Isolation and Preliminary Characterization of A Bacteriocin-Producer Bacillus Strain Inhibiting Methicillin Resistant Staphylococcus Aureus
In a multivalent approach to discover new antimicrobial substance, a total of 160 Bacilli were isolated from termitarium soil, characterized on the basis of their morphological and physiological characters and screened for their antimicrobial activity by agar well diffusion method against certain drug resistant pathogenic bacteria such as Staphylococcus aureus, Methicillin resistant Staphylococcus aureus and common food contaminating bacteria Listeria monocytogenes. After preliminary screening, sixteen isolates showed inhibitory activity against test pathogens. Among them Bacillus isolate TSH58 exhibited maximum inhibitory activity against MRSA, Staphylococcus aureus and Listeria monocytogenes. Based on morphological, physiological, biochemical and 16S rDNA characteristics isolate TSH58 was identified as a member of the Bacillus cereus species group. Various nutrient sources and culture conditions were optimized, the partially purified antimicrobial metabolite was subjected to various treatments such as heat, pH and proteolytic enzymes. Complete loss in the activity observed when the crude metabolite was treated with proteolytic enzymes suggesting its proteinaceous nature and termed as bacteriocin like inhibitory substance (BLIS). Minimal inhibitory concentration of the partially purified bacteriocin determined by microtiter plate assay was 80 μg/ml for MRSA and 40 μg/ml for L. monocytogenes. Tricine SDS PAGE analysis revealed that the partially purified bacteriocin produced by the Bacillus strain TSH58 had an apparent molecular weight of about 4.0 KDa.
KeywordsBacillus Staphylococcus aureus MRSA Listeria monocytogenes bacteriocin
Unable to display preview. Download preview PDF.
- 4.Aunpad, R., Sripotong, N., Khamlak, K., Inchidjuy, S., Rattanasinganchan, P., Pipatsatitpong, D. (2011) Isolation and characterization of bacteriocin with anti-listeria and anti-MRSA activity produced by food and soil isolated bacteria. Afr. J. Microbiol. 5, 5297–5303.Google Scholar
- 10.Dubey, R. C., Maheshwari, D. K. (2012). Practical Microbiology. S. Chand & Co., New Delhi, India.Google Scholar
- 11.Holt, J. G., Krieg, N. R., Sneath, P. H. A., Staley, J. T., Williams, S. T. (1994). Bergey’s Manual of Determinative Bacteriology. Williams and Wilkins Press, Baltimore, USA.Google Scholar
- 14.Kumar, S., Stecher, G., Tamura, K. (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Mol. Biol. Evol. 8, 54–59.Google Scholar
- 15.Manjula, A., Sathyavathi, S., Pushpanathan, M., Gunasekaran, P., Rajendhran, J. (2014) Microbial diversity in termite nest. Curr. Sci. 106, 1430–1434.Google Scholar
- 17.Naghmouchi, K., Baah, J., Hober, D., Jouy, E., Rubrecht, C., Sané, F., Drider, D. (2013) Synergistic effect between colistin and bacteriocins in controlling Gram-negative pathogens and their potential to reduce antibiotic toxicity in mammalian epithelial cells. Antimicrob. Agents Chemother. 57, 2719–2725.CrossRefGoogle Scholar
- 22.Saleem, F., Ahmad, S., Yaqoob, Z., Rasool, S. A. (2009) Comparative study of two bacteriocins produced by representative indigenous soil bacteria. Pak. J. Pharma Sci. 22, 252–258.Google Scholar
- 23.Sambrook, J., Russel, D. (2001). Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, USA.Google Scholar
- 28.Shokri, D., Zaghian, S., Khodabakhsh, F., Fazeli, H., Mobasherizadeh, S., Ataei, B. (2014) Antimicrobial activity of a UV-stable bacteriocin-like inhibitory substance (BLIS) produced b. Enterococcus faecium strain DSH20 against vancomycin-resistan. Enterococcus (VRE) strains. J. Microbiol. Immunol. Infect. 47, 371–376.CrossRefGoogle Scholar
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.