Abstract
The emergence of resistant bacteria to aminoglycosides in pathogenic Gram-negative bacilli is a growing concern. The study identifies the prevalence of genes encoding resistance to aminoglycoside in Gram-negative bacterial infections in tertiary hospitals in Makkah, Saudi Arabia. A stock of 246 clinical isolates were tested for aminoglycoside resistance using phenotypic and genotypic techniques. Of the 246 isolates, resistance rates against tobramycin, kanamycin, gentamicin, neomycin, amikacin and streptomycin were 35%, 34.1%, 33%, 32.5%, 32.1% and 31.3%, respectively. The maximum resistance rates against other antibiotics was seen in cefotaxime (48.0%) followed by amoxicillin clavulanic acid (41.5%) and ciprofloxacin (24.8%). PCR results confirmed the existence of one or more aminoglycoside-resistant genes in 69 (28%) isolates. The rmtD was the highest-detected gene (58.0%), followed by aac(6 ')-Ib (56.5%), aac(3)-II (52.2%), rmtB (52.2%), rmtA (3) (43.5%), and aph(3 ')-Ia (42.0%). There was significant association (p < 0.05) between aac(3)-II resistance gene and the type of isolate. Our study demonstrates the existence of aminoglycoside-resistant genes in (28%) of the isolates, mostly in K. pneumonia and E. coli, the rmtD gene was the most predominant. Multiple drug-resistant monitoring must be continuous through the identification of genes encoding resistance to aminoglycosides to implement effective measures to reduce the spread of antimicrobial resistance.