The influence of efflux pump, outer membrane permeability and β-lactamase production on the resistance profile of multi, extensively and pandrug resistant Klebsiella pneumoniae

Abstract

Background: An important chance of nosocomial acquired infections are caused by the opportunistic bacterium Klebsiella pneumoniae. Urine, wound, sputum, and blood samples were collected from all patients. This study aimed to detect the antibiotic resistance profile, the frequency of MDR, XDR, PDR, and detection of efflux pump and outer membrane permeability genes in K. pneumoniae isolates.

Methods: One hundred twenty samples were collected from patients who were admitted to the Ramadi Teaching Hospitals in Al-Anbar Governorate. Fifty five of K. pneumoniae strains were collected from patients. The VITEK®2 Compact B System was used to detect the antibiotic resistance pattern of studied bacteria. The isolates were classified as MDR, XDR, or PDR based on established guidelines. The data were analyzed using Clinical and Laboratory Standards Institute (CLSI) breakpoints. PCR was used to detect the efflux pumps and porins genes.

Results: Out of the 120 samples studied, 45.83 % (55) tested positive for K. pneumoniae. The isolates displayed the greatest amount of resistance to cefazolin, ceftriaxone (98.2 %), ampicillin (100 %), and ceftazidime, cefepime (90.9 %). 20 % of the isolates were found to produce metallo-lactamases, and 41.81 % tested positive for extended-spectrum beta-lactamases. Overall, the rates of multi-drug resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) isolates were 57.2 %, 10.9 %, and 9.09 %, respectively. Additionally, the prevalence of efflux pump genes acrAB, mdtK, and tolC were 94.54 %, 14.54 %, and 89.09 %, respectively, while the porin-encoding genes ompK35 and ompK36 were found in 96.36 % and 98.18 % of the isolates.

Conclusion: This investigation concluded that the study isolates had a high degree of antibiotic resistance heterogenicity. High frequencies of resistance to ampicillin, cefazolin, and ceftriaxone are present in study isolates. Most strains were categorized as MDR strains, with six being XDR strains and five being PDR strains. One of the main routes of antibiotic resistance in multidrug-resistant K. pneumoniae strains is through the acrAB efflux system. The high prevalence of the acrAB, tolC, ompk35, and ompK36 genes were increases the ability of these isolates combat antimicrobial treatments.

Keywords: Antibiotic resistance; Efflux pump; Klebsiella pneumoniae; acrAB; ompK35; ompK36; tolC.