Antimicrobial resistance of bacteria isolated from patients with bloodstream infections at a tertiary care hospital in the Democratic Republic of the Congo

Background. Bloodstream infection (BSI) is a life-threatening condition that requires rapid antimicrobial treatment. Methods. We determined the prevalence of bacterial isolates associated with BSI at Bukavu General Hospital (BGH), South Kivu Province, Democratic Republic of the Congo, and their patterns of susceptibility to antimicrobial drugs, from February 2013 to January 2014. Results. We cultured 112 clinically relevant isolates from 320 blood cultures. Of these isolates, 104 (92.9%) were Gram-negative bacteria (GNB), with 103 bacilli (92.0%) and one coccus (0.9%). Among GNB, Escherichia coli (51.9%), Klebsiella spp. (20.2%), Enterobacter spp. (6.7%), Shigella spp. (5.8%) and Salmonella spp. (4.8%) were the most frequent agents causing BSIs. Other GNB isolates included Proteus spp., Citrobacter spp. and Pseudomonas aeruginosa (both 2.9%), and Acinetobacter spp. and Neisseria spp. (both 0.9%). High rates of resistance to co-trimoxazole (100%), erythromycin (100%) and ampicillin (66.7 - 100%) and moderate to high resistance to ciprofloxacin, ceftazidime, ceftriaxone, cefuroxime and cefepime were observed among GNB. Furthermore, there were high rates of multidrug resistance and of extended-spectrum β-lactamase (ESBL) production phenotype among Enterobacteriaceae. Gram-positive bacteria included three Staphylococcus aureus isolates (2.7%), four oxacillin-resistant coagulase-negative staphylococci (CoNS) isolates (3.6%) and one Streptococcus pneumoniae (0.9%). No oxacillin-resistant S. aureus was isolated. Among clinically relevant staphylococci, susceptibility to co-trimoxazole and ampicillin was low (0 - 25%). In addition, 58 contaminant CoNS were isolated from blood cultures, and the calculated ratio of contaminants to pathogens in blood cultures was 1:2. Conclusions. Multidrug-resistant and ESBL-producing GNB are the leading cause of BSI at BGH.