Bioindicator potentiality of the chironomine larvae (diptera: chironomidae) for determination of antibiotic resistant microbial load of the aquatic ecosystem

Abstract

Aerobic heterotrophic and Gram-negative, enteric, along with the antibiotic resistant microbial flora were enumerated in the pond / sewage-fed drain water and resident chironomine larvae. Microbial population level was found significantly higher in the drain water than that of pond water. Among the resistant microbial flora, ampicillin resistant population dominated over the streptomycin, chloramphenicol and tetracycline resistant flora. Microbial populations were much higher in the larvae than in the surrounding water. The relative percentage of resistant larval isolates was higher in the drain water inhabiting larvae than those of pond for each of the antibiotics tested. An assay of multi-antibiotic resistance of specific bacterial isolates revealed that larval isolates from pond water were sensitive to chloramphenicol, kanamycin, nalidixic acid, streptomycin and tetracycline, whereas larval isolates from drain water were found resistant to all the antibiotics except colistin methane sulphonate. Ampicilin resistance was 100% in both cases. Results of the present study suggest that midge larvae may be used as potent bioindicator organism to apprise their inhabiting aquatic environment by evaluating the accumulation of antibiotic resistant microbial load therein.