Epidemiological Insights into Feline Leukemia Virus Infections in an Urban Cat (Felis catus) Population from Brazil.

Feline leukemia virus (FeLV) is a retrovirus distributed worldwide in domestic cats and with different outcomes (progressive, regressive, abortive, focal). The present study reports an epidemiological survey of FeLV frequency and the evaluation of some risk factors and the two main disease outcomes (progressive and regressive) in an urban cat population from Brazil. A total of 366 cats with sociodemographic information and p27 FeLV antigen test performed were included in the study. FeLV DNA (provirus) in the blood samples of all cats was detected via real-time polymerase chain reaction (qPCR). Plasma samples from 109 FeLV-positive and FeLV-negative cats were also submitted to reverse transcription (RT-qPCR) to determine the FeLV viral load. The results demonstrated that 112 (30.6%) cats were positive through the p27 antigen and/or qPCR. A risk factor analysis demonstrated that cats without vaccination against FeLV (OR 9.9, p < 0.001), clinically ill (OR 2.9, p < 0.001), with outdoors access (OR 2.7, p < 0.001), and exhibiting apathetic behavior (OR 3.1, p < 0.001) were more likely to be infected with FeLV. FeLV-infected cats were also more likely to present with anemia (OR 13, p < 0.001) and lymphoma (OR 13.7, p = 0.001). A comparative analysis of the different detection methods in a subset of 109 animals confirmed FeLV infection in 58 cats, including 38 (65.5%) with progressive, 16 (27.6%) with regressive, and 4 (6.9%) with probably focal outcome diseases. In conclusion, this study demonstrates a high prevalence of FeLV in this urban cat population from Brazil and highlights the need to establish more effective prevention strategies (such as viral testing, vaccination programs, specific care for FeLV-positive cats) to reduce diseases associated with this virus in Brazil.

Canine parvovirus type 2 (CPV-2) serological and molecular patterns in dogs with viral gastroenteritis from southern Brazil.

Canine Parvovirus type 2 (CPV-2) is a highly contagious virus that can cause severe systemic disease with gastroenteric symptoms in dogs, particularly in young puppies. Originating from the feline parvovirus in the late 1970s, it swiftly propagated globally, instigating a pandemic in dogs. Despite vaccination advancements, CPV-2 remains a substantial challenge for veterinary professionals and pet owners. This study aimed to contribute knowledge about the current situation of CPV-2 among dogs in southern Brazil. In this study, the sera of 125 dogs (mostly with gastroenteritis symptoms) were screened for antibodies against CPV-2 and their faeces for the virus itself. The results showed that 40% (50/125) of dogs were infected with CPV-2. Most animals (65.5%) had previously been exposed to CPV-2 (with serotitres equal or above 1:40), and only 37.6% had protective antibody titres equal or above 1:80. The findings have also demonstrated that vaccination against CPV-2 significantly reduced the risk of infection, with positive cases decreasing from 56.9% (unvaccinated) to 2.0% (fully vaccinated). Furthermore, the prevalence of CPV-2 decreased as dogs aged, with younger dogs and those with an incomplete or non-existent vaccination history at the highest risk of infection. In conclusion, this study provides valuable insight into the prevalence and risk factors associated with CPV-2 infection in dogs in southern Brazil, thereby providing valuable knowledge for the improvement of veterinary care and pet health.

Antiviral alternatives against important members of the subfamily Parvovirinae: a review.

Parvoviruses are responsible for multiple diseases, and there is a critical need for effective antiviral therapies. Specific antiviral treatments for parvovirus infections are currently lacking, and the available options are mostly supportive and symptomatic. In recent years, significant research efforts have been directed toward understanding the molecular mechanisms of parvovirus replication and identifying potential targets for antiviral interventions. This review highlights the structure, pathogenesis, and treatment options for major viruses of the subfamily Parvovirinae, such as parvovirus B19 (B19V), canine parvovirus type 2 (CPV-2), and porcine parvovirus (PPV) and also describes different approaches in the development of antiviral alternatives against parvovirus, including drug repurposing, serendipity, and computational tools (molecular docking and artificial intelligence) in drug discovery. These advances greatly increase the likelihood of discoveries that will lead to potent antiviral strategies against different parvovirus infections.

Antimicrobial activity of essential oils against Staphylococcus aureus and Staphylococcus chromogenes isolated from bovine mastitis.

