Characterization of Indoor Air Bacterial Isolates from Rafidia Hospital, Nablus-Palestine and their Roles in Nosocomial Infections

Air can play a vital role as a reservoir for both pathogenic and non pathogenic living microorganisms. Microbial contamination of hospitals air is considered as a source of hospital-associat¬ed infections. The present study aimed to assess microbial profile of air contamination in different wards of Rafidia Hospital, Nablus-Palestine using both active and passive sampling methods, and to ascertain the contribution of some of these microorganisms to infection using cultures from hospitalized patients at the same time using ERIC PCR technique. Results of this research showed that total viable count of Gram-positive bacteria was the most frequent microorganisms cultured from different wards of the hospital. Coagulase negative Staphylococci (CoNS) and Micrococcus spp, were the most predominant among isolates from air samples from all operation rooms, ICU and neonatal room by passive air sampling method. The percentage of CoNS and Micrococcus spp in air of surgical operation rooms, intensive care unit and neonatal room ranged from 61.8%-100% and the average was 5158 CFU/m2/h-20187 CFU/m2/h. Staphylococcus aureus was the most common microorganisms isolated from neonatal room by active air sampling method, the percentage was 35% and the average was 100 CFU/m3. Total bacterial level range was116 CFU/ m3-1085 CFU/m3. The percentage of CoNS and Micrococcus spp in air of surgical operation rooms, intensive care unit by active air sampling was 58.8%-100% and the average was 70-1080 CFU/ m3. The results showed that most frequent Colony Forming Units were obtained from Blood agar with a range of 4085 CFU/ m2/h -8721 CFU/ m2/h and Tryptic Soy Agar with a range of 2043 CFU/ m2/h-7935 CFU/ m2/h by passive air sampling method. Antimicrobial susceptibility pattern of bacterial isolates revealed that the most effective antibiotics were ciprofloxacin , norfloxacin and tetracycline against S. aureus; tetracycline, ciprofloxacin and norfloxacin against CoNS and Micrococcus spp and ciprofloxacin, Trimethoprim/Sulfamethoxazole and tetracycline against Bacillus spp. ERIC PCR profile based on number and size of generated bands revealed that clinical bacterial strains of S. aureus, E. coli and Klebsiella spp were not clonally related to airborne isolates collected at the same time. Data presented in this study may be valuable to develop interventions to improve microbial indoor air quality in various hospital wardsand also for preventing or decreasing the occurrence of the nosocomial infections.