Effects of irradiation on the survival of Sarcocystis bradyzoites in beef.

BACKGROUND: Sarcocystis is a food-borne zoonotic protozoan whose final hosts are humans, dogs, cats, and other carnivores and intermediate hosts are birds and mammals, especially humans and herbivores. Humans become infected by eating raw and undercooked meat contaminated with bradyzoites or by consuming water or food contaminated with the sporocyst stage of the parasite. OBJECTIVES: The aim of this study was to investigate the effects of gamma radiation and electron beam on the survival rate of Sarcocystis bradyzoites in infected beef and to determine the effective dose. METHODS: Three replicates of 100 g of infected meat were treated with different doses (0.5, 1, 1.5 and 2 kGy). As a control, 20 g of contaminated meat was stored separately at 4°C. The viability of the bradyzoites after digestion in pepsin solution was assessed, stained (trypan blue) and unstained, under a stereomicroscope. To assess survival of the bradyzoites, the irradiated meat samples were fed to 30 dogs. After 10 days, faecal samples were examined for sporocysts. RESULTS: The results showed that the highest and lowest mortality rate of Sarcocystis bradyzoites in infected organs using electron beam at a dose of 2 kGy were 92.5% and 100%, respectively, and the lowest mortality rate at a dose of 0.5 kGy were 2.5% and 7.89%, respectively. CONCLUSION: The results of statistical analysis showed that the mortality rate of Sarcocystis bradyzoites was significant between different doses of gamma ray and electron beam, so that gamma rays were better compared to electron beam in destroying Sarcocystis bradyzoites.

Detection of Toxoplasma gondii infection in buffaloes (Bubalus bubalis) and cattle (Bos taurus) at the Tabriz abattoir, Iran.

BACKGROUND: Toxoplasma gondii is a widely prevalent zoonotic protozoan parasite in humans and warm-blooded animals worldwide. Infection of humans by this parasite can result in severe clinical symptoms, particularly in individuals with congenital toxoplasmosis or immunocompromised patients. Contamination mainly occurs through foodborne routes, especially the consumption of raw or undercooked meat from animals. OBJECTIVES: The aim of this study was to use PCR to detect T. gondii in tissues and organs of buffaloes and cattle slaughtered at Tabriz slaughterhouse, in Iran. METHODS: Fifty grams of heart, thigh, diaphragm and tongue from 50 buffaloes and 100 cattle slaughtered at the Tabriz industrial slaughterhouse were selected for sampling using a combination of convenience sampling. The samples were tested using a previously published PCR method. RESULTS: Out of the 150 animal samples, T. gondii was detected in 10 (6.7%, 95%CI: 3.2-11.9), including one buffalo (2%, 95%CI: 0.1-10.6) and nine cattle (9%, 95%CI: 4.2-16.4). There was no statistically significant difference in the rate of T. gondii infection among cattle based on age and sex (p > 0.05). CONCLUSIONS: The results indicated a potential risk of T. gondii transmission to humans through the consumption of infected meat. Therefore, appropriate and effective preventive measures should be taken to limit the transmission of this parasite to humans, and the consumption of raw and undercooked meat should be discouraged.

Prevalence and risk factors of Linguatula spp. in slaughter animals in Tabriz, Iran, and methods for nymphal stage inactivation.

Linguatula is a food born zoonotic parasite in which carnivores and herbivores serve as final and intermediate hosts, respectively. Human infection with Linguatula spp. occurs following consumption of raw or undercooked infected internal organs of the intermediate host and/or consumption of water and/or vegetables contaminated with eggs released from final hosts. The aim of this study was to determine prevalence and risk factors of Linguatula spp. in sheep, cattle, buffalo, goats and camels slaughtered at the Tabriz abattoir, Iran. In addition, effect of temperature and sodium chloride (NaCl) on survival time of Linguatula spp. nymphs was assessed. For this purpose, 25,520 mesenteric lymph nodes from 2552 animals and the livers and lungs from 656 animals were collected randomly and examined. To evaluate the effect of temperature and NaCl on the survival of Linguatula spp. nymphs in infected livers and lungs, 30 g of each liver and lung with dimensions of 2 × 3 × 4 cm, were exposed to temperatures of -20, 10, 50, 60 and 72 °C and NaCl concentrations of 5 %, 10 %, 15 % and 20 % for 3, 6, 12, 24, 48 and 72 h, in triplicate. Based on the mesenteric lymph nodes, 25.7 % (656 of 2552 animals) were infected with Linguatula spp. Of the 656 liver and lungs assessed, 141 (21.5 %) and 62 (9.5 %) were infected with Linguatula spp., respectively. The rate of infection of mesenteric lymph nodes in all animals was significant with age (P < 0.05), with more older animals infected. In regards to sex, except for camels, more female animals were infected than male animals (P < 0.05). There was a significant difference in survival of nymphs based on temperature and/or NaCl and time (P < 0.0001). At 72 h, all temperatures assessed except 10 °C, resulted in all nymphs being inactivated. Sodium chloride was more effective against Linguatula spp. nymphs in livers than in lungs with 100 % efficacy only achieved against nymphs in livers at 20 % concentration after 48 h and at 10 and 15 % concentration after 72 h. Based on these results, heating and application of common salt as a food preservative in meat products reduces the survival time of Linguatula spp. nymphs and their use could decrease the risk of food-born microorganisms.

