Antimicrobial Effects of Four Lactobacilli Strains Isolated from Yoghurt against Escherichia Coli O157:H7. Issue 2 (14th March 2014)

• Record Type: Journal Article
• Authors: Imani Fooladi, Abbas Ali; Chavoshi Forooshai, Maryam; Saffarian, Parvaneh; Mehrab, Rezvan
• Is Part Of: Journal of food safety. Volume 34:Issue 2(2014:Apr.)
• Page Start: 150
• Page End: 160
• Publication Date: 2014-03-14
• Subjects: Food adulteration and inspection -- Periodicals; Food contamination -- Periodicals; Food -- Analysis -- Periodicals; Food -- Microbiology -- Periodicals; Pathogenic bacteria -- Periodicals; Food handling -- Periodicals; Food preservatives -- Periodicals; 664
• DOI: 10.1111/jfs.12108
• Languages: English
• ISSNs: 0149-6085

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="jfs12108-sec-0001" sec-type="section"> <p>This study aimed to isolate <italic>L</italic><italic>actobacillus</italic> species from yoghurt and to evaluate its antimicrobial activity against enterohemorrhagic <italic>E</italic><italic>scherichia coli</italic> O157:H7. After incubation of different yoghurt samples in MRS (de Man, Rogosa and Sharpe) agar at 37C under anaerobic conditions, four <italic>L</italic><italic>actobacillus</italic> species, <italic>L</italic><italic>. casei</italic>, <italic>L</italic><italic>. acidophilus, </italic> <italic>L</italic><italic>. helveticus</italic> and <italic>L</italic><italic>. delbrueckii</italic> ssp. <italic>bulgaricus</italic> were identified. Standard growth curves of <italic>E</italic><italic>. coli</italic> O157:H7 in proximity with lactobacilli test strains were obtained. The antibacterial effects of lactobacilli cell debris and culture supernatant against <italic>E</italic><italic>. coli</italic> O157:H7 were determined. The results showed that the antibacterial effects of culture supernatant were stable at different temperature conditions (56–100C) for 30 and 60 min; also, it was stable at pH 3–10. With regard to the antibacterial effect of the lactobacilli strains in this study, they may help in the treatment of <italic>E</italic><italic>. coli</italic> O157:H7‐associated diseases and can be applied as a biological preservative in the food industry.</p> </sec> <sec id="jfs12108-sec-0002" sec-type="section"> <title>Practical Applications</title> <p>In recent years, foodborne diseases become a health problem in most of the population. One of the most important etiologic agents of such diseases is <italic>E</italic><italic>scherichia coli</italic> O157:H7, which can be transmitted through eating undercooked infected meat and leads to hemorrhagic diarrhea and kidney failure. There is increasing evidence that lactobacilli bacteria produce potential agents (H<sub>2</sub>O<sub>2</sub>, small organic compounds, lactic acid, etc.) that can inhibit growths of some invasive foodborne bacteria, such as enterohemorrhagic <italic>E</italic><italic>. coli</italic>. The results of this study also confirmed these reports and showed that the use of lactobacilli bacteria is a promising way to prevent the infection of <italic>E</italic><italic>. coli</italic> O157:H7; also, they can be used as a biological preservative in the food industry.</p> </sec> </abstract>