A Snapshot of Co-Resistance to Carbapenems and Tigecycline in Clinical Isolates of Enterobacter cloacae

作者：Huang Ling Fu; Lee Chao Tai; Su Lin Hui; Chang Chin Lu

来源：Microbial Drug Resistance, 2017, 23(1): 1-7.

DOI：10.1089/mdr.2015.0311

• Enterobacter cloacae
• carbapenem resistance
• tigecycline resistance
• IMP-8
• efflux
• international clones

Enterobacter cloacae is one of the most common carbapenem-resistant Enterobacteriaceae (CRE) global wide. Resistance to tigecycline, one of the few therapeutic options for CRE infections, in carbapenem-resistant E. cloacae is of clinical significance. Fourteen E. cloacae clinical isolates (EC1-EC14) co-resistant to tigecycline and carbapenems were studied. Two tigecycline-susceptible/carbapenem-resistant isolates (TS1-TS2) were used for comparison. Genotyping by pulsed-field gel electrophoresis and multilocus sequence typing identified seven pulsotypes and three sequence types (STs). All three STs belonged to the published international clones. Polymerase chain reaction (PCR) and sequence analysis revealed the coexistence of bla(SHV-12) and bla(IMP-8) in 11 EC isolates from five pulsotypes/two STs. Reverse transcription PCR demonstrated overexpression of the chromosomal AmpC-like beta-lactamase in seven EC isolates (four pulsotypes/two STs) and TS1 (pulsotype F/ST78). Reduced expression of outer membrane protein C (OmpC) was found in three EC isolates (all pulsotype C/ST204), whereas reduced expression of OmpF was found in nine EC isolates (three pulsotypes/two STs) and TS2 (pulsotype G/ST114). Overexpression of the efflux pump AcrB was found in all EC isolates although three showed borderline significance. Multiple mechanisms jointly contributed to the observed co-resistance to tigecycline and carbapenems. Some international clones have infiltrated into Taiwan and acquired various resistance traits independently.

• 出版日期2017-1
• 单位长春大学