Abstract
Reports on extended-spectrum beta-lactamases (ESBL) producers and the genes responsible for ESBL phenomenon are few in Saudi Arabia. Hence, we determined the prevalence of ESBL in K pneumonia and E. coli from AlMadenah Al-Monawwarah and characterized the predominant ESBL gene in these isolates, taking into consideration the emergence of CTX-M gene in the community. Three hundred and fifty nine (n = 359) gram negative isolates were collected from Prince Sultan Military Hospitals in Al-Madenah Al-Monawwarah, KSA. Identification of the isolates was done by using conventional biochemical methods and BD phoenix 100 system. ESBLs were screened according to CLSI guidelines. ESBLs positive strains were tested for the presence of ESBL encoding genes using Multiplex PCR with specific primers for the detection of CTX-M, SHV and TEM genes. Out of the total 359 enterobacterial isolates, E. coli was isolated from 189 (52.6%) and K. pneumonia from 87 (24.2%). ESBL was demonstrated in 85 (23.7%) of the total 359 isolates. Urine samples were the most frequent in this study (61.7%) followed by blood (15.1%), pus cells (8.2%), wound (4.5%), sputum (4.1%), eye swap (2.7%) and high vaginal swap (2.7%). CTX-M was found to be the most dominant gene (74.1%) followed by TEM (31.8%) and SHV (14.1%). High resistance of ESBL producers was observed among antibiotics belonging to different families including Aztereonam (95.3%), Cephalothin (95.3%), Ampicillin (95.3%), Ciprofoxacin (72.9%), Trimethoprime-Sulfamethaxazole (71.8%), Norfloxacin (68.2%), Levofloxacin (60.0%), Amikacin (33.9%) and Gentamicin (24.7%). The study concluded that all ESBL genes were carried by K. pneumoniae and Escherichia coli with the proved prevalence of CTX-M in Al-Madenah community, which reflects the continuous strategies followed by Enteriobactertiacea to evade antimicrobial action. This represent challenge to the clinicians in this important part of Saudi Arabia as ESBLs, being a cause of outbreaks, is a public health concern.