Microbiological assessment of bioaerosols in the residential areas of Dhaka City, Bangladesh

This study looked at particulate matter (PM10) in terms of its microbiological features and how bacterial populations are related to PM10. It also tested the antibiotic resistance of different types of microbes that live in PM10. We conducted the study in six different locations (Badda, Chittagong Road, Basabo, Jurain, Mirpur, and Gulshan) of Dhaka city, taking into account residential and commercially important areas, traffic congestion, and infrastructure development. The microbiological study revealed that Bacillus spp. and Staphylococcus spp. were primarily present in PM10. The study also revealed that the total bacterial count (46585±1226.8 CFU/m 3 ) of the Badda zone is higher than in another area. Similar findings were also observed in the case of Bacillus spp. (15625±5729 CFU/m 3 ), Staphylococcus spp. (18518±5730 CFU/m 3 ), and total fungal count (726852± 98209 CFU/m 3 ). Moreover, a positive correlation was observed among Bacillus spp. and Staphylococcus spp. vs. mean PM10 concentration, which implies that airborne microbes in Dhaka city are likely to propagate with the increase of dust concentration. The antibiotic sensitivity assay of Bacillus spp. and Staphylococcus spp. revealed that all the Bacillus spp. (n=16) and Staphylococcus spp. (n=3) were resistant to Ceftazidime (30 µg), Oxacillin (1 µg) and Cefixime (5 µg). So, the research findings highlighted the increased levels of Bacillus spp. and Staphylococcus spp. than the international standard in PM10 of Dhaka city, suggesting potential health risks and indicating antibiotic resistance among these bacterial strains. • The research work indicates significant presence of Bacillus spp. and Staphylococcus spp. as predominant microbes in PM 10 samples of Dhaka city. • A positive correlation was observed between the concentrations of Bacillus spp. and Staphylococcus spp. with mean PM 10 levels. • MDR strains of Bacillus spp. and Staphylococcus spp. indicating a potential threat to the environment, underscoring the need for urgent measures to mitigate health risks associated with airborne pathogens.