ابراهیم رحیمی

 Milk and its products are a suitable environment for the growth of pathogenic microorganisms, among the cold-loving pathogens Yersinia enterocolitica is one of the bacteria whose spread can threaten the health of consumers. The aim of the present study was to Prevalence of antibiotic-resistant strains of Yersinia enterocolitica isolated from traditional and industrial dairy products sold in Isfahan county.

 First, 300 samples of traditional and industrial dairy products were sampled and transferred to the laboratory, and the level of contamination with Y. enterocolitica was determined by standard methods. Multiplex PCR method was used to determine the frequency of virulence genes and Disk-Diffusion method was used to evaluate antibiotic resistance.

 The results showed that the level of contamination with Yersinia enterocolitica was 15 samples (7.5%) out of a total of 200 traditional dairy samples, and none of the industrial samples were contaminated with Yersinia enterocolitica. According to the PCR test, the frequency of the highest and lowest carrier genes, respectively, includes ail 14 samples (4.66 %), yadA 7 samples (2.33 %), inv 10 samples (3.33 %), yst 9 samples (3 %), rfbe 9 samples (3%) and virF 6 samples (2%). The results of antibiotic resistance showed that the highest resistance was related to penicillin (80%) and ampicillin (73.33%), and the lowest resistance was to imipenem (6.66%).

 The results of this study showed that traditional dairy products were contaminated with Yersinia enterocolitica bacteria and had virulence genes, so the use of traditional dairy products should be limited and the use of antibiotics should be limited in the event of illness.

This article deals with the strength evaluation of concrete obtained by adding different percentages of three types of nanominerals, including nanocalcite, nanobarite and nanofluorite. To measure the velocity of ultrasonic waves and compressive strength of concrete, 15×15×15 cm cube samples were prepared with 7-, 28- and 90-days curing. 10 types of mix  designs with 0.39 water-cement ratio, including the control sample (without additives) and the samples with 0.5, 0.75 and 1% nanominerals were subjected to the mentioned tests. The results showed that the addition of nanocalcite, nanofluorite, and nanobarite with values of 0.75%, 1%, and 0.75%, respectively, have the highest compressive strength compared to the control sample. Although these do not have pozzolanic properties, they play a positive role in increasing the concrete strength by filling concrete voids and due to their high specific gravity, increasing concrete density.

Clostridium difficile (Clostridioides difficile) is known as one of the main causes of pseudomembranous colitis and is considered an important enteropathogen in humans. Antibiotic use has been introduced as one of the most significant risk factors contributing to the prevalence and incidence of “Clostridium difficile nosocomial infection”. The aim of this study is to investigate the prevalence, antibiotic resistance, and genetic diversity of Clostridium difficile in semi-cooked ready-to-eat products in stores of Isfahan Province in Iran.

A total of 240 samples of semi-cooked ready-to-eat products, including potato kuku, herb kuku, cordon bleu, and chicken nuggets (each 60 samples), were randomly collected from stores of Isfahan Province between July 2020 and February 2021. Clostridium difficile was identified by culturing the samples in Clostridium difficile moxalactam norfloxacin. To determine the characteristics of the toxins, tcdA and tcdB genes were detected through multiplex polymerase chain reaction (M-PCR). The antibiotic sensitivity of the isolates was determined based on the minimum inhibitory concentration (MIC) test. The results were analyzed using chi-square test in SPSS software and P-value was considered significant at 0.05.

37 samples were infected with Clostridium difficile. The contamination rate was 13.3%, 20.0%, 11.6%, and 16.6% in potato kuku, herb kuku, cordon bleu, and chicken nugget, respectively. The highest contamination was related to the semi-cooked herb kuku product. TcdA and tcdB gene toxins were identified in 15 and 17 isolates of Clostridium difficile, respectively. Among Clostridium difficile strains, the highest level of resistance was seen for ampicillin and penicillin antibiotics, and the highest sensitivity was related to chloramphenicol and metronidazole.

Semi-cooked ready-to-eat products can be considered as potential sources of antibiotic-resistant Clostridium difficile. Thus, complete cooking process of semi-cooked ready-to-eat foods at appropriate temperature and time (85° C and 30 minutes) and following hygiene principles in food processing plants can prevent the probable gastrointestinal infections caused by strains of Clostridium difficile in consumers.

