Investigation of antibiotic resistance profiles, characteristics of ESBL (extended spectrum beta-lactamase) and PMQR (plasmid mediated quinolone resistance) genes of Klebsiella pneumoniae strains isolated from hospitals in Konya province

Klebsiella pneumoniae (K. pneumoniae) is a bacterium that causes the production of thick, viscous mucus. Lower respiratory tract infections caused by K. pneumoniae are characterized by the presence of thick mucus. It can also lead to surgical site infections, urinary tract infections (UTIs), diarrhea, upper respiratory tract infections, wound infections, meningitis, bacteremia, and septicemia. This study aimed to determine the phenotypic and genotypic ESBL production, antibiotic susceptibility, and plasmid-mediated quinolone resistance (PMQR) genes in 192 K. pneumoniae strains (55.2% urine) isolated from clinical samples in hospitals in Konya province. Phenotypic ESBL production was assessed using the double disc synergy test. The presence of blaCTX-M, blaTEM, blaOXA, and blaSHV genes was investigated by multiplex PCR. PMQR genes (qnrA, qnrD, qnrB, qnrS, oqxAB, aac(6’)-Ib-cr, qepA, qnrC) were also screened by multiplex PCR. Among the 192 isolates, 36 (18.75%) were phenotypically ESBL-positive and 186 (96.87%) were genotypically positive. Of the 19 antibiotics tested, the highest resistance was to Ampicillin (10 µg) (97.9%), and the lowest to Colistin (10 µg) (11.45%). All strains were resistant to at least one antibiotic, with 113 different resistance profiles identified. According to the multiple antibiotic resistance (MAR) index, 72% (139) of strains had an index > 0.2. The most prevalent ESBL gene was blaSHV (184; 95.83%), followed by blaTEM (95; 49.47%), blaOXA (87; 45.31%), and blaCTX-M (27; 14.06%). The most common ESBL gene combination was blaSHV + blaTEM + blaOXA (26.5%). Among PMQR genes, oqxAB was most frequent (156; 81.25%), while qnrC was least frequent (7; 3.6%). These findings highlight the importance of detecting ESBL-producing strains and PMQR genes for effective therapy. Rapid identification using multiplex PCR may help prevent prolonged hospitalization and improve patient outcomes.