Multiple and high-risk clones of extended-spectrum cephalosporin-resistant and blandm-5-harbouring uropathogenic escherichia coli from cats and dogs in thailand

Abstract

Resistance to extended-spectrum cephalosporins (ESC) and carbapenems in Escherichia coli (E. coli), increasingly identified in small animals, indicates a crisis of an antimicrobial resistance situation in veterinary medicine and public health. This study aimed to characterise the genetic features of ESC-resistant E. coli isolated from cats and dogs with urinary tract infections in Thailand. Of 72 ESC-resistant E. coli isolated from diagnostic samples (2016–2018), blaCTX-M including group 1 (CTX-M-55,-15 and-173) and group 9 (CTX-M-14,-27,-65 and-90) variants were detected in 47 isolates (65.28%) using PCR and DNA sequencing. Additional antimicrobial resistance genes, including plasmid-mediated AmpC (CIT and DHA), blaNDM-5, mcr-3, mph(A) and aac(6′ )-Ib-cr, were detected in these isolates. Using a broth microdilution assay, all the strains exhibited multidrug-resistant phenotypes. The phylogroups were F (36.11%), A (20.83%), B1 (19.44%), B2 (19.44%) and D (4.17%), with several virulence genes, plasmid replicons and an integrase gene. The DNA fingerprinting using a repetitive extragenic palindromic sequence-PCR presented clonal relationships within phylogroups. Multiple human-associated, high-risk ExPEC clones associated with multidrug resistance, including sequence type (ST) 38, ST131, ST224, ST167, ST354, ST410, ST617 and ST648, were identified, suggesting clonal dissemination. Dogs and cats are a potential reservoir of ESC-resistant E. coli and significant antimicrobial resistance genes.