Patterns of Microorganisms Present on Non-Critical Equipment and Environmental Surfaces in Selected Medical Microbiology Laboratory Units of a Tertiary Hospital in North-Central Nigeria

Abstract

ABSTRACTLaboratory equipment and environmental surfaces can act as reservoirs for pathogenic microorganisms, facilitating cross-contamination and increasing the risk of healthcare-associated infections. This study assessed the diversity of microorganisms persisting on selected non-critical equipment and environmental surfaces in Benue State University Teaching Hospital, Makurdi, Nigeria. A cross-sectional study was conducted using swab samples collected from frequently used laboratory equipment and environmental surfaces. Samples were cultured on appropriate microbiological media, and isolates were identified using standard microbiological techniques based on cultural, morphological, and biochemical characteristics. Total aerobic plate counts (TAPC) were determined to assess the level of microbial contamination on each sampled surface. Study findings showed that a total of eight microbial species were isolated from the sampled equipment and surfaces, namely: Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. Laboratory tables/benches harboured the highest diversity of microbial contaminants. The mean TAPC ranged from 1.3 x 10⁵ to 3.7 x 10⁵ CFU/mL. The highest counts were recorded on tables (3.7 x 10⁵ CFU/mL), sinks (3.5 x 10⁵ CFU/mL), and wire loops (3.2 x 10⁵ CFU/mL), while autoclaves and scissors exhibited the lowest counts (1.3 x 10⁵ CFU/mL each). The isolation of both bacterial and fungal pathogens from frequently touched surfaces and equipment indicates substantial environmental contamination within the laboratory setting. The study demonstrated significant microbial contamination of laboratory equipment and environmental surfaces. Frequently used work surfaces and moist environments exhibited the highest microbial loads and diversity of contaminants. These findings underscore the importance of routine environmental surveillance, effective cleaning and disinfection procedures, proper sterilization of reusable instruments, and strict adherence to infection prevention and control measures to minimize microbial transmission, and promote a safer working environment for healthcare workers and patients.