Staphylococcus aureus and Staphylococcus chromogenes are pathogens frequently detected in bovine mastitis. Treatment and prevention of this disease have been usually carried on with antimicrobials. However, the emergence of bacterial isolates with antimicrobial resistance has aroused interest in new therapeutic alternatives. Plant essential oils (EOs) have been largely studied as antibacterial treatments. In the present study, EOs from five plants were evaluated for their antibacterial activities against S. aureus and S. chromogenes. Bacterial isolates were obtained in a previous study of clinical cases of bovine mastitis. EOs from lemongrass, eucalyptus, lavender, peppermint, and thyme were obtained by hydrodistillation and their chemical compositions were evaluated by gas chromatography (GC). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for all EOs. The results demonstrated that citral (40.9%), myrcene (24.7%), and geraniol (1.9%) were detected in lemongrass EO; 1,8-cineole (76.9%), α-pinene (8.2%), and ledene (5.1%) in eucalyptus EO; 1,8-cineole (45.2%), camphor (18.2%), and fenchone (14.6%) in lavender EO; L-menthol (38.5%), menthofuran (16.3%), and citronellal (10.6%) in peppermint EO; and thymol (44.2%), p-cymene (24.6%) and 1,8-cineole (9.9%) in thyme EO. More effective antibacterial activities were observed only with the use of lemongrass (MIC and MBC ranging from 0.39 to 3.12 mg/mL and 0.39 to 6.35 mg/mL, respectively) and thyme (MIC and MBC ranging from 0.39 to 1.56 mg/mL and 0.39 to 3.12 mg/mL, respectively). Peppermint, lavender and eucalyptus EOs did not show bactericidal activities. In conclusion, lemongrass and thyme EOs are promising antibacterial alternatives against Staphylococcus species associated with bovine mastitis.

Canine Parvovirus 2 in Free-Living Wild Mammals from Southern Brazil.

Pathogens from domestic canines represent a significant and constant threat to wildlife. This study looked for four common canine pathogens, Babesia vogeli, Ehrlichia canis, Leishmania infantum, and canine parvovirus 2 (CPV-2) in mammals from the Pampa Biome, southern Brazil. Animals killed by vehicular trauma on a road traversing this biome were evaluated over a 1-yr period. Tissues collected from 31 wild mammals and six dogs were further analyzed by specific real-time PCR assays for each pathogen. Babesia vogeli and L. infantum were not detected in any investigated animal. Ehrlichia canis was detected in one dog and CPV-2 in nine animals: four dogs, three white-eared opossums (Didelphis albiventris), one pampas fox (Lycalopex gymnocercus), and one brown rat (Rattus norvegicus). These results demonstrate the occurrence of important carnivore pathogens (E. canis and CPV-2) in domestic dogs and wild mammals from the Pampa Biome in southern Brazil.

Canine parvovirus type 2 vaccines in Brazil: Viral load in commercial vaccine vials and phylogenetic analysis of the vaccine viruses.

Canine parvovirus type 2 (CPV-2) is the etiological agent of a highly contagious and frequently fatal disease in dogs. Live attenuated vaccines (LAV) are recommended to prevent and control this disease. Commercial vaccines are typically produced with CPV-2 strains adapted to cell culture and usually non-pathogenic. The present study aimed to determine the viral load of CPV-2 vaccines commercially available in Brazil and to characterize the vaccine virus by DNA analysis of its capsid gene. The results demonstrated that all vaccine strains presented high homology of the VP2 gene and they were all closely related to the original CPV-2 strains. However, vaccine strains presented several differences in comparison with field strains currently circulating in Brazil. Seventy-one vials contained viral loads ranging from 7.4E3 to 4.9E10 DNA copies/ml. Nine vials did not contain any detectable CPV-2 DNA. In conclusion, there are genetic and antigenic differences among CPV-2 vaccines and field strains. Additionally, some vaccines have been commercialized with low titers of CPV-2. It is important to improve the quality of the vaccines to prevent or reduce the spread of CPV-2 in Brazil.

Emergence, Dissemination and Antimicrobial Resistance of the Main Poultry-Associated Salmonella Serovars in Brazil.

