African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5169

Full Length Research Paper

The effect of short-time microwave exposures on Escherichia coli O157:H7 inoculated onto beef slices

A. Jamshidi1*, H. A. Seifi2 and M. Kooshan3
1Department of food hygiene, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran. 2Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran. 3DVM degree, Graduated from School of Veterinary Medicine, Ferdowsi University of Mashhad, Iran.
Email: [email protected]

  •  Accepted: 06 September 2010
  •  Published: 18 November 2010

Abstract

 

Escherichia coli O157:H7 is an important human pathogen causing haemorrhagic colitis, hemolytic-ureamic syndrom and thrombotic thrombocytopenic purpura. In this study the effect of microwave irradiation of beef samples which were inoculated withE. coli O157:H7 were investigated. The portions of fresh beef slices weighting 200 g each and about 10 × 10 × 2 cm in size, were soaked in fully growth of E. coli O157:H7, in BHI broth. The swab samples were taken from the contaminated samples, after different times of radiation (10, 20, 30, 40 and 50 s), using a domestic microwave oven at full power. The bacterial counts were performed by using surface plating on sorbitol Mac Conkey agar supplemented with cifixime and potassium tellurite. After each experiment the surface temperature of treated samples were measured. The experiment was carried out in triplicate and it was concluded that the microwave radiation which enhance the surface temperature more than 70°C, can eliminate the superficial contamination of cattle beef  slices with E. coli O157:H7.    

 

Key words: Escherichia coli O157:H7, microwave, beef.