BACKGROUND: Staphylococcus aureus is one of the most important human pathogens that cause infection and also food intoxication by secreting various enterotoxins. Conventional culturing methods to detect S. aureus have some limitations such as being time-consuming due to bacterial growth and low precision and sensitivity in detecting viable but non-cultivable cells. OBJECTIVES: The objective of this study was to detect and quantify enterotoxigenic (A-E) S. aureus in cream pastry products applying PCR coupling with propidium monoazide (PMA) to distinguish dead and live cells. METHODS: One hundred samples were randomly collected from pastry shops in Amol, in a period of 2 months. After preparing dilutions, bacterial pellets were separated and treated with PMA before DNA extraction. Real time PCR was conducted in order to quantify S.aureus cells and enterotoxigenic strains using specific primers. RESULTS: Results of conventional method were close to PMA-qPCR data (P>0.05), but data from qPCR that includes live and dead cells shows more bacterial count than two other methods. Sensitivity of the method applied in the present study, detecting low number of S.aureus cells (less than 10/g) seems considerable. CONCLUSIONS: Findings showed that applying PCR coupling with PMA results in more reliable data than conventional culturing method. Regarding this approach being time-effective, considerably sensitive and specific, it is expected that it be used in food quality control labs in monitoring systems in future.

BACKGROUND: Toxoplasma gondii is an intracellular protozoan parasite that can infect most species of warm-blooded animals, including birds and humans. Because of feeding habits of domestic chickens, prevalence of Toxoplasma infection in free-range chickens is considered as a suitable indicator of environmental distribution of oocysts. OBJECTIVES: The present study was designed to investigate the seroprevalence of Toxoplasma infection in domestic chickens from Khorramabad and compare the results obtained from serological and molecular methods. METHODS: In total, 97 serum samples were randomly obtained from domestic chickens and examined for the presence of anti-Toxoplasmaantibodies using modified agglutination test (MAT). Fifty grams of muscles (mixture of breast and heart) and whole brain from seropositive chickens were separately homogenized and examined by PCR which targets the repeated element (RE) of the parasite. RESULTS: Anti-Toxoplasma antibodies were observed in 21 of 97 (21.64%) sera. T. gondii DNA was detected in 10 out of 21 (47.61%) seropositive chickens (with titres of ≥1:20). The low agreement between serological and molecular results can be explained by several factors such as possibility of cross-reactions in MAT and/or limited sample size in PCR. CONCLUSIONS: These results indicate that domestic chickens may have an important role as a source of infection for cats and individuals living in rural areas.

BACEKGROUND: Toxoplasmosisis one of the most important zoonotic diseases in Iran and the world. OBJCTIVES: Due to the high consumption of lamb meat and the high frequency of Toxoplasma infection in sheep in Iran, the aim of study was to determine frequency of Toxoplasma infection in the slaughtered sheep of Mashhad area. METHODS: In order to do this study, from summer 2015 to spring 2016, 25 blood and 25 heart muscle samples were seasonally collected from Torghabae slaughterhouse in Mashhad area. The samples were transferred to parasitology laboratory. First, the blood samples were centrifuged and the serum samples were isolated, then a portion of the heart muscles sample was taken for PCR examination. The sera and muscles samples were kept at -20 ºC in freezer until examination time. The sera samples were examined to detect antibody against T.gondii by ELISA method. DNA of heart muscle was extracted by commercial extraction kit and was examined to detect Toxoplasma DNA by nested –PCR. RESULTS: In the present study, of 100 sampled sheep, only 1 (1%) of the serum samples was seropositive, while 22 (22%) of the DNA samples were PCR positive. In this study, the highest frequency of Toxoplsma PCR-Positive was seen in spring and the lowest in summer in sheep. Also, the result of this study showed that the agreement between the molecular and EISA method was “fair”. CONCLUSIONS: Based on the high frequency of Toxoplasma infection in heart muscle of sheep, it seems that the risk of transmission of Toxoplasma infection from sheep meat is high.

BACKGROUND: Ovine theileriosis is an important hemoprotozoal disease of sheep and goats in tropical and subtropical regions which causes high economic loss in the livestock industry. OBJECTIVES: The aim of this study was the differential detection of Theileria species in sheep using PCR method. METHODS: Two hundred blood samples of sheep were investigated in order to differentially diagnose Theileria species. DNA was extracted from blood samples and DNA samples were amplified using specific primers designed for 18S rRNA, TamS1 and TaSp genes. RESULTS: In this study, from 200 examined samples, 42 samples (21%) were infected by Theileria spp. and none of them were infected by Babesia spp. Moreover, from these 42 positive samples, 24 samples (57.1%) were only infected by T. ovis. 12 samples (28.5%) were only infected by T. lestoquardi, 2 samples (4.7%) were only infected by T. annulata and 4 samples (9.5%) were simultaneously infected by T. lestoquardi and T. ovis. The results of nucleotide sequencing showed that PCR product of 18S rRNA from T. lestoquardi has 99 and 95% similarity with T. annulata and T. ovis respectively. T. lestoquardi and T. annulata showed 86% similarity. Also TaSp gene of T. ovis in comparison with T. annulata and T. lestoquardi showed 96 and 86% similarity, respectively. CONCLUSIONS: In the present study could be shown that the two genes (TamS1 and TaSp) from examined three genes could be used for Theileria species specific diagnosis by PCR.