Milk, recognized worldwide as a nutritious and essential food, is susceptible to fraud that compromises its quality and poses health risks to consumers. This study aims to investigate the prevalence of adulteration in raw milk sold in Shahrekord City during both cold and hot seasons. A total of 100 raw milk samples were collected from distribution centers in Shahrekord and analyzed at the food hygiene laboratory of Shahrekord Azad University. Chemical parameters including water content, sodium bicarbonate, salt, formalin, hypochlorite, detergents, starch, and hydrogen peroxide were assessed for seasonal variations. Results indicated a significant difference in lactose levels between cold and hot seasons, while other parameters showed no statistically significant variance. Moreover, findings revealed a higher incidence of adulteration during the hot season compared to the cold season, with average adulteration percentages across both seasons as follows: water (54%), salt (35%), detergents (34%), starch (25%), formalin (14%), sodium bicarbonate (6%), hypochlorite (4%), and hydrogen peroxide (4%). Given these findings, relevant authorities must intensify oversight and regulatory measures to safeguard public health against milk fraud.

Pseudomonas is asignificant spoilage bacterium in poultry meat, impacting its organoleptic properties. This study investigated the prevalence of antibiotic resistance and virulence genes of Pseudomonas isolated from broiler poultry sold in Tehran, Iran. Over a year, 400 poultry meat samples (chichen, tukey, duck, quail, goose) were collected. Additionally, swap samples were taken vendors’ hands, knives, cutting boards, and refrigerators. All samples were transferred in sterile conditions to the laboratory of the Veterinary Department of Tehran Province for testing. PCR analysis identified virulence genes (ToxA, exoS, exoU) in isolated strains. A total of 25.75% (103/400) of poultry meat samples, were contaminated with Pseudomonas. Contamination rates varied across poultry types (chicken: 26.67%, 1turkey: 31%, duck: 54%, quail: 2%, goose: 8%. PCR identified that 8 chicken samples, 5 duck samples, and 2 goose samples were infected with toxA, exoS, and exoU genes, respectively. The highest antibiotic resistance was observed for gentamicin (89%) and tetracycline (81%). Moreover, swaps from refrigerators and vendors’ hands showed the highest contamination. This study highlights the high prevalence of Pseudomonas in Tehran’s broiler poultry, with concerning levels of antibiotic resistance and virulace genes. Improved hygines practices and judicious antibiotic use in poultry production are crucial to mitigate these risks.

Arcobacteria are the cause of common diseases between humans and animals and are transmitted through water and food. So far, little information has been published about the pathogenic mechanisms of Arcobacteria. These bacteria can also opportunistically infect people with weak immunity. cause severe diseases. The present study was conducted with the aim of investigating drug resistance of Arcobacter and identifying virulence and resistance genes in raw milk in Isfahan province. In this study, to detect Arcobacter, 350 samples of raw milk from 5 species of animals, including cows, sheep, goats, camels, and buffaloes, and 400 samples of milk products, including cheese, cream, butter, and traditional ice cream, were randomly selected. Samples were taken from the dairies of Isfahan city and around Isfahan and were transferred to the microbiology laboratory of Kurd University in the shortest possible time. Then, bacteria grown in Preston medium with the help of a sterile loop on CAMP medium (Merck-Germany), enriched with defibrinated sheep blood containing antibiotics such as vancomycin 2 mg/ml, polymyxin 0.005 mg/ml, tri Methoprim was 1 mg/ml, linear culture was done. Also, in order to evaluate the phenotypic antibiotic resistance, the simple disk diffusion method was used according to CLSI (2017) criteria Results showed that out of a total of 350 samples of raw milk and 400 samples of milk products examined, 18 samples were infected with at least one species of Arcobacter. These 18 cases were only isolated from raw milk and none of the milk products were infected with this bacterium. Also, out of 18 samples infected with Arcobacter species, 15 samples were infected with Arcobacter botzeleri and 3 samples were infected with Arcobacter cari aerophilus. It was concluded that the highest antibiotic resistance was also evaluated for ampicillin, amoxicillin-clavulanic acid, cephalothin, cefotaxime and tetracycline.

Active packaging enhances the safety and shelf life of food products by unwanted chemical or biological changes to the contents or internal environment of the packaging. In this study, the effect of chitosan/eggplant peel anthocyanin/ZnONPs synthesized from eggplant cap extract (at three levels of 1, 3, and 5%) in a HPMC film matrix on the shelf life of Caspian Sea white fish fillets was investigated.