Salmonella infects poultry, and it is also a human foodborne pathogen. This bacterial genus is classified into several serovars/lineages, some of them showing high antimicrobial resistance (AMR). The ease of Salmonella transmission in farms, slaughterhouses, and eggs industries has made controlling it a real challenge in the poultry-production chains. This review describes the emergence, dissemination, and AMR of the main Salmonella serovars and lineages detected in Brazilian poultry. It is reported that few serovars emerged and have been more widely disseminated in breeders, broilers, and layers in the last 70 years. Salmonella Gallinarum was the first to spread on the farms, remaining as a concerning poultry pathogen. Salmonella Typhimurium and Enteritidis were also largely detected in poultry and foods (eggs, chicken, turkey), being associated with several human foodborne outbreaks. Salmonella Heidelberg and Minnesota have been more widely spread in recent years, resulting in frequent chicken/turkey meat contamination. A few more serovars (Infantis, Newport, Hadar, Senftenberg, Schwarzengrund, and Mbandaka, among others) were also detected, but less frequently and usually in specific poultry-production regions. AMR has been identified in most isolates, highlighting multi-drug resistance in specific poultry lineages from the serovars Typhimurium, Heidelberg, and Minnesota. Epidemiological studies are necessary to trace and control this pathogen in Brazilian commercial poultry production chains.

Molecular phylogenetic assessment of the canine parvovirus 2 worldwide and analysis of the genetic diversity and temporal spreading in Brazil.

Canine parvovirus type 2 (CPV-2) is a relevant pathogen for dogs and causes a severe disease in carnivore species. CPV-2 reached pandemic proportions after the 1970s with the worldwide dissemination, generating antigenic and genetic variants (CPV-2a, CPV-2b, and CPV-2c) with different pathobiology in comparison with the original type CPV-2. The present study aimed to assess the current global CPV-2 molecular phylogeny and to analyze genetic diversity and temporal spreading of variants from Brazil. A total of 284 CPV-2 whole-genome sequences (WGS) and 684 VP2 complete genes (including 23 obtained in the present study) were compared to analyze phylogenetic relationships. Bayesian coalescent analysis estimated the time to the most recent common ancestor (tMRCA) and the population dynamics of the different CPV-2 lineages in the last decades. The WGS phylogenetic tree demonstrated two main clades disseminated worldwide today. The VP2 gene tree showed a total of four well-defined clades distributed in different geographic regions, including one with CPV-2 sequences exclusive from Brazil. These clades do not have a relationship with the previous classification into CPV-2a, CPV-2b, and CPV-2c, despite some having a predominance of one or more antigenic types. Temporal analysis demonstrated that the main CPV-2 clades evolved within a few years (from the 1980s to 1990s) in North America and they spread worldwide afterwards. Population dynamics analysis demonstrated that CPV-2 presented a major dissemination increase at the end of the 1980s / beginning of the 1990s followed by a period of stability and a second minor increase from 2000 to 2004.

Viral Fitness and Antigenic Determinants of Porcine Parvovirus at the Amino Acid Level of the Capsid Protein.

Since 2001, strains of porcine parvovirus (PPV), designated 27a-like strains, were observed in Europe, suggesting a predominance of these viruses over older strains. The reasons for the obvious evolutionary advantage are unknown. Here, a series of mutants containing amino acid replacements found in the predominant field strains were generated in a PPV-NADL2 background, and their impact on replication efficiency and antibody binding activity was determined. Some amino acid substitutions observed in the 27a-like strains significantly increased viral fitness and decreased neutralization activity of serum samples raised against commercial vaccines and old virus strains (e.g., NADL2). These mutant viruses and a monoclonal antibody raised against a classical PPV strain defined a 27a-specific neutralizing epitope around amino acid 228 of the capsid protein VP2. Based on the analysis of the mutant viruses, it is hypothesized that the predominant factor for the global spread of the PPV-27a strain substitutions is an increased viral fitness of the 27a-like viruses, possibly supported by partial immune selection. This is reminiscent to the evolution of canine parvovirus and worldwide replacement of the original virus by the so-called new antigenic types. IMPORTANCE Porcine parvovirus is one of the most important causes of reproductive failure in swine. Recently, despite the continuous use of vaccines, "new" strains emerged, leading to the hypothesis that the emergence of new amino acid substitutions could be a viral adaptation to the immune response against the commercial vaccines. Our results indicate the amino acid substitutions observed in the 27a-like strains can modify viral fitness and antigenicity. However, an absolute immune escape was not evident.

