Extensive dissemination of CTX-M-producing Escherichia coli with multidrug resistance to 'critically important' antibiotics among food animals in Hong Kong, 2008-10

Abstract

This study shows that food animals are a major reservoir of E. coli with multidrug resistance to many antibiotics that are ranked as critically important in human medicine.

Molecular Characterization of ESBL-Producing Escherichia Coli Isolated from Healthy Cattle and Sheep

“…A number of investigations have been conducted in various parts of the world to investigate the presence and types of ESBL in cattle [8][9][10][11][12][31][32][33], but research on ESBL in sheep is limited [8,11,33]. In Turkey, only one study has been conducted so far in which both the presence and types of ESBLs in cattle and sheep were investigated, and this was in the northwest of Turkey [15].…”

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

“…It should be pointed out that live poultry are sold in wet markets in 16 of the 18 districts. Our previous work found that ESBL-producing E. coli was carried by eight out of ten live poultry (Ho et al, 2011a). It is possible that better access of some rodents to faecal materials of food animals might have contributed to the variation in resistance rates.…”

“…Previous studies assessed changes in human population density over ranges of ,1 km 22 , ,50 km 22 and 200 km 22 (Skurnik et al, 2006), while the 18 districts in the present study had densities from 800-55200 km 22 . Besides sewage, variations in resistance rates may be explained by other possibilities such as better access of some rats to farms, wet markets, grocery stores, hospitals, human food sources and garbage disposal areas (Guenther et al, 2013;Ho et al, 2011a;Kola et al, 2012). In Hong Kong, farms producing food animals (poultry and pigs) are almost exclusively located in the Yuen Long district (Fig.…”

“…Given that E. coli is carried by humans and a wide range of animals as part of the commensal gut flora, this organism is often chosen as an indicator organism for detection of antimicrobial resistance (Lo et al, 2010). While companion and foodproducing animals have been extensively studied as potential sources of ESBL strains and resistance (bla CTX-M ) genes (Ho et al, 2012a;Woerther et al, 2013), the potential for pests, in particular urban rodents, to act as a reservoir of this emerging resistance mechanism has received little attention (Guenther et al, 2012(Guenther et al, , 2013Ho et al, 2011a). Urban rodents, especially the brown rat (Rattus norvegicus) and black rat (Rattus rattus), may carry zoonotic pathogens that can be transmitted to humans through animal contact, contamination of food items or the environment (Himsworth et al, 2013).…”

“…Individual faecal materials (~0.1 g) were collected with sterile swabs (TRANSWAB; Medical Wire and Equipment), transported in Amies media and seeded onto three MacConkey agar plates (one plain and two supplemented with 2 mg cefotaxime l 21 or 2 mg ceftazidime l 21 , Sigma). For each agar plate, at least one and up to five colonies were investigated (Ho et al, 2011a(Ho et al, , 2013. Bacteria were identified as E. coli by Vitek GNI system (bioMérieux).…”