Chemical (pH, TVB-N, and TBARs) and microbiological (psychrophilic, mesophilic bacteria, and Enterobacteriaceae count) tests, sensory attributes (flavor, odor, color, texture and overall acceptance) were used to determine the quality of fish fillets during 14 days (at days 0, 1, 7, 10, and 14) of storage at refrigerated temperature.

The average size of the synthesized nanoparticles was 0.527 nm. The uniform dispersion of nanoparticles on the synthesized films from eggplant cap extract was confirmed by DLS test with PDI of 0.332. Overall, the results indicated a positive effect of packaging film on the shelf life of Caspian Sea white fish fillets. The highest levels of pH, TVB-N, TBARs, and mesophilic, psychrophilic, and enterobacterial bacterial populations were observed in the control sample, while the lowest levels were observed in the nanocomposite film containing 5% eggplant cap extract-synthesized ZnO nanoparticles. Fish fillets packaged in the nanocomposite film containing 5% ZnO nanoparticles had the highest sensory scores during storage.

Therefore, the produced nanocomposite film can be used as active packaging to increase the shelf life of Caspian Sea fish fillet.

Staphylococcus aureus, a gram-positive bacterium known for its resistance to desiccation and production of enterotoxins, is a prominent foodborne pathogen causing gastroenteritis and vomiting through its enterotoxin genes. This study aimed to assess the prevalence of S. aureus strains carrying enterotoxins A and B in traditional dairy products, salads, and nuggets distributed in Shahrekord. Additionally, antibiotic resistance profiles of these isolates were investigated. A total of 300 food samples were randomly collected from the Shahrekord market in spring 2023 and processed under sterile conditions to prevent contamination. Results indicated contamination rates of 63% in salads, 5% in nuggets, and 28.43% in traditional dairy products. Specifically, one seasonal salad isolate (0.33%) tested positive for the A gene, and one sandwich isolate (0.33%) contained the B gene. Antibiotic susceptibility testing revealed a high resistance rates to ampicillin (86.18%) and gentamicin (88.8%), while resistance was the lowest for imipenem (38.6%) and tetracycline (39.2%). The findings underscore the critical need for stringent regulations to enhance hygiene standards and mitigate the prevalence of toxin-producing microorganisms in fast-food settings, given the serious implications of antibiotic resistance and inadequate oversight on food safety.

Benzo[a]pyrene is an organic compound naturally found in tobacco smoke and exhaust emissions from vehicles. This compound is recognized as an environmental pollutant and is abundantly present in urban and industrial environments. The effects and hazards of benzo[a]pyrene due to its presence in tobacco smoke and vehicle exhaust gases, particularly on human health, are significant. This compound can increase the risk of carcinogenesis, as it possesses toxic and carcinogenic properties that can cause serious harm to humans through direct or indirect contact. This study examined the protective effects of the hydroalcoholic extract of Rhamnus frangula on liver and kidney toxicity induced by benzopyrene in mice and compared it with vitamin E.

In this study, 55 male mice were randomly divided into 11 groups of 5 each. The first to third groups were used as negative control (normal diet), olive oil (solvent for benzo[a]pyrene), and positive control (benzo[a]pyrene) respectively. Benzo[a]pyrene was administered at a dose of 20 mg/kg body weight for 4 weeks via gavage. The fourth group received vitamin E alone (250 mg/kg via gavage), and the fifth group received vitamin E along with benzo[a]pyrene. The sixth, seventh, and eighth groups received the hydroalcoholic extract of Rhamnus frangula L. daily at doses of 250, 500, and 1000 mg/kg body weight orally, respectively. Additionally, three intervention groups received the hydroalcoholic extract of Rhamnus frangula L. at high doses along with benzo[a]pyrene for 4 weeks.

Administration of benzo[a]pyrene at a dose of 20 mg/kg resulted in liver damage, as evidenced by a significant increase in liver enzymes ALT and AST, as well as bilirubin, compared to the control group. Benzo[a]pyrene also caused an increase in ALP levels, although this increase was not significant. Although the slight increase in ALP due to benzo[a]pyrene was reduced in the group treated with a high dose of Rhamnus frangula L., treatment with Rhamnus frangula L. at any of the doses used in this study was not able to reduce ALT, AST, and bilirubin levels. In contrast, treatment with vitamin E reduced the activity of ALT and AST compared to the benzo[a]pyrene group. A significant increase in urea and creatinine in the benzo[a]pyrene group compared to the control group indicates kidney damage caused by benzo[a]pyrene. Rhamnus frangula L. only at the highest dose of 1000 mg/kg reduced urea and creatinine levels, and vitamin E did not affect improving the nephrotoxic effects of benzo[a]pyrene.