Species identification and antimicrobial susceptibility profile of bacteria associated with cow mastitis in southern Brazil / Identificação de espécies e perfil de suscetibilidade aos antimicrobianos de bactérias associadas à mastite bovina no sul do Brasil

Bovine mastitis is the most common disease in dairy cattle and responsible for economic losses in the milk industry. The present study aimed to identify the main species and to evaluate the antimicrobial susceptibility of bacterial isolates from cow herds with mastitis in dairy farms from southern Brazil. A total of 107 milk samples were collected from different cow herds in one important dairy producing region in southern Brazil, including farms located in ten cities from the Northeast region in the Rio Grande do Sul state. Bacterial strains were isolated and submitted to presumptive identification by classical bacteriological methods. Bacterial species were also identified by MALDI-TOF MS and antimicrobial susceptibility testing was performed with 12 antimicrobials commonly used in dairy farms. Fifty-one bacterial strains were isolated and the presumptive identification demonstrated the occurrence of Staphylococcus spp. (82.3%), Bacillus spp. (3.9%), Klebsiella spp. (3.9%), Streptococcus spp. (3.9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) and Serratia sp. (2%). Forty-one isolates were successfully identified in the MALDI-TOF analysis, including 35 isolates from eleven different bacterial species. Importantly, there were eight different Staphylococcus species, with a high frequency of Staphylococcus chromogenes (48.6%) and Staphylococcus aureus (20%). Overall, bacterial isolates demonstrated resistance to penicillin (46.3%), tetracycline (39%), amoxicillin (36.6%), ampicillin (34.1%) and sulfamethoxazole/trimethoprim (31.7%). Enrofloxacin was the unique antimicrobial that all isolates were susceptible. In addition, there were six multidrug resistant isolates (five S. chromogenes and one S. aureus). This study highlights that bacterial pathogens with resistance to several antimicrobials were identified in cows from dairy farms in a very important milk producing region located in southern Brazil. Microbial identification of the bovine mastitis pathogens and determination of the antimicrobial profile is necessary for the rational use of the medicines.(AU)

A mastite bovina é a doença mais comum em gado leiteiro e responsável por perdas econômicas na indústria de laticínios. O presente estudo teve como objetivo identificar as principais espécies e avaliar a suscetibilidade antimicrobiana de isolados bacterianos de rebanhos bovinos com mastite em fazendas leiteiras no sul do Brasil. Um total de 107 amostras de leite foram coletadas em diferentes rebanhos bovinos em uma importante região produtora de leite do sul do Brasil, incluindo fazendas localizadas em 10 cidades da região Nordeste do estado do Rio Grande do Sul. As cepas bacterianas foram isoladas e submetidas à identificação presuntiva por métodos bacteriológicos clássicos. A identificação bacteriana foi confirmada por MALDI-TOF MS e o teste de sensibilidade antimicrobiana foi realizado com antimicrobianos comumente usados em fazendas leiteiras. Cinquenta e uma cepas bacterianas foram isoladas e a identificação presuntiva demonstrou a ocorrência de Staphylococcus spp. (82,3%), Bacillus spp. (3,9%), Klebsiella spp. (3,9%), Streptococcus spp. (3,9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) e Serratia sp. (2%). Os 41 isolados foram identificados com sucesso na análise MALDI-TOF, incluindo 35 isolados de onze espécies bacterianas diferentes. É importante ressaltar que houve a ocorrência de oito espécies diferentes de Staphylococcus, com alta frequência de Staphylococcus chromogenes (48,6%) e Staphylococcus aureus (20%). No geral, os isolados bacterianos tiveram alta resistência à penicilina (46,3%), tetraciclina (39%), amoxicilina (36,6%), ampicilina (34,1%) e sulfametoxazol/trimetoprima (31,7%). A enrofloxacina foi o único antimicrobiano que todos os isolados foram suscetíveis. Além disso, havia seis isolados multirresistentes (cinco S. chromogenes e um S. aureus). Este estudo destaca que os patógenos bacterianos com resistência aos antimicrobianos estão presentes em fazendas leiteiras de subsistência em uma importante região produtora no sul do Brasil. É necessário o monitoramento constante dos patógenos da mastite bovina e a determinação de seu perfil antimicrobiano para o uso racional dos medicamentos.(AU)

Species identification and antimicrobial susceptibility profile of bacteria associated with cow mastitis in southern Brazil / Identificação de espécies e perfil de suscetibilidade aos antimicrobianos de bactérias associadas à mastite bovina no sul do Brasil

