Antimicrobial Susceptibility and Genetic Epidemiology of Extended-Spectrum ß-Lactamase-Positive Enterobacterales Clinical Isolates in Central Poland.

ABSTRACT

The extended-spectrum ß-lactamases (ESßLs) are bacterial enzymes capable of hydrolyzing penicillins, cephalosporins, and aztreonam. The prevalence of ESßL is increasing among clinically significant microorganisms worldwide, drastically reducing the therapeutic management of infectious diseases. The study aimed to determine the drug susceptibility of ESßL-positive clinical isolates acquired from patients hospitalized in Lodz, central Poland, and analyze the prevalence of specific genes, determining acquired resistance in these bacteria. The samples of ESßL-positive clinical isolates were gathered in 2022 from medical microbiological laboratories in the city of Lodz, central Poland. The strains were subjected to biochemical identification and antimicrobial susceptibility testing following EUCAST guidelines. The presence of studied genes (blaCTX-M, blaSHV, blaTEM, blaPER, blaVEB) was confirmed by PCR. Over 50% of studied isolates were resistant to gentamicin, cefepime, ceftazidime and ciprofloxacin. The most common ESßL gene was blaCTX-M. In most isolates, the resistance genes occurred simultaneously. The blaPER was not detected in any of the tested strains. ESßL-producing strains are largely susceptible to the currently available antibiotics. The observation of the coexistence of different genes in most clinical isolates is alarming.