JOURNAL OF FOOD MICROBIOLOGY
Year:2017 | Volume:4 | Issue:2|Papers Count:11

The importance of medicinal plants, with the intensification of the therapeutic effect, is that in many cases it can also avoid the toxicity and adverse effects of medication. In this studyPotentilla recta, one of the Iran and Azerbaijan region-native medicinal plants, was studied in terms of chemical composition, antimicrobial and antioxidant effect. After collecting, drying and milling of plants, the methanol, ethanol and ethyl acetate extracts obtained by maceration method. To identify the constituents of the extracts, gas chromatography connected tomass spectrometry was conducted. The DPPH radical scavenging method used to measure the antioxidant potential and the results was reported based on the IC50 index. After determine MIC and MBC using broth micro dilution method, agar well diffusion assay conducted to assess the antimicrobial effect of extracts. Data were analyzed by one-way analysis of variance (ANOVA) and means were compared using Duncan test at P<0.05 using SPSS software ver.16. The results of the antimicrobial activity showed that the extracts had antimicrobial effect and in this case methanol extract significantly increase L.monocytogenesmicrobial growth inhibition zone area (p<0.05). All prepared extracts had the ability to scavenging radical 1, 1-Diphenyl-2-picrylhydrazyl and the highest antioxidant potency after 30 minutes related to methanol extract. Most chemical compounds in methanol, ethanol and ethyl acetate extracts, were respectively: methyllinoleate and ethyl linoleate. This study showed that the methanol extract of Potentilla recta has great antibacterial and antioxidant properties and with more research can be used in various applications.

Zoonoses involving transmission of disease and biotoxin producing agents from fish to humans have been documented in the literature mostly including bacteria, biotoxins and parasites. The list of potential fish-borne zoonoses is quite large. Twenty six infectious agents are discussed in this review and there are also many other infectious organisms of fish origin that have not been reported but have the potential to infect and harm human. The status of the human host immune system plays a vital role in the severity of the disease. The major exposure routes include ingestion and introduction of organisms through open wounds or abrasions. More specifically, ingestion includes consumption of raw or under-cooked infected fish tissue, ingestion of fish tissue contaminated with feces from infected fish. Overall 46.15 % of fishborne zoonoses are transmitted orally which are mostly helminthic diseases are caused by Trematodes, Cestodes and nematodes. Yet these zoonoses are responsible for large numbers of human infections around the world. Ingestion of water harboring infectious organisms with 23.07 % and Dermal exposure includes introduction of infectious agents into open wounds or abrasions through handling infected fish or infected water with 19.23 % are other transmission ways and importantly 15.38 % of fish-borne zoonoses are transmitted by more than one way. Distribution, epidemiology, clinical aspects, and the research needed for improved risk assessments, clinical management and prevention and control of these important diseases are reviewed.

Salmonellais a food borne pathogens and pose a public health problem in the world counts. Food poisoning caused by this pathogen with symptoms such as gastroenteritis, diarrhea, abdominal cramps, and fever enteric (typhoid fever) occurs. This study aimed to isolate and identify Salmonella typhimurium in various stages of destruction was carried camel meat. For this purpose, a total of 150 samples of camel meat in various stages of destruction (after peeled, after unloading viscera after the wash), (each 50 samples) in return when summer 2016 to winter 2017 the slaughterhouse city Ben Chaharmahal and Bakhtiari Province and the city of Najaf Abad and Esfahan Golden city, were taken. The results showed that 22 of 150 samples of camel meat as species of Salmonella were detected. Using PCR showed that of the 22 positive samples, 3 (2%) Salmonella typhimurium and 19% (6.12) were other species. From the 50 samples collected after unloading viscera 11 positive cases were detected in 2 (4%) are Salmonella typhimurium. After washing the other 50 samples were collected 4 cases (8%) is related to Salmonella spp and Salmonella typhimurium serotypes 4 none of it.

An experiment was conducted to evaluate the effect of different levels of threonine on microbial carcass with use of 450 numbers of broiler chicks of the Ross 308.The chicks randomly are allocated to five experimental treatments and six replications (15 chicks in each replicates) in a completely randomized design. The experimental diets are including different levels of threonine with five levels of 90, 100, 110, 120 and 130 percent of the recommended Ross 308. The findings of the study shows the effect of experimental diets on microbial carcass in female and male broiler are (p<0.05) significant. In carcass broiler chicks (different treatment) salmonella are not observed (P>0.05). In dilution (-1) most level microbial carcass in treatment 90٪ Threonine became observation, where with treatment 110٪threonine are significant (p<0.05). Dilution (-2) least level microbial carcass in treatment 110٪ became observation than another treatments are significant (p<0.05).Too in total content microbial carcass least level relevant on treatment 110% threonine was than another treatments are significant (p<0.05). Results showed that the increase of threonine up to %10 leads to improvement of broiler chicks.

