Prevalence and antimicrobial resistance of Salmonella spp isolated from free-ranging wild boars in the state of São Paulo, Brazil / Prevalência e resistência antimicrobiana de Salmonella spp isoladas em javalis de vida livre no estado de São Paulo

European wild boars (Sus scrofa) are considered exotic invasive species worldwide. Invasions of wild boars are a growing public health concern, as wild boars may represent an important reservoir of zoonotic pathogens, including bacteria of the genus Salmonella. The aim of this study was to determine the prevalence and serovars of Salmonella spp. in free-ranging wild boars legally hunted in the state of São Paulo, Brazil, and the susceptibility of those Salmonella spp. to antimicrobials. Fecal samples and mesenteric lymph nodes were acquired from 63 wild boars. The prevalence of Salmonella spp. in free-ranging wild boars was 9.5 % (6/63; confidence interval: 4.4 % - 19.2 %). Six serovars were isolated: S. enterica subsp. enterica ser. 4,5,12:-:1,2, S. enterica ser. Cerro, S. enterica ser. Madelia, S. enterica ser. Typhimurium, S. enterica ser. I (4,5,12:i:-) and S. enterica ser. Muenster. Analysis of antimicrobial resistance of Salmonella spp. showed that the majority of serovars were fully susceptible to the tested antimicrobials. Only S. enterica ser. Typhimurium and S. enterica ser. Muenster showed a resistance pattern to at least one antimicrobial analyzed. To our knowledge, this study is the first report the prevalence and serovars of Salmonella spp. in free-ranging wild boars in the State of São Paulo, Brazil. Results indicate a low prevalence with variability of Salmonella serovars, with some pattern of antimicrobial resistance. This study highlights the potential role of wild boars as carriers of Salmonella and could pose a risk to wild and domestic animals as well as humans.

Os javalis europeus (Sus scrofa) são considerados uma espécie exótica invasora em todo o mundo. As invasões de javalis são uma preocupação crescente de saúde pública, pois os javalis podem representar um importante reservatório de patógenos zoonóticos, incluindo bactérias do gênero Salmonella. O objetivo deste estudo foi determinar a prevalência e os sorovares de Salmonella spp. em javalis de vida livre caçados legalmente no Estado de São Paulo, Brasil, e a suscetibilidade dessa Salmonella spp. aos antimicrobianos. Amostras fecais e linfonodos mesentéricos foram adquiridos de 63 javalis. A prevalência de Salmonella spp. em javalis selvagens foi de 9,5% (6/63; intervalo de confiança: 4,4% - 19,2%). Seis sorovares foram isolados: S. enterica subsp. enterica ser. 4,5,12:-:1,2, S. enterica ser. Cerro, S. enterica ser. Madelia, S. enterica ser. Typhimurium, S. enterica ser. I (4,5,12:i:-) e S. enterica ser. Muenster. As análises de resistência antimicrobiana de Salmonella spp. evidenciaram que a maioria dos sorovares era pansensível aos antimicrobianos testados. Apenas S. enterica ser. Typhimurium e S. enterica ser. Muenster mostraram um padrão de resistência a pelo menos um antimicrobiano analisado. A saber, este estudo é o primeiro relato da prevalência e de sorovares de Salmonella spp. em javalis de vida livre no Estado de São Paulo, Brasil. Os resultados indicaram baixa prevalência com variabilidade de sorovares de Salmonella, com algum padrão de resistência antimicrobiana. Este estudo destaca o papel potencial dos javalis como portadores de Salmonella spp. e pode representar um risco para os animais domésticos e selvagens, bem como para os humanos.