The study results indicated that biomarkers under investigation can serve as useful tools for assessing hepatic and renal toxicity induced by benzo[a]pyrene. Furthermore, the hydroalcoholic extract of Rhamnus frangula L. exhibited significant protective properties against hepatic (increased ALP) and renal (increased urea and creatinine) damages caused by benzo[a]pyrene and may perform better than vitamin E in certain cases. These findings underscore the importance of utilizing plant extracts in combating the adverse effects of pollutants.

poultry meat is considered as the main sources of animal proteins, essential amino acids, minerals and vitamins, however, contamination of poultry meat with heavy metals can cause irreparable damage to consumers. In this regard, the aim of the present study is to evaluate lead, arsenic and cadmium in poultry meat offered in Tehran city. The number of 45 samples of breast meat, including 15 samples of chicken meat, 15 samples of turkey meat and 15 samples of quail meat, were randomly sampled from the supply centers of this product in Tehran, and after being transferred to the laboratory, the number of heavy metals was determined by the atomic absorption device. Were measured. The results showed that the average heavy metals in 15 samples of quail meat were 0.04 cadmium, 0.07 arsenic and 0.108 lead, in chicken meat 0.748 cadmium, 0.43 arsenic and 0.717 lead in turkey meat for Cadmium was 0.569, arsenic was 0.08 and lead was 1.184 mg/kg. Statistical analyzes showed that there is a significant difference between the number of heavy metals and the type of food (p<0.05). The results showed that the concentration of heavy metals in all samples exceeded the national standard, and therefore it.

</strong> Listeria monocytogenes</em> is an opportunistic human pathogen that affects food of animal origin and mainly immunocompromised people, the elderly, infants and pregnant women. The purpose of this study was to investigate the prevalence and antibiotic resistance of Listeria monocytogenes</em> isolated from goat and sheep meat sold in Tehran city.
</strong> 50 samples of goat and sheep meat were randomly isolated from supply centers in Tehran and transferred to the veterinary laboratory of Tehran University in the fall of 2023. Sampling was also done with swap in tools and equipment used in supply centers.
</strong>The results showed that out of a total of 25 samples of goat meat and 25 samples of sheep meat, 4 samples (16%) of sheep meat and 8 samples (32%) of goat meat were infected with Listeria monocytogenes</em>. There was a statistically significant relationship between the amount of coliform</em> contamination in goat and sheep meat (p<0.05). The results of antibiotic resistance showed that the highest level of resistance was related to sulfamethoxazole and amoxiclav. Also, the highest and lowest level of contamination was in the refrigerator (50%) and knife (10%).
</strong>The high level of contamination and high antibiotic resistance for Listeria monocytogenes</em> isolates indicates the poor health status in the meat product supply centers in Tehran, and it is necessary for the quality centers to make more efforts to establish strict regulations. Also, in case of gastroenteritis caused by Listeria monocytogenes</em>, the use of antibiotics should be limited.</div>

Psychrotrophic bacteria in raw milk, due to their ability to produce heat-resistant enzymes and biofilms, face the dairy industry with significant corruption and technical problems, and can also cause risks such as gastroenteritis in humans. In this regard, the purpose of this study is to investigate the prevalence of antibiotic resistance of Yersinia enterocolitica, Listeria monocytogenes and Pseudomonas isolates in raw milk sold in Gachsaran County. In this study, 100 samples of raw milk were randomly sampled from the supply centers of this product and transferred to the food hygiene laboratory under sterile conditions. The results showed that the level of infection with Pseudomonas was 30 samples (30%), Listeria monocytogenes was 10 samples (10%) and Yersinia enterocolitica was 4 samples (4%), also statistical analysis showed that there was a difference between the level of infection with Pseudomonas and Yersinia enterocolitica and Listeria monocytogenes. The difference is statistically significant (P<0.05). The results of antibiotic tests showed that the highest resistance in Pseudomonas was related to amoxiclav and ampicillin, in Listeria monocytogenes it was related to amoxiclav and sulfamethoxazole, and in Yersinia enterocolitica it was penicillin and gentamicin. Due to the high level of contamination of raw milk with psychrotrophic microorganisms, it is recommended to refrain from consuming raw milk and to apply restrictions for the treatment of gastroenteritis caused by the spread of food pathogenic bacteria.