Molecular detection, biotyping and serotyping of Yersinia enterocolitica isolated from chicken livers in Tabriz.

INTRODUCTION AND PURPOSE: Yersinia enterocolitica belongs to the family of Enterobacteriaceae and is a psychrophilic pathogen that is associated with foodborne infections. It usually causes gastroenteritis, mesenteric lymphadenitis, and septicemia. This study aimed to molecular detection, biotyping, and serotyping of Yersinia enterocolitica isolated from chicken livers in Tabriz. MATERIALS AND METHODS: One hundred chicken liver samples were collected randomly from poultry slaughterhouses in Tabriz for three months. After enrichment process, the presence of Yersinia enterocolitica in studied samples was determined through culture-based methods, biochemical and molecular tests. Then the biotype and serotype of the isolates were determined. RESULTS: 31 samples (31%) were positive for Yersinia enterocolitica by both phenotypic and molecular assays. Among positive samples, 25 (80.64%) had non-pathogenic biotype 1 A with serotype O: 5 (23 samples) and O: 8 (2 samples). 6 (19.36%) had biotype 1B and all of them had O: 3 serotype. The serotype Yersinia enterocolitica O: 9 was not found. CONCLUSION: the present study highlighted the significance of chicken liver as potential source of Yersinia enterocolitica infection in Tabriz city.

Zoonotic parasitic organisms on vegetables: Impact of production system characteristics on presence, prevalence on vegetables in northwestern Iran and washing methods for removal.

Fresh vegetables are essential components of a healthy and nutritious diet, but if consumed raw without proper washing and/or disinfection, can be important agents of transmission of enteric pathogens. This study aimed to determine the prevalence of zoonotic parasites on vegetables freshly harvested and "ready to eat" vegetables from greengrocers and markets in northwestern Iran. In addition, the effect of cropping system and season on contamination levels were assessed as well as the efficacy of washing procedures to remove parasites from the vegetables. A total of 2757 samples composed of field (n = 1, 600) and "ready to eat" (n = 1157) vegetables were analyzed. Vegetables included leek, parsley, basil, coriander, savory, mint, lettuce, cabbage, radish, dill, spinach, mushroom, carrot, tomato, cucumber and pumpkin. Normal physiological saline washings from 200 g samples were processed using standard parasitological techniques and examined microscopically. A total of 53.14% of vegetable samples obtained from different fields and 18.23% of "ready to eat" vegetables purchased from greengrocers and markets were contaminated with different parasitic organisms including; Entamoeba coli cysts, Giardia intestinalis cysts, Cryptosporidium parvum oocysts, Fasciola hepatica eggs, Dicrocoelium dendriticum eggs, Taenia spp. eggs, Hymenolepis nana eggs, Ancylostoma spp. eggs, Toxocara cati eggs, Toxocara canis eggs, Strongyloides stercoralis larvae, and Ascaris lumbricoides eggs. In both field and "ready to eat" vegetables, the highest parasitic contamination was observed in lettuce with a rate of 91.1% and 55.44%, respectively. The most common parasitic organism was Fasciola hepatica. A seasonal difference in contamination with parasitic organisms was found for field and "ready to eat" vegetables (P < 0.05). There was a significant difference in the recovery of parasitic organisms depending on the washing method with water and dishwashing liquid being the least effective. Proper washing of vegetables is imperative for a healthy diet as the results of this study showed the presence of zoonotic parasites from field and ready to eat vegetables in Iran.

Prevalence of Linguatula sp., a food-borne zoonotic aberrant arthropod, in river buffaloes slaughtered at Tabriz slaughterhouse, Iran.

BACKGROUND: Canids and herbivores are the definitive and intermediate hosts of Linguatula sp., respectively. METHODS: Mesenteric lymph nodes (n=32 525) were randomly collected from 7585 buffaloes from July 2016 to July 2019 and examined macroscopically. RESULTS: Results showed that 388 (5.11%) buffaloes were infected. The intensity of infection was determined to be 3.07±0.07. Significant statistical association was identified between infection rate and age and sex. Although there were no significant differences in the infection rate over different seasons, the highest infection rate was observed in autumn. CONCLUSIONS: These data highlight the importance of inspection at slaughter.

Molecular detection of Campylobacter species and Cytolethal distending toxin isolated from chicken livers in Tabriz.

