Aim: This study aimed to investigate the prevalence of gram negative and gram positive bacteria in addition to the investigation of antibiotic resistance rates in 2021 at a military hospital in Riyadh Region. Materials and Methods: This observational study included the retrospective review of bacterial isolates from 1st of January 2021 to 30th of June 2021. Results: Most of the infections were caused by gram negative bacteria (64.52%). The most common gram negative bacteria were Escherichia coli (43.63%) followed by Pseudomonas aeruginosa (20.52%). The most common gram positive bacteria were Staphylococcus aureus isolates (71.74%). The study also showed that Acinetobacter baumannii was a pandrug-resistant bacterium and Enterobacter cloacae, Proteus mirabilis, Morganella morganii, and Enterococcus faecalis bacteria were multidrug resistant. Conclusion: There was a high resistance for some bacteria to numerous antibiotics. Antibiotic susceptibility testing is an essential guide for physicians to help them in the selection of the suitable antibiotic for bacterial infections.
Key words: Antibiotic resistance, Antimicrobial resistance, Gram negative bacteria, Gram positive bacteria, Multidrug-resistant bacteria, Prevalence.
