The presence of verotoxin-producing Escherichia coli (VTEC) on bovine (n = 330) and pig (n = 120) carcasses in Poland was investigated using the ISO/TS 13136 standard. A total of 115 (34.8%) and 37 (30.8%) cattle and pig samples were positive in real-time PCR, respectively. Isolation of the bacteria revealed that from bovine carcasses 37 (32.2%) VTEC were obtained whereas only 5 (13.5%) pig carcasses were positive for the stx gene. The VTEC were characterized using whole genome sequencing (WGS) and bovine isolates were classified into 25 serotypes with the most prevalent O113:H21 (5 strains) whereas pig strains belonged to 5 different serotypes which were not identified among cattle strains. The majority of bovine VTEC (35; 94.6% isolates) were positive for the stx2 gene, either alone or together with the stx1 gene. All strains isolated from pig carcasses resulted positive for the stx2 gene only. Only two isolates of bovine origin contained the eaeA intimin gene, together with the ehxA and lpfA markers. VTEC were highly molecularly diverse as shown by classification into 29 different MLST STs. The obtained results suggest that further studies related to cattle and pig carcasses are needed to assess the role of these sources for human VTEC infections.

使用ISO / TS 13136标准研究了波兰牛（n = 330）和猪（n = 120）屠体上产生维毒素的大肠杆菌（VTEC）的存在。实时荧光定量PCR分别检测到115份（34.8％）和37份（30.8％）牛和猪样品呈阳性。分离出的细菌表明，从牛car体中获得了37（32.2％）个VTEC，而只有5个（13.5％）猪pig体对stx基因呈阳性。使用全基因组测序（WGS）对VTEC进行了特征分析，并将牛分离株分类为25种O113：H21最流行的血清型（5株），而猪株则属于5种不同的血清型，在牛株中未发现。大部分牛VTEC（35; 94.6％分离株）对stx2呈阳性基因，单独或与stx1基因一起使用。从猪car体中分离出的所有菌株仅对stx2基因呈阳性。只有两个牛源菌株含有EAEA紧密素基因，与一起ehxA和lpfA标记。如分类为29个不同的MLST ST所示，VTEC具有高度的分子多样性。获得的结果表明，需要进行与牛和猪尸体有关的进一步研究，以评估这些来源对人类VTEC感染的作用。