In vitro antimicrobial activity and interactions of plant extracts and antibiotics against multi-drug resistant isolates | |
| Author | Arunagiri, Kalpana Soundappan |
| Call Number | AIT Thesis no.FB-12-08 |
| Subject(s) | Extraction (Chemistry) Antibiotics Anti-infective agents |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-12-08 |
| Abstract | In vitro antimicrobial activity and interactions between plant extracts and antibiotics against clinically acquired pathogens namely Methicillin resistant Staphylococcus aureus(0193), Escherichia coli (0172) (ESBL),Streptococcus sp, Escherichia coli (0038) were studied. Four plant extracts Emblica officinalis, Azadirachta indica, Acacia nilotica and Murraya koenigii and antibiotics Penicillin, Tetracycline, Chloramphenicol and Kanamycin were used for bacterial susceptibility testing. All the plant extracts showed good antimicrobial activity against the test pathogens. Antibiotics did not show effective activity against drug resistant isolates especially with Gram-negative isolates. Minimum inhibitory concentration of extracts and antibiotics were determined. Emblica officinalis and Acacia nilotica showed greater effect against drug resistant isolate MRSA (0193) and MIC value was found to be 0.78 mg/ml (for both the plant extracts) and the MIC value was 12.5 mg/ml and 1.56 mg/ml respectively against E. coli (0172) (ESBL). The extracts of Emblica officinalis, Azadirachta indica, Acacia nilotica and drugs Tetracycline and Chloramphenicol were used to determine the combined effect against pathogens. The interactions between extracts and antibiotics at 1x MIC, 0.5xMIC, 0.25x MIC, 0.125xMIC against drug resistant pathogens were studied and the combinations showed promising results. Inhibition at sub inhibitory concentration (0.25 x MIC) was considered for synergism assays. Synergism between the antimicrobial agents was determined using fractional inhibitory concentration (FIC) Index. The combinations of tetracycline and extracts of Acacia nilotica and Emblica officinalis showed strong synergistic effect against both MRSA (0193) and E. coli (0172) (ESBL) with FIC index ranging from 0.24 - 0.25. Similarly, the interaction of the drug chloramphenicol with Acacia nilotica and Emblica officinalis extract inhibited the growth of test organisms and showed synergistic effect with FIC index ranging from 0.240- 0.5. The interactions between chloramphenicol and Azadirachta indica showed synergistic effect against the strain MRSA 0193 but antagonistic effect against E. coli (0172) (ESBL) with FIC index greater than 2. In general, the results obtained were encouraging and can provide alternative method to treat infectious diseases caused by drug resistant organisms using lower levels of antibiotics. |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-12-08 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Rakshit, Sudip Kumar; |
| Examination Committee(s) | Athapol Noomhorm;Anal, Anil Kumar; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2012 |