Borham Mohamed, Oreiby Atef, El-Gedawy Attia, Hegazy Yamen, Hemedan Ahmed, Al-Gaabary Magdy
Bacteriology Department, Animal Health Research Institute Matrouh Lab, Matrouh, Egypt.
Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh, Egypt.
Transbound Emerg Dis. 2022 Mar;69(2):434-450. doi: 10.1111/tbed.14001. Epub 2021 Feb 21.
Bovine tuberculosis is a transboundary disease of high economic and public health burden worldwide. In this study, post-mortem examination of 750 cattle and buffalo in Tanta abattoir, Centre of the Nile Delta, revealed visible TB in 4% of animals and a true prevalence of 6.85% (95% CI: 5.3%-8.9%). Mycobacterial culture, histopathology and RT-PCR targeting all members of M. tuberculosis complex were performed, upon which 85%, 80% and 100% of each tested lesions were confirmed as TB, respectively. Mpb70-targeting PCR was conducted on ten RT-PCR positive samples for sequencing and identified nine Mycobacterium (M.) bovis strains and, interestingly, one M. tuberculosis (Mtb) strain from a buffalo. Bioinformatics tools were used for prediction of mutations, nucleotide polymorphisms, lineages, drug resistance and protein-protein interactions (PPI) of the sequenced strains. The Mtb strain was resistant to rifampicin, isoniazid and streptomycin, and to the best of our knowledge, this is the first report of multidrug resistant (MDR)-Mtb originating from buffaloes. Seven M. bovis strains were resistant to ethambutol and ethionamide. Such resistances were associated with KatG, rpoB, rpsL, embB and ethA genes mutations. Other mutations and nucleotide polymorphisms were also predicted, some are reported for the first time and require experimental work for validation. PPI revealed more interactions than what would be expected for a random set of proteins of similar size and had dense interactions between nodes that are biologically connected, as a group. Two M. bovis strains belonged to BOV AFRI lineage (Spoligotypes BOV 1; BOV 2) and eight strains belonged to East-Asian (Beijing) lineage. In conclusion, visible TB was prevalent in the study area, RT-PCR is the best to confirm the disease, MDR-Mtb is associated with buffalo TB, and mycobacteria of different lineages carry many resistance genes to chemotherapeutic agents used in treatment of human TB constituting a major public health risk.
牛结核病是一种在全球范围内具有高经济和公共卫生负担的跨界疾病。在本研究中，对尼罗河三角洲中心坦塔屠宰场的750头牛和水牛进行的尸检显示，4%的动物有可见的结核病病变，实际患病率为6.85%（95%置信区间：5.3%-8.9%）。对结核分枝杆菌复合体的所有成员进行了分枝杆菌培养、组织病理学检查和逆转录聚合酶链反应（RT-PCR），据此分别有85%、80%和100%的每个检测病变被确认为结核病。对10个RT-PCR阳性样本进行了靶向Mpb70的PCR测序，鉴定出9株牛分枝杆菌（M. bovis）菌株，有趣的是，从一头水牛中鉴定出1株结核分枝杆菌（M. tuberculosis，Mtb）菌株。使用生物信息学工具对测序菌株的突变、核苷酸多态性、谱系、耐药性和蛋白质-蛋白质相互作用（PPI）进行预测。该Mtb菌株对利福平、异烟肼和链霉素耐药，据我们所知，这是源自水牛的耐多药（MDR）-Mtb的首次报告。7株牛分枝杆菌菌株对乙胺丁醇和乙硫异烟胺耐药。这些耐药性与KatG、rpoB、rpsL、embB和ethA基因突变有关。还预测了其他突变和核苷酸多态性，其中一些是首次报道，需要进行实验工作以验证。PPI显示的相互作用比一组大小相似的随机蛋白质预期的更多，并且在作为一个群体的生物学上相关的节点之间有密集的相互作用。2株牛分枝杆菌菌株属于BOV AFRI谱系（寡核苷酸分型BOV 1；BOV 2），8株属于东亚（北京）谱系。总之，可见的结核病在研究区域很普遍，RT-PCR是确诊该病的最佳方法，MDR-Mtb与水牛结核病有关，不同谱系的分枝杆菌携带许多对用于治疗人类结核病的化疗药物的耐药基因，构成了重大的公共卫生风险。