A comparative evaluation of methods for estimating the colostrum quality in sows / Avaliação comparativa de métodos para estimar a qualidade do colostro em porcas

Colostrum is the main source of immunoglobulins (Ig) for neonate piglets and plays a crucial role within the health and growth of the piglet. Currently in pig farming, there are still no widespread practical methods for measuring the Ig concentration in colostrum at herd level. We evaluated sows' colostrum IgG concentration using an optical and a digital Brix refractometer and their performance was correlated to an IgG ELISA test, and flow cytometry. Colostrum concentrations of IgG and IgA averaged 74.05 ± 21.37mg/mL and 20.2 ± 5.32mg/mL respectively. The mean value of the Brix percentages for optical refractometer was 26.32%, and for digital was 28.32%. The Brix refractometer measurements of colostrum samples presented high correlation for IgG content analyzed by ELISA (Optical = 0.74, Digital = 0.87; P <0.001). Considering the immunophenotyping, the values for IgG and IgA lymphoblasts indicated a highly significant relationship to ELISA (IgG=0.77, IgA=0.84; P<0.001). The Brix refractometer can be considered a useful tool to be included in a colostrum monitoring program to improve potentially neonatal health. In addition, we demonstrated that flow cytometry can be an important tool to analyze and characterize the immunological potential of sow colostrum.(AU)

O colostro é a principal fonte de imunoglobulinas (Ig) para leitões recém-nascidos e desempenha um papel crucial na saúde e no crescimento dos leitões. Atualmente, na suinocultura, ainda não existem métodos amplamente utilizados na prática de produção para medir a concentração de imunoglobulinas no colostro suíno. Avaliou-se a concentração de IgG no colostro de porcas usando refratômetros Brix óptico e digital, e o desempenho foi comparado com ELISA e citometria de fluxo. As concentrações de IgG e IgA no colostro foram 74,05 ± 21,37mg/mL e 20,2 ± 5,32mg/mL, respectivamente. A percentagem de Brix média das amostras de colostro para o refratômetro óptico foi 26,32%, e para o digital foi 28,32%. As medições dos refratômetros de Brix apresentaram elevada correlação com a concentrações de IgG medidas por ELISA (óptico=0,74, digital=0,87; P<0,001). Considerando a imunofenotipagem, os valores dos linfoblastos IgG e IgA apresentaram alta correlação com o ELISA (IgG=0,77, IgA=0,84; P<0,001). O refratômetro Brix pode ser considerado uma ferramenta útil para ser incluída em um programa de monitoramento de colostro para melhorar a saúde neonatal. Além disso, foi demonstrado que a citometria de fluxo pode ser uma ferramenta importante para analisar e caracterizar o potencial imunológico do colostro de porcas.(AU)

Serosurvey of anti-Neospora caninum antibodies in wild boars (Sus scrofa), hunting dogs and hunters of Brazil.

The protozoan Neospora caninum is an important cause of abortion in cattle worldwide, with domestic dogs serving as the definitive hosts. Although hunting activities have been indicated as a potential risk factor for N. caninum infection in dogs, no serological evidence has so far been reported in hunting dogs, wild boars (Sus scrofa), and hunters. A total of 98 wild boars, 168 hunting dogs, and 15 hunters from three Brazilian regions were sampled and tested for anti-N. caninum antibodies by indirect immunofluorescence antibody test, resulting in 15/168 (9%) seropositive hunting dogs, and 0/98 wild boars, and 0/15 hunters seropositive. The absence of N. caninum antibodies in wild boars may suggest low exposure to oocysts shed by hunting dogs and wild canids in three different Brazilian regions. Finally, the absence of hunter seropositivity supports the current lack of evidence that N. caninum is a zoonotic parasite.

Increased vitamin supplement to sows, piglets and finishers and the effect in productivity.

With still limited information on vitamin requirements and considering that many commercial practices adopt dietary vitamin levels above the values suggested by nutritional tables, this study aimed to assess the effect of administering vitamin supplementation to sows in gestation and lactation and to their litters on the reproductive performance and body condition of the sows and on the performance and immune profile of the litters until slaughter. The trial was split into two phases. The first phase used 104 sows, assigned to be randomized to blocks according to parity, submitted until 21 days of lactation to two treatments: control-standard (standard levels of vitamins) and test-elevated (elevated levels of vitamins). Each sow and its respective farrow were considered an experimental unit. The sows underwent evaluations of body condition score, back fat thickness and reproductive performance. In the second phase, 60 barrows and 60 gilts at 21 days of age and mean initial weight of 5.33 ± 1.5 kg until slaughter at 164 days of age. The piglets were assigned to randomized blocks according to the weight and sex of the animals in a 2 × 2 factorial model, with 10 replicates per treatment, where a pen with three animals represented the experimental unit. Following the same treatments of the first phase, the piglets were evaluated for daily weight gain, daily feed intake, feed conversion, mortality rate and humoral immune response. Vitamin supplementation had no positive effects on the reproductive parameters or body composition of sows. However, it positively impacted the performance of the litters in the early nursery stage, but did not lead to superior effects on the immune responses to vaccination against circovirus or mycoplasma.