Bovine mastitis is the most common disease in dairy cattle and responsible for economic losses in the milk industry. The present study aimed to identify the main species and to evaluate the antimicrobial susceptibility of bacterial isolates from cow herds with mastitis in dairy farms from southern Brazil. A total of 107 milk samples were collected from different cow herds in one important dairy producing region in southern Brazil, including farms located in ten cities from the Northeast region in the Rio Grande do Sul state. Bacterial strains were isolated and submitted to presumptive identification by classical bacteriological methods. Bacterial species were also identified by MALDI-TOF MS and antimicrobial susceptibility testing was performed with 12 antimicrobials commonly used in dairy farms. Fifty-one bacterial strains were isolated and the presumptive identification demonstrated the occurrence of Staphylococcus spp. (82.3%), Bacillus spp. (3.9%), Klebsiella spp. (3.9%), Streptococcus spp. (3.9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) and Serratia sp. (2%). Forty-one isolates were successfully identified in the MALDI-TOF analysis, including 35 isolates from eleven different bacterial species. Importantly, there were eight different Staphylococcus species, with a high frequency of Staphylococcus chromogenes (48.6%) and Staphylococcus aureus (20%). Overall, bacterial isolates demonstrated resistance to penicillin (46.3%), tetracycline (39%), amoxicillin (36.6%), ampicillin (34.1%) and sulfamethoxazole/trimethoprim (31.7%). Enrofloxacin was the unique antimicrobial that all isolates were susceptible. In addition, there were six multidrug resistant isolates (five S. chromogenes and one S. aureus). This study highlights that bacterial pathogens with resistance to several antimicrobials were identified in cows from dairy farms in a very important milk producing region located in southern Brazil. Microbial identification of the bovine mastitis pathogens and determination of the antimicrobial profile is necessary for the rational use of the medicines.

A mastite bovina é a doença mais comum em gado leiteiro e responsável por perdas econômicas na indústria de laticínios. O presente estudo teve como objetivo identificar as principais espécies e avaliar a suscetibilidade antimicrobiana de isolados bacterianos de rebanhos bovinos com mastite em fazendas leiteiras no sul do Brasil. Um total de 107 amostras de leite foram coletadas em diferentes rebanhos bovinos em uma importante região produtora de leite do sul do Brasil, incluindo fazendas localizadas em 10 cidades da região Nordeste do estado do Rio Grande do Sul. As cepas bacterianas foram isoladas e submetidas à identificação presuntiva por métodos bacteriológicos clássicos. A identificação bacteriana foi confirmada por MALDI-TOF MS e o teste de sensibilidade antimicrobiana foi realizado com antimicrobianos comumente usados em fazendas leiteiras. Cinquenta e uma cepas bacterianas foram isoladas e a identificação presuntiva demonstrou a ocorrência de Staphylococcus spp. (82,3%), Bacillus spp. (3,9%), Klebsiella spp. (3,9%), Streptococcus spp. (3,9%), Corynebacterium sp. (2%), Enterococcus sp. (2%) e Serratia sp. (2%). Os 41 isolados foram identificados com sucesso na análise MALDI-TOF, incluindo 35 isolados de onze espécies bacterianas diferentes. É importante ressaltar que houve a ocorrência de oito espécies diferentes de Staphylococcus, com alta frequência de Staphylococcus chromogenes (48,6%) e Staphylococcus aureus (20%). No geral, os isolados bacterianos tiveram alta resistência à penicilina (46,3%), tetraciclina (39%), amoxicilina (36,6%), ampicilina (34,1%) e sulfametoxazol/trimetoprima (31,7%). A enrofloxacina foi o único antimicrobiano que todos os isolados foram suscetíveis. Além disso, havia seis isolados multirresistentes (cinco S. chromogenes e um S. aureus). Este estudo destaca que os patógenos bacterianos com resistência aos antimicrobianos estão presentes em fazendas leiteiras de subsistência em uma importante região produtora no sul do Brasil. É necessário o monitoramento constante dos patógenos da mastite bovina e a determinação de seu perfil antimicrobiano para o uso racional dos medicamentos.

