Prevalence of antibiotic resistance among blood pathogens isolated from routine laboratory specimens at Livingstone Central Hospital in Zambia

Abstract

Introduction. Bloodstream infections (BSI) are a major public health burden with high mortality, and when coupled with antimicrobial resistance, the healthcare costs increase. This study aimed to establish the prevalence of antimicrobial resistance patterns of pathogens isolated from blood cultures at Livingstone Central Hospital (LCH) from 2019 to 2021. Methods. A single-centre laboratory based retrospective study with information collected from electronic laboratory system generated reports on all isolated organisms at LCH microbiology laboratory for a period of 3 years. Results. A total of 765 specimens were processed from January 2019 to December 2021 and only 331 (43.3%) met the inclusion criteria. More specimens from female (61.3%) than males (38.7%), and from out-patient departments (65.9%) than in-patient departments (34.1%) specimens were processed. Amongst the bacteria isolates identified, Escherichia coli (27.2%) was the commonest isolate followed by Enterobacter agglomerans (22.7%), Klebsiella pneumoniae (13%), Klebsiella oxytoca (6.3%), Enterobacter aerogenes (5.4%), Enterobacter cloacae (5.4%), Citrobacter freundii (C4.8%), Serratia marcescens (3.6%), Proteus mirabilis (3.3%), and Staphylococcus aureus (2.7%). Antibiotic susceptibility testing identified the least potent antibiotic as ampicillin (92.9%) followed by co-trimoxazole (82.7%), nalidixic acid (68.3%), penicillin (66.7%), tetracycline (63.5%), and chloramphenicol (50.3%) whereas the most effective antibiotic was imipenem (84.6%) followed by norfloxacin (64.7%) and nitrofurantoin (61.2%). Resistance maybe affected by patient gender and location. Conclusion. Multidrug resistance strains causing BSI are increasing and imipenem is still effective but risk being over-used. This will impact healthcare costs and increase mortality rates at the hospital level.