Assessing the implications of mycotoxins on productive efficiency of broilers and growing pigs

The effects of mycotoxins on the productive performance of growing pigs and broilers were evaluated using meta-analytical approach. Two databases were constructed: (1) Broilers, with information collected from 51,497 birds and published in 158 scientific papers from 1980 to 2016; and (2) Pigs, with information collected from 7,743 animals and published in 72 scientific papers from 1980 to 2015. The meta-analyses were performed independently for each specie, following three sequential analyses: graphical, correlation, and variance-covariance. Broilers and pigs challenged by mycotoxins reduced (p < 0.05) feed intake by 9 and 6 %, weight gain by 15 and 11 %, and feed efficiency by 6 and 4 % compared with non-challenged animals, respectively. Aflatoxins were the most studied mycotoxins in both databases. Birds and pigs challenged by aflatoxins reduced (p < 0.05) feed intake by 10 and 8 %, growth by 15 and 11 %, and feed efficiency by 6 and 7 % compared to non-challenged animals, respectively. In both databases, variation on growth performance due to mycotoxins showed a linear relationship (p < 0.05) with the feed intake variation caused by the challenge. The intercepts of the regression-based equations were different from zero and negative, which may indicate that mycotoxins altered the maintenance requirements in challenged animals. In conclusion, both broilers and growing pigs show losses in performance responses and worse nutritional efficiency when challenged by mycotoxins.

Assessing the implications of mycotoxins on productive efficiency of broilers and growing pigs

The effects of mycotoxins on the productive performance of growing pigs and broilers were evaluated using meta-analytical approach. Two databases were constructed: (1) Broilers, with information collected from 51,497 birds and published in 158 scientific papers from 1980 to 2016; and (2) Pigs, with information collected from 7,743 animals and published in 72 scientific papers from 1980 to 2015. The meta-analyses were performed independently for each specie, following three sequential analyses: graphical, correlation, and variance-covariance. Broilers and pigs challenged by mycotoxins reduced (p < 0.05) feed intake by 9 and 6 %, weight gain by 15 and 11 %, and feed efficiency by 6 and 4 % compared with non-challenged animals, respectively. Aflatoxins were the most studied mycotoxins in both databases. Birds and pigs challenged by aflatoxins reduced (p < 0.05) feed intake by 10 and 8 %, growth by 15 and 11 %, and feed efficiency by 6 and 7 % compared to non-challenged animals, respectively. In both databases, variation on growth performance due to mycotoxins showed a linear relationship (p < 0.05) with the feed intake variation caused by the challenge. The intercepts of the regression-based equations were different from zero and negative, which may indicate that mycotoxins altered the maintenance requirements in challenged animals. In conclusion, both broilers and growing pigs show losses in performance responses and worse nutritional efficiency when challenged by mycotoxins.(AU)

A case of incidental infection of Hepatitis E virus (HEV) genotype 1 in a domestic pig.

Hepatitis E virus (HEV) infection involving zoonotic genotypes is a public health problem in high-income and non-endemic developing countries. Herein we report the detection of a human genotype 1 (HEV-1) strain infecting a domestic pig, which is not considered a natural reservoir of this genotype. Viral load was quantified in stool by Real-Time qPCR and sequence analyses were performed. Infectivity of the HEV-1 strain was assesed by in vitro isolation in A549 cell line. Results suggest that certain epidemiological settings might favour accidental spillover infection and thus influence the host range restriction of HEV.

Detection of influenza A virus in aerosols of vaccinated and non-vaccinated pigs in a warm environment.

