Serological study of small ruminant lentiviruses in sheep population of Khorasan-e-Razavi province in Iran.

Maedi-Visna (MV) virus and caprine arthritis encephalitis (CAE) virus known as small ruminant lentiviruses (SRLVs) cause chronic diseases in susceptible animals. The main reservoirs of these viral agents are sheep and goat. In sheep, MV virus causes a disease as the same name of the virus. This is the first seroprevalence survey of SRLVs in sheep population of Khorasan-e-Razavi province in Iran. Two hundred and twenty sheep from 30 flocks in 12 regions of the province were selected by random cluster sampling method. Serum samples were analyzed for the presence of antibodies against MV/CAE viruses. The seroprevalence in sheep was 34.5% (95.0% CI: 28.3 to 40.7%). Totally, the seroprevalence was in the range of 6.7 to 72.2 %. In 26 flocks of sheep (89.6%; 95.0%CI: 74.4 to 98.8%), at least one seropositive case was detected. The relationship between seropositivity and age, sex, flock size and breeds of sheep were statistically analyzed. In logistic regression model, only age was correlated with SRLV seroprevalence (p < 0.05). This study showed relatively high seroprevalence against SRLVs in sheep population in this area of the country. Due to difficulty in clinical diagnosis, chronic course of the disease, the absence of effective vaccine and treatment and huge economic loss, more epidemiological studies with regards to prevention and control of the disease are necessary.

Serological evaluation of relationship between viral pathogens (BHV-1, BVDV, BRSV, PI-3V, and Adeno3) and dairy calf pneumonia by indirect ELISA.

In this study, viral pathogens associated with nine outbreaks of naturally occurring dairy calf pneumonia in Mashhad area of Khorasan Razavi province from September 2008 to May 2009 were assessed. Five diseased calves from each farm were chosen for examination. Acute and convalescent serum samples were taken from calves with signs of respiratory disease. Sera were analyzed for antibodies to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PI-3V), and bovine adenovirus-3 (BAV-3) by indirect ELISA kits. Among 42 serum samples collected at sample 1, seroprevalence values for viruses BHV-1, BVDV, BRSV, PI-3V, and BAV-3 were 61.9% (26), 57.1% (24), 64.2% (27), 90% (38), and 61.9% (26), respectively. Seroconversion to BVDV, BRSV, PI-3V, and BAV-3 occurred in 11.9% (5), 16.6% (7), 26.1% (11), and 21.4% (9) of animals, and 52.3% (22) had generated antibodies against one or more viral infections at sample 2. In addition, no significant relationship between seroprevalence of BHV-1, BVDV, BRSV, PI-3V, and BAV-3 and dairy herd size was observed (P > 0.05). According to serological findings, BHV-1, BVDV, BRSV, PI-3V, and BAV-3 are common pathogens of the dairy calf pneumonia in dairy herds in Mashhad area of Khorasan Razavi province, Iran.

Evaluation of relationship between Rotavirus and Coronavirus infections with calf diarrhea by capture ELISA.

Rotavirus and Coronavirus are two main causes of severe diarrhea in human infants and many animal species worldwide. Calves up to 3 months old can be affected by these viruses. The importance of these viruses in cattle industry is due to substantial economic loss, treatment costs, and reduced growth rates in beef and dairy calves. Mixed infections caused by Rotavirus and Coronavirus can lead to severe form of diarrhea. In present case-control study, 261 samples of healthy and diarrheic calves from farms around Mashhad were collected. These samples were tested by antigen-capture enzyme-linked immunosorbent assay (Bio-X diagnosis kit). The results showed that the prevalence of Rotavirus and Coronavirus infection in diarrheic calves is 26.98% and 3.17%, respectively. Also, there was no significant relationship between infection with Rotavirus, Coronavirus, and diarrhea in the studied population.

Molecular cloning and expression analysis of chicken MyD88 and TRIF genes.

Toll-like receptors (TLRs) trigger the innate immune system by responding to specific components of microorganisms. MyD88 and TRIF are Toll/interleukin (IL)-1 (TIR)-domain containing adapters, which play essential roles in TLR-mediated signalling via the MyD88-dependant and -independent pathways, respectively. Genes encoding several TLRs have been identified in the chicken genome, however, elements of their signalling pathways have not been well characterized. Here we describe the cloning of chicken MyD88 and TRIF orthologs, and examine the spatial and temporal expression of these genes. The chicken MyD88 cDNA was shown to have an open reading frame (ORF) of 1104 bp, encoding a predicted protein sequence of 368 aa, 8 aa short of a previously published coding sequence due to a premature stop codon. MyD88 gene expression was detected in each tissue tested except in muscle. The chicken TRIF cDNA possessed an ORF of 2205 bp, encoding a predicted protein sequence of 735 aa, which shared 37.3% similarity and 28.9% identity to human TRIF protein sequence. TRIF was ubiquitously expressed in all tissues.