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Recently, special attention has been paid to enterococci for use as probiotics in dairy products. All these desirable features are a stimulus for the producers of dairy products to use enterococci isolated from dairy products such as Liqvan cheese. Despite having all these features, enterococci are not recognized as GRAS and their presence in food products is a sign of fecal contamination. The purpose of this research is to investigate enterococci isolated from Liqvan and Koze cheese in terms of having pathogenic indicators in order to confirm that they are safe for consumers and finally to investigate the possibility of using them as starters or starter aids in dairy products. Especially cheeses. Based on this, 57 isolates of Enterococcus faecium from traditional Iranian cheeses were examined for the presence of pathogenic genes, and finally 23 isolates did not have any pathogenic genes. Then the technological properties of these isolates such as acidification, proteolytic, lipolytic, autolytic, heat and acid resistance and exopolysaccharide production were investigated. The results showed that among the 23 investigated strains, 19 isolates had antimicrobial activity against pathogenic bacteria, 16 strains were able to produce exopolysaccharide and 20 isolates had moderate acidification properties. The highest proteolytic and lipolytic activity was related to strains c18 and c16, respectively, and strain LR78 showed the highest acid and heat resistance. [ABSTRACT FROM AUTHOR]

Humanity is currently facing a life-threatening challenge from the infectious and epidemic disease SARS-CoV-2. To date, the various modes of transmission of the virus have not been fully elucidated. In this regard, there is a possibility of transmission of the virus through food products. The covid-19 pandemic disease not only can be spread through the respiratory tract, such as diseases associated with SARS and MERS, but the presence of fragments of the genetic virus (RNA) in the feces of several patients suggests that their fecal-oral route may be expanded. In addition, people with gastrointestinal disorders such as metaplasia and atrophic gastritis may be prone to Covid-19 infection. Accordingly, food may act as a potential carrier of Covid-19 due to environmental or cross-contamination. According to the available evidence, the spread and possibility of transmission of Covid-19 contamination from humans to food products are possible. Beyond that, there is some evidence that some food sources of animal origin, such as pigs and rabbits, can be contaminated by Covid-19. Therefore, the transmission of the virus through some meat products may be conceivable. Due to the rapid release rate of Covid-19 and its stability in different environments, especially food processing surfaces, it may enter the matrix during different stages of traditional or industrial food processing. Therefore, preventive measures are recommended to be applied in food processing units. The present study investigated the risk of a variety of food products including meat and meat products, dairy products, bread, fruits, vegetables, and processed foods as potential carriers for the transmission of Covid-19. [ABSTRACT FROM AUTHOR]

Background and Objective: Due to the importance of Mordab river, the concentration and distribution of heavy metals in sediments and part of Caspian sea coast, mostly affected by the Mordab river, were evaluated. Additionally, considering the possibility of heavy metals release from sediments to water column and transfer to crops, the health risk of rice consumption in the region was assessed. Materials and Methods: 21 sediments samples and 4 rice samples from paddy fields along the Mordab River were collected. Heavy metal contents of the samples were measured using ICP-MS. Data analysis was performed using enrichment factor (EF), ecological risk index (RI), health risk index, principal component analysis (PCA) and Mann-Whitney test. Results: The maximum concentrations of elements was higher in coastal sediments than the Mordab River. The results showed low to moderate risk of elements in most stations except for two coastal stations which exhibited considerable risk of contamination with regard to Cr. Principal component analysis categorized the elements into three components of different origin. Moreover, the estimation of weekly intake of elements through rice consumption were less than their permissible concentration set by World Health Organization. Conclusion: The concentration of chromium in sediments, especially coastal sediments, is high, which may be partly due to the concentration of heavy minerals (chromium) in this fraction. Therefore, the origin of elements, particularly chromium, should be determined through sequential extraction methods. On the other hand, despite the pollution of river sediments and high consumption of rice among the residents of the study area, there is no danger to rice consumers in terms of heavy metals. [ABSTRACT FROM AUTHOR]

Various methods have been developed to detect the presence of contamination with Coliforms and E. coli in foods. The pour plate technique using VRBA medium is confirmed as a standard method in Iran. The biggest disadvantage of thismethod is the need to spend a lot of time, high volume of laboratory operations, multiple stages and ultimately long time to achieve the results. Today, due to the mass productionof various foodstuffs, the need for faster methods with high sensitivity to control the quality of food is necessary for the responsible oversight centers. The use of chromogenic medias is also one of the fastest diagnostic methods that have been developed. According to this matter,a comparative study was considered from the results of application of three chromogenic media and reference method in food quality control. Totally 100 samples of foodstuffs were evaluated for contamination to Coliform and E.coli using standard method and three chromogenic medias. Based on the obtained results, 86, 79, 85 and 80 samples were contaminated to Coliform using the standard method, Coliform Agar ES, ChromAgar ECC and Rapid E.coli 2/Agar respectively. Also, using four mentioned methods, contamination to E.coli was reported at 66, 80, 84 and 80, respectively. Cochrane test showed that there was no significant difference between the four methods in Coliform diagnosis (p>0.05). However, four methods did not have the same function in the detection of E. coli so that the chromogenic methods showed significant difference with the standard method (p< 0/001). But there was no significant difference between these chromogenic methods in detecting E.coli (p>0.05). According to the statistical analysis of present study, three chromogenic medias can be used instead of the standard method for the detection of Coliform, but the use of these chromogenic medias is not recommended for the identification of E.coli. [ABSTRACT FROM AUTHOR]

