Clonal diversity of CTX-M-producing, multidrug-resistant Escherichia coli from rodents

Abstract

This territory-wide study investigated the occurrence of faecal carriage of extended-spectrum blactamase (ESBL)-producing Escherichia coli among wild rodents from the 18 districts in Hong Kong. Individual rectal swabs were obtained from the trapped animals and cultured in plain and selective media. A total of 965 wild rodents [148 chestnut spiny rats (Niviventer fulvescens), 326 Indo-Chinese forest rats (Rattus andamanensis), 452 brown rats (Rattus norvegicus) and 39 black rats (Rattus rattus)] were sampled. ESBL carriage was 0 % in chestnut spiny rats, 0.6 % in Indo-Chinese forest rats, 7.7 % in black rats and 13.9 % in brown rats. Among brown rats, the prevalence of ESBL carriage differed markedly by geographical location: absent in two districts, low (7-10 %) in six districts, moderate (11-19 %) in seven districts and high (21-50 %) in three districts. Nonetheless, there was no correlation between the prevalence of ESBL in brown rats and human population density in the 18 districts. CTX-M-type enzymes were detected in 92.0 % of the ESBL-producing isolates, of which 83.1 % were resistant to three or more non-b-lactam drugs. The CTX-M producing isolates were genetically diverse but a large proportion (47.8 %) were included in six successful clones that are strongly associated with human diseases and CTX-M dissemination, viz. sequence type complex [STC]10/phylogroup A, STC23/phylogroup B1, STC38/phylogroup D, STC155/phylogroup B1, ST405/phylogroup D and ST131/ phylogroup B2. In conclusion, our results show that brown rats often carry potentially zoonotic clones of CTX-M producing, multidrug-resistant E. coli. The potential for rats to be a source of CTX-M producing E. coli for humans deserves further consideration.

Occurrence and Antimicrobial Resistance Traits of Escherichia coli from Wild Birds and Rodents in Singapore

“…Once wild birds and rodents acquire antimicrobial resistant bacteria, these bacteria could continue to colonise and infect the hosts [ 64 ]. Therefore, wild birds and rodents could play a role for the dissemination of antimicrobial resistant bacteria and/or genes across different wildlife species and environmental sectors, perhaps via their faecal materials, as supported by other E. coli studies on wild birds and rodents [ 10 , 16 , 21 , 40 , 65 ]. An increasing number of cities today are undergoing urban rewilding, which transforms dense urban areas into green cities with nature assimilated.…”

“…However, to our knowledge, there is limited information on AMR in the environment such as in wild birds and rodents in Singapore. Wild birds and rodents, due to their potential interactions with humans and mobility [ 9 ], are potential reservoirs and vectors for transmission of antimicrobial resistant bacteria to humans, through pathways such as contact of faecal materials and contamination of food items [ 4 , 9 , 10 ]. This study aimed to investigate the occurrence and AMR of E. coli from wild birds and rodents in Singapore.…”

A metagenomic glimpse into the gut of wild and domestic animals: Quantification of antimicrobial resistance and more

“…AMR found in rodents from urban areas or from regions with high livestock density seems to be more abundant [73,74]. Studies on E. coli derived from rats from Hong Kong revealed high rate of ESBL producers in the rodents living in underground sewers [75]. Recent metagenomic analysis of urban sewage proved the broad diversity of AMR genes in that material [6].…”

Antimicrobial resistance and gene regulation in Enteroaggregative Escherichia coli from Egyptian children with diarrhoea: Similarities and differences

“…Note that the extended spectrum βlactamases (ESBL) type CTX-M and TEM found in both strains are often associated with EAEC isolates and the sequence types to which each strain belongs (i.e. ST38 and ST1380) [31][32][33]68].…”