Drug resistance patterns of bacterial isolates from infected wounds at Bahir Dar Regional Health Research Laboratory Center, Northwest Ethiopia

Background: An increased antibiotic resistance of bacterial isolates from wound infections is a major therapeutic challenge. The aim of this study was to identify bacterial isolates associated with wound infection and to determine their current antimicrobial susceptibility profile. Methods: This is a retrospective cross-sectional study in which we analyzed the records of 380 wound swab culture results that have been processed at Bahir Dar Regional Health Research Laboratory Center in the period of 1 January 2013 to 30 December 2015. Swabs from different wound types were collected aseptically and analyzed using standard bacteriological procedures. Antimicrobial susceptibility testing was performed using disc diffusion technique as per the standard protocol. Demographic and bacteriological data were collected using a data extraction sheet. The data were cleaned, entered and analyzed using SPSS version 22. Results: The overall bacterial isolation rate was at 61.6% (234/380). More than half 123 (52.6%) of the isolates were gram positive and 111 (47.4%) were gram negatives. The predominant isolates were S. aureus at 100 (42.7%) followed by E. coli, 33 (14.1%), P. aeruginosa, 26 (11.1%) and S. pyogenes, at 23 (9.8%). The proportion of multidrug resistant (MDR) bacterial pathogens was at 54.3%. Out of these, 35 (15.1%) of the isolates were resistant to more than five drugs. The highest resistance rate at (85.9%) was documented for ampicillin by gram-negative isolates. Whereas the highest resistance rate among gram positive isolates was against erythromycin (31.1%). The resistance rate of S. aureus for penicillin was at 69.7%. Conclusions: High frequency of mono and multi-drug resistant bacterial pathogens were documented. Thus, an alternative method to the causative agent and antimicrobial susceptibility testing surveillance in areas where there is no culture facility is needed to assist health professionals for the selection of appropriate antibiotics.