BACKGROUND: Toxoplasma gondii is a zoonotic obligate intracellular protozoan parasite that infects all warm-blooded animals as well as human worldwide. Human is infected with Toxoplasma parasites by eating half-cooked meat of livestock or oocyte. OBJECTIVES: The purpose of this study was to determine the presence of Toxoplasma in aborted fetuses of sheep using the serological method in North Khorasan province. METHODS: In this study, from 2015 to 2017, 133 samples of the thoracic fluid in aborted fetuses of sheep from different cities of North Khorasan Province were collected and sent to the central laboratory of Bojnourd. For each sample, a questionnaire was prepared for gathering information such as age and city, and then, the antibody level was determined in each sample by ELISA method. RESULTS: In this study, the age of 133 aborted fetuses of sheep was more than 120 days. Also, of the 133 aborted fetuses of sheep, 14 samples (10.53%) were infected with Toxoplasma parasites. The highest and lowest rate of Toxoplasma infection was observed in 2016 and 2017, respectively. Also, the most infection was found in Shirvan and Faroj cities. Results of chi-square test showed that there was a significant difference between year and abortion in sheep due to infection with Toxoplasma parasite (P<0.05). There was not significant difference between the frequency of this parasite infection and aborted fetuses in different areas (P> 0.05). CONCLUSIONS: The results of this study indicate that Toxoplasma gondii infection is one of the causes of abortion of sheep in North Khorasan province, and sheep is one of important sources of meat and dairy products in this area, Therefore, observance of public health tips and the complete cooking of meat and boiling milk is emphasized.

BACKGROUND: Mycobacterium avium subspecies paratuberculosis is the cause of a common disease in dairy herds. Early diagnosis of paratuberculosis infection can improve Johne’s disease control programs.OBJECTIVES: This study aimed to compare the sensitivity, and specificity to methods; blood serum ELISA and stool Nested-PCR for the detection of Mycobacterium avium subspecies paratuberculosis infection in dairy cattle.METHODS: A commercial ELISA kit was used to perform the absorbed ELISA test, which was conducted after exposing serum samples to Mycobacterium phlei antigens to limit cross-reactions. Nested-PCR test was performed using nucleotide sequences related to specific MAP gene fragments, i.e. IS900.RESULTS: As a result of the ELISA antibodies kit, out of the total 2203 serum samples, 112 samples were positive (5.08 %) and 2091 samples were negative (94.92 %). The results of Nested-PCR tests of rectal feces showed that out of 59 cows with the positive results in serum ELISA, 47 (79.66 %) samples were positive and 12 (20.34 %) samples were negative. Moreover, out of 31 cattle with a negative result on the ELISA test, 15 (48.38%) and 16 cattle (51.62 %) had positive and negative results, respectively, on the nested PCR tests of the feces samples.CONCLUSIONS: Due to the low sensitivity of PCR compared to ELISA, the positive and negative predictive values, and the accuracy of ELISA test, as well as the high cost and time-consuming nature of PCR and the need for more and more complex facilities than ELISA, the authors concluded that ELISA is a more suitable method for screening and epidemiological studies than PCR.

BACKGROUND: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).

BACKGROUND: Equine arteritis virus (EAV) causes respiratory disease, abortion and sometimes, neurological signs. Stallions which are permanently infected with the virus, are the constant carriers of the virus in their semen and transmit the virus to other horses through sexual contact. OBJECTIVES: The aim of this study was to evaluate EAV infection in horses in four provinces of Iran and its relationship with age, sex, and race. METHODS: Blood samples were taken from 149 horses with different sex, age and race with history or clinical signs associated with equine viral arteritis, including the manifestation of respiratory disease (fever, nasal secretion, coughing), nervous signs (ataxia, dysmetria, recumbency) and abortion. The commercial ELISA kit was used for viral antibody detection. RESULTS: From 149 sampled horses, 11 cases (7.4%) were found to be positive for EAV. Seropositive cases were recorded in Tehran (2.7%), Golestan (4.3%), Khuzestan (6.7%) and West Azerbaijan (23.8%) provinces. CONCLUSIONS: This survey confirmed the presence of EVAV in horses from four provinces of Iran with the sensitive (98.3%) and special (98.9%) test. Therefore, consideration should be given to the control and prevention programs for the spread of this virus.

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: Aflatoxin M1 (AFM1) is the main monohydroxylated derivative of aflatoxin B1 (AFB1) formed in liver and excreted into milk. AFM1  creates  certain hygienic risks for human health. OBJECTIVES: The aim of this study was to determine AFM1 level in raw milk samples in Yazd province. METHODS: This investigation was a descriptive-cross sectional study. Eighty raw milk samples were collected from four cities (Yazd, Taft, Mehriz and Sadogh) in Yazd province in winter and spring seasons. The concentration of AFM1 was determined by ELISA method. The analysis of the results was performed using ANOVA and Chi-square tests. RESULTS: All samples (100%) were contaminated with AFM1, with the concentrations ranging from 3.18 to 92.24 ng/l with a mean concentration of 22.07 ng/l. AFM1 level in 13.7% of raw milk samples was higher than the maximum tolerance limit of 50 ng/l accepted by the European Union (EU). The contamination level of AFM1 in winter samples (28.21 ng/l) was higher than spring samples (15.92 ng/l). Also, the highest and lowest contamination levels were observed in milk samples collected from Sadogh (mean 42.21 ng/l) and Yazd (12.79 ng/l) cities, respectively. CONCLUSIONS: Results demonstrated AFM1 was detected with a mean concentration of 22.07 ng/l in milk samples of Yazd province. Moreover, 13.7% of samples contained AFM1 at hazardous levels for human health.

