JOURNAL OF MICROBIAL BIOTECHNOLOGY
Year:2010 | Volume:2 | Issue:6|Papers Count:8

Background and objectives: Salmonellosis is an infectious disease for all animal species which caused by different species of Salmonellae and manifested clinically by preacute septicemia or enteritis. Most recent investigation suggested that some probiotics such as Saccharomayces boulardii can inhibit multiplicity of enteropathogenic bacteria such as Salmonella in vitro and it is possible to prevent pathological changes caused by these bacteria in vivo. This prospective study was conducted to investigate the protective effects of Saccharomyces boulardii on liver pathologic lesions of Salmonella typhimurium in rat.Materials and Methods : Thirty Conventional male rats were divided in to three groups (A, B, C). ALT and AST values were determined from blood samples before administration of Saccharomyces boulardii and bacterium. Rats in group B and C received 1 ml of saline contained 107 ­and 108 CFU/ml of Saccharomyces boulardii orally for 5 days respectively. Control group (A) received only 1 ml saline as experiment groups; On day five, all animals were exposed orally with 107 Salmonella typhimurium. On day 10, all rats inoculated with bacterium then blood sample were obtained and all animals were euthanized.Results: In biochemical examination serum level of ALT and AST in the control group (A) significantly increased (p<0/001) but not significant changes in the experiment group (B and C) were seen. In addition ALT and AST increased level between group B and C were not significant. In other hand 108 and 107 cfu/ml Saccharomyces boulardii doesn’t have any significant difrentiation for protection of Salmonellosis.Conclusion: This study indicates that Sacharomyces boulardii has protective effect on Salmonella typhimurium infection in rat and some serum biochemical examination confirm this result.

Background and Objective: Food borne diseases due to consumption of contaminated food are considered as a critical health problem worldwide and many funds are compensated for treatment of such diseases annually. Cream-containing pastries are most prone to contamination with variety of microorganisms due to their ingredients, handling as well as storage conditions. The aim of current study is to determine the rate of microbial contamination of cream-containing pastry from confectionaries in south of Tehran.Materials and Methods: A total of 121 cream-containing pastry samples were taken from different confectionaries randomly. The rate and type of contamination were assessed according to Iran National Standards.Results: This study revealed that 72.7% of all of cream-filled pastries collected from south of Tehran were contaminated with various microbes. Most contamination was due to Enterobacteriaceae and yeasts. The examined samples were also contaminated with other bacteria, so that 100% of contaminated products had more than one microorganism. No Salmonella was isolated from cream filled pastries. Furthermore, the monthly assessment of rate of contamination, showed that the most and least rate of contamination was in summer (June, Mean of contamination 86%) and winter (December, Mean of contamination 50%) respectively.Conclusion: It seems that training of workers and supervision on the preparation and storage of cream pastries through health centers is necessary for public health.

Background and Objective: One of the methods for compensating nutrient´s deficiency of feedstuff is using probiotics to processing feed. As citrus wastages have low protein value in animal nutrition so we can use of them better by processing with yeasts and fungi.Materials and Methods: In this experiment lemon wastages from juice factories were used and Saccharomyces cerevisiae was used for processing and increasing their nutrients concentration.Results: The results showed that processing lemon pulp with yeast caused a significant increase in lemon pulp´s crude protein and ADF (P<0.05) but its NDF percent (P<0.01) and organic matter (P<0.05) were decreased. Results of lab degradability showed that after processing digestible organic matter in dry matter digestibility was decreased significantly, although dry matter and also organic matter digestibility were not changed significantly. Moreover metabolisable energy was decreased significantly (P<0.05).Conclusion: We can conclude that processing lemon pulp with Saccharomyces cerevisiae yeast increases the efficiency of this product.

Background and Objective: The aim of present study is detection of the diversity of responsible bacterial isolates have identified from bile duct infections and investigation of the sensitivity of RFLP-DGGE method as an alternative method for discrimination of these isolates.Materials and Methods: 60 bile samples were collected from Taleghani hospitalized patients in Tehran. Identification of bacteria and antimicrobial susceptibility tests were done according to the standard methods. For the detection of different isolates, PCR on 16s rRNA region and RFLP-DGGE were done.Results: 16 out of 38 bacterial isolates were identified as E.coli. The highest resistance phenotypes were belonged to Amoxicillin (100%) and Ampicillin (75%). RFLP-DGGE show ed different banding patterns, so that different isolates could be discriminated from each others, easily.Conclusion: These results showed that RFLP- DGGE on 16s rRNA PCR products could be considered as a suitable method for differentiation of bacterial isolates from clinical samples.

