Beta-lactam Resistance Profile among Klebsiella pneumoniae Clinical Isolates from Alexandria, Egypt.

Abstract

Klebsiella pneumoniae is a major drug-resistant human pathogen accountable for a wide range of infections. In this cross-sectional study, we aimed to determine the phenotypic and genotypic features of β-lactamase-producing K.pneumoniae clinical isolates from Alexandria, Egypt. A total of 50 nonduplicated clinical isolates of K.pneumoniae were obtained from various specimens. They were identified biochemically and by biotyping using mass spectrometry. For molecular characterization, plasmid profile analysis was performed. Screening for extended spectrum β-lactamases (ESBLs), carbapenemases and AmpC production was carried out phenotypically and genotypically. Correlation analysis was performed to assess the relationship between phenotype, genotype and resistance patterns among the studied isolates. The dendrogram demonstrated 38 distinct plasmid profiles among 62% of our isolates. According to antimicrobial susceptibility testing, 90% of isolates were multi/extensive-drug resistant. Nineteen out of 50 (38%) were resistant to cefoxitin, while only 10 (20%) were resistant to imipenem. All isolates were susceptible to colistin. Phenotypically, ESBL producers (78%) were the most common, followed by carbapenemase producers (24%). Genotypically, the most common ESBL gene was blaSHV (90%), followed by blaCTX-Mu (74%), while the most common carbapenemase genes were blaNDM (56%) and blaOXA-48 (54%). No blaKPC or blaIMP were detected. Plasmid-mediated AmpC resistance was confirmed in only two out of 19 cefoxitin-resistant isolates. Both the blaNDM and blaOXA.48 genes were significantly positive correlated (rho = 0.56, p = 0.004). Absence of blaKPC among carbapenem resistant K.pneumoniae isolates in Alexandria, Egypt. AmpC production is not the main factor behind the resistance to cefoxitin among our isolates.