ciprofloxacin (71.1%) and clarithromycin (73.3%) as second-line drugs. Conclusion: There is a growing risk for isolation of MDR-TB from raw milk and lymph nodes of field tuberculin positive cattle as well as sputum of veterinarians and workers existed in farms and abattoirs. PCR-based techniques have become the gold standard for the identification of mycobacterial species, showing high efficiency compared to bacteriological and microscopic examination. Application of the first- and second-line antituberculosis drugs in combination could counter the MDR-TB concern once infections are identified.

Comparative diagnosis of bovine tuberculosis using single intradermal cervical tuberculin technique, conventional methods, enzyme-linked immunosorbent assay, and the gamma-interferon assay

“…Others have reported higher infection rates, ranging from 4.35% to 18.7% [ 20 - 22 ]. In this study, microscopic examination yielded results similar to those reported elsewhere [ 4 ], with rates of 2.56% in raw cow’s milk and 51.59% in lymph nodes. Microscopic examination of lymph nodes collected from tuberculin-positive animals by Z-N stain revealed M. bovis in 52/108 samples (48.1%), higher than the prior report, citing 21.43% [ 23 ].…”

“…In humans, it causes approximately 3 million deaths every year. It affects domestic and wild animals and is characterized by progressive development of tubercles or characteristic granulomatous lesions in lung tissue, lymph nodes, or other organs [ 4 ]. Diagnosis of TB requires measuring either a humoral or cellular immune response.…”

Bacteriological and Molecular studies on Mycobacterium Bovis in Cattle, with Special Reference to its Antimicrobial Resistance

“…From Table 1, it appears that results of direct smear were less than those reported by Sohair and Riad (2002) who detected 69% positive cases but higher than 46.88% and 48.04% reported by Silva et al (2018) and Abdelsadek et al (2020). Regarding culture, the obtained results in Table 1 are consistent with those reported by Silva et al (2018) and Hamed et al (2021) who detected M. bovis in 68.75% and 64.9% of tested samples, respectively, but were less than 80%, 71.4% and 85% reported by Nasr et al (2016), Mohammed (2017) and Borham et al (2021), respectively.…”

“…As per CPCSEA guidelines (Pandey and Sharma 2011), a study involving clinical and postmortem samples does not require the approval of the Institute Animal Ethics Committee. Those guidelines were followed in the study (Abdelsadek et al 2020) which was conducted on postmortem samples. However, all owners of slaughtered cattle have signed a consent form.…”

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

“…Furthermore, they confirmed the absence of genetic relationship between human M. bovis strains or between human and bovine strains. Recently, Abdelsadek et al in Egypt tested 135 MBTC isolates obtained from both infected cattle and veterinarians or workers in contact with these animals [ 158 ]. The study reported high resistance for both PZA and INH of 78.5% and 59.3%, respectively.…”