Dissemination and evolution of SARS-CoV-2 in the early pandemic phase in South America.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic spread rapidly and this scenario is concerning in South America, mainly in Brazil with more than seven million cases of infection. Three major pandemic lineages/clades could be identified along with SARS-CoV-2 dissemination (G, GR, and GH) in the Americas. These clades differ according to their genomic characteristics, virulence, and spreading times. The present study describes the main clades and the respective temporal spreading analyses based on SARS-CoV-2 whole-genome sequences (WGS) from South America, obtained in the early pandemic phase (from March 1 to May 31 in 2020). SARS-CoV-2 WGSs with available information from country and year of sampling were obtained from different countries and the main clades were identified and analyzed independently with a Bayesian approach. The results demonstrated the prevalence of clades GR (n = 842; 54.6%), G (n = 529; 34.3%), and GH (n = 171; 11.1%). The frequencies of the clades were significantly different between South American countries. Clade G was the most prevalent in Ecuador, Suriname, and Uruguay, clade GR in Argentina, Brazil, and Peru, and clade GH in Colombia. The phylodynamic analysis indicated that all these main lineages increased viral spreading from February to early March and after an evolutionary stationary phase was observed. The decrease observed in the virus dissemination was directly associated to the reduction of social movement after March. In conclusion, these data demonstrated the current predominance of clades G, GR, and GH in South America because of the early dissemination of them in the first pandemic phase in South America.

Use of plant extracts and essential oils in the control of bovine mastitis.

Bovine mastitis is the most important disease affecting dairy herds worldwide, causing direct impacts on farms' profitability and food safety issues. The prevention and treatment of this pathology is especially done through antimicrobials, but the increasing antimicrobial resistance of pathogens to this disease may affect the efficiency of conventional drugs. Besides, antimicrobials residues in milk and the environment are a potential threat to human health. Thereby, the use of plant extracts and essential oils may become promising alternatives for the control of bovine mastitis. Antimicrobial properties present in several plants are well described and plant extracts and essential oils are often considered safe to animals, humans and environment. This review summarizes the current problems encountered in the conventional treatment of mastitis, the possibilities of the use of plant extracts and essential oils as alternative agents for the control of these pathogens and the limitations found in the use of these plant derivatives. Finally, the perspectives to the use of plant extracts and essential oils for the treatment of bovine mastitis are presented.

Porcine Parvovirus.

Porcine parvovirus (PPV) is considered the main cause of reproductive disorders in pigs, which are summarized under the acronym SMEDI (stillbirth, mummification, embryonic death, and infertility). In this review the biology of the virus and its structure, pathogenic potential and strain variation, as well as the disease induced by the virus, are described. Known aspects of pathogenesis, diagnosis and prevention, particularly by vaccination, are summarized. Furthermore, in recent years 'new' parvoviruses (PPV2 to 7) have been described in pigs. They have been detected in pigs from various parts of the world and their association with clinical signs or disease will be discussed.

Presentation of hemolytic and hemorrhagic rangeliosis in Cerdocyon thous.

Rangeliosis, caused by protozoan Rangelia vitalii, is transmitted by the tick Amblyomma aureolatum. The disease is characterized by hemolytic and hemorrhagic disorder and has been described in dogs and other wild canids. The aim of this study was to compare clinicopathological findings and laboratory results of a Rangelia infection in a crab-eating fox (Cerdocyon thous) with those of canine rangeliosis. The zoo of Universidade de Caxias do Sul, received a crab-eating fox with marked jaundice in mucous membranes, dark-colored stools and neurological signs. The animal underwent an ear tip smear examination and blood collection for complete blood counts, serum biochemistry and PCR. Free-living and intraerythrocytic pyriform structures consistent with R. vitalii were found in the blood smear of the ear tip. The erythrogram revealed normocytic normochromic anemia, moderate macrocytosis, polychromasia and metarubricytosis. The leukogram revealed leukocytosis with neutrophilia and monocytosis, as well as severe thrombocytopenia. Serum biochemistry showed hypoproteinemia, hypoalbuminemia and elevated levels of urea and creatinine. The treatment was performed with imidocarb hydrochloride and dexamethasone, however 24 h after initiation of treatment the animal died. Macroscopic examination revealed jaundice, subcutaneous edema, enlarged superficial lymph nodes, splenomegaly, and hemorrhage of internal organs. Histological sections of the cerebellum, lung, pancreas, intestine and heart were consistent with R. vitalii infection of the vascular endothelium. Pathological and hematological findings were similar to those found in infected dogs, with clinical presentation characterized by hemolytic anemia and hemorrhage. The description of this case showed that C. thous does not only serve as reservoir of R. vitalii but may also develop disease.

