Molecular evidence of bovine herpesvirus 1 and 5 in cattle with suspected rabies in Rio Grande do Sul state, Brazil.

Rabies and herpetic encephalitis are the main viral infections in bovines with neurological symptoms. Bovine rabies has a high prevalence in Central and South America, while bovine encephalitis associated with herpesvirus is especially important in South America. Viral isolation is the classical way to confirm herpesvirus infection, but molecular evidence of the presence of the virus in affected animals is gaining importance in the diagnosis of the disease in the laboratory. This study investigated the presence of herpesvirus type 1 and 5 (BoHV-1 and BoHV-5) in 182 encephalon of rabies-suspected cattle in Rio Grande do Sul state (RS), Brazil using multiplex real-time polymerase chain reaction (mRT-PCR). The rabies virus was investigated by direct fluorescent antibody assay and intracerebral suckling mouse inoculation. The genomes of BoHV-1 and BoHV-5 were detected in 17% of samples. BoHV-5 and BoHV-1 were detected in 100% and 19% of BoHV positive samples, respectively, indicating the circulation of the pathogens in cattle herds in RS. The high Ct values and the absence of isolation suggest viral latency. Coinfection of herpesvirus and the rabies virus was detected in 28% of samples, although no significant association between pathogens was observed. Rabies was detected in 57.7% of suspected samples, confirming the importance of the disease in the state. Concerning the method by which samples were conserved, no significant difference was observed between the number of positive results in frozen and refrigerated samples.

Fibropapillomatosis in green turtles Chelonia mydas in Brazil: characteristics of tumors and virus.

Fibropapillomatosis (FP) is a benign neoplasia that affects physiological functions of sea turtles and may lead to death. High prevalence of FP in sea turtle populations has prompted several research groups to study the disease and the associated herpesvirus, chelonid herpesvirus 5 (ChHV5). The present study detected and quantified ChHV5 in 153 fibropapilloma samples collected from green turtles Chelonia mydas on the Brazilian coast between 2009 and 2010 to characterize the relationship between viral load and tumor characteristics. Of the tumor samples collected, 73 and 87% were positive for ChHV5 in conventional PCR and real-time PCR, respectively, and viral loads ranged between 1 and 118.62 copies cell⁻¹. Thirty-three percent of turtles were mildly, 28% were moderately and 39% were severely affected with FP. Skin samples were used as negative control. High viral loads correlated positively with increasing FP severity in turtles sampled on the Brazilian coast and with samples from turtles found dead in the states of São Paulo and Bahia. Six viral variants were detected in tumor samples, 4 of which were similar to the Atlantic phylogenetic group. Two variants were similar to the western Atlantic/eastern Caribbean phylogenetic group. Co-infection in turtles with more than one variant was observed in the states of São Paulo and Bahia.

Herd-level risk factors for bovine viral diarrhea virus infection in dairy herds from Southern Brazil.

A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 300 randomly selected dairy herds which were tested for antibodies in bulk tank milk (BTM) using a commercial indirect ELISA kit (SVANOVA). Results from the analysis were interpreted according to the Swedish BVDV control scheme. The testing revealed 129 (43%) BTM BVDV antibody-positive herds. Use of artificial insemination (AI) and herd size were significantly associated with BVDV serological status (P<0.05). Dairy herds that use AI had 2.82 increased odds of BVDV-seropositivity (95% CI: 1.02-7.24). Since the semen used in the studied population come from known selected sires, it was hypothesized that AI technicians should represent an important risk factor because the increasing number of visitors in the farm can introduce the virus through the clothes, shoes and contaminated equipment.

Molecular diagnosis of Salmonella species in captive psittacine birds.

Cloacal swabs were collected from 280 captive psittacine birds belonging to 13 species. Samples of dna were tested by PCR using a pair of primers that amplify a 284 base pair fragment of the Salmonella genus invA gene, and the PCR-positive samples were tested by standard microbiological techniques. Thirteen per cent of the samples were positive by PCR, but negative by microbiological techniques. The infection rates were significantly different among the 13 species, the most commonly infected being Amazona amazonica (28 per cent) and Amazona pretrei (20 per cent). Specific tests for Salmonella Typhimurium Salmonella Enteritidis, Salmonella Pullorum and Salmonella Gallinarum did not produce positive results.

Evaluation of selective and non-selective enrichment PCR procedures for Salmonella detection.

AIMS: To compare PCR combined with enrichment media with the standard microbiological techniques (SMT) and to determine the most sensitive method for the detection of Salmonella and the identification of Salm. typhimurium (ST), Salm. enteritidis (SE), Salm. gallinarum (SG) and Salm. pullorum (SP). METHODS AND RESULTS: We analysed 87 samples from poultry using PCR and SMT, PCR being performed from non-selective (NS) and Rappaport-Vassiliadis (RV) media. PCR-NS was less sensitive than PCR-RV and SMT for the detection and identification of Salmonella. PCR-RV detected more positive samples of Salmonella sp. than SMT but both these methods showed similar sensitivity regarding the identification of Salmonella serovars. CONCLUSIONS: PCR-RV was more sensitive and decreased the time necessary to detect and identify Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR-RV is a powerful tool for the rapid and accurate detection and identification of Salmonella and can be implemented in diagnostic and food analysis laboratories.