M.(2009) Assessment of airborne pathogens in healthcare settings African

An investigation of the air quality and quantity of airborne microbes in selected hospitals of Zarqa city, Jordan, was carried out to assess the level of airborne pathogens and to establish standards for further reference. Using a microbial air sampler, air samples were taken from a governmental and a private hospital in Zarqa city. Three factors were investigated to determine how these factors affect the microbial counts, namely the kind of hospital, the type of room and the time of sampling. Nine bacterial species were identified. In a governmental hospital, Staphylococcus aureus (16.2%) was found to be the most common organism, followed by Micrococcus luteus (13.3%) and coagulasenegative Staphylococcus (13%). Coagulase-negative Staphylococcus (17.2%), followed by S. aureus (16.8%) and M. luteus (10.7%) were found to be the most common in a private hospital. Aspergillus spp., Penicillium spp., Rhizopus spp. and Alternaria spp. were isolated in both hospitals. The indoor air of the governmental hospital was more contaminated than that of the private hospital in all units. Maximum bacterial rates were detected in the patient rooms, while minimum bacterial rates were detected in the operating rooms and neonatal wards. The time of visit showed higher microbial rates in governmental hospital, while the private hospital was not affected by this factor. Microbial rates in the patient room, main entrance and intensive care unit (ICU) were found to be influenced by the time of sampling, while the operating room and neonatal ward were not. Several explanations might be involved in these variations, that is, the age of hospital building, the number of beds, the number of visitors, disinfection procedures and ventilation systems. We concluded that the indoor air quality of hospitals in Zarqa city, especially the governmental hospital, needs more care and surveillance and should be given priority in Jordan

Morphological and chemical changes of aerosolized E. coli treated with a dielectric barrier discharge

This study presents the morphological and chemical modification of the cell structure of aerosolized Escherichia coli treated with a dielectric barrier discharge (DBD). Exposure to DBD results in severe oxidation of the bacteria, leading to the formation of hydroxyl groups and carbonyl groups and a significant reduction in amine functionalities and phosphate groups. Near edge x-ray absorption fine structure (NEXAFS) measurements confirm the presence of additional oxide bonds upon DBD treatment, suggesting oxidation of the outer layer of the cell wall. Electron microscopy images show that the bacteria undergo physical distortion to varying degrees, resulting in deformation of the bacterial structure. The electromagnetic field around the DBD coil causes severe damage to the cell structure, possibly resulting in leakage of vital cellular materials. The oxidation and chemical modification of the bacterial components are evident from the Fourier transform infrared spectroscopy and NEXAFS results. The bacterial reculture experiments confirm inactivation of airborne E. coli upon treating with DBD.Peer reviewe