Cefotaxime-resistant E. coli in pigs during slaughter

This cross-sectional study investigates the abundance of cefotaxime-resistant Escherichia coli (CREC) in the faeces and tonsils of 96 pigs during slaughter. Moreover, different isolates from a selected number of pigs were tested to study the diversity of blaESBL genes within E. coli isolates from one pig. Cefotaxime-resistant bacteria (CRB; based on enumeration results on MacConkey agar supplemented with 1 mg/L cefotaxime) were found in the faeces of 77 pigs (80%; 95% CI: 70 to 87%) and the tonsils of 91 pigs (95%; 95% CI: 88% to 98%). Cefotaxime-resistant E. coli (CREC; based on enumeration results on Tryptone Bile X-glucuronide agar supplemented with 1 mg/L cefotaxime) were detected in 72 faecal samples (75%; 95% CI: 64 to 83%) and 45 tonsil samples (47%; 95% CI: 35 to 59%), in numbers up to 5.5 and 5.6 log10 CFU/g, respectively. Within one sample, CREC isolates with up to five different combinations of ESBL genes were observed. In three out of 16 faecal samples and six out of 14 tonsil samples, only one ESBL gene profile was found.

本横断面研究旨在调查屠宰阶段96头猪粪便与扁桃体中头孢噻肟耐药大肠埃希菌（cefotaxime-resistant Escherichia coli, CREC）的携带丰度。此外，本研究还对筛选出的部分猪的不同分离株进行检测，以探究单头猪源大肠埃希菌分离株中blaESBL基因的多样性。基于添加1mg/L头孢噻肟的麦康凯琼脂（MacConkey agar）计数结果，77头猪粪便中检出头孢噻肟耐药菌（cefotaxime-resistant bacteria, CRB），检出率为80%（95%置信区间：70%~87%）；91头猪扁桃体中检出该类细菌，检出率为95%（95%置信区间：88%~98%）。基于添加1mg/L头孢噻肟的胰蛋白胨胆盐X-葡萄糖醛酸琼脂（Tryptone Bile X-glucuronide agar）计数结果，72份粪便样本（75%；95%置信区间：64%~83%）与45份扁桃体样本（47%；95%置信区间：35%~59%）中检出头孢噻肟耐药大肠埃希菌，其最高载量分别可达5.5 lg₁₀ CFU/g与5.6 lg₁₀ CFU/g。单一样本中可检出最多携带5种不同超广谱β-内酰胺酶（ESBL）基因组合的CREC分离株。16份粪便样本中有3份、14份扁桃体样本中有6份仅检出1种超广谱β-内酰胺酶基因谱。