Pollock Jolinda, Foster Geoffrey, Henderson Katrina, Bell Jennifer, Hutchings Michael R, Paterson Gavin K
Microbiology Department, SRUC Veterinary Services, Edinburgh/Inverness, UK.
Animal and Veterinary Sciences, SRUC, Edinburgh, UK.
Epidemiol Infect. 2025 Jan 17;153:e15. doi: 10.1017/S0950268824001754.
are opportunistic pathogens which can cause mastitis in dairy cattle. mastitis often has a poor cure rate and can lead to the development of chronic infection, which has an impact on both health and production. However, there are few studies which aim to fully characterize by whole-genome sequencing from bovine mastitis cases. Here, isolates associated with mastitis in dairy cattle were identified using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and whole-genome sequencing. Furthermore, whole-genome sequence data were used for phylogenetic analyses and both virulence and antimicrobial resistance (AMR) prediction, in parallel with phenotypic AMR testing. Forty-two isolates identified as were subject to whole-genome sequencing, with 31 multi-locus sequence types being observed, suggesting the source of these isolates was likely environmental. Isolates were examined for key virulence determinants encoding acquired siderophores, colibactin, and hypermucoidy. The majority of these were absent, except for (encoding yersiniabactin) which was present in six isolates. Across the dataset, there were notable levels of phenotypic AMR against streptomycin (26.2%) and tetracycline (19%), and intermediate susceptibility to cephalexin (26.2%) and neomycin (21.4%). Of importance was the detection of two ESBL-producing isolates, which demonstrated multi-drug resistance to amoxicillin-clavulanic acid, streptomycin, tetracycline, cefotaxime, cephalexin, and cefquinome.
是机会性病原体，可导致奶牛患乳腺炎。乳腺炎的治愈率往往很低，并可能导致慢性感染的发展，这对健康和生产都会产生影响。然而，很少有研究旨在通过对奶牛乳腺炎病例进行全基因组测序来全面表征。在这里，使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）和全基因组测序鉴定了与奶牛乳腺炎相关的分离株。此外，全基因组序列数据用于系统发育分析以及毒力和抗菌药物耐药性（AMR）预测，并与表型AMR测试并行进行。42株被鉴定为的分离株进行了全基因组测序，观察到31种多位点序列类型，表明这些分离株的来源可能是环境。对分离株检测了编码获得性铁载体、大肠杆菌素和高黏液性的关键毒力决定因素。除了在6株分离株中存在的（编码耶尔森菌素）外，大多数这些因素都不存在。在整个数据集中，对链霉素（26.2%）和四环素（19%）的表型AMR水平显著，对头孢氨苄（26.2%）和新霉素（21.4%）有中度敏感性。重要的是检测到两株产超广谱β-内酰胺酶（ESBL）的分离株，它们对阿莫西林-克拉维酸、链霉素、四环素、头孢噻肟、头孢氨苄和头孢喹肟表现出多重耐药性。
