Das Gupta M, Das A, Islam M Z, Biswas P K
Department of Microbiology and Veterinary Public Health,Chittagong Veterinary and Animal Sciences University,Bangladesh.
Department of Genetics and Animal Breeding,Chittagong Veterinary and Animal Sciences University,Bangladesh.
Epidemiol Infect. 2016 Sep;144(12):2501-8. doi: 10.1017/S0950268816001047. Epub 2016 Jun 8.
A cross-sectional survey was carried out in Bangladesh with the sampling of 514 Black Bengal goats on smallholdings to determine the presence of sorbitol non-fermenting (SNF) Shiga toxin-producing E. coli (STEC). Swab samples collected from the recto-anal junction were plated onto cefixime and potassium tellurite added sorbitol MacConkey (CT-SMAC) agar, a selective medium for STEC O157 serogroup, where this serogroup and other SNF STEC produce colourless colonies. The SNF E. coli (SNF EC) isolates obtained from the survey were investigated by PCR for the presence of Shiga toxin-producing genes, stx1 and stx2, and two other virulence genes, eae and hlyA that code for adherence factor (intimin protein) and pore-forming cytolysin, respectively. The SNF EC isolates were also assessed for the presence of the rfbO157 gene to verify their identity to O157 serogroup. The results revealed that the proportions of goats carrying SNF EC isolates and stx1 and stx2 genes were 6·2% (32/514) [95% confidence interval (CI) 4·4-8·7)], 1·2% (95% CI 0·5-2·6) and 1·2% (95% CI 0·5-2·6), respectively. All the SNF STEC tested negative for rfbO157, hlyA and eae genes. The risk for transmission of STEC from Black Bengal goats to humans is low.
在孟加拉国开展了一项横断面调查，对小农场饲养的514只黑孟加拉山羊进行采样，以确定是否存在不发酵山梨醇的产志贺毒素大肠杆菌（STEC）。从直肠肛门交界处采集的拭子样本接种在添加了头孢克肟和亚碲酸钾的山梨醇麦康凯（CT-SMAC）琼脂平板上，这是一种用于STEC O157血清型的选择性培养基，该血清型及其他不发酵山梨醇的STEC在其上会产生无色菌落。对调查中获得的不发酵山梨醇大肠杆菌（SNF EC）分离株进行PCR检测，以确定是否存在产志贺毒素基因stx1和stx2，以及另外两个分别编码黏附因子（intimin蛋白）和形成孔道的细胞溶素的毒力基因eae和hlyA。还评估了SNF EC分离株是否存在rfbO157基因，以验证其与O157血清型的一致性。结果显示，携带SNF EC分离株以及stx1和stx2基因的山羊比例分别为6.2%（32/514）[95%置信区间（CI）4.4 - 8.7]、1.2%（95% CI 0.5 - 2.6）和1.2%（95% CI 0.5 - 2.6）。所有检测的不发酵山梨醇的STEC的rfbO157、hlyA和eae基因均为阴性。黑孟加拉山羊将STEC传播给人类的风险较低。
