Detection of bacteriocin-producing lactic acid bacteria from milk in various farms in north-east Algeria by a new procedure

H. Daba¹,* and S. Saidi¹

¹University of Setif 1, Nature and Live Sciences Faculty, Department of Microbiology, 19000, Setif, Algeria; *Correspondence: dabhoc@yahoo.fr

Abstract:

Twelve samples of bacteriocin-producing lactic acid bacteria were isolated from raw milk. The screening procedure has the advantage of differentiating directly on agar plates active colonies among thenatural microbial population without subsequent culture. Five of milk isolates had effective inhibitory activity against Staphylococcus, Bacillus and all Listeria monocytogenes strains tested. In addition, two bacteriocinogenic isolates were effective against Gram-negative bacteria including Pseudomonas aeruginosa and Escherichia coli. The action of the bacteriocins was eliminated by a proteolytic enzyme. Simulation tests in liquid medium showed a 3 log reduction of Listeria growth in presence of bacteriocin during a period stockage of 14 days at 4°C.

Key words:

Review of the contamination and health risks related to Campylobacter spp. and Listeria monocytogenes in the food supply with special reference to Estonia and Latvia

M. Roasto¹, K. Kovalenko², K. Praakle-Amin³,K. Meremäe¹, T. Tamme¹, T. Kramarenko⁴

¹Estonian University of Life Sciences, Institute of Veterinary Medicine andAnimal Sciences, Department of Food Hygiene, Kreutzwaldi 58A, Tartu, Estonia, 51014; e-mail: mati.roasto@emu.ee
²Latvia University of Agriculture, Faculty of Veterinary Medicine, Departmentof Food and Environmental Hygiene, K. Helmana iela 8, Jelgava, Latvia, LV–3004; e-mail: ch@no.lv
³University of Helsinki, Faculty of Veterinary Medicine, Department of FoodHygiene and Environmental Health, P.O. Box 66, FI-00014, Finland; e-mail: kristi.praakle@helsinki.fi
⁴Estonian State Veterinary and Food Laboratory, Kreutzwaldi 30, Tartu, Estonia,51006; e-mail: toomas.kramarenko@vetlab.ee

Abstract:

The present study gives a review of the contamination and health risks related to Campylobacter spp. and L. monocytogenes in the Estonian and Latvian food supply. Campylobacteriosis and human listeriosis are important zoonotic diseases. Therefore, biosecurity measures at the farm level and Good Hygiene Practices at the industry level must be strictly followed. Further improvements in the state surveillance and food industry self-control systems are needed both in Estonia and Latvia.

Key words:

Campylobacter spp., contamination, health risks, Listeria monocytogenes