MOLECULAR IDENTIFICATION AND ANTIBIOTIC SENSITIVITY PATTERN OF BACTERIA ASSOCIATED WITH DECOMPOSED FOOD WASTES FROM AKURE METROPOLIS

Abstract

This research assessed the molecular identities and antibiotic sensitivity pattern of the bacteria initially isolated from decomposed food wastes in Akure metropolis. Minimum inhibitory concentrations of most potent antibiotics were also investigated. Fifteen bacteria were provided by the Department of Microbiology, Federal University of Technology Akure. Their DNA molecules were extracted using bacterial DNA Mini-Prep Kit, amplified using universal bacterial primers and sequenced with an ABI Prism DNA sequencer and their nucleotides were blasted. The antibiotic sensitivity test of the bacteria was carried out using the pour plate method. Commercial antibiotic discs and minimum inhibitory concentration (MIC) were carried out using standard methods. The probable genus and species names were retained for eight of the bacteria at molecular level were Bacillus megaterium, Clostridium difficile, B. thuringiensis, B. sphaericus, B. mycoides, B. cereus, Pseudomonas asplenii, Paenibacillus macerans, Lactobacillus jensenii, B. badius, B. licheniformis, B. Subtilis and L. delbrueckii. The other two bacteria C. humiferium and B. pumilus changed their species names to pseudotuberculosis and cereus respectively. The molecular techniques also revealed the strain names of the bacteria. The antibiotic sensitivity profile of the bacteria revealed that erythromycin caused the best inhibition (59.77±0.66 mm) against L. delbrueckii which was also resistant to amoxicillin, chloramphenicol and cefriazone. However, with C. difficile, only one of the ten antibiotics (gentamycin) could inhibit the growth with zone of inhibition of 13.93±0.47 mm. The (MIC) test showed that cotrimoxazole required 25.0 μg/mL to inhibit C. pseudotuberculosis 33. However, the following antibiotics needed the minimum concentration of 2.50 μg/mL to inhibit their corresponding microbes: ciprofloxacin (B. lincheniformis ATCC 14580), erythromycin (L. delbreuckii subsp. bulgaricus ND02 and B. thurigiensis serovar israelensis strain AM65-52) and gentamycin (P. macerans). No MICs were achieved within the range of concentrations used in this study against P. Asplenii. This study has revealed correct identities of the bacteria and some of the bacteria C. pseudotuberculosis, B. cereus, B. licheniformis, B. subtilis, and B. cereus which are known to be pathogenic demonstrated multidrug resistant property. These microbes could constitute a serious threat to the health of the people living in the environment where the wastes are dumped and allowed to decay