University of Bristol Vet School, Bristol, UK.
University of Bristol School of Cellular and Molecular Medicine, Bristol, UK.
J Appl Microbiol. 2022 Apr;132(4):2633-2641. doi: 10.1111/jam.15419. Epub 2021 Dec 28.
To investigate whether on-farm antibacterial usage (ABU), environmental antibacterial-resistant (ABR) Escherichia coli prevalence, sampling and sample handling methodologies are associated with ABR E. coli positivity in individual faecal samples from dairy heifers.
Three hundred and sixty-four heifers from 37 farms were sampled via rectal or faecal pat sampling. Samples were stored at -80°C for variable periods before microbiological analysis. Data analysis was done through a multilevel, multivariable logistic regression approach. Individual rectal samples had increased odds of positivity for amoxicillin-, cefalexin- and tetracycline-resistant E. coli. Sample storage for 6-12 months was associated with decreased odds of finding amoxicillin- and tetracycline-resistant E. coli. On-farm ABU had little influence, and environmental ABR E. coli prevalence had no significant influence on the odds of sample-level positivity for ABR E. coli.
Sampling methodology and sample handling have a greater association than on-farm factors with the detection of ABR E. coli in individual faecal samples from dairy heifers.
Sampling and storage methodologies should be considered carefully at the point of designing ABR surveillance studies in livestock and their environments and, where possible, these methodologies should be standardized between and within future studies.
研究农场内抗菌药物使用（ABU）、环境中抗菌耐药（ABR）大肠杆菌流行情况、采样和样本处理方法是否与奶牛犊牛粪便中单个样本的 ABR 大肠杆菌阳性有关。
从 37 个农场中采集了 364 头奶牛的直肠或粪便样本。样本在 -80°C 下储存不同时间，然后进行微生物分析。数据分析采用多层次、多变量逻辑回归方法进行。直肠样本中阿莫西林、头孢氨苄和四环素耐药大肠杆菌阳性的可能性增加。样本储存 6-12 个月与发现阿莫西林和四环素耐药大肠杆菌的可能性降低有关。农场内 ABU 的影响较小，环境中 ABR 大肠杆菌的流行情况对单个粪便样本中 ABR 大肠杆菌阳性的可能性没有显著影响。
采样方法和样本处理与农场因素相比，与奶牛犊牛粪便中 ABR 大肠杆菌的检测更相关。
在设计家畜及其环境中的 ABR 监测研究时，应仔细考虑采样和储存方法，如有可能，应在未来的研究中在不同研究之间和内部标准化这些方法。
