Methicillin-resistant Staphylococcus aureus (MRSA) isolated from chicken meat and giblets often produces staphylococcal enterotoxin B (SEB) in non-refrigerated raw chicken livers

Int J Food Microbiol. 2020 Sep 2:328:108669. doi: 10.1016/j.ijfoodmicro.2020.108669. Epub 2020 May 20.

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for several difficult-to-treat infections and staphylococcal food poisoning (SFP). This study was conducted to investigate the prevalence and enterotoxigenicity of MRSA in broiler chicken meat and giblets. A total of 5.5% (8/144) of the examined samples were contaminated with mecA positive/mecC negative MRSA, with staphylococcal counts of approximately 102 colony forming units (CFU)/g in breast, leg and gizzard samples and approximately 3.3 × 103 CFU/g in frozen liver samples. Most MRSA isolates (75%, 6/8) harboured the staphylococcal enterotoxin B (seb) gene. Reverse transcription-PCR (RT-PCR) showed that MRSA isolates initiated SEB production in experimentally contaminated chicken livers within 24 h of storage at temperatures over 8 °C. SEB was maximally produced at 24 °C when the MRSA counts reached 7.3 × 103 ± 1.2 × 103 CFU/g sample homogenate. The current study concludes that the main broiler chicken MRSA isolates in Egypt harbour the seb gene. To mitigate possible SEB production, especially in broiler chicken livers, a maximum "out of refrigeration" time limit should be implemented for cold chain poultry products.

Keywords: Chicken meat and giblets; Liver; MRSA; Refrigeration; SEB; enterotoxin expression.

MeSH terms

  • Animals
  • Chickens / microbiology
  • Egypt / epidemiology
  • Enterotoxins / genetics*
  • Food Microbiology
  • Food Storage / methods*
  • Liver / microbiology*
  • Meat / microbiology*
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Methicillin-Resistant Staphylococcus aureus / metabolism
  • Poultry Products / microbiology*
  • Refrigeration
  • Staphylococcal Infections / epidemiology

Substances

  • Enterotoxins
  • enterotoxin B, staphylococcal