Assessment of Airborne Microbial Composition and Antibiotic Susceptibility Profiles in Dumpsite Environments within Rivers State University

Abstract

The study was aimed at determining the microbial air quality and antimicrobial susceptibility of dumpsites within Rivers State University. The samples were collected from 5 different dumpsites and 10 meters away using the plate sedimentation method. Petri dishes containing culture media were used as sampling surfaces. The sampled media were incubated at 37oC and 30oC for bacteria and fungi respectively. The isolates from the culture were subcultured and identified by biochemical test methods. The multidrug resistance sensitivity of the isolates was determined by Kirby-Bauer disc diffusion method and multiple antibiotic resistance (MAR) index was determined. The total heterotrophic bacterial count of the dumpsites ranged from 1.43×103CFU/m3 to 5.8×104CFU/m3. The total heterotrophic fungal count of the dumpsites ranged from 1.06×103CFU/m3 to 2.3×103CFU/m3. The different bacteria identified were Bacillus sp, Micrococcus sp, Pseudomonas sp, Serratia sp, Staphylococcus sp. The fungi, Aspergillus niger, Saccharomyces sp, Fusarium sp, Aspergillus flavus, Candida albican, Penicillium sp and Mucor sp, Rhodotorula sp, A. fumigatus were identified. The antibiotic sensitivity study showed that 100% of the Gram-positive isolates were resistant to Augmentin, cefuroxime, 66.6% were resistant to cefotaxime, 50% were resistant to ceftriaxone, sulbatam, 33.3% were resistant to cefexime and erythromycin while 16.66 of the Gram-positive bacteria were resistant to, levofloxacin, gentamycin, ofloxacin, imipenem and cefotaxime. For the Gram-negative bacteria, 83.3 were resistant to ampiclox, cefuroxime, levofloxacin, 66.6% were resistant to cefexime, 50% were resistant to augmentin, cefotaxime, 33.3% were resistant to imipenem, gentamycin, nitrofurantoin, 16% were resistant to ceftraxime and all (100%) the bacterial isolates were sensitive to nalidixic acid. The study revealed that the dumpsite had impact on both the microbial load and quality of the environment. The microorganisms identified could contain pathogenic sp and impact on human health especially the immune-compromised. Also, the microbial load of the air around the dumpsites decreased with increase in distance from the dump sites.  The presence of multidrug resistant isolates could be of public health concerns.