Bacteraemia at the tertiary care University Hospital Yalgado Ouedraogo: Bacterial species and their antibiotic resistance profiles Bactériémies au Centre Hospitalier Universitaire Yalgado Ouedraogo: Espèces bactériennes et leur profil de résistance aux antibiotiques

Abstract

Background: Bloodstream infections are serious health problem because of the significant morbidity and mortality they cause. The number of deaths increases in the presence of multidrug resistant bacteria. The aim of this study was to determine the bacteriological and resistance profiles of bacteria isolated from blood cultures.
Methodology: This is a retrospective descriptive study over 3 years (1st January 2019 to 31st December 2021) of all blood cultures received in the Bacteriology-Virology Laboratory at CHU-YO. Bacteria were isolated from blood cultures after routine processing in automated BD BACTEC FX40 machine. Bacteria identification and antibiotic susceptibility test (AST) was by conventional biochemical tests and API 20E, and Kirby-Bauer disc diffusion method respectively from Jan to Sept 2019, and by BD Phoenix M50 from Sept 2019 to Dec 2021. All proven cases of bacteraemia documented by culture, identification and AST were included in the study. Data analysis was done using EPI-INFO 7.2.4.0 software.
Results: A total of 335 pathogenic bacteria were isolated from non-duplicate blood cultures collected from a total of 2345 patients, with 1209 males and 1136 females, giving a male to female ratio of 1.06. Gram-negative bacilli accounted for 63.6% (n=213) with a predominance of Enterobacteriaceae (40.6%, n=136). The leading species were Klebsiella spp (18.5%, n=62) followed by E. coli (14.0%, n=47). Gram-positive cocci accounted for 36.4% (n=122), mostly Staphylococcus aureus (22.1%, n=74). Klebsiella spp and E. coli strains showed high levels of resistance to beta-lactams (60 to 71.0% for piperacillin-tazobactam, 87 to 89.0% for amoxicillin-clavulanic acid
and 79 to 90.0% for ceftriaxone), fluoroquinolones (75 to 78.0% for ciprofloxacin) and sulphonamides (82 to 96.0% for cotrimoxazole). The lowest levels of resistance were observed with cefoxitin (5-20.0%) and imipenem (5-7.0%). Strain sensitivity to aminoglycosides was highly variable, ranging from 0-5.0% for amikacin to 54-67.0% for gentamicin. The main mechanism of resistance of Klebsiella spp and E. coli strains to beta-lactam antibiotics was ESBL production; 64.5% (40/62) and 60.0% (28/47), respectively. Staphylococcus aureus strains were resistant to methicillin (MRSA) in 13.0% of cases. All were sensitive to fusidic acid and vancomycin.
Conclusion: Klebsiella pneumoniae, E. coli and S. aureus are the main bacteria responsible for bacteremia in Burkina Faso. Their resistance to antibiotics is very high and remains of concern. The introduction of rapid tests to detect resistant bacteria directly from blood culture broths is essential for the early adaptation of empirical antibiotic therapy.