Mahanti A, Samanta I, Bandyopadhyay S, Joardar S N
Ph.D. Scholar, Department of Veterinary Microbiology, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, 37, K. B. Sarani, Kolkata-700037, West Bengal, India;
Department of Veterinary Microbiology, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, 37, K. B. Sarani, Kolkata-700037, West Bengal, India;
Iran J Vet Res. 2015 Winter;16(1):31-5.
The present study was conducted to detect the occurrence, serotype, genotype, phylogenetic relationship and antimicrobial resistance pattern of STEC from healthy goats of West Bengal, India. From the 125 faecal samples collected from healthy goats, 245 isolates were identified as Escherichia coli. The E. coli harbouring any gene for Shiga toxins (stx 1/stx 2) was detected in 36 (14.7%) of the 245 E. coli isolates. These STEC strains belonged to 22 different serogroups (O2, O5, O20, O21, O22, O25, O41, O44, O45, O60, O71, O76, O84, O85, O87, O91, O103, O112, O113, O120, O156, and O158) and three were untypeable. The stx 1 and stx 2 was detected in 26 (72.2%) and 21 (58.3%) of Shiga toxin producing-E. coli (STEC) isolates, respectively. Further, E. coli harbouring eaeA only (Enteropathogenic E. coli) and ehxA was detected in 22 (61.1%) and 28 (77.7%) isolates, respectively. Whereas the saa was present in 8 (22.2%) E. coli isolates. The subtyping of the 26 E. coli strains possessing stx 1 showed that 73.% (19/26) of these isolates were positive for stx 1C subtype. Of the 21 isolates with the stx 2 gene, 42.8% (9/21) were positive for stx 2C, and 38.1% (8/21) were positive for stx 2d gene. The phylogenetic analysis of STEC strains after RAPD reveals eight major clusters. However, no serogroup specific cluster was observed. Resistance was observed most frequently to erythromycin (80.5%), amikacin (52.7%), cephalothin (50%), kanamycin (41.6%), neomycin (36.1%) and gentamycin (36.1%) and less frequently to norfloxacin (2.7%), enrofloxacin (2.7%), and ciprofloxacin (2.7%). Multidrug resistance was observed in eleven STEC isolates.
本研究旨在检测印度西孟加拉邦健康山羊中肠出血性大肠杆菌（STEC）的发生情况、血清型、基因型、系统发育关系及抗菌药物耐药模式。从健康山羊采集的125份粪便样本中，鉴定出245株大肠杆菌。在245株大肠杆菌分离株中，36株（14.7%）检测到携带任何志贺毒素基因（stx1/stx2）的大肠杆菌。这些STEC菌株属于22个不同血清群（O2、O5、O20、O21、O22、O25、O41、O44、O45、O60、O71、O76、O84、O85、O87、O91、O103、O112、O113、O120、O156和O158），3株无法分型血清型。在产志贺毒素大肠杆菌（STEC）分离株中，分别有26株（72.2%）和21株（58.3%）检测到stx1和stx2。此外，仅携带eaeA基因的大肠杆菌（肠致病性大肠杆菌）和ehxA分别在22株（61.1%）和28株（77.7%）分离株中检测到。而saa在8株（22.2%）大肠杆菌分离株中存在。对26株携带stx1的大肠杆菌菌株进行亚型分析表明，这些分离株中有73%（19/26）的stx1C亚型呈阳性。在21株携带stx2基因的分离株中，42.8%（9/21）的stx2C呈阳性，38.1%（8/21）的stx2d基因呈阳性。RAPD分析后STEC菌株的系统发育分析显示有八个主要聚类。然而，未观察到血清群特异性聚类。观察到对红霉素（80.5%）、阿米卡星（52.7%）、头孢噻吩（50%）、卡那霉素（41.6%）、新霉素（36.1%）和庆大霉素（36.1%）的耐药最为常见，对诺氟沙星（2.7%）、恩诺沙星（2.7%）和环丙沙星（2.7%）的耐药较少见。在11株STEC分离株中观察到多重耐药。
