Department of Microbiology, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria
Correspondence to: ayorinde.akinbobola@aaua.edu.ng
Abstract:
Background: Acinetobacter baumannii poses significant threat in healthcare facilities due to its innate ability to persist on harsh environmental surfaces for extended periods and its common resistance to multiple antibiotics, through mechanisms such as extended-spectrum β-lactamase (ESBL) production. Healthcare-associated (HAI) A. baumannii infections are a growing concern in low-and-middle-income countries (LMICs), with environmental surfaces serving as important reservoirs for transmission. However, there is limited information on A. baumannii contamination rates of environmental surfaces in healthcare facilities. This study determined the contamination rates and antimicrobial susceptibility profiles of A. baumannii from high-touch surfaces in selected hospitals in Akoko area of Ondo State, southwest Nigeria.
Methodology: A total of 204 environmental samples were collected by swabbing selected surfaces (48 door- knobs, 120 bedframes, and 36 handwashing basins) of 4 selected hospitals (hospital A, B, C and D). Samples were cultured on MacConkey agar plates and incubated aerobically at 37oC for 24 hours. Colonies isolated from the samples were identified as A. baumannii based on cultural morphology and conventional biochemical test scheme. The susceptibility of the isolates to selected antibiotics was determined by the Kirby Bauer disc diffusion method in line with the Clinical and Laboratory Standards Institute (CLSI) guidelines, and ESBL production in selected isolates was detected by the double disk synergy test (DDST). Multi-drug resistance (MDR) in an isolate was defined as resistance to three or more antibiotic categories. Differences in contamina- tion rates between the hospital sites and touch surfaces were compared using Pearson’s Chi squared test, with p<0.05 considered as statistical significance.
Results: Acinetobacter baumannii was isolated from 13.7% (28/204) of the environmental samples, with the highest contamination rate recorded for samples collected from handwashing basins (33.3%, 12/36) while bed frames had the lowest A. baumannii contamination rate (4.2%, 5/120) (x2=24.372, p<0.0001). Hospital site D had the highest A. baumannii contamination rate of 19.5% (10/51) while hospital site A had the lowest rate of 7.8% (4/51) (x2=4.305, p=0.2303). The A. baumannii isolates were commonly resistant to the third-generation cephalosporins (39.3% to ceftazidime, 32.1% to ceftriaxone and 28.5% to cefotaxime), with 7 of 11 (63.6%) cephalosporin-resistant isolates positive for ESBL production. Four (14.3%) A. baumannii isolates were MDR. `
Conclusion: The isolation ESBL-producing and MDR A. baumannii from environmental surfaces in the selected hospitals in this study underscores the importance of stringent infection control practices and environmental surveillance in resource-limited settings to ensure patient safety.
Keywords: Acinetobacter baumannii, ESBL, MDR, high-touch surface, hospital, contamination
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