School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia.
Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, Australia.
Vet Microbiol. 2020 Jun;245:108685. doi: 10.1016/j.vetmic.2020.108685. Epub 2020 Apr 18.
Extraintestinal pathogenic Escherichia coli (ExPEC) can cause urinary tract and other types of infection in cats, but the relationship of cat ExPEC to human ExPEC remains equivocal. This study investigated the prevalence of ExPEC-associated sequence types (STs) from phylogenetic group B2 among fluoroquinolone-susceptible cat clinical isolates. For this, 323 fluoroquinolone-susceptible cat clinical E. coli isolates from Australia underwent PCR-based phylotyping and random amplified polymorphic DNA analysis to determine clonal relatedness. Of the 274 group B2 isolates, 53 underwent whole genome sequencing (WGS), whereas 221 underwent PCR-based screening for (group B2) sequence type complexes (STc) STc12, STc73, ST131, and STc372. Group B2 was the dominant phylogenetic group (274/323, 85 %), whereas within group B2 ST73 dominated, according to both WGS (43 % of 53; followed by ST127, ST12, and ST372 [4/53, 8 % each]) and ST-specific PCR (20 % of 221). In WGS-based comparisons of cat and reference human ST73 isolates, cat isolates had a relatively conserved virulence gene profile but were phylogenetically diverse. Although in the phylogram most cat and human ST73 isolates occupied host species-specific clusters within serotype-specific clades (O2:H1, O6:H1, O25:H1, O50/O2:H1), cat and human isolates were intermingled within two serotype-specific clades: O120:H31 (3 cat and 2 human isolates) and O22:H1 (3 cat and 5 human isolates). These findings confirm the importance of human-associated group B2 lineages as a cause of urinary tract infections in cats. The close genetic relationship of some cat and human ST73 strains suggests bi-directional transmission may be possible.
肠外致病性大肠杆菌（ExPEC）可引起猫的尿路感染和其他类型的感染，但猫 ExPEC 与人类 ExPEC 的关系仍存在争议。本研究调查了来自澳大利亚的对氟喹诺酮敏感的猫临床分离株中，与肠外致病性大肠杆菌相关的序列类型（ST）在进化群 B2 中的流行情况。为此，对 323 株对氟喹诺酮敏感的猫临床大肠杆菌分离株进行了基于 PCR 的系统发育分型和随机扩增的多态性 DNA 分析，以确定克隆相关性。在 274 株 B2 组分离株中，有 53 株进行了全基因组测序（WGS），而 221 株进行了基于 PCR 的筛选，以检测（B2 组）序列型复合物（STc）STc12、STc73、ST131 和 STc372。B2 组是优势进化群（274/323，85%），而在 B2 组中，根据 WGS（53 株的 43%；其次是 ST127、ST12 和 ST372[53 株的 4/53，各 8%]）和 ST 特异性 PCR（221 株的 20%），ST73 占主导地位。在基于 WGS 的猫和参考人类 ST73 分离株的比较中，猫分离株具有相对保守的毒力基因谱，但在系统发育上具有多样性。尽管在系统发育树中，大多数猫和人类 ST73 分离株在血清型特异性分支内占据宿主种特异性聚类，但在两个血清型特异性分支内，猫和人类分离株相互混合：O120:H31（3 株猫和 2 株人类分离株）和 O22:H1（3 株猫和 5 株人类分离株）。这些发现证实了人类相关的 B2 谱系作为猫尿路感染的病因的重要性。一些猫和人类 ST73 菌株的密切遗传关系表明，双向传播可能是可能的。