Mycotoxins are secondary metabolites that are naturally produced by molds and cause contamination of human and livestock food. Aflatoxins are toxic substances that can cause acute and chronic human poisoning with teratogenic effects. They are toxic substances produced by the secondary metabolism of several fungal species such as Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius, which grow in major food crops under a wide range of climatic conditions. Aflatoxin M1 contamination in milk is a growing concern. Milk is a very nutritious food that has protein, fat, micronutrients and water in its composition, and its contamination with aflatoxin is not far from expected. Considering the high toxicity of aflatoxin M1, and the harmful effects on human health, its measurement in milk is of great importance. The aim of this study was to investigate the occurrence of aflatoxin M1 in ruminant milk supplied in Karaj Counti.

60 raw milk samples in summer and autumn seasons (including 20 cow milk samples, 10 buffalo milk samples, 10 camel milk samples, 10 sheep milk samples, 10 goat milk samples) from the supply centers of these products in Karaj Counti was randomly sampled and to evaluate the amount of aflatoxin M1 by ELISA according to the instructions of the AFM1 ELISA kit (Biopharm-R, Germany) was used to measure aflatoxin M1 in milk. They were transferred to the food hygiene and quality control laboratory of the Faculty of Veterinary Medicine of Shahrekord Islamic Azad University. Statistical analysis was performed to determine the differences in the amount of AFM between milk samples in different ruminants using one-way ANOVA and Duncan method. The mean difference was measured at the significance level of p<05.00. Excel software was used to draw graphs.

The results showed that aflatoxin M1 was detected in all raw milk samples, including cow, sheep, goat, buffalo and camel milk. 29 samples (48.3 %) have contamination less than 5 ng/kg, 27 samples (45 %) have contamination in the range of 20-5 ng/liter, and 4 samples (6.70 %) in the range of 20-50 ng/liter were contaminated with aflatoxin. Also, in this study, none of the raw milk samples of ruminants had contamination beyond 50 ng/liter.

The results showed that none of the aflatoxins in the present study exceeded the standard. due to lower pollution than Iran's standard; Europe and America In the present study, the use of ruminant milk sold in Karaj Counti cannot pose any risk to the health of consumers.

Salmonella is one of the gram-negative pathogens, whose presence in food reduces the quality of production and the occurrence of gastroenteritis in humans. The prevalence of salmonella in dairy products and the antibiotic resistance of this bacterium is one of the current crises. The purpose of this study is to investigate the prevalence of Salmonella Typhimurium and Enteritidis in traditional and industrial dairy products sold in Shahrekord city and the antibiotic resistance of the isolates. In this study, 140 samples from different traditional and industrial dairies were isolated and transferred to the food hygiene laboratory under sterile conditions, and the samples were evaluated for bacterial isolation by standard methods, and the resistance of the isolates was performed by disk diffusion method. took The results showed that out of a total of 60 industrial dairy samples, 2 samples (3.33%) were contaminated and 38 samples (47.5%) out of 80 traditional dairy samples were contaminated with Salmonella, and the highest contamination was related to industrial curd (6.42%). And then there was traditional butter and cheese (71.5%); Also, the highest level of resistance was related to sulfamethoxazole (71%) and the lowest resistance was related to Amoxiclav (50%). The results of this study showed that the detection of bacteria by PCR method is preferable to other traditional methods and considering the high occurrence of antibiotic resistance for the treatment of gastroenteritis caused by salmonella, the use of antibiotics for treatment should be minimized.

The aim of the present study is to investigate the antioxidant and antimicrobial properties of hydro alcoholic and aqueous extracts of grape seed varieties on Gram-positive and Gram-negative microorganisms isolated from poultry meat. 94 poultry meat samples including chicken, quail, turkey and ostrich were randomly collected from sales centers of Isfahan province. Microorganisms were identified by biochemical tests. Aqueous and hydro alcoholic extracts of grape seeds of black alfi, black gohari, black shahani, Rish-Baba, Shasat-arus and Rooster tail varieties were prepared by soaking method. Antimicrobial properties of hydro alcoholic and aqueous extracts of grape seeds were investigated by disk diffusion and MIC (minimum inhibitory concentration) methods. The antioxidant property of the extracts was evaluated by DPPH method and the IC50 value was calculated. The phenolic compounds present in aqueous and hydro alcoholic extracts of grape seeds were measured by high-performance liquid chromatography. The frequency of Arcobacter butzleri, Campylobacter jejuni, Listeria monocytogenes and Staphylococcus aureus was 11.45%, 17.70%, 1.04% and 16.66%, respectively. The antimicrobial effect of aqueous and alcoholic extracts of grape seed was higher on gram positive bacteria in both methods. Alcoholic extracts had more antimicrobial effect than aqueous extracts, Rish-Baba grape showed the most antimicrobial effect. The highest percentage of DPPH in hydro alcoholic extracts is related to black alfi and Rish-Baba grape seed extracts, and in aqueous extracts of black alfi and black shahani grape seeds.