BACKGROUND: There is paucity of information about Anaplasma marginale (A. marginale) infection in water buffaloes and there have not been any reports of clinical anaplasmosis in the buffaloes in Iran. OBJECTIVES: Molecular and hematologic survey on A. marginale infection in apparently healthy buffaloes referring to Ahvaz abattoir. METHODS: Samples of blood and spleen tissue were obtained from 103 healthy buffaloes referring to the slaughterhouse. Blood samples were subjected to microscopic examination and PCR assay while spleen specimens were only analyzed by PCR. In this study, a nested-PCR method was used to amplify a fragment of the groEL gene of the bacterium. RESULTS: According to PCR, 31.1% and 1.9% of examined blood and spleen samples were found positive for A. marginale, respectively. The buffaloes which were positive in spleen tissue PCR test were positive in blood PCR, as well. Microscopically, Anaplasma-like organisms were found in 15.5% of stained blood smears. There was a slight Kappa agreement between stained blood smears and PCR. No significant difference was found in hematologic values between the infected and non-infected buffaloes based on PCR results. CONCLUSIONS: Significant occurrence of infection with A. marginale in the studied buffaloes can indicate the probable role of buffalo as a reservoir of the disease agent and its transmission to the cattle.

BACKGROUND: Salmonella are endemic on most large intensive dairy farms and salmonellosis is a common cause of neonatal morbidity and mortality. Disease and mortality usually reflect a variety of management events and environmental stressors that contribute to compromised host immunity and increased pathogen exposure. OBJECTIVES: In this study, PCR method was used to identify Salmonella Enteritidis, Infantis, Dublin and serovars isolated from diarrhea samples and aborted fetuses of Tehran and Alborz provinces dairy Farms. Further observation showed that the isolation of S. Enteritidis and S. Infantis is closely related to the consumption of contaminated poultry meat powder in diet of cows. METHODS: Forty-one Salmonella were isolated from diarrhea and aborted fetus samples in Tehran and Alborz provinces Farms and were confirmed by biochemical assays, then the isolates were identified by serological methods by polyvalent and monovalent Salmonella antisera. DNA of samples was extracted by Boiling method and was tested by PCR. Salmonella serovars were identified according to the presence of specificgenes for Salmonella Enteritidis, Infantis and Dublin.  RESULTS: All samples were tested by PCR were positive. 32 samples were identified as Salmonella Enteritidis (78/04 %), 4 samples were identified as Salmonella Infantis (9/77 %) and 5 samples were identified as Salmonella Dublin (12/19 %). CONCLUSIONS: According to the results, it seems that PCR can be used as a alternative method to the expensive and time consuming biochemical and serological methods for identifying Salmonella serovars. As Salmonella Enteritidis was usually isolated from poultry, isolation from cows may be due to has been used chicken meat powder in diet of the dairy farms.

BACKGROUND: Bordetella bronchiseptica is a gram negative pathogen of the respiratory tract in dogs, pigs, cats, horses, laboratory animals and human beings. OBJECTIVES: The goal of this study was detection of Bordetella bronchiseptica in oropharynx region of pet and kenneled dogs by PCR and culture and evaluation of antibiotic susceptibility of the isolates in Iran. METHODS: The samples were collected by sterile swabs from oropharynx region of 62 pet dogs (including 31 dogs with clinical respiratory disease signs and 31 dogs without clinical respiratory disease signs) and 62 kenneled dogs (including 31 dogs with clinical respiratory disease signs and 31 dogs without clinical respiratory disease signs). Bordetella bronchiseptica was detected by PCR and culture and antibiotic susceptibility of the isolates were evaluated. RESULTS: Based on the PCR results, Bordetella bronchiseptica was detected in 16.1% of pet dogs with clinical respiratory disease signs, 9.6% of pet dogs without clinical respiratory disease signs, 22.5% of kenneled dogs with clinical respiratory disease signs and 16.1% of kenneled dogs without clinical respiratory disease signs. On bacterial culture, Bordetella bronchiseptica was isolated from 3.2% pet dogs with clinical respiratory disease signs, 3.2% kenneled dogs with clinical respiratory disease signs and 6.4% kenneled dogs without clinical respiratory disease signs, none of the pet dogs without clinical respiratory disease signs was positive on bacterial culture. The isolates tested by the agar dilution method were susceptible to tetracycline, enrofloxacin, co-trimoxazole and doxycycline, moderately susceptible to ceftriaxone and resistant to ampicillin. CONCLUSIONS: This study has shown the high prevalence of Bordetella bronchiseptica infection in dogs in Iran. Bordetella bronchiseptica can infect the people who have contact with the affected pet dogs and those kept in overcrowded shelters.