Antimicrobial resistance, biofilm formation, and molecular detection of efflux pump and biofilm genes among Klebsiella pneumoniae clinical isolates from Northern Jordan.

The current study aimed to investigate the antimicrobial susceptibility profiles, biofilm production capabilities, and the prevalence of efflux pump and biofilm-associated genes among Klebsiella pneumoniae clinical isolates. One hundred sixty-seven K. pneumoniae isolates were collected from microbiology laboratories in Northern Jordan hospitals. Antimicrobial susceptibility was tested using the Kirby-Bauer method. The double-disk synergy test was used to detect the extended-spectrum beta-lactamase (ESBL) phenotype. PCR was used to detect the frequency of acrAB, tolC, and mdtk efflux pump genes and fimH-1, mrkA, and mrkD biofilm-associated genes among the isolates. The highest nonsusceptibility was observed against azithromycin (87.4 %) and nitrofurantoin (85.0 %). Among the isolates, 75.4 % and 92.2 % were multidrug resistant and produced biofilms, respectively. Efflux pump genes acrAB, tolC, and mdtK were found in 96.4 %, 95.2 %, and 90.4 % of the isolates, respectively. Biofilm-associated genes mrkD, mrkA, and fimH-1 were found in 92.2 %, 89.2 %, and 88.6 % of the isolates, respectively. The presence of the mrkA was significantly associated with biofilm formation. Overall, high percentages of multi-drug resistance, efflux pump, and biofilm-associated genes were observed among the isolates. Subsequent studies are recommended to monitor changes in the prevalence of resistance phenotypes and genotypes of isolates.

Resistance to aminoglycoside and quinolone drugs among Klebsiella pneumoniae clinical isolates from northern Jordan.

This study aimed to identify phenotypic and genotypic aminoglycoside and quinolone non-susceptibility and the prevalence of aminoglycoside-modifying enzymes and plasmid-mediated quinolone resistance genes among K. pneumoniae clinical isolates from northern Jordan. K. pneumoniae isolates (n = 183) were tested for antimicrobial susceptibility using the Kirby-Bauer disk diffusion method. The double-disk synergy test was used for the detection of the extended-spectrum beta-lactamase phenotype. Polymerase chain reaction was used to detect genes encoding aminoglycoside-modifying enzyme (aac (3')-II, aac (6')-II, aac (6')-Ib, ant (3″)-I, aph (3')-VI, armA, and rmtB), and plasmid-mediated quinolone resistance (qnrA, qnrB, qnrC, qnrD, qnrS, acc(6')-Ib-cr, qepA, and oqxAB) genes. Multi-locus sequence typing was used to elucidate the genetic diversity of selected isolates. The non-susceptibility percentages to aminoglycosides and quinolones were 65.0 % and 61.7 %, respectively. The most frequent aminoglycoside-modifying enzyme gene was ant (3″)-I at 73.8 %, followed by aac (6')-Ib at 25.1 %, aac (3')-II at 17.5 %, aph (3')-VI at 12.0 %, armA at 9.8 %, and rmtB at 0.5 %. Aac (6')-II was not detected among the isolates. The most frequent plasmid-mediated quinolone resistance gene was oqxAB at 31.7 %, followed by qnrS at 26.2 %, qnrB at 25.7 %, and aac(6')-Ib-cr at 25.7 %. QnrA, qnrD, qebA, and qnrC were not detected among the isolates. Aac (3')-II, aac (6')-Ib, aph (3')-VI, armA, qnrB, qnrS, and acc(6')-Ib-cr were significantly associated with non-susceptibility to aminoglycosides, quinolones, and beta-lactams. Among 27 randomly selected K. pneumoniae isolates, the most common sequence type was ST2096, followed by ST348 and ST1207. Overall, 19 sequence types were observed, confirming a high level of genetic diversity among the isolates. High percentages of non-susceptibility to the studied antimicrobials were found and were associated with the presence of several resistance genes. Similar studies should be periodically carried out to monitor changes in the prevalence of resistance phenotypes and genotypes of isolates.