Pathogenic bacteria are responsible for a significant number of food poisoning in humans through infected Poultries. Our study was aimed to evaluate the effect of post-chilled washing process in a slaughterhouse and types of temperature dependent-transport vehicles on bacterial load of common food-borne pathogens; Staphylococcus aureus, Salmonella spp. and Escherichia coli of chicken carcass. One hundred and eighty fresh chicken carcasses were randomly gathered from a commercial poultry processing plant in West of Tehran After sampling in slaughterhouse, the carcass samples were taken from 3 types of vehicles, pickup, cool isolated and cool-off isolated vehicles. The mean value of the total count of whole carcasses in pickup group reached the maximum (18.63´106 ± 2.82´106) and showed greater value (p<0.05) than the standard value (5´106) CFU/gr while in cool-off isolated vehicle reached the minimum (0.65´106±0.048´106) lesser in comparison to the standard. it is concluded that chicken transport by un-cooled or unusual vehicles could prepared inappropriate condition cause to integrated growth the bacteria and resulted in transmission the food borne zoonotic pathogens to humans.

The aims of this study were evaluating the probiotic properties and phylogenetic relationship of dominant lactic acid bacteria (LAB) isolated from whole barley sourdough. At the beginning, dominant LAB isolates were identified by specific PCR. Then probiotic properties of the isolates including survival in simulated conditions of gastrointestinal tract, antagonistic effects against Staphylococcus aureus, Listeria monocytogenes, Escherichia coliand Salmonella enterica as foodborne indicator bacteria, ability of aggregation withE. coli and S. enterica as infection agents of intestine and resistance of these LAB isolates against some of routine antibiotics were investigated. For determination of phylogenetic relationship between LAB isolates, maximum likelihood method was also used. Sequencing results of PCR products lead to identification of Lactobacillus brevis, Lactobacillus curieae, Pediococcus pentosaceusand Weissella cibaria as dominant isolated LAB from whole barley sourdough. Among mentioned isolates, L. brevis had significantly (P<0.05) higher survival in pH 2 and 0.3% bile salt in comparison to other isolates. Inhibition zone diameter of foodborne indicator bacteria in the presence of P. pentosaceuswas the highest. P. pentosaceus had also significantly (P<0.05) more effective aggregation ability towards E. coli and S. enterica than the others and four LAB isolates were resistant to vancomycin. Analysis of aligned sequences in phylogenetic tree showed that L. curieae and P. pentosaceus had very closely phylogenetic relationship while, the most genetic difference was observed between L. brevis and W. cibaria.

Nowadays a large part of microorganisms are going to become resistant against common antibiotics. In this study the effect of bioactive peptides obtained from enzymatic hydrolysis of pumpkin oil cake protein as natural anti-microbial agents was examined. In this research pumpkin (Cucurbita pepo) oil cake protein was hydrolyzed by pepsin, trypsin and alcalase. Optimum treatments were selected based on DPPH radical scavenging activity and anti-microbial activity of total and diluted extracts (1.2, 1.4, 1.8 and 1.16) were evaluated against Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus and Escherichia coli.peptides produced by 1% pepsin, 30 ˚C and 2h hydrolysis (P3012), 1% pepsin, 35 ˚C, 3.5h hydrolysis (P35135), 1% alcalase, 50 ˚C, 3.5h hydrolysis (A50135), 2% alcalase 50 ˚C, 3.5h hydrolysis (A50235), 1% trypsin, 35 ˚C, 5h hydrolysis (T3551) and 1% trypsin, 45 ˚C and 5h hydrolysis (T4551) were selected as optimum treatments. Total extracts of P3012, T4551 and A50135 showed an appropriate inhibitory effect on tested bacteria while total extract of T3551 had no inhibitory activity against pathogens. The minimum inhibitory concentration of P35135 was 1.2 against Bacillus, 1.8 against Escherichia and 1.16 against Listeria. Minimum inhibitory concentration of A50235 was 1.4 on Staphylococcus and Bacillus and 1.8 against Listeria. Based on the results, enzymatic hydrolysis can be employed as an effective approach to produce natural anti-oxidative and anti-microbial agents.

Contamination of milk and its products with pathogenic organisms such as Listeria could be considered as a health threat for the consumers. The aim of this study was to investigate the occurrence and diversity of Listeia spp. in traditional cheeses of Tabriz area and to assess antibiotic resistance, biofilm formation and thermal-resistance of the isolates. A total number of 100 traditional cheese was collected randomly. Listeria spp. were isolated and identified using conventional culture methods. According to the results, 12 out of 100 cheese samples were found positive forListeria spp. Amongst, 5 and 7 isolates were identified as monocytogensand ivanovii, respectively. The highest rate of resistance was observed for oxacillin (100%) and nalidixic acid (75%), and the highest rate (100%) of sensitivity was related to cotrimoxazole, tetracycline, gentamicin, erythromycin and vancomycin. Results of biofilm assay reveled that all 5 strains of L. monocytogens produced low amount of biofilm, meanwhile strains ofL. ivanovii produced a range (weak, moderate and high) of biofilm level. Based on thermal-resistance outcomes, thermalisation process had insignificant impact on Listeria strains; whereas application of “rapid pasteurization” process for 5 sec, reduced the populations of both Listeia specis to below the detectable limit (P<0.01). In the case of batch pasteurization, two Listeria species demonstrated significant (P<0.01) degree of resitsnce. Since L. monocytogenes, and in a lesser extent L. ivanivi are human pathogens of concern, it was concluded that traditional cheeses of Tabriz area could pose a health hazard dealing with Listeria.