MOLECULAR IDENTIFICATION OF AIRBORNE BACTERIA FROM METRO STATIONS IN RIYADH

Multiple factors such as ambient humidity, oxygen, temperature, and microbial pollutants affect the way bioaerosols initiate health complications, including allergic, respiratory, and infectious diseases, even in indoor environments such as metro stations. The growth of these bacterial species is affected by seasonal and climatic conditions (temperature and humidity). As the indoor air pollutant control in a transit system is an important public health and safety concern, we performed this study between January and September 2019 to analyse and report the prevalence of bacterial populations in closed environment systems in Saudi Arabia. Thirteen metro stations were chosen, and samples were obtained from 21 collection sites at these stations at specified dates and time. Bacterial samples were grown and incubated at 37 °C for 48 h, respectively. The isolated bacteria were tested for antimicrobial sensitivity and resistance. A total count of 84 bacterial samples were obtained from the 13 collection sites. There were 49 bacterial species belonging to 29 genera, and the most common species included Carno-bacteriaceae, Neisseria animaloris i zoodegmatis, Bacillus pumilus, Microcossus luteus, Granulicatella elegans, Staphylococcus hominis subsp. hominis, Globicatella suldifaciens, Kocuria rosea, Kocuria twfanensis, and Kocuria sediminis. Antimi- crobial sensitivity test results showed that only five of the isolated bacterial species were susceptible to the tested antibiotics. Temperature and humidity affected the growth of bacteria.