BACKGROUND: Staphylococcal foodborne intoxication is the most common cause of foodborne illnesses by Staphylococcus aureus strains and most are caused by the enterotoxins of S. aureus. Staphylococcal enterotoxin A (SEA) is the most frequently responsible for staphylococcal food poisoning outbreaks. From a food safety and human health point of view, lactic acid bacteria (LAB) may provide a promising strategy in the fight against S. aureus.OBJECTIVES: Increasing product shelf life, and enhancing the safety of food and human health using natural microflora are the aims of this study. METHODS: In this study we evaluate the inhibitory effects of three lactobacillus strains isolated from yoghurt, namely lactobacillus acidophilus, lactobacillus fermentum and lactobacillus paracasei, on the growth and enterotoxin production of Staphylococcus aureus by co-incubating each strain with enterotoxigenic S. aureus at two temperatures: 25 and 35°C. Expression of the SEA gene of S. aureus was assessed by real-time PCR. RESULTS: All the strains decreased the bacterial count at both temperatures compared to the control. This effect was greater at 25°°C than at 35°C. The production of SEA, SEC and SEE was inhibited by all the isolates tested. Furthermore, expression of the sea gene was significantly suppressed in S. aureus co-cultured with the lactobacillus isolates and the greatest impact was on Lactobacillus acidophilus at 35 ° C. CONCLUSINS: This research highlights the potential of lactic acid bacteria isolated from traditional foods for use as natural preservatives in foodstuffs and suggests a new approach for biocontrol of Staphylococcus aureus.

Background: The Endothelial PAS domain-containing protein 1 (EPSA1) is the key transcriptional regulator of hypoxic response and Vascular Permeability Factor (VPF) is an important growth factor for vascular development and angiogenesis. OBJECTIVES: In the present study, the levels of the EPSA1 coding gene and VPF transcripts were evaluated during Larval development of Beluga, Huso huso. METHODS: Samples at 12 developmental time-points including 1, 2, 4 days before hatch (eyed eggs), fresh hatched larvae (0), and larvae 1, 3, 6, 10, 15, 20, 25 and 50 days post-hatching were collected and  stored in a −80 °C freezer until RNA extraction. Changes in EPSA1 and VPF mRNA expression were studied and differences in normalized mRNA expression levels among the different developmental stages of H. huso were analyzed by one-way analysis of variance (ANOVA). RESULTS: The transcripts of EPSA1 and VPF were detected in all developmental time-points of H. huso from embryos to fingerling fish. Our results revealed that the mRNA expression of EPSA1 and VPF was low during embryonic development and then upregulated significantly at the time of hatch and early larval time-points, whereas in the late larval development stages they started to decline. CONCLUSIONS: This study showed that there is an association between the EPSA1 and VPF mRNA expression during larval development of H. huso. The up regulation of EPSA1 and VPF transcripts at the time of hatch and during yolk sac fry development of H. huso is likely tied to the role of them in vasculogenesis and angiogenesis.

Background: Coccidiosis caused by Eimeria necatrix has the most economic impact onpoultry production. Micronemal proteins in Eimeria necatrix are thoughtto be critical ligands determining host cell specificity at the time ofinvasion.               OBJECTIVES: Isolation and purification of Eimeria necatrix oocysts from  Khuzestan province of Iran was performed. AcDNA encoding microneme 5 (EnMIC5) protein was cloned and expressed asrecombinant protein before the evaluation of its immunogenicity by Westernblotting. METHODS: A primer pair was designed based on the publishednucleotide sequence of Eimeria necatrix LZ strain micronem5 gene. APartial cDNA sequence fragment of 758 bp coding for microneme 5 protein(EnMIC5) was amplified by semi- Nested RT-PCR. PCR products were cloned andexpressed in a Maltose Binding protein (MBP) containing expression vector(pMAL-c2x) in Escherichia coli. The cDNA which is encoded for 252 aminoacids shows high degree of conservation. It contains the adhesive plasmapre-kallikrein and seven hydrophilic motifs. RESULTS: The results of SDS-PAGErevealed that the recombinant protein with a molecular weight of 70 kDa wasover-expressed after induction with IPTG. Western blotting results revealedthat the expressed recombinant protein was reacted with sera of the chicksinfected with Eimeria necatrix. It was suggested that this proteinshould have a good immunogenicity and can be used for further studies. CONCLUSIONS: In conclusion, the high degree of sequence homology indicates that thisprotein is immunogenic and  might be aninteresting vaccine target, and deserves further investigation