Dissemination of Extended-Spectrumβ-Lactamase-Producing Enterobacteriaceae in Intensive Care Units of a Medical Center in Taiwan

Abstract

The prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in a tertiary hospital in Taiwan was assessed over a 16-month period. A total of 125 nonrepetitive ESBL-producing isolates of Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae were available for investigation using molecular methods. Four predominant intensive care units (ICUs) were identified, and SHV-12 (59%), CTX-M- 3 (36%), and CTX-M-14 (14%) were the three most frequent ESBLs. SHV-12 was predominant among E. cloacae in the burn unit and K. pneumoniae in the other three chest medicine-related ICUs. CTX-M-3 was predominant among E. coli and K. pneumoniae in three other ICUs. The dissemination of ESBL-producing Enterobacteriaceae in four ICUs of a medical center in Taiwan is a consequence of the clonal dissemination of a few epidemic strains along with the horizontal transmission of resistance genes-carrying plasmids among bacterial organisms.

Large IncHI2-plasmids encode extended-spectrum β-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates, and support ESBL-transfer to Escherichia coli

“…has been considered by some to be of limited clinical value, because cephalosporins are seen as inappropriate treatment of infections caused by these species. In contradiction to this, several studies have reported outbreaks of ESBL-producing Enterobacter species in health-care facilities [2,[5][6][7]. It is plausible that Enterobacter spp.…”

“…isolates has been comparable to, or higher than, among Escherichia coli and Klebsiella spp. [1,2]. As in E. coli and Klebsiella spp., CTX-M and SHV-type b-lactamases have been the predominant ESBLs in Enterobacter spp.…”

“…As in E. coli and Klebsiella spp., CTX-M and SHV-type b-lactamases have been the predominant ESBLs in Enterobacter spp. [1][2][3][4].…”

Characterization of IS26‐composite transposons and multidrug resistance in conjugative plasmids from Enterobacter cloacae

“…The emergence of multidrug resistance Enterobacter cloacae strains has become a global concern . SHV‐type, CTX‐M‐type ESBLs and/or chromosomally encoded AmpC β‐lactamases are widely distributed among E. cloacae , where they confer resistance to broad‐spectrum β‐lactam‐containing antibiotics . As with most antibiotic resistance genes that are carried by plasmids and transposons and result in high clonal dissemination, extended‐spectrum β‐lactamase genes are located on large conjugative plasmids, thus facilitating intra‐ and inter‐species spread .…”

“…In previous studies, SHV‐12 has been the most frequently identified ESBL in several enterobacterial species, including E. cloacae, recovered from hospitalized patients in Taiwan . Genetic mechanisms involved in the acquisition of bla SHV have been described and IS 26 ‐mediated mobilization of bla SHV ‐containing fragments of Klebsiella chromosome has been frequently observed .…”