Microbiota of critical areas prior to reopening in an oncology center: Potential uncommon nosocomial pathogens for vulnerable populations

Healthcare-associated infections are linked with the contamination of inanimate surfaces and the air in occupied hospital areas by recognized pathogens. However, there is limited information about the presence of these microorganisms or other potential pathogens in critical areas prior to their clinical operation. Here, we determined the microbial community in critical areas prior to their validation for hospital care and reviewed the background for the potential pathogenic role of this microbiota for populations susceptible to opportunistic infections. We evaluated environmental samples from operating theatres (OTs) and bone marrow transplant rooms (BMTRs) at the Peruvian National Cancer Center. A total of 164 samples (58 air samples and 106 surface samples) were collected for bacterial and fungal culture. In the OTs, the air conditioning sample yielded the highest microbial isolation from air, with a predominance of the genera Bacillus (5/12 isolates; 41.7%) and Aspergillus (5/8 isolates; 62.5%), including Nigri (2/5) and Flavi (2/5) sections and Aspergillus sp. (1/5). Meanwhile, the surface sample with the highest bacterial isolation came from the shelf in the stock area, where there was a predominance of non-glucose-fermenting Gram-negative bacilli (NF-GNB) (8/15 isolates; 53.3%), including the genera Pseudomonas (4/8), Acinetobacter (2/8) and Stenotrophomonas (2/8). In BMTRs, the only microorganisms isolated from the air were coagulase-negative Staphylococcus species and Penicillium sp. In conclusion, the microbial community composition of the critical areas prior to their reopening was consistent with their unoccupied status, consisting of nosocomial saprophytic microorganisms. Furthermore, the predominant species of the basal microbiota included uncommon hospital pathogens for people susceptible to opportunistic infections, such as cancer patients.