Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.
Department of Clinical Microbiology, School of Medicine and Health Sciences, University for Development Studies, Tamale, Ghana.
PLoS Negl Trop Dis. 2022 Aug 11;16(8):e0010649. doi: 10.1371/journal.pntd.0010649. eCollection 2022 Aug.
We conducted an abattoir-based cross-sectional study in the five administrative regions of Northern Ghana to determine the distribution of bovine tuberculosis (BTB) among slaughtered carcasses and identify the possibility of zoonotic transmission.
Direct smear microscopy was done on 438 tuberculosis-like lesions from selected cattle organs and cultured on Lowenstein-Jensen media. Acid-fast bacilli (AFB) isolates were confirmed as members of the Mycobacterium tuberculosis complex (MTBC) by PCR amplification of IS6110 and rpoß. Characterization and assignment into MTBC lineage and sub-lineage were done by spoligotyping, with the aid of the SITVIT2, miruvntrplus and mbovis.org databases. Spoligotype data was compared to that of clinical M. bovis isolates from the same regions to identify similarities.
A total of 319/438 (72.8%) lesion homogenates were smear positive out of which, 84.6% (270/319) had microscopic grade of at least 1+ for AFB. Two hundred and sixty-five samples (265/438; 60.5%) were culture positive, of which 212 (80.0%) were MTBC. Approximately 16.7% (34/203) of the isolates with correctly defined spoligotypes were negative for IS6110 PCR but were confirmed by rpoß. Spoligotyping characterized 203 isolates as M. bovis (198, 97.5%), M. caprae (3, 1.5%), M. tuberculosis (Mtbss) lineage (L) 4 Cameroon sub-lineage, (1, 0.5%), and M. africanum (Maf) L6 (1, 0.5%). A total of 53 unique spoligotype patterns were identified across the five administrative regions (33 and 28 were identified as orphan respectively by the SITVIT2 and mbovis.org databases), with the most dominant spoligotype being SIT1037/ SB0944 (77/203, 37.93%). Analysis of the bovine and human M. bovis isolates showed 75% (3/4) human M. bovis isolates sharing the same spoligotype pattern with the bovine isolates.
Our study identified that approximately 29% of M. bovis strains causing BTB in Northern Ghana are caused by uncharacterized spoligotypes. Our findings suggest possible zoonotic transmission and highlight the need for BTB disease control in Northern Ghana.
我们在加纳北部五个行政区进行了一项基于屠宰场的横断面研究，以确定屠宰牛群中牛结核病（BTB）的分布情况，并确定可能发生的人畜共患传播。
从选定的牛器官中对 438 个结核样病变进行直接涂片显微镜检查，并在 Lowenstein-Jensen 培养基上培养。通过 PCR 扩增 IS6110 和 rpoß，将抗酸杆菌（AFB）分离物确认为结核分枝杆菌复合群（MTBC）成员。通过 spoligotyping 对特征进行表征和分配到 MTBC 谱系和亚谱系中，并借助 SITVIT2、miruvntrplus 和 mbovis.org 数据库进行辅助。将 spoligotype 数据与来自同一地区的临床 M. bovis 分离株进行比较，以确定相似性。
在 438 个病变匀浆中，共有 319 个（319/438；72.8%）直接涂片阳性，其中 84.6%（270/319）AFB 的显微镜分级至少为 1+。265 个样本（265/438；60.5%）培养阳性，其中 212 个（212/438；80.0%）为 MTBC。大约 16.7%（34/203）正确定义 spoligotype 的分离株对 IS6110 PCR 呈阴性，但通过 rpoß 得到确认。 spoligotyping 将 203 个分离株表征为牛分枝杆菌（M. bovis）（198，97.5%）、山羊分枝杆菌（M. caprae）（3，1.5%）、结核分枝杆菌（Mtbss）谱系（L）4 喀麦隆亚谱系（1，0.5%）和非洲分枝杆菌（M. africanum）（Maf）L6（1，0.5%）。在五个行政区共鉴定出 53 种独特 spoligotype 模式（SITVIT2 和 mbovis.org 数据库分别鉴定出 33 种和 28 种为孤儿 spoligotype），最主要的 spoligotype 模式为 SIT1037/SB0944（77/203，37.93%）。对牛和人 M. bovis 分离株的分析表明，4 个人类 M. bovis 分离株中有 3 株（3/4）与人畜共患传播株的 spoligotype 模式相同。
我们的研究表明，加纳北部约 29%引起 BTB 的 M. bovis 菌株由未鉴定的 spoligotype 引起。我们的研究结果表明可能存在人畜共患传播，并强调需要在加纳北部进行 BTB 疾病控制。
