139 Characteristic evaluation of bacteria in air and oral samples in surgical and medical intensive care units

The characteristics of bacteria taxonomy, biodiversity, and human-associated bacteria (HAB) in patients’ mouths and indoor air were evaluated and compared in surgical and medical intensive care units (ICUs). A six-stage viable Andersen cascade impactor was used to collect bioaerosols and to determine their size distributions. The sterilized cotton swabs were used to collect oral samples from four randomly selected patient’s mouths. A BD Phoenix-100 automated interpretation system was used to identify the sampled bacteria species. The results was showed Tatumella ptyseos, Staphylococcus scouri, Stenotrophomonas maltophilia, Moellerella wisconsensis, and Enterococcus faecalis were isolated from oral samples. Mannheimia spp. (28.5%), Staphylococcus spp. (19%), and Burkholderia spp. were the dominated bacteria which were isolated from the air samples. The proportion of HAB concentration in the oral sample was 6.3%, while the HAB concentration in the air was 19%. The low HAB rate indicated most of the cultured bacteria (non HAB) were possibly from the outside environment during work shifting or guest-visiting. Fifteen species of bacteria were collected in the air, and 2 species of them matched the bacteria collected from oral samples. The source of bacteria cultured from the patient’s mouth might be related to the distribution of bacteria in the air. However, the airborne bacteria might also come from the patient’s cough droplets. The phenomenon deserves further research in the future. It is recommended that the patient’s mouth should be cleaned regularly with sterilized cotton swabs or covered with sterilized gauze to reduce infection.