Emergence of extended-spectrum β-lactamase (ESBL) and/or carbapenemase producing Enterobacteriaceae (CPE) and their antimicrobial resistance.

OBJECTIVES

We focused on detecting the most frequent resistance mechanisms in selected multidrug-resistant (MDR) strains and determining their antimicrobial resistance.

BACKGROUND

MDR pathogens pose urgent public health threat due to limited treatment options, rigorous control measures and significant mortality.

METHODS

We confirmed extended-spectrum β-lactamase (ESBL) and carbapenemase producing Enterobacteriaceae through guidelines, as well following β-lactamases: AmpC by cloxacillin, class A carbapenemase with phenylboronic acid, class B metallo-β-lactamase with ethylenediaminetetraacetic acid. Multilocus sequence typing was used to investigate 20 Escherichia coli strains.

RESULTS

Overall 205 mostly ESBL Escherichia coli demonstrated resistance against amikacin (4.7 %), tigecycline (1.2 %), and no resistance to ceftazidime/avibactam, meropenem, nitrofurantoin and fosfomycin. Out of 41 Klebsiella species (spp.), 37 (90.2 %) showed carbapenemase activity, 13 (35.1 %) of class A and 24 (64.9 %) of class B. Resistance was following: meropenem 66.7 %, tigecyclin 10.2 % and colistin 0 %. From Enterobacter spp. 21 strains, 14 (66.7 %) were ESBL, 5 produced ESBL and/or AmpC and 2 were MDR. We ascertained 14 (70 %) E. coli sequence type - ST131.

CONCLUSIONS

The study revealed various resistance mechanisms in concert with different agents and association of specific ST131 within E. coli. These characteristics considerably contribute to emergence of antimicrobial resistance (Tab. 4, Ref. 30).