The 2009 influenza pandemic, the variant H3N2v viruses in agricultural fairs and the zoonotic poultry H5N9 infections in China have highlighted the constant threat that influenza A viruses (IAV) present to people and animals. In this study we evaluated the effect of IAV vaccination on aerosol shedding in pigs housed in warm environmental conditions. Thirty-six, three-week old weaned pigs were obtained from an IAV negative herd and were randomly allocated to one of 4 groups: 1) a homologous vaccine group, 2) a heterologous multivalent vaccine group, 3) a heterologous monovalent group and, 4) a non-vaccinated group. After vaccination pigs were challenged with the triple reassortant A/Sw/IA/00239/04 H1N1 virus. Environmental temperature and relative humidity were recorded throughout the study. Nasal swabs, oral fluids and air samples were collected daily. All samples were tested by RRT-PCR and virus isolation was attempted on positive samples. Average temperature and relative humidity throughout the study were 27°C (80°F) and 53%, respectively. A significantly higher proportion of infected pigs was detected in the non-vaccinated than in the vaccinated group. Lower levels of nasal virus shedding were found in vaccinated groups compared to non-vaccinated group and IAV was not detected in air samples of any of the vaccinated groups. In contrast, positive air samples were detected in the non-vaccinated group at 1, 2 and 3 days post infection although the overall levels were considered low most likely due to the elevated environmental temperature. In conclusion, both the decrease in shedding and the increase in environmental temperature may have contributed to the inability to detect airborne IAV in vaccinated pigs.

Occurrence of antibodies against Neospora caninum in wild pigs (Sus scrofa) in the Pantanal, Mato Grosso do Sul, Brazil / Ocorrência de anticorpos contra Neospora caninum em porcos-monteiro (Sus scrofa) do Pantanal, Mato Grosso do Sul, Brasil

Serum samples from 83 free living wild pigs (Sus scrofa) from the Nhecolândia region, Pantanal do Mato Grosso, Brazil, were examined for the presence of antibodies against Neospora caninum by means of the indirect fluorescence antibody test (IFAT) with a cut off of 50. Antibodies were present in 10.8%, with titers of: 1:200 in one animal, 1:400 in four and 1:800 in four. Analysis using the χ2 test showed an association between sex and presence of antibodies, with females showing occurrence of 20.5% and males 2.3% (p = 0.017). No association was found between age and occurrences of antibodies against this parasite. This was the first observation of N. caninum antibodies in Brazilian wild pigs from Pantanal(AU)

Amostras de soro de 83 porcos-monteiro (Sus scrofa) selvagens, oriundos da região de Nhecolândia, Pantanal do Mato Grosso, Brasil, foram examinadas para a presença de anticorpos contra Neospora caninum pela reação de imunofluorescência indireta (RIFI) com ponto de corte de 50. A ocorrência de anticorpos foi de 10,8%, com um animal apresentando título de 1:200, quatro com 1:400 e quatro com 1:800. Quando analisados pelo teste do X2, foi observada a existência de associação entre sexo e presença de anticorpos, com as fêmeas apresentando ocorrência de 20,5% e os machos 2,3% (p = 0,017). Não houve associação entre idade e ocorrência de anticorpos contra este parasito. Esta é a primeira observação de porcos-monteiro da região do Pantanal, apresentando anticorpos contra N. caninum(AU)

Occurrence of antibodies against Neospora caninum in wild pigs (Sus scrofa) in the Pantanal, Mato Grosso do Sul, Brazil / Ocorrência de anticorpos contra Neospora caninum em porcos-monteiro (Sus scrofa) do Pantanal, Mato Grosso do Sul, Brasil

Serum samples from 83 free living wild pigs (Sus scrofa) from the Nhecolândia region, Pantanal do Mato Grosso, Brazil, were examined for the presence of antibodies against Neospora caninum by means of the indirect fluorescence antibody test (IFAT) with a cut off of 50. Antibodies were present in 10.8%, with titers of: 1:200 in one animal, 1:400 in four and 1:800 in four. Analysis using the χ2 test showed an association between sex and presence of antibodies, with females showing occurrence of 20.5% and males 2.3% (p = 0.017). No association was found between age and occurrences of antibodies against this parasite. This was the first observation of N. caninum antibodies in Brazilian wild pigs from Pantanal...

