Microbial growth onto HVAC filters was observed in real conditions with possible degradation of the indoor air quality. The filtration performance of marketed antimicrobial filters containing zinc pyrithione was tested under laboratory conditions and compared to that of similar filters with the same classification, F7 (EN779:2002). The filtration performance of the two tested filters during loading with PM10 particles was quantified in an experimental setup with filter pressure drop measurement and particle counting upstream and downstream of the filters. The microbial growth on the new and loaded filters, both contaminated with a microbial airborne consortium composed of two bacteria (Gram-positive and -negative) and fungi, was quantified by colony-forming units after conditioning the filters for a few days under controlled temperature (25 °C) and humidity (50% or 90% relative humidity). The results reveal that there was no degradation of the filtration performance of the filters treated with the antimicrobial agent. The efficiency of the antimicrobial treatment, i.e., the ability to inhibit the growth of microorganisms during the incubation period, was significant with the new filters regarding the fungal growth, but the results demonstrate that the antimicrobial treatment became inefficient with the loaded filters.

The study aims at isolating and identification of Burkholderia cepacia bacteria from clinical samples from various pathological conditions such as diabetic foot ulcers, burn, wound, sputum and urine. The present study includes 280 samples collected from patients suffering from diabetic foot ulcer, cystic fibrosis, burns, sputum, and wounds who attend Alsader Medical City and Al-Hakim General Hospital during the period extended from September 2020 to February 2021 ( men and women ) with age groups between (1 -75) years. The identification of bacterial isolates were detected by classical and molecular technique (PCR), where the frequency among males 213 (79.2%) was more than that in female 67 (20.8%). The samples distribution is made according to age group; it appears high for the following high 26.8% with group (31-45) years male and female; 22% with group (31-45) years in male and 7.6% with the group (1-15) years in female. The results revealed that 42/80 specimens of the total number of samples are Burkholderia cepacia by using 16SrRNA gene to differentiate the B. cepacia from other (G-) bacteria, and 30/80 recA gene to differentiated B. cepacia from B. cepacia complex.