Background and Objective: Considering 829000 annual diarrhoeal deaths due to water pollution worldwide, the World Health Organization has emphasized that countries should reduce this rate by upgrading their was tewater treatment sys tems. The purpose of this s tudy was to evaluate the performance of a modified up flow septic tanks reactor for treatment of synthetic was tewater. Materials and Methods: In this experimental s tudy, a modified septic tank sys tem based on the ups tream hydraulic regime, and also a conventional septic tank sys tem was designed, manufactured, and operated. The municipal was tewater was used to operate, and synthetic was tewater was used to maintain. The major performance indicators of septic tanks include: volatile solids (VS), volatile suspended solids (VSS), total suspended solids (TSS) and chemical oxygen demand (COD) were sampled and measured in triplicates. The experiments were done in three hydraulic retention times of 24, 48, and 72 hr. Finally, the results of the s tudy were analyzed by s tatis tical tes ts in the SPSS software. Results: The average removal of TSS, VS, VSS, and COD in HRT 24 h for the conventional reactor were 55.07, 27.36, 30.82, and 55.52%, respectively, and for the ups tream-modified reactor at HRT 24 h were 66.57%, 34.05%, 38.47%, and 65.57%, respectively. Conclusion: Changing septic tanks to up flow regimes and creating a cylindrical shape in conventional septic tanks, the removal efficiency of conventional septic tanks was improved, and the effluent contamination load was reduced. [ABSTRACT FROM AUTHOR]

Background and Objective: Surface water and underground water quality in countries that facing dehydration have increased the interest of the community to use Household Water Treatment devices. The aim of this study was the evaluation of the quality of drinking water of Household Water Treatment devices and general distribution network in Garmsar, which is under the control of the water safety plan. Materials and Methods: A descriptive cross-sectional study administered in 6 regions and 41 cities of Garmsar city in spring and summer seasons in 2018. Chemical tests performed according to the standard methods for the examination of water and wastewater, general measurements were performed using the multitube fermentation method and counting of heterotrophic bacteria by pour plate method. The results analyzed by using Excel and SPSS software. Results: The average values during two seasons were reported as: EC= 1507 (μS/ cm), TDS= 786.8 (mg/L), F= 0.048 (mg/L), residual free chlorine= 0.67 (mg/L), pH=7.9, total coliform= 0.16 (MPN/100 mL), fecal coliform= 0.14 (MPN/100 mL) and HPC= 112 (CFU/mL). No significant difference found between the chemical and microbial parameters in the general distribution network and the output of the Household Water Treatment devices during the two seasons. Conclusion: Household water treatment devices did not affect the microbial burden but caused a change in the amounts of some chemical parameters. Drinking water from the distribution network, with the proper application of the water safety plan, is of good quality. [ABSTRACT FROM AUTHOR]

Background: Escherichia coli (E. coli) is an indicator of potential human fecal contamination. Polymerase Chain Reaction (PCR) as an ideal detection method for detecting E. coli has some advantages like rapidity, high sensitivity and accuracy, easy performance, ability to run in high numbers and inexpensiveness. On the other hand, the disadvantage of PCR is possibility of its false positive results. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) method was used to overcome the problem, and the results were compared to most probable number (MPN). Materials and Methods: 16srRNA forward (SF) and 16srRNA reverse (SR) primers were designed using E. coli 16srRNA sequence. After preparing different diluted samples of E. coli in distilled water, the bacteria were separated by FHLP and HAWP filters and its 16srRNA was propagated using mentioned primers. To confirm the sensitivity of the RTPCR method compared to MPN one, samples obtained from 15 water sources in Arak city were examined. Results: The number of bacteria in dilutions were confirmed with culture. RT-PCR data showed that FHLP compared to HAWP filters have a higher capability in separating of bacteria in different dilutions. Also there was a higher sensitivity of RT-PCR compared to RT- PCR and MPN. Conclusion: RT-PCR can detect the bacteria in lower dilutions of bacterial suspension. Hydrophobic filters (e.g. FHLP) compared to hydrophilic filters (e.g. HAWP) have higher capability in separating bacteria. To detect all coliform bacteria RT-PCR amplifications achieved by cells concentrated with hydrophobic filters are recommended. [ABSTRACT FROM AUTHOR]