RESUMEN
Porcine circovirus type 3 (PCV3) is considered a new circovirus and since it first description has been widely reported in most of the swine-producing countries. Multisystemic inflammation and reproductive failure are consistent and concerning issues associated with PCV3 infection. This report describes the clinical and pathological features of a chronic reproductive disorder in a swine herd in Argentina associated with the presence of PCV3. Mummified (n = 42) and stillborn piglets (n = 20) from a case of chronic reproductive disorder (Study A) and mummified and stillborn piglets (n = 141) from normal deliveries (Study B) were retrospectively assessed for the presence of multiple reproductive pathogens (PCV3, PCV2, ADV, PPV, Leptospira spp. and Brucella spp). On study, A PCV3 and PPV were detected in 15 and 8 pools, respectively, with a coinfection rate of 100% in all PPV-positive cases. Three out of 131 foetuses from three different sows from Study B were positive only for PCV3. Histological evaluation of hearts from stillborn also showed lesions similar to those previously described in the literature for PCV3-reproductive disease. Partial genome of PCV3 was amplified and phylogenetic analysis showed that strains of Study A and B clustered within the PCV3a and PCV3b clades, respectively. This study demonstrates, for the first time, the PCV3 has been circulating in Argentina at least since 2016 and its potential role in reproductive disorders. Further studies are warranted to determine the role of PCV3 in the reproductive disease complex and its prevalence in the swine industry in Argentina.
Asunto(s)
Infecciones por Circoviridae , Circovirus , Enfermedades de los Porcinos , Animales , Argentina/epidemiología , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/veterinaria , Circovirus/genética , Femenino , Filogenia , Estudios Retrospectivos , Porcinos , Enfermedades de los Porcinos/epidemiologíaRESUMEN
This study uses network analysis to evaluate how swine movements in Argentina could contribute to disease spread. Movement data for the 2014-2017 period were obtained from Argentina's online livestock traceability registry and categorized as follows: animals of high genetic value sent to other farms, animals to or from markets, animals sent to finisher operations and slaughterhouse. A network analysis was carried out considering the first three movement types. First, descriptive, centrality and cohesion measures were calculated for each movement type and year. Next, to determine whether networks had a small-world topology, these were compared with the results from random Erdös-Rényi network simulations. Then, the basic reproductive number (R0 ) of the genetic network, the group of farms with higher potential for disease spread standing at the top of the production chain, was calculated to identify farms acting as super-spreaders. Finally, their external biosecurity scores were evaluated. The genetic network in Argentina presented a scale-free and small-world topology. Thus, we estimate that disease spread would be fast, preferably to highly connected nodes and with little chances of being contained. Throughout the study, 31 farms were identified as super-spreaders in the genetic network for all years, while other 55 were super-spreaders at least once, from an average of 1,613 farms per year. Interestingly, removal of less than 5% of higher degree and betweenness farms resulted in a >90% reduction of R0 indicating that few farms have a key role in disease spread. When biosecurity scores of the most relevant super-spreaders were examined, it was evident that many were at risk of introducing and disseminating new pathogens across the whole of Argentina's pig production network. These results highlight the usefulness of establishing targeted surveillance and intervention programmes, emphasizing the need for better biosecurity scores in Argentinean swine production units, especially in super-spreader farms.
