Open AccessClonal spread of <i>Escherichia coli</i> O101:H9-ST10 and O101:H9-ST167 strains carrying <i>fosA3</i> and <i>bla</i><sub>CTX-M-14</sub> among diarrheal calves in a Chinese farm, with Australian <i>Chroicocephalus</i> as the possible origin of <i>E. coli</i> O101:H9-ST10
Author(s) -
Wan-Yun He,
Xingxing Zhang,
Guolong Gao,
Ming-Yi Gao,
Fagang Zhong,
Luchao Lv,
Zhongpeng Cai,
Xingfeng Si,
Jun Yang,
Jianhua Liu
Publication year - 2021
Publication title -
zoological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 19
ISSN - 2095-8137
DOI - 10.24272/j.issn.2095-8137.2021.153
Subject(s) - biology , fosfomycin , escherichia coli , plasmid , microbiology and biotechnology , pulsed field gel electrophoresis , genetics , genotype , gene , antimicrobial
During a 2018 antimicrobial resistance surveillance of Escherichia coli isolates from diarrheal calves in Xinjiang Province, China, an unexpectedly high prevalence (48.5%) of fosfomycin resistance was observed. This study aimed to reveal the determinants of fosfomycin resistance and the underlying transmission mechanism. Polymerase chain reaction (PCR) screening showed that all fosfomycin-resistant E. coli carried the fosA3 gene. Pulsed-field gel electrophoresis (PFGE) and southern blot hybridization revealed that the 16 fosA3 -positive isolates belonged to four different PFGE patterns (i.e., A, B, C, D). The fosA3 genes of 11 clonally related strains (pattern D) were located on the chromosome, while others were carried by plasmids. Whole-genome and long-read sequencing indicated that the pattern D strains were E. coli O101: H9-ST10, and the pattern C, B, and A strains were O101: H9-ST167, O8: H30-ST1431, and O101: H9 with unknown ST, respectively. Among the pattern C strains, the bla CTX-M-14 gene was co-localized with the fosA3 gene on the F18: A-: B1 plasmids. Interestingly, phylogenetic analysis based on core genome single nucleotide polymorphisms (cgSNPs) showed that the O101: H9-ST10 strains were closely related to a Australian-isolated Chroicocephalus -origin E. coli O101: H9-ST10 strain producing CTX-M-14 and FosA3, with a difference of only 11 SNPs. These results indicate possible international dissemination of the high-risk E. coli clone O101: H9-ST10 by migratory birds.