Biofilm formation of Yersinia enterocolitica and its response against GRAS compounds in meat juice

Abstract

Yersinia enterocolitica is a food-borne pathogen that causes yersiniosis, and its primary sources are animal-originated foods. This work aimed to analyze the effect of fresh pork meat juice (MJ) on planktonic and biofilm growth of Y. enterocolitica strains and to investigate the activity of some generally recognized as safe (GRAS) food preservatives. Twenty-eight Y. enterocolitica strains were used to test growth and biofilm formation in MJ, trypticase soy broth supplemented with 0.25% of glucose (TSBG) alone and in combination with 50% MJ (TSBG:MJ). All strains grew in MJ but most of them to lesser extent than in TSBG. Although TSBG:MJ was the most favorable medium for biofilm formation, many strains were able to form biofilm in MJ. To determine GRAS compounds activity, one B1A and one B1B Y. enterocolitica strain were selected. In nutrient broth with MJ, acetic acid was the most effective compound with MIC of 0.78 mg ml-1, MBC of 3.14 mg ml-1, and BIC of 1.57 mg ml-1 for both strains; for B1A strain, BBC was 12.56 mg ml-1 and for B1B strain, it was 25.12 mg ml-1. Although not all strains exhibited the same ability to form biofilms in MJ, it reduces the susceptibility of Y. enterocolitica to GRAS compounds.

Keywords: Yersinia enterocolitica; GRAS; biofilm; inhibition; meat juice.