Multidrug-Resistant Extraintestinal Pathogenic Escherichia coli Exhibits High Virulence in Calf Herds: A Case Report

作者：Didi Zhu, Xinrui Li, Tengfei Ma, Jiaqi Chen, Changsheng Ge, Shao-Hua Yang, Wei Zhang, Jiu Chen, Jiajia Zhang, Miaomiao Qi, Liang Zhang, Hongjun Yang · 发表于：Microbiology Research · 年份：2025 · DOI：10.3390/microbiolres16030059 · 被引用次数：4 · 研究领域：Clostridium difficile and Clostridium perfringens research、Escherichia coli research studies、Mycobacterium research and diagnosis

Extraintestinal pathogenic Escherichia coli (ExPEC) is a group of Escherichia coli strains that can cause severe infectious diseases outside the gastrointestinal tract, such as urinary tract infections, meningitis, septicemia, etc. We report a case of a calf herd infection by ExPEC with high rates of morbidity and mortality. The research purpose of this study was to thoroughly investigate the characteristics of the ExPEC responsible for the calf herd infection. Specifically, we aimed to understand the mechanisms underlying its multidrug resistance and high pathogenicity. Clinical samples were collected for the isolation and identification of ExPECs, cultured on MacConkey agar, and further tested by PCR for the uidA gene, 16S rRNA gene sequencing, and adhesion patterns on HEp-2 cells. The antimicrobial activity was determined using the disk diffusion method according to Clinical & Laboratory Standards Institute (CLSI) guidelines. The pathogenicity was assessed through the experimental infection of Kunming mice, tracking their survival and weight changes, and performing autopsies for bacterial counts and histopathological analysis. Additionally, whole-genome sequencing (WGS) and a comprehensive analysis were performed, including multilocus sequence typing (MLST), serotyping, drug-resistance gene analysis, virulence factor analysis, metabolic pathway analysis, and enrichment analysis, using various online tools and databases. An ExPEC strain named RZ-13 was responsible for t...