Abstract
The coexistence of different classes of beta-lactamases in multiple drug-resistant (MDR) bacteria has widely increased, thus rising diagnostic and treatment challenges. The study aimed at evaluating the prevalence of extended-spectrum beta-lactamase (ESBLs) and Metallo-beta-lactamase (MBL) genes in confirmed ESBL producing Gram-negative (G-) bacteria. A stock of 220 G- isolates were studied for producing ESBL and MBL using phenotypic and PCR methods. The results showed that ESBLs were identified in 35.4% of the isolates, out of which 32.1% were MBLs producers, the most prevalent isolates were K. pneumoniae (15.4%), E. coli (7.7%), and Ps. aeruginosa (6.4%), respectively. PCR test confirmed the presence of >= 1 ESBL and MBL genes in 78.2% and 73.1% of the isolates, respectively. CTX-M was the most prevalent gene (70.5%) followed by IMP (61.5%), TEM (27%), VIM (21.8%), and SHV (21.8%). Also, 39.7% of the isolates carried two genes, while 10.8% carried three genes, and 20.5% carried 4 genes. The combination (CTX-M+ IMP) was the most frequent (33.4%) among the isolates. The high prevalence of ESBLs and MBLs in combination was noted, especially in E. coli and K. pneumoniae. Continuous monitoring of beta-lactamases coexistence in G- bacteria will help to stop their dissemination and control their spread.