The existing landfill site for Sari city is situated in an unhygienic manner in a village, at the southernmost point of the provincial capital. Unfortunately, this location has led to numerous environmental incidents affecting the local residents. In this study, a multi-criteria approach was employed using analytic network analysis (ANP) to identify the optimal waste landfill site. The evaluation process involved considering 24 layers of information, including geology, engineering geology (such as erosion, lithology, soil science, and seismicity), hydrology, hydrogeology (including rivers, dams, and well depths), topography (elevation and slope), socio-economic factors (distance from urban areas, villages, main roads, side roads, mines, and airports), climate (rainfall), and environmental aspects (protected areas and land use). Based on the findings, we selected five potential locations, with ‘Site 1’ in the southeast of Sari city receiving the highest average score and being recommended as the most suitable landfill site.

 The present study investigates the probiotic, antibacterial, technological, and safety properties of lactic acid bacteria (LAB) isolated from traditional yogurt in Chaharmahal and Bakhtiari, Iran.

 After serial dilution, culture was carried out in MRS culture media with 19 distinct rods bacteria. The gram-positive and catalase-negative LAB isolates were identified using Gram Staining, catalase, H2S, Indole, Motility and Oxidase biochemical assays, carbohydrate fermentation patterns, and 16S rDNA analysis. Then their probiotic potential (resistance to stomach acid and bile salt, hydrophobicity, auto-aggregation and co-aggregation, adherence capacity, and safety analysis) was evaluated.

 It was found that LAB strains belonged to Seven species belonging to five genera, including L. plantarum, L. brevis, L. rhamnosus, L. paracasei, L. casei, L. fermentum, and L. jensenii. After three hours of incubation at pH 2, strains lost 3–6 log units with L. rhamnosus strain IDC-D21 and L. paracasei strain DBR-D20, showing the most resilience to low pH and simulated GIT juices. The L. rhamnosus strain IDC-D21 and L. plantarum strain LRO-7 strains had the highest and lowest hydrophobicity (34.8 and 25.6%), respectively. Besides, the L. rhamnosus strain IDC-D21 had the highest degree of auto-aggregation (17.29%), followed by the L. paracasei strain DBR-D20 (14.28%). Also, the L. rhamnosus strain IDC-D21 showed the highest co-aggregation degree (19.07%).

 According to the research findings, L. rhamnosus strain IDC-D21 is recommended for application as a coculture in the dairy industry. Indeed, it has the best probiotic and technical features.

Aflatoxins are secondary metabolites of fungi, which can have very dangerous consequences for human health in addition to spoiling food and changing organoleptic properties. Aflatoxin entering the body and targeting the liver as the main organ involved can cause liver and blood cancer. Hence, the aim of the present study is to measure aflatoxin B1 in corn flour and wheat flour supplied in Shahrekord using ELISA method in 2022.

In this study, 40 samples of flour, including 20 samples of corn flour and 20 samples of wheat flour, were randomly sampled from the supply centers and sent to the food hygiene laboratory to track and determine the amount of aflatoxin B1.

The results showed that all samples of wheat flour and corn flour contained aflatoxin 1B. The average of aflatoxin B1 in wheat flour and corn flour was calculated as 2.58 ± 0.95 and 3.47 ± 2.07 (µg/kg) of the sample, respectively; Among the 20 examined samples of corn flour, the concentration of aflatoxin B1 ranged from 3.4 (µg/kg) to 1.9 (µg/kg) and in 20 samples of wheat flour (µg/kg) from 7.90 to (µg/kg) was 1.4; Therefore, the concentration of none of the samples was higher than the Iranian standard.

The occurrence of aflatoxin B1 in all the samples examined in the current study is lower than the risk range determined by the Iranian standard, so in this case, its aasociated high risk does not threaten the health of consumers.

