Indoor air quality, hygiene practices and the antimicrobial resistance profiles of airborne bacteria in selected areas of a tertiary health facility in Ibadan, Nigeria

Abstract Background Hospital indoor air is contaminated with multidrug-resistant bacteria, and this contributes to their spread. However, there is limited information linking environmental and atmospheric factors to the levels of these resistant bacteria in indoor hospital air. Hence, this study assessed the levels of multi-drug resistant bacteria in the indoor air of a tertiary hospital and the contributing environmental and atmospheric factors. Methods This cross-sectional study observed hygiene practices, sanitary conditions, occupancy ratio, activity rates, temperature and humidity levels in selected indoor areas of University College Hospital, Ibadan. Airborne bacteria were sampled with their loads via a volumetric sampler, and they were tested for susceptibility against 13 antibiotics via the disk diffusion method. Data was collected twice daily, thrice weekly for two weeks, and analyzed using SPSS version 26. Results The hygiene practices observed varied across the sampled areas with the office area (10.00 ± 0.00) and psychiatry (9.17 ± 0.41) wards showing best practices, and the laundry area (6.00 ± 0.00) with the worst, sanitary conditions also followed a similar pattern. The study identified 93 bacterial isolates from the MacConkey agar, Staphylococcus aureus (33.3%), Bacillus species (31.18%), Klebsiella pneumoniae (15.05%), Escherichia coli (10.75%), and Coagulase-negative Staphylococcus (9.68%). The mean bacterial load (CFU/m3) varied significantly across sampled areas (p < 0.01): Laundry (2962.96 ± 547.59) > Children Emergency Ward (2537.03 ± 551.67) > Neurosurgery (2310.19 ± 560.31) > Psychiatry (1828.70 ± 431.93) > Office (421.30 ± 311.09), with the exception of office area, the loads were above the WHO acceptable limit of 1000 CFU/m3. Bacterial load correlated negatively with hygiene practices and sanitary conditions, but positively with occupancy ratio, activity levels, humidity and temperature, all p < 0.01. The identified bacteria exhibited a high multidrug resistance, this includes the identification of Methicillin Resistant Staphylococcus aureus and extended spectrum beta lactamases producing Escherichia coli and Klebsiella pneumoniae. Conclusion Healthcare environments, particularly indoor air remains highly contaminated with multidrug-resistant bacteria, with environmental factors like hygiene, sanitation, occupancy, activity, and atmospheric factors like temperature and humidity contributing to their spread. Therefore, improved environmental practices, routine indoor air surveillance and antimicrobial stewardship is advocated.