INTRODUCTION AND PURPOSE: Campylobacter jejuni and coli are zoonotic bacteria commonly associated With human diarrhea and usually transmit through consumption of meat and poultry contaminated products such as heart and liver. Cytolethal distending toxin (cdt) in Campylobacter spp. is among the significant virulence factors of these bacteria in the intestine. The purpose of this study was to determine the prevalence of Campylobacter spp. and presence of cdt genes among isolated bacteria. MATERIALS AND METHODS: In this cross sectional study, 100 chicken livers were examined. Detection, bacterial enumeration and isolation of Campylobacter spp. was done using Campylobacter selective agar media containing Campylobacter growth supplement, gram staining, catalase and oxidase production, hippurate hydrolysis and PCR molecular technique. Also the presence of cdt genes were detected using PCR assay. RESULTS: From 100 studied liver samples, 43 were contaminated with Campylobacter spp. Among them 31(72 %) samples had Campylobacter jejuni and 12 (28 %) had Campylobacter coli. All Campylobacter jejuni isolates contained cdtA ،cdtB and cdtC genes. However, all of these genes detected in 9 (75 %) of isolated coli. CONCLUSION: The results of this study showed that great percentages of chicken livers in Tabriz were contaminated with Campylobacter.

Effects of chitosan edible coating containing grape seed extract on the shelf-life of refrigerated rainbow trout fillet.

In recent years, use of edible coatings as carriers of food additives and antimicrobial compounds has been considered in fishery products. This study was carried out to evaluate the effects of 2.00% chitosan coating singly and combined with 0.10% grape seed extract (GSE) on microbial (mesophils and psychrophils counts), chemical (thiobarbituric acid; TBA), pH and peroxide value (PV) and sensorial properties of rainbow trout fillet stored at 4 °C over a period of 15 days. The coating had a significant effect in reducing aerobic mesophilic and psychrophilic bacteria counts. The TBA, PV and pH of samples of chitosan coating alone and with GSE were lower than control ones indicating a significant influence of coating on fillet shelf-life. Moreover, chitosan coating represented an equal sensorial quality with controls. It can be concluded that chitosan coating containing GSE can help to maintain the sensorial quality and increase the shelf-life of rainbow trout fillets at refrigerated conditions.

Lead concentration in the muscles of slaughtered buffalos in northwest regions of Iran.

BACKGROUND: The topic of food safety has become a major public health issue worldwide. Over recent decades, the growing concern for food safety has brought about greater research regarding the risks associated with the consumption of produce that has been contaminated by pesticides, heavy metals and/or toxins. OBJECTIVE: The study was conducted to determine the concentration of Pb in the muscle of buffalos slaughtered in the northwest regions of Iran (Ardabil, Urmia and Tabriz cities). METHODS: The present was a descriptive cross-sectional study in the northwest regions of Iran during 2013 to 2014. A total of 30 muscle samples from individual buffalos were analyzed for Pb concentrations using Atomic Absorption Spectrophotometer (ASS). Statistical analysis was performed using SPSS 17.0. All results were computed as mean standard deviation and subjected to one-way analysis of variance to establish whether the differences in Pb concentrations in meat samples from different cities were significant or not. The Statistical significance was determined at p<0.05. RESULTS: The results showed that the mean concentration of Pb in muscle samples were measured 0.043±0.035 ppm. The highest Pb concentration (0.11 ppm) was detected in the buffalo muscle samples from Urmia city. In total, 25 muscle samples (80.33%) were contaminated with Pb and concentration of Pb in 3.33% of contaminated samples exceeded the permissible limits advised by the European Commission (EC) (0.1 ppm). CONCLUSION: We recommend identifying Pb sources in order to eliminate or control Pb contamination of food, and monitor environmental exposures and hazards to prevent lead poisoning.

A study on rate of infestation to Sarcocystis cysts in supplied raw hamburgers.

This study was carried on for determination of presence of Sarcocystis cysts in raw hamburgers in Tabriz North West of Iran. Ninety-six samples of industrial (70 % meat content) and traditional (30 % meat content) hamburgers (80 samples industrial and 16 samples traditional) were obtained from retail fast food stores. The samples were examined by gross examination, and microscopic examination methods consist impression smear and peptic digestion. Macroscopic cysts did not observed in any of the samples in gross examination. Microscopic study showed that from 96 samples 54 (56.25 %) samples were infected by at least one bradyzoites of Sarcocystis. From 54 infected samples, 45 industrial hamburgers and nine traditional hamburgers samples were infected. Statistical analysis showed that there was not significant differences between industrial and traditional hamburgers in infection to Sarcocystis. Infestation of hamburgers to Sarcocystis in summer was higher than other seasons but this difference was not significant. In Iran, beef meat is used for preparation of 70 % of hamburger and infestation of cattle to sarcocystosis was reported in many investigations in Iran. With regard to the high prevalence of Sarcocystis infection in meat products such as hamburgers in this study, it is strongly recommended to avoid eating raw or under-cooked hamburgers or keep them at freezing temperature for at least 3-5 days.