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Abstract：
Despite extensive characterisation of uropathogenic Escherichia coli (UPEC) causing urinary tract infections (UTIs), the genetic background of non-urinary extraintestinal pathogenic E. coli (ExPEC) in companion animals remains inadequately understood. In this study, we characterised virulence traits of 104 E. coli isolated from canine pyometra (n = 61) and prostatic abscesses (PAs) (n = 38), and bloodstream infections (BSIs) in dogs (n = 2), and cats (n = 3). A stronger association with UPEC of pyometra strains in comparison to PA strains was revealed. Notably, 44 isolates exhibited resistance to third-generation cephalosporins and/or fluoroquinolones, 15 were extended-spectrum ß-lactamase-producers. Twelve multidrug-resistant (MDR) strains, isolated from pyometra (n = 4), PAs (n = 5), and BSIs (n = 3), along with 7 previously characterised UPEC strains from dogs and cats, were sequenced. Genomic characteristics revealed that MDR E. coli associated with UTIs, pyometra, and BSIs belonged to international high-risk E. coli clones, including sequence type (ST) 38, ST131, ST617, ST648, and ST1193. However, PA strains belonged to distinct lineages, including ST12, ST44, ST457, ST744, and ST13037. The coreSNPs, cgMLST, and pan-genome illustrated intra-clonal variations within the same ST from different sources. The high-risk ST131 and ST1193 (phylogroup B2) contained high numbers of ExPEC virulence genes on pathogenicity islands, predominating in pyometra and UTI. Hybrid MDR/virulence IncF multi-replicon plasmids, containing aerobactin genes, were commonly found in non-B2 phylogroups from all sources. These findings offer genomic insights into non-urinary ExPEC, highlighting its potential for invasive infections in pets beyond UTIs, particularly with regards to high-risk global clones.
摘要：
尽管尿路致病性大肠杆菌（UPEC）引起尿路感染（UTI）的广泛特征，伴侣动物中的非泌尿肠外致病性大肠杆菌（ExPEC）的遗传背景仍未得到充分理解。在这项研究中,我们表征了104个从犬子宫积脓（n=61）和前列腺脓肿（PAs）（n=38）分离的大肠杆菌的毒力性状，和狗的血液感染（BSI）（n=2），和猫（n=3）。与PA菌株相比，与子宫积脓菌株的UPEC具有更强的相关性。值得注意的是,44株对第三代头孢菌素和/或氟喹诺酮类药物表现出耐药性，15个是广谱β-内酰胺酶生产者。12株多重耐药（MDR）菌株，从积脓中分离（n=4），PAs（n=5），和BSI（n=3），以及7种先前表征的来自狗和猫的UPEC菌株，被测序。基因组特征显示，MDR大肠杆菌与UTI相关，子宫积脓,BSIs属于国际高风险大肠杆菌克隆，包括序列类型(ST)38、ST131、ST617、ST648和ST1193。然而,PA菌株属于不同的谱系，包括ST12、ST44、ST457、ST744和ST13037。核心SNP，cgMLST,泛基因组显示了来自不同来源的同一ST内的克隆内变异。高风险的ST131和ST1193（系统群B2）在致病性岛上含有大量的ExPEC毒力基因，在子宫积脓和UTI中占主导地位。杂交MDR/毒力IncF多复制子质粒，含有aerobactin基因，常见于所有来源的非B2系统组中。这些发现提供了对非尿液ExPEC的基因组见解，强调其在UTI以外的宠物中侵入性感染的潜力，特别是关于高风险的全球克隆。