Amostras de soro de 83 porcos-monteiro (Sus scrofa) selvagens, oriundos da região de Nhecolândia, Pantanal do Mato Grosso, Brasil, foram examinadas para a presença de anticorpos contra Neospora caninum pela reação de imunofluorescência indireta (RIFI) com ponto de corte de 50. A ocorrência de anticorpos foi de 10,8%, com um animal apresentando título de 1:200, quatro com 1:400 e quatro com 1:800. Quando analisados pelo teste do X2, foi observada a existência de associação entre sexo e presença de anticorpos, com as fêmeas apresentando ocorrência de 20,5% e os machos 2,3% (p = 0,017). Não houve associação entre idade e ocorrência de anticorpos contra este parasito. Esta é a primeira observação de porcos-monteiro da região do Pantanal, apresentando anticorpos contra N. caninum...

Leptospirosis in pigs, dogs, rodents, humans, and water in an area of the Colombian tropics.

Leptospirosis is a reemerging zoonosis of global distribution and is one of the causes of hemorrhagic fevers in the tropics. We sought to determine seroprevalence in humans and animals and isolate Leptospira interrogans sensu lato in domestic animals, rodents, and water sources. The study was conducted in a tropical area of the middle Sinú in Cordoba, Colombia. In a prospective descriptive study, we collected blood and urine from pigs and dogs, sera from rural human workers, sera and kidney macerates of rodents, and water samples from environmental sources. We used microagglutination to screen for antibodies to 13 serovars. Strains were cultured on the Ellinghausen-McCullough-Johnson-Harris medium and confirmed by PCR amplifying lipL32 gene. Seroprevalence was 55.9% in pigs, 35.2% in dogs, and 75.8% in humans; no antibody was detected, and no Leptospira were isolated from kidney macerates of rodents. Seven L. interrogans sensu lato strains were isolated: three from pigs, two from dogs, and two from water. High seroprevalence in pigs, dogs, and humans, concomitant to isolation of strains, demonstrates that in Cordoba, transmission exists among animals, the environment, and humans, which warrants the implementation of public health intervention measures to reduce the epidemiological impact of leptospirosis in the region.

IgY antibodies protect against human Rotavirus induced diarrhea in the neonatal gnotobiotic piglet disease model.

Group A Rotaviruses are the most common cause of severe, dehydrating diarrhea in children worldwide. The aim of the present work was to evaluate protection against rotavirus (RV) diarrhea conferred by the prophylactic administration of specific IgY antibodies (Ab) to gnotobiotic piglets experimentally inoculated with virulent Wa G1P[8] human rotavirus (HRV). Chicken egg yolk IgY Ab generated from Wa HRV hyperimmunized hens specifically recognized (ELISA) and neutralized Wa HRV in vitro. Supplementation of the RV Ab free cow milk diet with Wa HRV-specific egg yolk IgY Ab at a final ELISA Ab titer of 4096 (virus neutralization -VN- titer = 256) for 9 days conferred full protection against Wa HRV associated diarrhea and significantly reduced virus shedding. This protection was dose-dependent. The oral administration of semi-purified passive IgY Abs from chickens did not affect the isotype profile of the pig Ab secreting cell (ASC) responses to Wa HRV infection, but it was associated with significantly fewer numbers of HRV-specific IgA ASC in the duodenum. We further analyzed the pigs immune responses to the passive IgY treatment. The oral administration of IgY Abs induced IgG Ab responses to chicken IgY in serum and local IgA and IgG Ab responses to IgY in the intestinal contents of neonatal piglets in a dose dependent manner. To our knowledge, this is the first study to show that IgY Abs administered orally as a milk supplement passively protect neonatal pigs against an enteric viral pathogen (HRV). Piglets are an animal model with a gastrointestinal physiology and an immune system that closely mimic human infants. This strategy can be scaled-up to inexpensively produce large amounts of polyclonal IgY Abs from egg yolks to be applied as a preventive and therapeutic passive Ab treatment to control RV diarrhea.

