Faecal carriage of extended‐spectrum β‐lactamase‐producing Enterobacteriaceae among humans in Java,Indonesia, in 2001–2002

Objective To characterise commensal Escherichia coli and other Enterobacteriaceae with reduced susceptibility to cefotaxime that were collected in a large survey carried out among 3995 patients and healthy persons in two urban regions on Java, Indonesia, in 2001–2002. Methods The putative extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae were analysed using double‐disk synergy tests, isoelectric focusing, PCR assays, DNA sequencing, and pulsed‐field gel electrophoresis (PFGE). Results On the day of discharge after five or more days of hospitalisation, at least 95 of 999 (9.5%) patients carried ESBL‐positive Enterobacteriaceae as dominant faecal flora. Six patients were simultaneously colonised with E. coli and Klebsiella pneumoniae isolates with ESBL activity. On admission, only 6 of 998 (0.6%) patients were colonised. Faecal carriage of ESBL‐producing Enterobacteriaceae among healthy persons or persons visiting a public health centre was not detected. The 107 ESBL‐positive strains included 68 E. coli, 35 K. pneumoniae, and four other Enterobacteriaceae. bla_CTX‐M‐15 was the most prevalent ESBL in both E. coli (47.1%) and K. pneumoniae (45.7%), but the E. coli O25b‐ST131 clone was virtually absent. Other ESBL types found were: SHV‐2, ‐2a, ‐5, ‐12, CTX‐M‐3, ‐9, ‐14, and TEM‐19. PFGE revealed extensive genetic diversity among the isolates. Conclusions In 2001–2002, faecal carriage of ESBL‐producing Enterobacteriaceae as dominant flora in Indonesia was almost exclusively hospital‐associated. The presence of various bla_ESBL genes and the extensive genetic diversity among isolates argue against a single/dominant strain outbreak.