Pseudomonas aeruginosa as a waterborne pathogen is a growing concern to public health sectors. Many sources of environmental water could potentially be acting as a reservoir for potentially pathogenic strains of P. aeruginosa. Due to the fact that P. aeruginosa is an opportunistic pathogen and causes serious problems, it seems necessary to know the pathogenesis, antibiotic resistance, genetic diversity and methods of removing it from drinking water. The pathogenesis of P. aeruginosa has been extensively studied and proven to be a multifactorial process, mediated by quorum sensing. P. aeruginosa possess two quorum sensing systems, las and rhl that facilitate cell to cell communication through production of signalling molecules termed autoinducers to target specific receptors for activation. P. aeruginosa is intrinsically resistant to various antibiotics due to a low permeability in the outer membrane, which acts as a selective barrier. However, this bacterium is a highly diverse pathogen that is capable of adaptation to the surrounding environment. When subjected to antibiotic selective pressure, the induced response facilitates bacterial survival and develops antibiotic resistance. literature suggests that the large genome size and genome complexity are responsible for the ability of this bacterium to adapt and thrive in a diverse range of environments. The presence and persistence of these bacteria in environmental waters may pose a great risk to the public health and requires further work to fully characterize and quantify the input of MDR P. aeruginosa strains from the hospitals compared with those originating from the general community or other wastewater related sources.

Dry leaf of trees, their powder and essential oil are used as flavoring agents in the food industry, and due to their antimicrobial and antioxidant properties, they increases the shelf life of food. The aim of this research is to investigate the chemical and antimicrobial properties of bay leaf essential oil. Extraction of essential oils was done by clevenger method. The results showed that the amount of carbohydrate, total fat and protein in the leaves were 2.93, 6.51 and 6.33 grams per 100 grams of dry matter, respectively, and antioxidant activity, total phenol and flavonoid content of the prepared essential oil, respectively, with IC50 of the number is 0.91 micrograms per milliliter, 0.65 m/g of gallic acid and 0.07 m/g of quercetin. The results of GC-MS showed that the main components of the essential oil include cineole (33.63 %), camphene (19.76 %), eugenol (11.73 %), terpineol (5.30 %), alphapinene (45.45 %.), Sabnin (3.42%), alpha-terpineol (0.45%) and methyl eugenol (0.33%). The evaluation of the antimicrobial activity of laurus nobilis essential oil indicates that the produced essential oil had antimicrobial activity against Staphylococcus aureus with a halo diameter of 14.60 ± 0.47 mm, while it was effective against Escherichia coli and Salmonella bacteria, respectively. It had less effect with halo diameter of 10.60 ± 0.47 and 9.60 ± 0.47 mm.

Nowadays, due to the existence of different occupations, it is not possible to cook food for all the people of a society, and most of the people have turned to using ready-made foods, which, in addition to all its advantages, can be a source of They are important bacterial contaminations that cause the spread of gastroenteritis. In this regard, the aim of this study is to investigate the prevalence of Arcobacter, Pseudomonas, Campylobacter and Bacillus cereus in sandwiches offered in Qom city and the antibiotic resistance of the isolates. 120 samples, including 30 samples of samosas, salads, traditional chicken nuggets, traditional hamburgers from the supply centers of Qom city, were randomly separated and transported to the food hygiene laboratory of Shahrekord Azad University along with ice flasks to prevent secondary contamination. The standards were evaluated. The results showed that Arcobacter 28.83%, Pseudomonas 16.65%, Bacillus cereus 23.35% and Campylobacter 14.75% were the highest and lowest contamination rates for Arcobacter and Campylobacter respectively. The highest level of resistance to antibiotics was related to Bacillus cereus with 78.56% and the lowest resistance was related to Campylobacter with 53.7%. Therefore, it is recommended to reduce the consumption of street food to a minimum, and in case of gastroenteritis caused by food contamination, the use of antibiotics should also be minimized.

Clostridium difficile is an obligate anaerobic, spore-forming bacterium with a length of 3-5 micrometers and most important enteropathogens in humans and livestock. Antibiotic use has been introduced as one of the most important risk factors in the spread of this disease. Antibiotics such as amoxicillin, erythromycin, lincomycin, clindamycin, linozoid, metopenem, metronidazole, amoxifloxacin, penicillin, pyracillin, tetracycline, and vancomycin have been introduced as common cases of "nosocomial Clostridium difficile infection". The purpose of this study is to investigate the prevalence, antibiotic resistance and genetic diversity of Clostridium difficile bacteria as a possible new foodborne pathogen in 300 domestic and industrial chicken and turkey meat samples in Chaharmahal and Bakhtiari provinces. The samples were grown in CDMN agar culture medium after an enrichment step to isolate Clostridium difficile. To determine the characteristics of the toxin, tcdA and tcdB genes were identified through multiplex PCR. The antibiotic sensitivity of these isolates was monitored based on the MIC test. The results showed that the highest prevalence was related to native chicken meat (5.6%) and the lowest prevalence was related to industrial turkey meat (1%). The genes responsible for the production of tcdB and tcdA toxins were observed in all Clostridium difficile isolates. Also, the highest resistance was related to erythromycin (14.85%) and the lowest resistance was related to vancomycin (97.38%). According to the isolation of two main genes causing hospital infection in clinical environments in the present study, the establishment of health systems in relation to the storage of the studied meats is necessary..

