Nedi, Teshome (PhD)Worku, Yalemzerf2018-06-272023-11-062018-06-272023-11-062017-01http://etd.aau.edu.et/handle/123456789/4078Infectious diseases are the leading causes of mortality and morbidity in developing countries. Management of infectious disease requires potent and effective antimicrobial drugs to which the virulent organisms are susceptible.. A retrospective cross-sectional study was done by reviewing 1500 microbiology records from September, 2009 to August, 2014. From 1500 microbiology records, 1086 bacteria were isolated. Among these (4.9%) were mixed infection . The most common isolated bacteria were S. aureus and P. aeruginosa with an isolation rate of (17.3) and (14.3%) respectively. About 47.4 % of S.aureus was oxacillin/methicillinresistant (MRSA).Ontheother hand, the resistance rate of S. aureus was lower to ceftriaxone 172 (19.8%). S. pyogenes was resistant to tetracycline while lower resistance was observed to erythromycin,. The highest resistance rate of P. aeruginosa and E. coli were found to ampicillin and amoxicillin. From multidrug resistant bacteria, majority were gram negative among which P. aeruginosa (97.7%) was the highest followed by E. coli (95.1%). Among gram positive MDR bacteria S.aureus (89.1%) was the highest followed by S. epidermidis (87.5%). The findings of this study show that there is high resistance rate of bacterial isolates to the commonly used antimicrobials. To benefit maximum antimicrobial effect from the active antimicrobials and to reserve the threatened ones rational use of antimicrobials should be practiced. Key Words: Antimicrobial Resistance, Antibiotic Susceptibility, Bacterial Isolates.enAntimicrobial ResistanceAntibiotic SusceptibilityBacterial IsolatesThesis