A comparison of bacterial resistance to antimicrobials in Riyadh, Medina, and Oklahoma City.

Many bacteria are known to develop resistance to anti-microbial agents following their clinical use. The resistance pattern varies from one geographic location to another depending upon the patient population and local history of antibiotic use. The bacterial resistance to commonly used antimicrobial agents in Oklahoma City was found to be different from two cities in Saudi Arabia, especially amongst Gram-negative bacilli. A total of 13,575 fresh clinical isolates from the Veterans Administration Medical Center (VAMC), Oklahoma City, Oklahoma; the King Faisal Specialist Hospital and Research Centre (KFSH), Riyadh; and the King Fahad Hospital (KFH), Medina, Saudi Arabia; were used. There were 6,270 isolates of Enterobacteriaceae, 2,799 pseudomonads and Acinetobacter, and 4,506 Gram positive strains of staphylococcus bacteria. Gram-negative bacteria from KFH were considerably more resistant to ampicillin, gentamicin, and trimethoprim-sulfamethoxazole than at KFSH and VAMC. On the other hand, Staphylococcus aureus isolated from VAMC exhibited a significantly higher degree of resistance to oxacillin and trimethoprim-sulfamethoxazole than those at KFSH and KFH.