To Örebro University

OBJECTIVES: This study investigates the frequency and characteristics of carbapenemase-producing Escherichia coli/Klebsiella pneumoniae (CPE/K) and extended-spectrum cephalosporinase-producing E. coli/K. pneumoniae (ESCE/K) in healthy humans and livestock in rural Cambodia. Additionally, household practices as risk factors for faecal carriage of ESCE/K are identified.

METHODS: Faecal samples were obtained from 307 humans and 285 livestock including large ruminants, pigs and poultry living in 100 households in rural Cambodia in 2011. Each household was interviewed, and multilevel logistic model determined associations between household practices/meat consumption and faecal carriage of ESCE/K. CPE and ESCE/K were detected and further screened for colistin resistance genes.

RESULTS: CPE/K isolates harbouring bla_OXA-48 were identified in two humans. The community carriage of ESCE/K was 20% in humans and 23% in livestock. The same ESBL genes: bla_CTX-M-15 , bla_CTX-M-14 , bla_CTX-M-27 , bla_CTX-M-55 , bla_SHV-2 , bla_SHV-12 , bla_SHV-28 ; AmpC genes: bla_CMY-2 , bla_CMY-42, bla_DHA-1 ; and colistin resistance genes: mcr-1-like and mcr-3-like were detected in humans and livestock. ESCE/K was frequently detected in women, young children, pigs and poultry, which are groups in close contact. The practice of burning or burying meat waste and not collecting animal manure indoors and outdoors daily were identified as risk factors for faecal carriage of ESCE/K.

CONCLUSIONS: Faecal carriage of E. coli and K. pneumoniae harbouring extended-spectrum cephalosporinase genes are common in the Cambodian community, especially in women and young children. Exposure to animal manure and slaughter products are risk factors for intestinal colonization of ESCE/K in humans.