To measure the concentration of serum amyloid A (SAA) protein in horses a sensitive and highly reproducible sandwich (ELISA) was established, using affinity purified SAA antibody. Results of the ELISA were found to have a high correlation (r = 0.95) with those of the single radial immunodiffusion test. Equine SAA concentration was measured by use of this ELISA. In clinically normal horses, the concentration of SAA was high immediately after birth to 2 weeks of age. After that, SAA concentration had periodic fluctuations in the range of approximately 10 to 30 microgram/ml. Mean (+/- SD) concentrations of SAA in foals (less than or equal to 12 months old) and adult horses (greater than or equal to 18 months old) were 21.23 +/- 12.20 and 14.93 +/- 9.07 microgram/ml, respectively. In mares during the perinatal period, SAA concentration remained stable within the reference range before parturition. It increased quickly after delivery, and reached a peak value of 101.29 +/- 98.82 microgram/ml on postpartum day 3, then began to decrease, at postpartum week 2, to the reference range by the end of postpartum month 1. In horses with experimentally induced inflammation, SAA concentration increased quickly and reached approximately four- to 40-fold increase over the pretreatment value on day 1 and remained high on days 2 to h after treatment. It then returned to the baseline value by 2 to 4 weeks in association with disappearance of local signs of inflammation. The SAA concentration was high in most horses with clinical signs of inflammation. It was concluded from these data that this ELISA is sensitive and reliable for measuring SAA in horses.

Two indirect ELISA containing outer membrane protein (OMP) and lipopolysaccharide (LPS) antigens from a field isolate of Salmonella choleraesuis var kunzendorf were developed and evaluated in experimentally infected and uninfected control pigs. Experimentally induced infection with S choleraesuis was successfully established in 10 pigs by oral inoculation with 10(8) organisms, and 3 pigs died of clinical salmonellosis at postinoculation (PI) weeks 1, 2, and 4. Swab specimens from tonsils, nostrils, and rectum of pigs were obtained for culture, and sera were evaluated at weekly intervals for 9 weeks after inoculation. The ELISA containing OMP and LPS antigens with either anti-swine IgG or protein albumin-to-globulin ratio (antiglobulin) conjugates were standardized for serologic evaluation. All 4 ELISA (2 OMP and 2 LPS) detected seroconversion by PI week 3 and had sensitivities and specificities of 97.8 and 88.8, 100 and 100, 95.6 and 88.8, and 93.3 and 72.5%, at their ideal cutoff points (negative mean optical density + 2 SD). There was excellent agreement between all 4 ELISA systems as determined by kappa values. Cultures of fecal, tonsil, and nasal swab specimens were positive for S choleraesuis until the fourth week of infection. Fecal swab specimens from 1 pig were positive for S choleraesuis until PI week 7. Persistent infection after antemortem culture results were negative was detected by all 4 ELISA, which indicated consistently high titers until the end of PI week 9. Conventional bacteriologic examination of intestines, mesenteric lymph nodes, bone marrow, lung, liver, spleen, and bile yielded positive results for S choleraesuis in the 3 pigs that died of clinical infection, whereas results were negative in the other 7 pigs infected by the end of PI week 9. Histologic examination of lung, liver, spleen, intestines, and mesenteric lymph nodes from the 3 pigs that died of S choleraesuis infection revealed severe ulceration and inflammatory cell infiltration.

An ELISA was developed and tested to detect antibodies to Eperythrozoon suis in swine. Results were compare with those of the indirect hemagglutination (IHA) test. Antigen isolated from swine heavily infected with E suis was used for both tests. Comparison of the ELISA with the IHA test revealed a significant (P < 0.001) correlation between results. Of 114 samples obtained from 9 swine infected with E suis, 8 7.7% were seropositive (titer greater than or equal to 200) via the ELISA, and 80.7% were seropositive (titer greater than or equal to 20) via the IHA test. The sensitivity of the ELISA was greater than that of the IHA test. All blood samples obtained from specific-pathogen-free swine tested negative for E suis antibody. Cross-reactions were not observed between E suis antigen and antisera against various swine and cattle disease agents using ELISA. We concluded that the ELISA may be used for rapid and effective diagnosis of infection with E suis in swine.

Serum samples obtained from 40,927 swine at various locations in North Carolina between Aug 1, 1987 and July 31, 1988, were tested for antibodies to Trichinella spiralis, using an ELISA based on a larval T spiralis excretory-secretory antigen. In the ELISA, samples were considered to have positive results if the optical density (OD) reading was equal to or 5 times greater than the mean OD value of 4 negative-control sera from trichina-free swine. Of the 40,927 serum samples tested, 154 (0.38%) were positive by ELISA; the rate for breeding swine was 0.35% (105/30,162), and the rate for cull swine was 0.45% (49/10,765). Of the 49 seropositive samples from cull swine, 11 were from out of the state, 22 had no identification, and 16 were known to originate from North Carolina. Seropositivity had a bimodally seasonal distribution, with peaks in March and September. There was no difference between the mean age of seropositive and seronegative swine, but males were at greater risk for seropositivity than were females. Pigs from lots with < 100 sera tested were at increased risk for seropositivity, as were pigs from the central coastal region of North Carolina.