African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

Antibiotic susceptibility testing of isolated Bacillus thuringiensis from three soil types around Iligan City, Philippines

Jing R. Bautista* and Franco G. Teves
Department of Biological Sciences, College of Science and Mathematics, MSU-Iligan Institute of Technology, 9200 Iligan City, Philippines
Email: [email protected]

  •  Accepted: 24 January 2013
  •  Published: 19 February 2013


This study was conducted with the aim of isolating and identifying entomopathogenic isolate of Bacillus thuringiensis (Bt) from the three different kinds of soils and to determine its antibiotic susceptibility. Soil samples were taken from three different uncultivated sites that have no history of treatment with Bt products. Isolation of the Bt strain was conducted based on the conventional biochemical method and the phenotypic characteristics of the isolated Bt were determined by making use of standard methods. 20 presumptively identified strains of Bt were subjected to antibiotic testing by using ampicillin, amoxicillin, tetracycline, streptomycin, and ofloxacin. Results show that the isolated strains of Bt were resistant to β-lactams (amoxicillin and ampicillin).


Keywords: antibiotic susceptibility, β-lactams, vermicast