The effect of Lactococcus lactis and Bifidobacterium bifidum probiotics cell free supernatants on the expression of HDC and TDC genes in Staphylococcus strains isolated from milk

Mohammad Ali Masiyan Moghadam,Seyed Amirali Anvar,Mohammadreza Khani,Kumarss Amini

doi:10.1590/fst.03221

Mohammad Ali Masiyan Moghadam, Seyed Amirali Anvar + Show 2 more

Open Access

https://doi.org/10.1590/fst.03221

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Abstract

The most important microorganisms contaminating milk, such as staphylococci, exert their influence by producing toxins and biogenic amines (BA). The purpose of this study was to evaluate the influence of cell-free supernatants (CFS) related to the probiotic strains of Lactococcus lactis and Bifidobacterium bifidum on the expression of BA-producing genes, histamine decarboxylase, and tyramine decarboxylase in staphylococci isolated from milk. Staphylococci isolates of cow raw milk were identified and isolated using standard methods. Samples containing these strains were analyzed by HPLC for BA production. Bacteria with target genes were treated with L. lactis and B. bifidum CFS, and the expression of target genes was measured by Real time PCR. Generally, 60 strains of Staphylococcus were isolated, and 90% of strains had HDC and TDC genes in genome. The levels of BAs were significantly higher on the second and third days after sampling compared with the first day (p <0.02). The analysis RT-PCR indicated that the under expression of target genes was statistically significant (P<0.05). This study showed that the use of probiotic bacteria can reduce the production of these amines and increase the quality of milk through reducing the expression of tyramine and histamine producing genes.

Highlights

Nowadays, cow milk and dairy products are among the most important foods in the world; adequate production and observance of hygienic points in their production and storage stages are of great importance
Our study evaluated the effect of L. lactis and B. bifidum probiotics on the expression of histamine and tyramine-producing genes of Staphylococcus species isolated from raw milk
This study aimed to examine the effect of L. lactis and B. bifidum probiotics on the expression of histamine and tyramine-producing genes of Staphylococcus species isolated from raw milk

Summary

Introduction

Cow milk and dairy products are among the most important foods in the world; adequate production and observance of hygienic points in their production and storage stages are of great importance. Milk is one of the most important human needs, especially in childhood; because it is rich in organic matter, it is a suitable environment for the growth of various food-borne pathogens This indicates the necessity for milk hygiene and elimination of pathogenic microorganisms and their products, including toxins and biogenic amines (Motaghifar et al, 2020; Acu et al, 2021; Amelia et al, 2021; Shabbir et al, 2020; Zendeboodi et al, 2020). Biogenic amines are very harmful products of milkcontaminating microorganisms These amines are low molecular weight compounds mainly formed by the decarboxylation of amino acids or amines and transfer of aldehydes and ketones (Poveda et al, 2020). Histamine is one of the most significant aromatic amines whose production is increased by bacteria undernutrient deficiency because in such conditions, histidine decarboxylation is an additional pathway for energy production (Durak-Dados et al, 2020; Elsanhoty & Ramadan, 2016; Luengo & Olivera, 2020)

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