This study aims to evaluate airborne environmental bacteria (environmental origin), mesophilic bacteria (human related bacteria) and fungi at governmental (GH) and private (PH) hospitals, in addition to assess sink drain biofilms and dust accumulated on air conditioning filters and floor surfaces to determine if they constitute potential sources of airborne microbial biodiversity. Samples were collected from intensive care unit (ICU), operating theatre (OT), admission department (AD) and outdoor for comparison. Airborne bacteria and fungi were collected using an Andersen two-stage impactor sampler which divides particles into fine (≤8 µm) and coarse (≥8 µm) size ranges. Airborne environmental bacteria, mesophilic bacteria and fungi concentrations, were respectively in the range of 0.0–2638; 0.0–1654.9 and 11.7–566.5 CFU/m3 indoors and 155–32436; 11.7–5554 and 35–664 CFU/m3 outdoors. Bacillus atrophaeus was commonly isolated in all locations. However, Alloiococcus otitis was only found at the GH and Bacillus licheniformis at the PH. Aspergillus and Penicillium were the common fungal types in the air state and dust. Dust was accumulated on air conditioning filters and floor surfaces and these would constitute important sources of airborne bacteria and fungi inside these hospitals.

No abstract

No abstract

No abstract

ACTERIAL and fungal contamination in the air and settled dust .... were studied in old and new book libraries located in the National Research Center (NRC), Dokki, Giza, Egypt. The investigated libraries differ in age, design, size, ventilation type, and a number of occupants in relation to microclimatic parameters and particulate matter (PM) load. Airborne microorganisms were collected using an Andersen two stage impactor sampler. Indoor airborne bacteria and fungi ranged from 0-1060.4 CFU/m 3 and 11.8-315.6 CFU/m 3 , respectively. Outdoor airborne bacteria and fungi ranged within 11.7-2514.7 CFU/m 3 and 0-713.7 CFU/m 3 , respectively. Bacteria and fungi associated surface settled. The dust ranged from 0.4-10x10 6 CFU/gm and 0-73x10 4 CFU/gm, respectively. Fine microbial fraction (particles ≤ 8 μm in size) constituted 2-24.94% and 68.35-94.15% of the total airborne bacterial and fungal concentrations, respectively. Indoor/outdoor (I/O) ratios of airborne microorganisms were less than 1 at both libraries, indicating no indoor microbial sources. Gram positive cocci (14.3-47%) and bacilli (52.9-85.7%) were the dominant bacterial isolates in the air state, while bacilli represented 100% of the total isolates in the surface settled dust. Bacillus pseudomycoides and B. subtilis dominated indoors while B. subtilis and Staphylococcus outdoors. Aspergillus and Penicillium, were the common fungal species in both libraries under investigation. Many of the isolated fungal taxa had enzymatic activities (lipase, protease and cellulase), with A. flavus, Curvularia pallescens, Fusarium oxysporium, P. notatum and Trichoderma viride presented all enzymatic activities. Complex correlations and no-clear patterns were found between the airborne microorganisms and the environmental factors.