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

Abstract

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 and bla in 11 EC isolates from five pulsotypes/two STs. Reverse transcription PCR demonstrated overexpression of the chromosomal AmpC-like β-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.

Contribution of acrB upregulation & OmpC/Ompk36 loss over the presence of blaNDM towards carbapenem resistance development among pathogenic Escherichia coli & Klebsiella spp.

“…Although previous studies reported the additive role of ESBL production, decreased OMP expression and an active efflux pump system towards carbapenem resistance development, association of carbapenemases with OMP loss and acrB upregulation was not explored before262728. In addition to exploring the well-known association between ESBL production and acrB upregulation/porin loss, a significant association of carbapenemase production with acrB upregulation was observed in the current study among CREs.…”

Factors associated to prevalence and treatment of carbapenem-resistant Enterobacteriaceae infections: a seven years retrospective study in three tertiary care hospitals

“…Treatment problems were mainly found in the treatment of CRE infection with only a few antimicrobial options, including polymyxin, aminoglycosides, tigecycline and fosfomycin [ 25 , 26 ]. In the possible combination regimen, the effect of carbapenem treatment remains to be determined, such as high-dose infusion or double carbapenem treatment [ 27 , 28 ].…”

Green tea extract-mediated augmentation of imipenem antibacterial activity against Enterobacter cloacae clinical isolates

“…In addition, this pathogen has also been reported to contaminate medical equipment in hospitals (Davin-Regli and Pagès, 2015). Clinical isolates of E. cloacae were previously reported to be resistant against carbapenem, tigecycline, colistin (Huang et al, 2017). It was found that out of 385 patient specimens, 64.68% were found to be positive for pathogenic bacteria, including E. cloacae (2%).…”