Frequency of isolation and antimicrobial susceptibility pattern of bacterial isolates from blood culture, Gondar University teaching hospital, Northwest Ethiopia

Abstract

Background: Bacterial bloodstream infections cause substantial morbidity and mortality, with up to one-quarter of affected patients dying as a result of their infection. Up-to-date information on blood culture isolates and their antimicrobial susceptibility pattern is very important as guide for immediate prescription of antimicrobial agents and monitoring of emergence of drug resistant strains.

Objective: To determine the frequency of blood culture isolation and antimicrobial susceptibility pattern of isolates in Gondar University teaching hospital.

Methods: This was retrospective analysis of records of blood culture results for febrile patients seen at Gondar University teaching hospital, bacteriology section from March 2001 to April 2005.

Results: During the four years period, blood cultures were done for a total of 472 febrile patients. Among these, 233 (49.4%) were females and 239 (50.6%) were males. The median age was 20.5 years (age range of 2 hours to 78 years). Out of these, total of 114 bacterial strains were isolated with culture positivity rate of 24.2%. Coagulase-negative Staphylococci (CoNS) were isolated with the highest frequency in 38 (33.3%), followed by Staphylococcus aureus in 34 (29.8%), Salmonella species other than Salmonella typhi in 12 (10.5%), Klebsiella species in 10 (8.8%), Streptococcus pneumoniae in 6 (5.3%), Salmonella typhi in 4 (3.5%), Enterobacter species in 3 (2.6%), Escherichia coli in 2 (1.7%). The gram positive and gram negative bacteria constituted 80 (70.2%) and 34 (29.8%) of the culture isolates, respectively. Culture positivity rates vary as for neonates, 63% (17 out of 27);followed by 25.6% (36 out of 141) in children and 20% (61 out of 304) in adults. The isolates especially gram negative bacteria showed multiple drug resistance, to Ampicillin and penicillin. However, ciprofloxacin is fairly effective against both gram negative and gram positive isolates.

Conclusion: An effective documented data may serve as a guide for initial empirical treatment of bloodstream infections but in view of these findings the presented data is only imperative to do large-scale prospective and quantitative studies. More importantly, an ongoing surveillance for antimicrobial susceptibility is of the essence to enhance efforts to identify resistance and attempt to limit its spread.