Asunto(s)
Crianza de Animales Domésticos/estadística & datos numéricos , Enfermedades Transmisibles/veterinaria , Enfermedades de los Porcinos/epidemiología , Transportes , Animales , Argentina/epidemiología , Enfermedades Transmisibles/epidemiología , Enfermedades Transmisibles/virología , Granjas , Sus scrofa , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
BACKGROUND: In 2014, a notification of porcine transmissible gastroenteritis virus (TGEV) was made by the National Services of Animal Health of Argentina (SENASA) to the World Organization of Animal Health (OIE). The notification was based on a serological diagnosis in a small farm with a morbidity rate of 2.3% without enteric clinical signs. In order to determine if TGEV was circulating before the official report, a retrospective study on cases of neonatal diarrhea was performed. The selection criteria was a sudden increase in mortality in 1- to 21-day-old piglets with watery diarrhea that did not respond to antibiotics. Based on these criteria, three clinical cases were identified during 2010-2015. RESULTS: All animals that were evaluated presented histological lesions consistent with enteric viral infection. The feces and ultrathin sections of intestine that were evaluated by electron microscopy confirmed the presence of round particles of approximately 80 nm in size and characterized by finely granular electrodense nucleoids consistent with complete particles of coronavirus. The presence of the TGEV antigen was confirmed by monoclonal specific immunohistochemistry, and final confirmation of a metabolically-active virus was performed by in situ hybridization to detect a TGE mRNA encoding spike protein. All sections evaluated in this case were negative for PEDV and rotavirus A. CONCLUSIONS: This is the first case series describing neonatal mortality with etiological confirmation of TGEV in Argentina. The clinical diagnosis of TGEV infections in endemic regions is challenging due to the epidemiological distribution and coinfection with other enteric pathogens that mask the clinical presentation.
Asunto(s)
Gastroenteritis Porcina Transmisible/diagnóstico , Enfermedades de los Porcinos/diagnóstico , Virus de la Gastroenteritis Transmisible/aislamiento & purificación , Animales , Argentina/epidemiología , Femenino , Gastroenteritis Porcina Transmisible/epidemiología , Masculino , Estudios Retrospectivos , Porcinos , Enfermedades de los Porcinos/epidemiologíaRESUMEN
Swine farms provide a dynamic environment for the evolution of influenza A viruses (IAVs). The present report shows the results of a surveillance effort of IAV infection in one commercial swine farm in Argentina. Two cross-sectional serological and virological studies (n=480) were carried out in 2011 and 2012. Virus shedding was detected in nasal samples from pigs from ages 7, 21 and 42-days old. More than 90% of sows and gilts but less than 40% of 21-days old piglets had antibodies against IAV. In addition, IAV was detected in 8/17 nasal swabs and 10/15 lung samples taken from necropsied pigs. A subset of these samples was further processed for virus isolation resulting in 6 viruses of the H1N2 subtype (δ2 cluster). Pathological studies revealed an association between suppurative bronchopneumonia and necrotizing bronchiolitis with IAV positive samples. Statistical analyses showed that the degree of lesions in bronchi, bronchiole, and alveoli was higher in lungs positive to IAV. The results of this study depict the relevance of continuing long-term active surveillance of IAV in swine populations to establish IAV evolution relevant to swine and humans.
Asunto(s)
Bronconeumonía/veterinaria , Monitoreo Epidemiológico , Subtipo H1N1 del Virus de la Influenza A , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/epidemiología , Animales , Anticuerpos Antivirales/sangre , Argentina/epidemiología , Bronconeumonía/epidemiología , Bronconeumonía/virología , Estudios Transversales , Humanos , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana , Pulmón/patología , Pulmón/virología , Nariz/virología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/fisiopatología , Infecciones por Orthomyxoviridae/virología , Sus scrofa , Porcinos , Enfermedades de los Porcinos/virología , Esparcimiento de VirusRESUMEN
Enterotoxigenic Escherichia coli (ETEC) is the major pathogen responsible for neonatal diarrhea, postweaning diarrhea, and edema disease in pigs. Although it can be harmless, ETEC is also present in the intestines of other animal species and humans, causing occasional diarrhea outbreaks. The evaluation of this pathogen's presence in food sources is becoming an increasingly important issue in human health. In order to determine the prevalence of ETEC in nondiarrheic pigs, 990 animals from 11 pig farms were sampled. Using end-time polymerase chain reaction (PCR), eltA, estI genes, or both, were detected in 150 (15.2%) animals. From the positive samples, 40 (26.6%) ETEC strains were isolated, showing 19 antibiotic-resistance patterns; 52.5% of these strains had multiple antibiotic resistances, and 17.5% carried the intI2 gene. The most prevalent genotypes were rfb(O157)/estII/aidA (32.5%) and estI/estII (25.0%). The estII gene was identified most frequently (97.5%), followed by estI (37.5%), astA (20.0%), and eltA (12.5%). The genes coding the fimbriae F5, F6, and F18 were detected in three single isolates. The aidA gene was detected in 20 ETEC strains associated with the estII gene. Among the isolated ETEC strains, stx(2e)/estI, stx(2e)/estI/estII, and stx(2e)/estI/estII/intI2 genotypes were identified. The ETEC belonged to 12 different serogroups; 37.5% of them belonged to serotype O157:H19. Isolates were grouped by enterobacterial repetitive intergenic consensus-PCR into 5 clusters with 100.0% similarity. In this study, we demonstrated that numerous ETEC genotypes cohabit and circulate in swine populations without clinical manifestation of neonatal diarrhea, postweaning diarrhea, or edema disease in different production stages. The information generated is important not only for diagnostic and epidemiological purposes, but also for understanding the dynamics and ecology of ETEC in pigs in different production stages that can be potentially transmitted to humans from food animals.