Dynamics of vanishing of maternally derived antibodies of Ungulate protoparvovirus 1 suggests an optimal age for gilts vaccination.

The prevention of Ungulate protoparvovirus 1 (UPV1) infection and consequently the reproductive losses is based on vaccination of all pigs intended for breeding. As maternally derived antibodies (MDA) can interfere with the development of immunity following vaccination, it is important to know the duration of anti-UPV1 MDA to determine the optimal age for the best vaccination efficacy. To elucidate the association between dam and piglet antibody levels against UPV1 and to estimate the decrease rate of MDA, sera and colostrum of 127 gilts (before the first vaccination against UPV1; 15 days after the second vaccine dose; at farrowing; and during the second pregnancy) and sera of 276 piglets (prior to initial colostrum intake; at 7, 21, 57, 87, and 128 days-old) were tested by ELISA. Most gilts (85.8%) had anti-UPV1 antibodies before vaccination and after vaccination all were positive. At 7 days old, the majority of the piglets had anti-UPV1 antibodies, but around 57 days old, only 35.3% were positive and at 87 days old, all were negative. The estimated average half-life of MDA was 29.8 (28.8-30.9) days. A strong correlation was determined between piglet serum at 7 days old with gilt serum at farrowing time (r = 0.77, n = 248, P < 0.001) and with piglet serum at 7 days old with colostrum (r = 0.73, n = 248, P < 0.001). The MDA decreased earlier and the antibody half-life was a little longer than previously reported. Based on these findings, UPV1 vaccination can be performed earlier than usual.

Spread of a Major Clone of Salmonella enterica Serotype Enteritidis in Poultry and in Salmonellosis Outbreaks in Southern Brazil.

Salmonella spp. are among the most important agents of foodborne diseases all over the world. Human Salmonella outbreaks are often associated with the consumption of poultry products (meat and eggs), and one of the most prevalent serotypes associated with these products is Salmonella Enteritidis. Brazil is one of the most important poultry exporters in the world. In southern Brazil, three closely related clones of Salmonella Enteritidis have been responsible for the majority of foodborne Salmonella outbreaks over the past decade. However, until now, there has been little information regarding the clonal relationship among the Brazilian Salmonella strains of avian origin and those involved in foodborne outbreaks. Therefore, the aim of the present study was to complete the molecular characterization of Salmonella Enteritidis strains isolated from poultry and food sources involved in Salmonella outbreaks. PCR ribotyping was performed to discriminate the strains into different ribotype profiles according to the banding pattern amplification. This technique was able to differentiate the Salmonella Enteritidis strains into two banding patterns: R2 and R4. R2 accounted for 98.7% of the strains. DNA sequencing of the 600-bp fragment, present in all ribotypes, was applied to confirm this result. The sequences generated showed high levels of similarity, ranging from 99.7 to 100%, and were grouped into a single cluster. These results suggest that there is a clonal relationship among the Salmonella Enteritidis strains responsible for several salmonellosis outbreaks and the strains collected from poultry sources.

Use of Molecular Pathogenicity Indices to Identify Pathogenic Strains of Pasteurella multocida.

In addition to being the causative agent of fowl cholera (FC), Pasteurella multocida is also one of the most prevalent opportunistic pathogens associated with respiratory diseases in various hosts. However, understanding of the traits that distinguish the virulent isolates that cause FC is still limited. The objective of this study was to characterize P. multocida isolates of Brazil by PCR-restriction fragment length polymorphism (PCR-RFLP) analysis in order to determine if strain-type correlates with virulence or with 22 previously studied virulence genes. The PCR-RFLP was used to classify the isolates into seven strain types, and the isolates in Profile II had a higher pathogenicity index (P < 0.05) than did those in Profiles I, V, and VI. The overall identity among the nucleotide sequences of the ompH was 89.8%. Furthermore, strains available in GenBank showed a high level of homology of the different bacterial serotypes with the groupings resulting from the PCR-RFLP. Strain Types I and II showed the highest identity with Serotypes 3 (100%) and 3-4 (99.1%), respectively. Detection of the pfhA gene indicated the presence of strains that are highly pathogenic. The screening detection of 22 virulence genes and inference through the decision tree models comparing the results of pathogenicity indices permitted the identification of the most highly pathogenic strains of P. multocida .

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

Abstract 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.