High prevalence of F4+ and F18+ Escherichia coli in Cuban piggeries as determined by serological survey.

Little information is available on the prevalence of swine enteropathogens in Cuba where diarrheic diseases are responsible for 31% and 37% of the total mortality during the neonatal and postweaning periods. F4+ and F18+ enterotoxigenic Escherichia coli and F18+ verotoxigenic E. coli induce diarrhea and edematous disease in pigs, but their distribution has never been thoroughly studied in the Cuban swine population. Therefore, the present study estimated the prevalence of F4- and F18-specific antibodies in sera of 1,044 6-month-old gilts distributed in 34 piggeries spread over the Cuban territory. For the data analysis, which included the optical density of individual samples tested by ELISA, random-effects models and a mixture model in R (package "mixAK"; Komárek, Computational Statistics and Data Analysis 53:3932-3947, 2009) were fitted. Low, moderate, and high levels of F4-specific antibodies were found in 67.6%, 26.8%, and 5.6% of the gilts, while 66.4% and 33.6% of gilts showed low and high levels of F18-specific antibodies. Hereby, we show that F4+ and F18+ E. coli are highly prevalent as potential enteropathogens in Cuban piggeries.

Mixed mycotic rhinitis and pneumonia in wild boars

Background: Wild boar population is present worldwide. Contact between wild boars and domestic pigs may occur occasionally, and several diseases, as well as the occurrence of opportunistic infections are observed in both species. Mycotic rhinitis and pneumonia were reported before in pig herds, mainly associated with immunosuppression caused by viral infection. This study reports the occurrence of mycotic rhinitis in two wild boars due to Aspergillus fumigatus, A. fl avus and Candida albicans, together with Pneumocystis sp. in the lungs, originating from a herd infected with PCV2. Cases: In a commercial wild boar herd, poor body condition, sneezing and diarrhea were observed. Three animals were euthanized and, in two of them, yellow and green plaque-like masses of fungal growth in the mucosal and in cartilage surface and accentuated atrophy of nasal turbinates were observed. Additionally, multifocal subcutaneous abscesses in the maxillary area and bilateral reddening of the ocular mucosa with muco-purulent discharge were noted. Microscopically, in fragments from the nasal cavity of the two affected wild pigs, massive ulceration of the mucosal surface and presence of hyphae with septations and dichotomous branching and pseudohyphae were observed. Multifocal moderated interstitial pneumonia and alveolar edema were the main histological lesions founded in the lungs of 3 animals. In the lymph nodes multifocal moderated lymphoid depletion and lymphohistiocytic infi ltrated was the main microscopical lesion. Aspergillus fumigatus, A. fl avus and Candida albicans were isolated in nasal cavity. Pseudomonas aeruginosa was isolated from the subcutaneous abscesses and Staphylococcus hyicus and Streptococcus equisimilis from ocular swab. Pneumocystis was detected in lungs from the three wild boars by nested PCR, Grocott´s staining and immunohistochemistry (IHC). Porcine circovirus 2 (PCV2) was detected in lungs by PCR. Virus detection by IHC was only confi rmed in one wild boar. Discussion: Diagnostic of mycotic rhinitis and pneumonia was based on macroscopical and microscopical fi ndings, as well as mycological analysis, IHC and Groccott ´s methenamine staining. Pneumocystis carinii, Aspergillus spp. and Candida spp. are considered as opportunistic fungal pathogens commonly associated with immunosuppression in animals and humans and have been found in lungs and in muco-cutaneous tissue of PMWS affected pigs. Clinically, immunodeficiency is usually associated with illness caused by organisms of low pathogenicity or well-know secondary pathogens, among other factors. Besides immunodefi ciency, prolonged antimicrobial therapy is another predisposing factor to the development of mycotic infections, well described in animals. In the present report, antimicrobial therapy was performed when respiratory signs were noted in therapeutic doses, suggesting that massive antibiotic use was not the trigger of mycotic rhinitis. PCV2 IHC result positive only in one wild pig, although all the samples were positive by PCR. This fi nding could indicate a subclinical infection or a recovery phase of the disease in the IHC negative cases, as previously suggested for domestic and wild pigs using in situ hybridization. PCV2 load in wild boar was lower when compared with domestic pigs. A viral load higher than 108 PCV2 genomes per 500 ng DNA was required to give a visible IHC staining in swine. Although quantitative PCR it was not used in order to detect PCV2 in the present report, the viral load could be another possible explanation for the IHC negative cases observed. The role of PCV2 as a cause of immunosupression, facilitating the infection with secondary agents as Aspergillus, Candida and Pneumocystis cannot be ruled out.(AU)

