A study of prevalence and antimicrobial resistance and pathogenic activity of bacteria in the air of certain areas of Dhaka city

Abstract

The economic hub of Bangladesh, it’s capital city Dhaka is subject to a high level of pollution all year round, which makes the air harmful to breathe. On average, around 14 m3 of air is inhaled by an individual every day. The ubiquity of pathogenic bacteria in the air that people inhale, presents the utmost health hazard for them. The purpose of the study is the enumeration of the prevalent bacteria in Dhaka city’s air, identifying the pathogens among them by analyzing their hemolysis pattern. This study was carried out in 10 bustling areas around Dhaka (Dhanmondi, Gulistan, Mohakhali, Khilgaon, Motijheel, Mohammadpur, Badda, Keraniganj, Shantinagar, Mirpur). For sample collection, different selective media (Nutrient agar, Mannitol Salt agar, MacConkey agar, EMB agar) were exposed in the air where the highest and lowest CFU were 189 and 1 respectively. Distinct colonies were chosen and sub-cultured in nutrient agar for running further tests. Pathogens were screened a through Hemolysis test in blood agar. A total of 157 isolates were screened for pathogenicity in blood agar and their hemolysis pattern showed 43 of them being capable of hemolysis. Among 157 isolates, 22 showed β hemolysis where they completely lysed the red blood cells; 12 isolates showed α hemolysis and 9 isolates showed γ hemolysis. In the DNAse test, out of 43 samples, 17 turned out to be DNAse negative, and 26 were DNAse positive. The results of the study indicate the potential presence of pathogens in the air which calls for an extension of it that would help find out the potential pathogens present in the air and act on time before the matter gets out of hand and give rise to new incidences, epidemics, or even pandemics.