Detection of Multidrug-Resistant Gram-Negative Organisms in Lagos state Public Hospitals environmental surfaces

Abstract

Background: Hospital-acquired infections constitute a significant challenge to patient safety due to the emergence of multidrug-resistant (MDR) organisms. Multidrug-resistant (MDR) Gram-negative bacteria have proved to be one of the major leading causes of hospital-acquired infections linked to high morbidity and mortality. The hospital environment serves as a reservoir for MDR bacteria. This study, therefore, investigates the burden of MDR Gram-negative bacterial infections from the hospital environment. Methods: This was a cross-sectional study. Two hundred swab samples were collected from different environmental sources at four public hospitals environment in Lagos, Nigeria. Samples were cultured on 5% blood agar and MacConkey agar (OXOID). Isolates were identified with biochemical tests and confirmed using the VITEK 2 System with the VITEK 2GN identification card (bioMe´rieux, Durham, NC), following the manufacturer’s directions. Antimicrobial susceptibility testing was performed using the Kirby Bauer disk diffusion technique. Extended-spectrum beta-lactamase (ESBL) was detected with the double-disk synergy test. A Modified Hodge test was used to detect carbapenemase production. Multidrug resistance was inferred from resistance to three classes of antibiotics. Results: Fifty-nine bacterial isolates were recovered from hospital environmental samples. Thirty (50.8%) were Gram-negative, while 49.2% were Gram-positive. Klebsiella pneumoniae (40%), Escherichia coli isolates (36.7%), Pseudomonas aeruginosa (10%), Acinetobacter baumannii (6.7%) and Proteus mirabilis (6.7%) were isolated. Twenty (66.7%) isolates were multidrug-resistant to three classes of antibiotics. Nine different antibiotic resistance patterns were observed, and five were characterized as multi-drug resistant. Nineteen isolates (63%) produced ESBL, and 27 (90%) were resistant to meropenem, with 6.7% positive for carbapenemase. Conclusion: Inanimate surfaces are a major environmental reservoir for MDR Gram-negative bacteria in healthcare facilities..