Mixed mycotic rhinitis and pneumonia in wild boars

Background: Wild boar population is present worldwide. Contact between wild boars and domestic pigs may occur occasionally, and several diseases, as well as the occurrence of opportunistic infections are observed in both species. Mycotic rhinitis and pneumonia were reported before in pig herds, mainly associated with immunosuppression caused by viral infection. This study reports the occurrence of mycotic rhinitis in two wild boars due to Aspergillus fumigatus, A. fl avus and Candida albicans, together with Pneumocystis sp. in the lungs, originating from a herd infected with PCV2. Cases: In a commercial wild boar herd, poor body condition, sneezing and diarrhea were observed. Three animals were euthanized and, in two of them, yellow and green plaque-like masses of fungal growth in the mucosal and in cartilage surface and accentuated atrophy of nasal turbinates were observed. Additionally, multifocal subcutaneous abscesses in the maxillary area and bilateral reddening of the ocular mucosa with muco-purulent discharge were noted. Microscopically, in fragments from the nasal cavity of the two affected wild pigs, massive ulceration of the mucosal surface and presence of hyphae with septations and dichotomous branching and pseudohyphae were observed. Multifocal moderated interstitial pneumonia and alveolar edema were the main histological lesions founded in the lungs of 3 animals. In the lymph nodes multifocal moderated lymphoid depletion and lymphohistiocytic infi ltrated was the main microscopical lesion. Aspergillus fumigatus, A. fl avus and Candida albicans were isolated in nasal cavity. Pseudomonas aeruginosa was isolated from the subcutaneous abscesses and Staphylococcus hyicus and Streptococcus equisimilis from ocular swab. Pneumocystis was detected in lungs from the three wild boars by nested PCR, Grocott´s staining and immunohistochemistry (IHC). Porcine circovirus 2 (PCV2) was detected in lungs by PCR. Virus detection by IHC was only confi rmed in one wild boar. Discussion: Diagnostic of mycotic rhinitis and pneumonia was based on macroscopical and microscopical fi ndings, as well as mycological analysis, IHC and Groccott ´s methenamine staining. Pneumocystis carinii, Aspergillus spp. and Candida spp. are considered as opportunistic fungal pathogens commonly associated with immunosuppression in animals and humans and have been found in lungs and in muco-cutaneous tissue of PMWS affected pigs. Clinically, immunodeficiency is usually associated with illness caused by organisms of low pathogenicity or well-know secondary pathogens, among other factors. Besides immunodefi ciency, prolonged antimicrobial therapy is another predisposing factor to the development of mycotic infections, well described in animals. In the present report, antimicrobial therapy was performed when respiratory signs were noted in therapeutic doses, suggesting that massive antibiotic use was not the trigger of mycotic rhinitis. PCV2 IHC result positive only in one wild pig, although all the samples were positive by PCR. This fi nding could indicate a subclinical infection or a recovery phase of the disease in the IHC negative cases, as previously suggested for domestic and wild pigs using in situ hybridization. PCV2 load in wild boar was lower when compared with domestic pigs. A viral load higher than 108 PCV2 genomes per 500 ng DNA was required to give a visible IHC staining in swine. Although quantitative PCR it was not used in order to detect PCV2 in the present report, the viral load could be another possible explanation for the IHC negative cases observed. The role of PCV2 as a cause of immunosupression, facilitating the infection with secondary agents as Aspergillus, Candida and Pneumocystis cannot be ruled out.