Aflatoxins are natural toxins that contaminate various types of food in humans and animals and pose a threat to their health. The aim of this study was to investigate the presence of aflatoxin B1 in dry cat and dog food offered in Isfahan province by ELISA method. The samples used in this study included 96 samples including 48 dog food samples from 12 commercially brands and 48 samples from 12 cat food brands that were collected by referring to pet shops in Isfahan. 200 g of sample was taken from each brand and transferred to the laboratory. It was then thoroughly ground in a mixer and tested according to the manufacturer's AFB1 Commercial Ready Kit. The results of the present study showed that the presence of aflatoxin B1 with a concentration range of 24 to 38 ng/g was detectable in the all samples. In addition, all brands showed higher levels of aflatoxin than normal level (20 ng/g). Among the studied dog food brands, no significant difference was observed between foreign and domestic brands, but in the comparison of aflatoxin levels of foreign and domestic brands of cats, the amount of this mycotoxin was higher in domestic brands. Since this mycotoxin affects the health of animals and causes serious disorders in these animals, and considering that in all brands studied in this study, aflatoxin level was higher than the allowable limit. Continuous monitoring of Aflatoxin B1 by dog and cat food industries as well as control of feed imports is essential.

Microbiological control of food is important to prevent food poisoning in humans. Pathogenic microorganisms are gram-positive or gram-negative pathogens found in food that cause gastroenteritis. The purpose of this study is to investigate the amount of Listeria monocytogenes and Salmonella in fish, shrimp and eggs presented in Shahrekord city. In this study, 300 samples, including 100 fish samples, 100 shrimp samples, and 100 egg samples, were randomly collected from retail stores in Shahrekord city and transferred to the specialized food hygiene laboratory of Shahrekord Islamic Azad University. The samples were enriched in Listeria enrichment culture medium for 48 hours and then on the selected culture medium and the suspected Listeria isolates from Palcam agar culture medium were counted after biochemical confirmation tests and for confirmation Salmonella was used from SS agar, BS agar and then TSI and LIA culture media. Research The results showed that 2 out of 100 fish samples (2 percent), 4 out of 100 shrimp samples (4 percent), and 5 out of 100 egg samples (5 percent) were contaminated. It was Listeria monocytogenes. The amount of Salmonella contamination for fish, shrimp and eggs was 9, 11 and 18 respectively. Due to the prevalence of Listeria, it is recommended to avoid consumption of undercooked seafood by at-risk populations. Strict implementation of sanitary conditions of food contact surfaces and handling areas, and good personal hygiene practices should reduce possible contamination of seafood products by L. monocytogenes.

Arcobacter is Gram-negative bacteria without curved spores, distinguished from Campylobacter by growth in the presence of oxygen and low temperatures. This study evaluates Arcobacter contamination in grilled meat, ready-to-eat salads, raw milk, and water in Yasouj City. In this study, 120 samples, including 30 grilled meat samples, 30 ready-to-eat salad samples, 30 raw milk samples, and 30 drinking water samples, were randomly collected from different parts of Yasouj City and transferred to the quality control laboratory of Shahrekord Islamic Azad University. The samples were tested according to the standard method. P<0.05 was considered a significant level in the present study. The results showed that out of 120 food samples tested, 22 were contaminated with Arcobacter. There was no significant relationship between the sampled foods and the level of Arcobacter contamination. According to the results, the drinking water contamination was zero, grilled meat was 13, salad was 1, and raw milk was 8. In total, 22 out of 120 samples were infected with Arcobacter. Considering the contamination of 18/33% in all the samples of this study and the possibility of contamination to humans and causing complications such as gastroenteritis, as well as the high consumption of meat, especially grilled meat, in roadside restaurants, it seems necessary to take measures to control this contamination. Bacteria from the production cycle to the consumption of meat, salad, raw milk, cooking meat, and boiling milk before consumption must be done carefully.