André Felipe Streck

First detection of canine parvovirus type 2c in Brazil

The presence of canine parvovirus type 2 (CPV-2), 2a and 2b has been described in Brazil, however, the type 2c had not been reported until now. In the current study, seven out of nine samples from dogs with diarrhea were characterized as CPV-2c, indicating that this virus is already circulating in the Brazilian canine population.

Effects of prebiotics and probiotics on the colonization and immune response of broiler chickens challenged with Salmonella Enteritidis

The present study aimed at evaluating the effect of the prebiotic Bio Mos™ (2 kg/ton up to 10 days; 1 kg/ton from 10 to 21 days; and 0.5 kg/ ton from 21 days to slaughter), of the probiotic Lac XCL 5x™ (by spraymixing), of a combination of the two supplements (prebiotic + probiotic), and of one growth promoter antimicrobial agent (Avilamycin at 15 ppm). Birds were orally challenged with inoculated Salmonella Enteritidis (SE) 10 6 CFU at 3 days of age. Four hundred and eighty male Ross chicks were used. The experiment lasted 28 days, and the analyses were conducted at 15 and 28 days of age. Cecum and liver bacterial colonization of production of anti-SE antibiodies, intestinal micrometry and bird performance were assessed. Neither the prebiotic, nor the probiotic influenced performance or production of anti-SE antibodies in SE-challenged birds. Intestinal micrometry and bird mortality were not influenced by prebiotic or probiotic supplementation, or by the antimicrobial agent. The use of an antimicrobial agent produced higher SE CFUs in cecum bacterial counts, while prebiotic and probiotic yielded lower counts. The combination prebiotic+probiotic did not produce significantly different results from the individual use of the additives.

Suplementação de vitaminas e minerais orgânicos e sua ação sobre a imunocompetência de frangos de corte submetidos a estresse por calor

The objective of this experiment was to evaluate the effect of diet supplementation with vitamins C and E and organic minerals Zn and Se on immunological parameters of broilers from 1 to 35 days, kept on cyclic heat stress (25 to 32°C) and to evaluate the usefulness of bovine serum albumin (BSA) inoculation to determine humoral immunity. A total of 272 Ross broilers were used to evaluate four types of vitamin-mineral supplementation (VMS): D1- control diet with 60 and 30 IU of vit E for starter and growing diet, respectively, zero vit C, 80 ppm of inorganic Zn, 0.3 ppm of inorganic Se; D2 - control diet + 100 UI vit E and 300 ppm vit C/kg; D3 - control diet + 40 ppm Zn and 0.3 ppm Se/kg, both from organic sources; D4 - control diet and levels of VMS used in D2 and D3), and two environments: thermoneutral (TNA) and cyclic heat stress (CHS) from 14 days of age. Six and five birds per type of supplementation in CHS and TNA, respectively, were inoculated with BSA at 12 and 24 days. Birds serum at 35 days-old was analyzed by ELISA. Supplementation with vitamins and minerals did not influence antibody production of broilers challenged with BSA. Heat stress improved antibody anti-BSA production regardless of the diet. Inoculation with BSA did not influenced broiler performance and was a good strategy to evaluate humoral immunity of broilers, since the birds responded to the challenge improved antibody production and increased bursal size, despite the higher individual variation.

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.

Molecular epidemiology and evolution of porcine parvoviruses

Porcine parvovirus (PPV), recently named Ungulate protoparvovirus 1, is considered to be one of the most important causes of reproductive failure in swine. Fetal death, mummification, stillbirths and delayed return to estrus are predominant clinical signs commonly associated with PPV infection in a herd. It has recently been shown that certain parvoviruses exhibit a nucleotide substitution rate close to that commonly determined for RNA viruses. However, the PPV vaccines broadly used in the last 30 years have most likely reduced the genetic diversity of the virus and led to the predominance of strains with a capsid profile distinct from that of the original vaccine-based strains. Furthermore, a number of novel porcine parvovirus species with yet-unknown veterinary relevance and characteristics have been described during the last decade. In this review, an overview of PPV molecular evolution is presented, highlighting characteristics of the various genetic elements, their evolutionary rate and the discovery of new capsid profiles driven by the currently used vaccines.

How many papillomavirus species can go undetected in papilloma lesions

A co-infection comprising to at least seven papillomavirus (PV) types was detected by next generation sequencing (NGS) of randomly primed rolling circle amplification (RCA) products of a bovine (Bos taurus) papilloma lesion from the Brazilian Amazon region. Six putative new PV types that could not be detected by commonly used PCR protocols were identified. Their overall L1 nucleotide identities were less than 90% compared to described PV species and types. L1 nucleotide BLAST sequence hits showed that each new type was related to Beta, Gamma, Dyokappa, Dyoeta, and Xipapillomavirus, as well as two likely new unclassified genera. Our results show that the employment of NGS is relevant to the detection and characterization of distantly related PV and is of major importance in co-infection studies. This knowledge will help us understand the biology and pathogenesis of PV, as well as contribute to disease control. Moreover, we can also conclude that there are many unknown circulating PVs.

