Survival of Escherichia coli 0157:H7 and non 0157 strains in synthetic gastric fluid inoculated on commercially available frankfurters

Betul Bozatli S., DİKİCİ A., Ergonul B.

Fresenius Environmental Bulletin, vol.30, no.2 A, pp.1579-1587, 2021 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 2 A
  • Publication Date: 2021
  • Journal Name: Fresenius Environmental Bulletin
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Environment Index, Geobase, Greenfile, Metadex, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Page Numbers: pp.1579-1587
  • Keywords: Frankfurter, STEC, Survival, Synthetic gastric fluid
  • Uşak University Affiliated: Yes

Abstract

In this study acid resistance of STEC 0157:H7 and non-0157 STEC serogroups of 026, O103 and 0145 were investigated during storage of commercially available frankfurters. Pathogens were surface inoculated on frankfurters ca. 5±1 log cfu/g and the inoculated frankfurters were stored at 4°C for 75 days. Microbiological analysis and pH measurements were conducted at days 0, 15, 30, 45, 60 and 75 of cold storage. In the first part of the study, different brands of commercially available frankfurters produced from cattle meat (Brand A, B, C, D, E) were investigated in order to evaluate which brand aided pathogen survival in acidic environment. Pathogen resistance to synthetic gastric fluid (SGF) was very weak in brands A, B, C, and D samples, and survivor counts were undetectable during SGF experiments after "Day 0" of the storage. These preliminary experiments showed that pathogens had stronger acid resistance on one brand of frankfurters, therefore in the second part of the study triplicate trials were conducted with this brand (Brand E). On brand E frankfurters, the pathogens were still detectable at the 45th day of storage after SGF exposure except for 0157:H7. The gradual decrease in the pH of this brand of frankfurters might have aided acid resistance of the pathogens. Results show that in every brand of samples tested, the non-0157 serogroups had higher survivor counts than 0157:H7, during storage and SGF experiments of frankfurters.