Background and Objective: Kaposi's sarcoma is a connective tissue malignancy which is more common in patients with immune suppression states like Acquired Immune Deficiency Syndrome (AIDS). This study was carried out to study prevalence of Herpes virus type 8 (HHV8) in Kaposi's Sarcoma patients in Tehran.Materials & Methods: Forty two tissue samples with suspicious diagnosis of Kaposi's sarcoma were found in paraffin embedded archives of Loghman, Shohada, Razi and Cancer institute hospitals of Tehran collected between 1379 and 1389. After DNA extraction, the presence of HHV-8 was evaluated using specific primers of ORF-26 fragment of viral genome with a nested PCR approach.Results: among 42 tested samples, 30 samples were positive for HHV8. The average age of positive samples was 61.6 years.23 samples were from male patients and 7 from females.Conclusion: We found 30 cases positive for HHV8 among 42 tested paraffin embedded samples. Considering 4 samples were primarily reported as pseudo Kaposi's sarcoma in pathologic examination, HHV8 was detected in 78.9% of Kaposi's sarcoma cases. This finding also supports the sensitivity of nested PCR method for detection of this virus.

Background and Objective: Salmonellosis is an important infectious disease in both animals and humans. Food of poultry origin is the most important sources of Salmonella infection in humans.The hyperinvasive locus A (hilA) gene has an important role in Salmonella pathogenicity. This gene encodes a transcriptional regulator that activates the expression of invasion gene and facilitates the entry of the bacteria into intestinal epithelial cells. The goal of this research was to isolate Salmonella from poultry, serogroup screening of them and detect of their hilA gene by Polymerase Chain Reaction (PCR) technique.Material and Methods: This research which was carried out in East Azarbayjan province in Iran, overall 520 samples were obtained from chicken (400 samples), ostrich (30 samples), and pigeon (90 samples). Samples were harvested from intestine, liver, spleen of poultry and examined by bacteriological tests. Serogroup screening was done by specific Salmonella antisera. PCR was applied with one pair of primers targeting the Salmonella hilA gene.Results: According to the results of bacteriological tests 45 Salmonella strains were found among 520 of total samples (8.65%). The prevalence of Salmonella spp in chicken, ostrich, and pigeon were determined as7.25%, 6.66% and 15.55%, respectively. Salmonella isolates represented four different serogroups (D1, B, C1, and C2) which Salmonella serogroup D1 with frequency 53.3% was the most dominant serogroup. The PCR of the hilA gene produced a band of 854 bp with all the Salmonella isolates.Conclusion: This research was indicated the relatively high frequency of Salmonella serogroup D1 in poultry and the high prevalence of salmonellosis in pigeon and also suggested that the hilA gene could be present in different Salmonella serogroups from different hosts in birds.

Background and Objective: Prevalence of allergic diseases has been increased in recent years. Allergy is defined as the response of immune system against external proteins. It has been indicated that spore and conidia of the fungi existing in air play a role in creation of different forms of allergy, especially the respiratory allergy. The typical method for identification of fungi is culture, which requires time for morphological characteristics identification of species. Molecular methods have been developed with the purpose of improving the sensitivity and specificity detection of pathogen and allergenic fungi. The aim of this research was studying on allergenic level of Aspergillus and Fusarium by an appropriate and reliable molecular method of colony PCR in order to decrease the identification time.Materials and Methods: After culture of Aspergillus and Fusarium on PDA medium and decomposition of fungus spores, DNA extraction was carried out using Gen Pajuhan Puya kit, which was subsequently used in PCR as pattern for amplification of the genes Aspf and Its4, 1. The same process was fulfilled in next stage in colony PCR without DNA extraction.Results: PCR results indicated that each primer caused a different amplified pattern and two fungi was discriminate by specific primer. In addition both PCR and colony PCR was identical. In this study colony PCR was applied to filament fungi and led to identical results compared to PCR. As the extraction step is time-consuming, colony PCR method is suggested.Conclusion: Through optimization of PCR and colony PCR sample infected by Aspergillus, a reliable molecular method can be provided for rapid identification of the mentioned fungi in clinical laboratories.

A greater understanding of how the survival of Lactobacillus acidophilus cells in the process of preparing and using it commercially as a probiotic bacterium is useful. So, the aim of this study is the effect of different environmental stresses on survival of L. acidophilus.As L. acidophilus is one of the most important probiotic microorganisms in food technology, so we decided to review different aspects of stress responses in L. acidophilus in published papers between 1980 and 2010.Results showed that L. acidophilus has possibility to adapt to one or more stresses, but not all stresses could provide cross-protection against every stresses tested. It appears that L. acidophilus is capable of displaying adaptive response to stress. It also proved that the resistance of L. acidophilus against stress in the stationary growth phase is more than the logarithmic growth phase.Considering the factors studied in this research L. acidophilus bacteria has possibility to adapt to against environmental stress and can be treated before using it in harsh conditions, in order to bacteria survival increase.