Objective:Probiotics such as lactobacilli prevent the development of a wide range of human and animal's pathogens. The aim of this study was evaluation of antagonistic effect of isolated lactobacilli from local dairy products against three standard strains of Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa.Materials and Methods:Twenty samples of local dairy products including cow milk, buffalo milk, cheese, and yogurt were collected from different areas of Ahwaz city. Antimicrobial disc diffusion method was applied on S. aureus (ATCC-6538), B. subtilis (ATCC-12711), and P. aeruginosa (ATCC-27853). Antimicrobial effects of isolates were evaluated by disc diffusion test on Mueller-Hinton agar medium plated with three pathogens.Results:Obtained results showed that only three strains of isolated lactobacilli of local dairy samples had inhibitory effects on understudy pathogens including Lactobacillus alimentarius, Lactobacillus sake, and Lactobacillus collinoides. All three isolates showed moderate activity (inhibition zone <15 mm) except of L. collinoides and L. alimentarius that had relatively strong activity (inhibition zone ≥15 mm) against P. aeruginosa and B. subtilis, respectively.Conclusion:These bacteria can be raised for the production of various kinds of food, pharmaceutical products, and functional foods.

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Objective:The Lactobacillus is a genus of lactic acid bacteria which are regularly rod-shaped, nonspore, Gram-positive, heterogeneous, and are found in a wide range of inhabitants such as dairy products, plants, and gastrointestinal tract. A variety of antimicrobial compounds and molecules such as bacteriocin are produced by these useful bacteria to inhibit the growth of pathogenic microbes in the food products. This paper aims to examine the isolation of Lactobacillus from local dairies as well as to determine their inhibition effect against a number of pathogens, such as two fungi: Penicillium notatum and Aspergillus fulvous.Materials and Methods:Twelve Lactobacillus isolates from several local dairies. After initial dilution (10−1–10−3) and culture on the setting, de Man, Rogosa and Sharpe-agar, the isolates were recognized and separated by phenotypic characteristics and biochemical; then their antifungal effect was examined by two methods.Results:Having separated eight Lactobacillus isolates, about 70% of the isolates have shown the inhabiting areas of antifungus on the agar-based setting, but two species Lactobacillus alimentarius and Lactobacillus delbrueckii have indicated a significant antifungal effect against P. notatum and A. fulvous. Except bacteriocin, lactic acid, and acetic acid, the inhibitor substance is produced by these bacteria.Conclusion:Given the vitality of Lactobacillus in human health, recognition and isolation of the species producing compound in antagonist to the pathogens existing in the food products can be a helpful and effective step toward maintaining the valuable native Lactobacillus and using them in the dairy industries.

The rotavirus is one of the major factors of inducing the acute gastroenteritis infection in children under 5 years of age. The laboratory diagnosis is progress and bringing it under control as well as avoiding its diffusion. The purpose of the present study was to determine the performance of enzyme linked immunosorbent assay (ELISA) and Latex agglutination (LA) tests against reverse transcription-polymerase chain reaction (RT-PCR) for evaluating the children’s acute gastroenteritis by rotavirus. One hundred feces specimens were collected from February to May 2014 and analyzed by LA, ELISA and RT-PCR. In this study, the positive results for rotavirus detected by ELISA, LA and RT-PCR were 37, 43 and 27%, respectively. In addition, the result showed that the sensitivity and specificity of ELISA and LA were 74 and 85%, respectively, when compared to RT-PCR. For laboratory detection of Rotavirus infection, RT-PCR has the highest sensitivity and specificity but because of the high costs, ELISA and LA based kits with good performance, as shown by this study, can be preferred for the routine use.