Molecular Characterization of Antibiotic Resistance Genes in Pathogenic Bacteria Isolated from Patients in Taif Hospitals, KSA

This study was carried out to detect the distribution of antibioticresistant genes in multi-antibiotic resistant bacteria isolated from Saudi Arabian patients in Taif city. Hence, simple methods were followed herein to isolate and characterize the antibiotic resistant bacteria by the common phenotypic, morphological, biochemical and molecular characters. Out of 200 cultures tested, 60 multidrug resistant bacteria isolates were randomly chosen for isolating the antibiotic resistance genes. About 47% of antibiotic resistant tested bacteria were isolated from urine samples and 53% from stool. The study further aimed to analyze antibiotic resistance rates against commonly used antibiotics among bacterial population of urine and stool samples. These bacterial isolates were identified and categorized into eight species, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Citrobacter freundi, Enterobactur sakazakii, Salmonella sp. and Shigella sp. The isolates exhibited resistance in decreasing order for Clindamycin (83%), Penicillin G (69.6 %), Rifampin (64.7%), Cefotaxime (53.6%), Cefaclor (51.7%), Ceftriaxone (47.2%), Nitrofurantoin (44.2%), and Norfloxacin (39.7%). Maximum resistance to extendedspectrum β-lactam antibiotics occurred in 11.3% of isolates and the production of extended spectrum β-lactamase was achieved by 3.5% of isolates. Multiple resistances to three or more antimicrobial agents were documented. PCR method was used to isolate the antibiotic resistance genes for analyzing the molecular classification of these isolates. It was based on CTX-M1, CTX-M2 and mecA genes which were used for rapid assignment of bacteria into genera and species. Address for