Antagonism of Lactobacillus spp. Isolated from Minas Artisanal Cheese Produced in Serra da Canastra, Brazil, against Staphylococcus spp

Introduction: Lactobacillus is a desirable lactic acid bacteria (LAB) found in a great variety of artisanal cheeses in which they play important roles as development of typical flavor and production of substances that reduce or inhibit the growth of pathogens. Staphylococcus is also found in artisanal cheeses and may elaborate enterotoxins that cause food intoxication.

Purpose: This study aimed to evaluate the inhibitory capacity of Lactobacillus spp. isolated from Minas artisanal cheese produced in Serra da Canastra, Brazil, against Staphylococcus spp. isolated from the same food.

Methods: Two samples of L. rhamnosus and one sample of L. plantarum, isolated from artisanal cheeses and identified by PCR ARDRA16S-23S, were submitted to in vitro antagonism test against 18 samples of Staphylococcus spp. isolated from the same cheeses. The analyses were carried out in triplicate considering three repetitions of the experiment. Means of inhibition halos were compared by the Kruskal-Wallis test (P < 0.05).

Results: All tested lactobacilli inhibited all samples of Staphylococcus spp. L. plantarum showed higher inhibition halos (P < 0.05) than the two samples of L. rhamnosus which presented similar mean inhibition halos (P > 0.05). These findings indicate that the inhibition behavior against Staphylococcus spp. may vary more between Lactobacillus species than between samples of the same species. 

Significance: The in vitro antagonism of Lactobacillus spp. against Staphylococcus samples observed in this study may also occur in artisanal cheeses avoiding the production of staphylococcal enterotoxins and the occurrence of foodborne outbreaks related to the consumption of cheeses made of raw milk.