High rate of multidrug-resistant Enterobacteriaceae carrying ESBL and plasmid-borne AmpC ß-lactamase in a Malaysian community

Abstract

Background: Even though Southeast Asia is generally regarded as the hotspot for antibiotic resistance, there have been limited studies investigating the prevalence of antibiotic resistance among healthy people in the region. We aimed to investigate the prevalence of two ß-lactamase genes, ESBL and plasmid-borne AmpC (pAmpC) among Enterobacteriaceae in a healthy community in Malaysia.

Methods and materials: We collected stool samples and screened for ESBL and pAmpC-producing Enterobacteriaceae using phenotypic and genotypic methods. The susceptibility profile of the isolates towards 13 different antibiotics was observed. Plasmid replicon group, E. coli phylogenetic group and MLST analyses were also conducted to observe the spread pattern of these resistance genes. Risk factors associated with the carriage of ESBL or pAmpC-producing Enterobacteriaceae were then analysed.

Results: ESBL and pAmpC production was observed in 21.6% (95% CI 13.9–28.8%) and 32.1% (95% CI 24.5–38.9%) of the participants, respectively. A high proportion of the isolates (99.9%, 95% CI 98.6–99.9%) were multidrug-resistant regardless of the resistance genes carried. Although E. coli B2:ST131 was detected, there was no dominance of a specific clonal strain. Possession of multiple plasmid groups was common, with incFIB being the most frequently detected type. Mixed effect logistic regression analysis found that ESBL production was associated with having allergy (p = 0.01, OR 3.86, 95% CI 1.32–11.23) and consumption of chicken meat (p = 0.02, OR = 8.66, 95% CI = 1.40–53.29), while consumption of fermented food significantly lowers the risk of colonisation with pAmpC producing Enterobacteriaceae (p = 0.02, OR 0.23, 95% CI = 0.06–0.79).

Conclusion: The high prevalence of ß-lactamase and multidrug resistance suggests that antibiotic resistance is endemic among healthy people in Malaysia.