Antimicrobial Susceptibility Profile of Extended Spectrum Beta- lactamases Producing Enterobacteriaceae isolated from clinical samples refereed to the National Bacteriology and Mycology Reference Laboratory, Ethiopia

Abstract Background Extended-spectrum beta-lactamases (ESBL) producing Enterobacteriaceae are prevalent worldwide and they are unique challenges for treatment and control of bacterial infectious diseases. ESBL genes not only confer resistance to oximino-cephalosporins and aztreonum but also, they are multidrug-resistant to other commonly available antimicrobial agents used in clinical practice.Objective To determine the prevalence and antimicrobial susceptibility profile of ESBL producing Enterobacteriaceae isolated from clinical samples referred to the national clinical bacteriology and mycology reference laboratory.Materials and Methods A cross-sectional study was conducted on Enterobacteriaceae culture- positive clinical samples that were referred to the national bacteriology and mycology reference laboratory from August 2018 to July 2019. Bacterial isolation was performed according to the inoculation and incubation conditions of each clinical specimen and identifications of the isolates were performed using standardized biochemical tests for gram-negative bacteria. Antimicrobial susceptibility profiles of these cultures were determined using the disk diffusion method on Muller Hinton agar according to the recommendation by Clinical and Laboratory Standard Institute (CLSI). ESBL production was detected using CLSI Screening and confirmation test. A double-disk synergy test was used for confirmation.Results Out of 371 culture positive for Enterobacteriaceae , 240 (64.7%) were positive for ESBL production, and the most prevalent species were Klebsiella sp 131(54.6%) followed by E. coli 79 (32.9%). Of 131 ESBL positive Klebsiella spp, 95 (72.5%) were obtained from blood samples and among 79 E. coli isolates, 51 (64.6%) of the strains were isolated from urine samples. All ESBL positive isolates were resistant to ampicillin and all generation of cephalosporins. In addition, 100% of them were multidrug resistant. There were also high proportions of resistant ESBL positive isolates to other classes of antimicrobial agents. Less resistance rates were documented for carbapenems drugs and amikacin from the class of aminoglycosides.Conclusion ESBL producing Enterobacteriaceae we reported in this study was not only highly prevalent but also they are multidrug resistant to most clinically available antimicrobial agents including carbapenems. Therefore, public awareness and regular monitoring