Microbiological Air Quality and Antibiotic Resistance in Isolated Bioaerosols from Various Activities in Zanjan, Iran

The aim of this study is the isolation and primary identification of isolated bioaerosols sampled from different locations, as well as determining their antibiotic resistance profile for the selected bacteria.

The air samples were collected from 35 stations in 17 buildings (bank, public, healthcare and industrial). An air-sampling pump (Flite3-SKC) with a flow rate of 14.1 l/min was used for five minutes at the respiratory height. The total bacterial count and primary identification were carried out, then the antibiotic susceptibility tests for ten selected antibiotics were conducted by the disk diffusion method. 

The bacterial population varied at a range of 128-5503 CFU/m3, and the fruit and vegetable bazaar of Zanjan showed the highest population of bioaerosols. The bioaerosols population among industrial samples was high. Most isolates were determined as gram-positive Cocci (> 70%) and Bacillus spp, respectively. The most antibiotic-resistant bacteria were related to manufacturing activities, showing resistance to Chloramphenicol and Trimethoprim/ Sulfamethoxazole (72%).

The type of activity affects the bacterial population and antibiotic resistance in industrial uses. The increase of multi-drug resistant bacteria, especially in medical settings, is known as a community health challenge and needs more attention.