16S rRNA gene identification of airborne pathogenic bacteria isolated from bioaerosols of wastewater treatment plant

Background and objective Wastewater treatment plants (WWTPs) represent a source of airborne bacteria. The presence of airborne bacteria in the environment of WWTPs could be considered as a potential health hazard for the exposed workers. This study aimed to isolate and identify cultivable bacteria from bioaerosols of different sites in a WWTP using 16S rRNA gene identification, as a first step to identify the pathogenic health hazards among the exposed workers. Materials and methods Air samples were collected from various locations in a selected WWTP. Airborne microorganism samples were collected on the nutrient agar plates by the settle-plate technique and were identified by the 16S rRNA gene sequencing technique. Results A total of 32 bacterial isolates were collected and sequenced. The study identified 25 different bacterial species. Of the 25 different strains, 10 (40%) belonged to pathogenic bacteria. Overall, 40% of the isolated pathogenic species were from the secretary room locations. The isolated bacterial species were Staphylococcus sp., Bacillus sp., Rhodococcus sp., Cellulosimicrobium funkei, Kytococcus sedentarius, and Kocuria rosea. The highest percentage occurrence was Bacillus sp. (37.5%), followed by Staphylococcus sp. (18.75%). Conclusions Disseminated infection can be associated with isolated pathogen, and this result gives a warning of the danger of the spread of pathogenic aerobic bacteria in WWTPs and their existence in indoor environments.