Asunto(s)
Antiinfecciosos/análisis , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli Enterotoxigénica/aislamiento & purificación , Genes Bacterianos , Carne Roja/microbiología , Animales , Antiinfecciosos/farmacología , ADN Bacteriano/genética , Diarrea/microbiología , Diarrea/veterinaria , Edematosis Porcina/microbiología , Escherichia coli Enterotoxigénica/efectos de los fármacos , Escherichia coli Enterotoxigénica/genética , Proteínas de Escherichia coli/genética , Contaminación de Alimentos , Microbiología de Alimentos , Técnicas de Genotipaje , Carne Roja/análisis , Porcinos , Enfermedades de los Porcinos/microbiologíaRESUMEN
BACKGROUND: Influenza A viruses (IAV) are important pathogens responsible for economic losses in the swine industry and represent a threat to public health. In Argentina, clinical, pathological, and virological findings suggest that IAV infection is widespread among pig farms. In addition, several subtypes of IAV, such as pH1N1, H3N2, δ1H1N1, and δ2H1N2, have been reported. OBJECTIVES: To evaluate the infection patterns of influenza virus in nine pig farms in Argentina. METHODS: Clinical, serological, pathological, and virological cross-sectional studies were conducted. RESULTS: Clinical and pathological results were characteristic of endemic influenza infection in eight of the nine farms studied. By rRT-PCR, six of the nine farms were positive to influenza. Five IAV were obtained. Genome analysis determined that four of the isolations were pH1N1 and that the remaining one was a reassortant human origin H3N2 virus containing pandemic internal genes. Serological results showed that all farms were positive to influenza A antibodies. Moreover, the hemagglutination inhibition test showed that infection with viruses containing HA's from different subtypes (pH1, δ1H1, δ2H1, and H3) is present among the farms studied and that coinfections with two or more subtypes were present in 80.5% of positive pigs. CONCLUSIONS: Because vaccines against IAV are not licensed in Argentina, these results reflect the situation of IAV infection in non-vaccinated herds. This study provides more information about the circulation and characteristics of IAV in a poorly surveyed region. This study provides more data that will be used to evaluate the tools necessary to control this disease.
Asunto(s)
Anticuerpos Antivirales/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/patología , Animales , Argentina/epidemiología , Estudios Transversales , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/virologíaRESUMEN
The purpose of this work was to characterize 47 Escherichia coli strains isolated from 32 pigs diagnosed with postweaning diarrhea and three pigs with edema disease by PCR. Forty two (95.5 %) of the strains isolated from diarrheic pigs were characterized as enterotoxigenic E. coli (ETEC) and 2 (4.5 %) as Shiga toxin-producing E. coli (STEC). Fourteen (33.3 %) ETEC strains were positive for est/estII/fedA genes. The most complex genotype was eltA/estI/faeG/aidA. Strains isolated from pigs with ED were classified as porcine STEC and were stx2e/aidA carriers. Eleven (25 %) strains carried the gene encoding adhesin protein AIDA-I. However, genes coding for F5, F6, F41, intimin and Paa were not detected. The development of vaccines generating antibodies against prevalent E. coli adhesins in Argentina could be useful for the prevention of PWD and ED.