Homologous recombination in pestiviruses: Identification of three putative novel events between different subtypes/genogroups

Viruses from the genus Pestivirus of the family Flaviviridae have a non-segmented, single-stranded RNA genome and can cause diseases in animals from the order Artiodactyla. Homologous recombination is rarely reported in this virus family. To detect possible recombination events, all complete pestivirus genomes that are available in GenBank were screened using distinct algorithms to detect genetic conversions and incongruent phylogenies. Three putative recombinant viruses derived from recombination from different pestivirus subtypes/genogroups were detected: Bovine viral diarrhea virus 1 (BVDV-1) strain 3156, BVDV-2 strain JZ05-1 and Classical swine fever virus (CSFV) strain IND/UK/LAL-290. The present study demonstrated that the pestivirus classification cannot be based only on the analysis of one fragment of the genome because genetic conversions can lead to errors. The designation of the recombinant forms (RF) provides a more informative structure for the nomenclature of the genetic variant. The present work reinforces that homologous recombination occurs in pestivirus populations under natural replication and describes the first evidence of recombination in BVDV-2.

Genetic characterization of Amazonian bovine papillomavirus reveals the existence of four new putative types

Papillomaviruses are small and complex viruses that belong to the Papillomaviridae family, which comprises 39 genera. The bovine papillomavirus (BPV) causes an infectious disease that is characterized by chronic and proliferative benign tumors that affect cattle worldwide. Different genotypes of BPVs can cause distinct skin and mucosal lesions and the immunity they raise has low cross-protection. This report aimed to genotype BPVs in cattle from Northern Brazil based on nucleotide partial sequences of the L1 ORF. Skin wart samples from 39 bovines clinically and histopathologically diagnosed as cutaneous papillomatosis from Acre and Rondônia States were analyzed. The results revealed four already reported BPV types (BPVs 1, 2, 11, and 13), nine putative new BPV subtypes and four putative new BPV types as well as two putative new BPV types that were already reported. To our knowledge, this is the first record of BPVs from the Brazilian Amazon region that identified new possible BPV types and subtypes circulating in this population. These findings point to the great genetic diversity of BPVs that are present in this region and highlight the importance of this knowledge before further studies about vaccination are attempted.

Phylogenetic characterization of the first Ungulate tetraparvovirus 2 detected in pigs in Brazil

Ungulate tetraparvovirus 2 (UTV2), formerly known as porcine hokovirus due to its discovery in Hong Kong, is closely related to a Primate tetraparvovirus (human PARV-4) and Ungulate tetraparvovirus 1 (bovine hokovirus). Until now, UTV2 was detected in European, Asian and North American countries, but its occurrence in Latin America is still unknown. This study describes the first report of UTV2 in Brazil, as well as its phylogenetic characterization. Tissue samples (lymph node, lung, liver, spleen and kidney) of 240 piglets from eight different herds (30 animals each herd) were processed for DNA extraction. UTV2 DNA was detected by PCR and the entire VP1/VP2 gene was sequenced for phylogenetic analysis. All pigs from this study displayed postweaning multisystemic wasting syndrome (PMWS). UTV2 was detected in 55.3% of the samples distributed in the variety of porcine tissues investigated, as well as detected in almost all herds, with one exception. The phylogenetic analysis demonstrated that Brazilian UTV2 sequences were more closely related to sequences from Europe and United States.

Influence of vaccine strains on the evolution of canine distemper virus

Canine distemper virus (CDV) is a major dog pathogen belonging to the genus Morbillivirus of the family Paramyxoviridae. CDV causes disease and high mortality in dogs and wild carnivores. Although homologous recombination has been demonstrated in many members of Paramyxoviridae, these events have rarely been reported for CDV. To detect potential recombination events, the complete CDV genomes available in GenBank up to June 2015 were screened using distinct algorithms to detect genetic conversions and incongruent phylogenies. Eight putative recombinant viruses derived from different CDV genotypes and different hosts were detected. The breakpoints of the recombinant strains were primarily located on fusion and hemagglutinin glycoproteins. These results suggest that homologous recombination is a frequent phenomenon in morbillivirus populations under natural replication, and CDV vaccine strains might play an important role in shaping the evolution of this virus.