Evaluation of colostral immunity in swine with commercial anti-leptospira polyvalent whole-bacteria vaccine.

The intensity and duration of passive immunity against swine leptospirosis were investigated by the microscopic agglutination test and in vitro leptospira growth inhibition. Twenty-one females at first parturition were divided into three groups: Group A (n=08): received two doses with 30 days interval of the commercial anti-leptospira bacterin A. Group B (n=06) received two doses with 30 days interval of the commercial anti-leptospira bacterin B and Group C (n=07) was the control. In all groups the colostrums were collected. Blood collection of piglets was performed in four different ages. Agglutinin antibodies were equally detected in sera and colostrums for serovars Canicola, Grippotyphosa, Copenhageni, Icterohaemorrhagiae and Pomona (Group A) and Canicola, Copenhageni, Icterohaemorrhagiae, Pomona and Hardjo (Group B). Mean neutralizing antibodies titers were low. Passive immunity was low duration.

Pig chromosome aberrations after vaccination against classical swine fever in field trials.

Chromosomal aberrations were observed after vaccination against classical swine fever (CSF) in a previous study done on experimental pigs. To determine if the same effect occurs in farm animals, field trials were done with immunized pigs. The cytogenetic analysis was made from lymphocyte cultures of pigs sampled in three farms of Río Cuarto region on six different periods: one, pre-vaccination (control) and in five post-vaccination (days 3, 7, 10, 15 and 22). Vaccine inoculation induced significant increase of cell frequency with chromosomal aberrations from days 3 to 10, when maximal frequencies of 6.78, 10.36 and 7.21% were observed in farms A, B and C, respectively. Afterwards, a decrease was recorded, reaching values not significantly different from controls. Mean frequencies of cells with chromosomal aberrations were 2.8+/-0.3, 5.9+/-0.4, 3.1+/-0.3%, for A, B and C farms, respectively. Cytogenetic effect was clastogenic, being chromosome breaks the first type of alteration to increase from the day 3 post-vaccination onwards, followed by chromatid exchanges and cells with multiple abnormalities. Chromosome pulverization was the last type to show increment, reaching a top value on day 10, after that it started to diminish gradually. There was no difference in the frequency of polyploid cells among sampling dates meaning that this type of alteration would not be induced by vaccination. Results of this field study confirm the mutagenic capacity of live virus vaccines against CSF and indicate that the evolution of chromosome alterations on the five evaluated post-vaccination periods was similar at different environments.

Potency analysis of inactivated vaccines for Aujeszky's disease virus (ADV), strain RC/79: lymphocyte stimulation in immunized pigs.

Mitogenic and antigenic lymphocyte stimulation was examined in pigs that had been immunized with 2 inactivated vaccines which had been prepared with Aujesky's disease virus (ADV), strain RC/79. One vaccine was partially purified by ultra-centrifugation (Vaccine A) the other one was not (Vaccine B). A second dose of vaccine had no influence over the blastogenic response when the lymphocytes were stimulated with phytohemoagglutinin (PHA). Lymphocyte response to the ADV antigen in the immunized pigs was significantly higher at day 30 post inoculation than at day 0 indicating that it was highly specific. Cellular antigens contained in the viral cultures produced a slight non-specific response as shown by a low increase in the levels of lymphocyte blastic transformation (LBT) in the control group at day 30 p.i., this group only received a non infected Vero cell suspension. This was the case in pigs that received vaccine A as well as in those that were vaccinated with vaccine B. Vaccine B contains a greater quantity of contaminating cellular antigens, since it is an impure vaccine. Such antigens could act as non-specific immunomodulators, potentiating cell-mediated immunity (CMI). This assay demonstrated that inactivated vaccines produced with VPR-RC/79, partially purified and unpurified are capable of inducing a humoral immune response. The blastogenic reaction of the peripheral blood lymphocytes to antigens of ADV strain RC/79, indicated that the employed immunogens also induced the CMI. Results indicate that the analyzed immunogens could be considered for the possible implementation of epidemiological measures, which imply the use of vaccines to prevent pseudo-rabies in Argentina.