BACKGROUND: Brucellosis is one of the most common zoonosis in Middle East and Iran. OBJECTIVES: The purpose of this study was genomic detection of Brucella spp. in sero-positive dairy cattle. METHODS: We have collected 28,519 blood samples from cows during 2012-2013. Samples were screened by Slide and tube agglutination and 2-Mercaptoethanol tests. Samples with anti-Brucella antibodies titer ≥ 1:80 and ≥1:40 in tube agglutination and 2-ME tests were considered as positive respectively. Tissue samples include: lymph nodes, liver, testicle and kidney from 122 samples of slaughtered cows were collected. The Sero-positive samples were examined by a collection of specific primers for Brucella abortus, Brucella melitensis, vaccinal strains included RB51 and Rev1 using PCR tests. RESULTS: Results showed that 450 samples were positive in slide agglutination test and 447 samples had anti-brucella antibodies titer equal to or more than 1:80. So they were positive by tube agglutination test. Three hundred eighty nine samples were positive by 2- mercaptoethanol test. PCR test results showed that 46 samples (37.7%) out of 122 samples had a specific sequence of Brucella or otherwise they have an active infection with Brucella species, whereas 62.3% of samples were negative. The PCR results showed that 2 samples (4.35%) were infected by B. melitensis, 2 samples (4.35%) infected by Rev1 strain and 42 samples (91.3%) were infected by B. abortus. CONCLUSIONS: The results showed that, as we had expected, the majority of cows were infected by B. abortus. Animals who infected by B. melitensis and Rev1 strain may be a result of contact with sheep or goats. We couldn’t find Brucella genome in 76 samples (62.3%) of sero-positive cows. It may be caused by cross reaction of sera with Brucella species in tests or activation of immune system response and elimination of organism from internal organs.

BACKGROUND: Bovine Herpes Virus-1 (BHV-1) belongs to the  Alpha herpesviral family. The virus is the cause of Infectious Bovine Rhinotracheitis (IBR) and Bovine Abortion. In the initial infection, the virus proliferates excessively. Moreover, shedding the virus leads to conditions in the latent phase of the disease. Infectious Bovine Vulvovaginit (IPV ) is the genital form of the disease that represents a genital infection and transmits via pustules and mucopurulent secretions. Exposure to the virus in genital mucosa leads to IPV infection through mating or artificial insemination and the diseases that can be transmitted to healthy livestock by frozen sperm during artificial insemination.OBJECTIVES: Viral contamination of the semen is one of the routes to spread the disease among dairy cattle. Therefore, we investigated the presence of the virus in domestic and frozen imported semen consumed in industrial dairy cattle farms.METHODS: In the present study, 140 frozen straws were collected. After melting each straw, 200 µl of obtained semen was used for DNA extraction, which was done directly on the semen samples and via a Genome Extraction Kit. Subsequently, to ensure the accuracy of the extraction, the PCR technique was done using PRM-1 gene primer. Tracking the viral genome was done using the PCR technique and known primers.RESULTS: In total, one out of 140 samples was found to be virally contaminated, and IBR contamination was confirmed by repeating all the steps and determining the gene sequence.CONCLUSIONS: It is necessary to further investigate the possibility that contamination can be transmitted via frozen semen, given that even one out of 140 samples is contaminated, and the importance of the disease.

BACKGROUND: Diarrhea is a common disease in the neonate calf which imposes significant economic burden on cattle industry around the world. During the first week after birth, Enterotoxigenic E.coli (ETEC) strains carrying F5 fimbria are one of the most important pathogens causing calf diarrhea. F5 fimbria is involved in early stage of pathogenesis and is responsible for attachment of bacteria to enterocytes; this attachment is mediated by FanC protein of F5 fimbria. Antibodies directed against F5 fimbriae play a significant role in prevention and control of the disease. Objectives: Evaluation and expression of recombinant expression of F5 Fimbriae of Enterotoxigenic Escherichia Coli associated with calf diarrhea. Methods: In the present study,  the fanC region of F5 fimbria was cloned in a pET28a plasmid. Results: The recombinant construct was confirmed by sequencing and protein production in Escherichia coli BL21 (DE3) was evaluated by western blotting procedure. Conclusions: Based on our findings, the recombinant FanC protein or the BL21 (DE3) strain are suitable candidates to develop an effective vaccine against calf colibacillosis or use in a diagnostic kit for F5+ ETEC.