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

Molecular typing and cytotoxicity testing of Staphylococcus aureus isolated from milk, meat and clinical sources

Williams L. L.*
  • Williams L. L.*
  • Center of Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, the North Carolina Research Campus, Kannapolis, NC 28081, North Carolina, United States
  • Search for this author on:
  • Google Scholar
Ajayi O. A.
  • Ajayi O. A.
  • 2. Department of Food and Animal Sciences, Alabama Agricultural and Mechanical University, Food Microbiology and Immunochemistry Laboratory, Normal, AL. 35762, United States; 3. Department of Food Science and Technology, Bowen University, Iwo, Osun State, Nigeria
  • Search for this author on:
  • Google Scholar
Johnson, J.U
  • Johnson, J.U
  • Department of Food and Animal Sciences, Alabama Agricultural and Mechanical University, Food Microbiology and Immunochemistry Laboratory, Normal, AL. 35762, United States
  • Search for this author on:
  • Google Scholar
Carter B.
  • Carter B.
  • Center of Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, the North Carolina Research Campus, Kannapolis, NC 28081, North Carolina, United States
  • Search for this author on:
  • Google Scholar
Khatiwada J
  • Khatiwada J
  • Center of Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, the North Carolina Research Campus, Kannapolis, NC 28081, North Carolina, United States
  • Search for this author on:
  • Google Scholar


  •  Received: 09 December 2013
  •  Accepted: 21 February 2014
  •  Published: 19 March 2014

Abstract

Staphylococcus aureus is one of the main causes of foodborne diseases and a leading cause of nosocomial infections worldwide. Eleven (11) isolates from milk; 34 from meat and 23 of clinical source were subjected to phenotypic and biochemical characterizations for confirmation and further analysis for the presence of virulent genes, clonal relatedness and cytotoxicity profile. All isolates were positive for catalase production; 3, 11, and 7 isolates from milk, meat and clinical sources were coagulase positive. Polymerase chain reaction technique was used for the detection of 16S rRNA, clumping factor (cflA) and methicillin resistance (mecA) virulent genes. All isolates were positive for 16S rRNA; 100 and 45% of clinical; 73 and 64% of milk and none of the meat isolates were positive for cflA and mecA genes, respectively. Eight SmaI-based pulse-field gel electrophoresis (PFGE) clusters were identified at 80% similarity. Cytotoxic potential of the strains showed that 27.8, 24.1 and 22.2% of the strains tested had high, medium and low lactate dehydrogenase (LDH) release, respectively. These findings clearly demonstrate the presence of S. aureus in food and also in clinical infections, thus it should be a public health concern because even when virulent genes were not amplified in some strains, there may still be cytotoxicity effects.

 

Key words: Staphylococcus aureus, pulse-field gel electrophoresis (PFGE), lactate dehydrogenase (LDH), cytotoxicity profile, molecular typing.

Copyright © 2024 Author(s) retain the copyright of this article.

This article is published under the terms of the Creative Commons Attribution License 4.0

Back to Vol. 8 No. 12
Back to articles
SUBSCRIBE TO RSS
SUBMIT MANUSCRIPT
CONFERENCES