University of Zurich, Vetsuisse Faculty, for Equine Internal Medicine, Winterthurerstrasse 260, 8057, Zurich, Zurich, Switzerland.
University of Copenhagen, Department of Veterinary and Animal Sciences, Stigbøjlen 4, 1870, Frederiksberg C, Denmark.
Vet Microbiol. 2020 Apr;243:108617. doi: 10.1016/j.vetmic.2020.108617. Epub 2020 Feb 26.
Fourth-generation cephalosporins can select for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in horses, but it is unknown to what extent this occurs compared to penicillin/gentamicin combination treatment. The objective was to evaluate the effect of different antimicrobial treatments on faecal shedding and diversity of ESBL-producing Escherichia coli (ESBL-EC) in horses. Upon hospital admission, 86 horses in need of antimicrobial treatment or prophylaxis were randomly allocated to receive penicillin and gentamicin (PG) or cefquinome (CEF). Untreated horses were included as controls (NOAMD, n = 33). Faecal samples from admission (T1), 3 days after admission (T2), and faecal swabs 28 days after discharge (T3) were cultured selectively. Differences in prevalence (T1, T2, T3) and counts (T1, T2) of ESBL-EC between groups and over time were analysed. On a subset of ESBL-EC isolates, antimicrobial susceptibility testing (n = 45) and whole-genome sequencing followed by SNP-analysis (n = 46) were performed. The prevalence of ESBL-EC at T1 was 12 % with no significant difference between groups. In all groups, significantly higher carriage rates were observed at T2 and T3 compared to T1. Carriage and counts of ESBL-EC at T2 were significantly higher in treated compared to untreated horses. There was no significant difference between PG and CEF at any time points. Despite a large genetic diversity, indistinguishable ESBL clones were observed in different horses over time. In conclusion, antimicrobial treatment and hospitalization increased prevalence and counts of ESBL-EC, and transmission of ESBL-EC in the hospital was suspected. These findings highlight the importance of antimicrobial stewardship and infection control practices in equine medicine.
四代头孢菌素可在马中选择产生超广谱β-内酰胺酶（ESBL）的肠杆菌科细菌，但与青霉素/庆大霉素联合治疗相比，其发生的程度尚不清楚。本研究旨在评估不同抗菌治疗方案对马肠道 ESBL 大肠杆菌（ESBL-EC）定植和多样性的影响。入院时，86 匹需要抗菌治疗或预防的马被随机分为青霉素和庆大霉素（PG）或头孢喹肟（CEF）治疗组。未治疗的马作为对照组（NOAMD，n=33）。入院时（T1）、入院后第 3 天（T2）和出院后第 28 天（T3）采集粪便样本进行选择性培养。分析组间和时间点上 ESBL-EC 的流行率（T1、T2、T3）和数量（T1、T2）差异。对部分 ESBL-EC 分离株进行药敏试验（n=45）和全基因组测序及 SNP 分析（n=46）。T1 时 ESBL-EC 的流行率为 12%，组间无显著差异。所有组在 T2 和 T3 时的定植率均显著高于 T1。与未治疗组相比，治疗组 T2 和 T3 时 ESBL-EC 的定植率和数量均显著升高。PG 和 CEF 组在任何时间点均无显著差异。尽管遗传多样性较大，但不同时间点不同马之间仍存在无法区分的 ESBL 克隆。总之，抗菌治疗和住院治疗增加了 ESBL-EC 的流行率和数量，并且怀疑 ESBL-EC 在医院内传播。这些发现强调了马医学中抗菌药物管理和感染控制实践的重要性。
