Performance of two swine manure treatment systems on chemical composition and on the reduction of pathogens

Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid-liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen - TKN - and NH(3)), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required.

Surveillance of human and swine adenovirus, human norovirus and swine circovirus in water samples in Santa Catarina, Brazil

Animal and human wastewater can potentially contaminate water sources and the treatment of drinking water may not effectively remove all contaminants, especially viruses. The purpose of the present study was to evaluate the viral contamination of water used for human and animal consumption in the city of Concórdia, located in southern Brazil. Porcine circovirus type 2 (PCV2), porcine adenovirus (PAdV), human adenovirus (HAdV) and human norovirus (NoV) were searched for using quantitative polymerase chain reaction (qPCR). HAdV-positive samples were tested for viral infectivity by plaque assay. The qPCR results showed that PAdV, PCV2 and HAdV genetic material were present in all sampling sites. NoV was absent in all samples. The presence of genetic material from PAdV and PCV2 was detected in 30% and 45% of the 36 analyzed samples, respectively, with an average of 10(2) gc mL(-1) for PAdV and 10(4) gc mL(-1) for PCV2. HAdV was present in 100% of the samples, with an average of 10(4) gc mL(-1). However, in plaque assay, only 36% of the samples were positive. As viable particles of HAdV were found in drinking water, these results confirm that swine manure and human sewage impact surface water and groundwater, endangering water quality and indicating a potential risk to public health.

Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies

Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.

Phylogenetic comparison of the carboxy-terminal region of glycoprotein C (gC) of bovine herpesviruses (BoHV) 1.1, 1.2 and 5 from South America (SA)

Different types and subtypes of bovine herpesvirus 1 and 5 (BoHV-1 and BoHV-5) have been associated to different clinical conditions of cattle, in such a way that type/subtype differentiation has become an essential tool for understanding the pathogenesis and epidemiology of BoHV infections. In search for a genomic region that would allow a clear distinction between BoHV-1 and BoHV-5, the carboxy-terminal portion of glycoprotein C (gC), corresponding to residues 321-450 (BoHV-1) and 301-429 (BoHV-5) of 23 South American (SA) isolates (Brazil mostly) was amplified and sequenced. The nucleotide sequence alignments revealed levels of genomic similarity ranging from 98.7 to 99.8% among BoHV-1 isolates, 88.3 to 92% between BoHV-1/BoHV-5 and 96 to 99.7% among BoHV-5 isolates. At the amino acid level, sequence similarity varied ranging from 97.5 to 99.5% among BoHV-1, 77.5 to 84.4% between BoHV-1/BoHV-5 and 92.1 to 99.5% (BoHV-5/BoHV-5). The isolates could be clearly separated into BoHV-1.1, BoHV-1.2 and BoHV-5 after phylogenetic analysis. The results suggest that the phylogenetic analysis performed here can be used as a potential molecular epidemiological tool for herpesviruses.

Experimental infection of calves with a gI, gE, US9 negative bovine herpesvirus type 5

In this work, a role for the genes encoding glycoproteins I (gI) and E (gE) and the US9 protein of bovine herpesvirus type 5 (BHV-5) in neuropathogenicity and reactivation of latent infections was examined. Calves infected intranasally with a gI/gE/US9 deleted recombinant shed up to 10(2.85) TCID50/ml infectious virus in nasal secretions. Calves infected with the wild type BHV-5 parental virus shed up to 10(5) TCID50/ml virus. No signs of disease were observed in calves infected with the recombinant virus, whereas those infected with wild type virus displayed respiratory and neurological signs. The recombinant was only able to reach the basal portions of the central nervous system. In contrast, wild type virus was found widespread within the brain. Reactivation with dexamethasone 60 days post-infection resulted in reactivation of wild type virus, whereas the recombinant virus could not be reactivated. These studies demonstrate that genes gI, gE and US9 of BHV-5 are important for its neuropathogenicity and its ability to reactive from latency.