Asunto(s)
Diarrea/veterinaria , Edematosis Porcina/microbiología , Escherichia coli Enterotoxigénica/genética , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Genes Bacterianos , Escherichia coli Shiga-Toxigénica/genética , Enfermedades de los Porcinos/microbiología , Adhesinas de Escherichia coli/genética , Animales , Argentina/epidemiología , Diarrea/epidemiología , Diarrea/microbiología , Brotes de Enfermedades , Edematosis Porcina/epidemiología , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Genotipo , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Sus scrofa , Porcinos , Enfermedades de los Porcinos/epidemiología , DesteteRESUMEN
Angiostrongylus is a metastrongylid nematode genus that includes species found in carnivores, rodents, and occasionally primates (including humans). About 100 species of wild sigmodontine rodents occur in Argentina, 16 of which are species of Akodon. The lungs of Akodon azarae and Akodon dolores from Sierra de la Ventana, Buenos Aires, Argentina, were examined, and 2 of 10 A. dolores specimens were positive for angiostrongylosis, showing macroscopic lesions of verminous pneumonia. Adults found were identified as Angiostrongylus morerai. Histopathology of the lungs revealed multiple nodules in the interstitium, alveoli, and vessels, resulting in interstitial fibrosis and the destruction of small capillaries and arterioles. Since extensive pathology in the lung was noted here from only 2 adults, it is probable that heavier infections may cause mortality in their hosts. This is the first record of this nematode species from A. dolores , expanding its geographic distribution to the southwest of Buenos Aires Province, and the first description of the histopathology of larval angiostrongylosis in a wild rodent from South America.
Asunto(s)
Pulmón/patología , Enfermedades de los Roedores/patología , Sigmodontinae/parasitología , Infecciones por Strongylida/veterinaria , Animales , Argentina/epidemiología , Arterias/parasitología , Arterias/patología , Femenino , Pulmón/irrigación sanguínea , Pulmón/parasitología , Masculino , Prevalencia , Arteria Pulmonar/parasitología , Arteria Pulmonar/patología , Enfermedades de los Roedores/epidemiología , Enfermedades de los Roedores/parasitología , Infecciones por Strongylida/epidemiología , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/patología , Venas/parasitología , Venas/patologíaRESUMEN
El objetivo del trabajo fue caracterizar mediante PCR 47 aislamientos de Escheríchia coli recuperados de 32 cerdos con diagnóstico clínico de diarrea posdestete (DPD) y de 3 cerdos con enfermedad de los edemas (ED). Sobre 44 aislamientos provenientes de cerdos con DPD, 42 (95,5 %) fueron caracterizados como E. coli enterotoxigénicos (ETEC) y 2 (4,5 %) como E. coli productores de toxina Shiga (STEC). Catorce aislamientos de ETEC (33,3 %) fueron positivos para los genes estl/estlI/fedA. El genotipo más complejo fue eltA/estll/east1/faeG/aidA. Los aislamientos provenientes de cerdos con ED se clasificaron como STEC porcinos y fueron portadores de stxJaidA. Once aislamientos (25 %) fueron portadores del gen que codifica la expresión de la adhesina AIDA-I. Sin embargo, en ningún aislamiento se detectaron los genes que codifican la expresión de las adhesinas F5, F6, F41, de intimina y de "Paa". La prevención de la DPD y de la ED podría realizarse mediante el desarrollo de vacunas que generen anticuerpos contra las adhesinas de las cepas de E. coli prevalentes en la Argentina.(AU)
The purpose of this work was to characterize 47 Escherichia coli strains isolated from 32 pigs diagnosed with postweaning diarrhea and tree pigs with edema disease by PCR. Forty two (95.5 %) of the strains isolated from diarrheic pigs were characterized as enterotoxigenic E. coli (ETEC) and 2 (4.5 %) as Shiga toxin-producing E. coli (STEC). Fourteen (33.3 %) ETEC strains were positive for est/estll/fedA genes. The most complex genotype was eltA/estl/faeG/aidA. Strains isolated from pigs with ED were classified as porcine STEC and were stxjaidA carriers. Eleven (25 %) strains carried the gene encoding adhesln protein AIDA-I. However, genes coding for F5, F6, F41, intimin and Paa were not detected. The development of vaccines generating antibodies against prevalent E. coli adhesins in Argentina could be useful for the prevention of PWD and ED.(AU)
Asunto(s)
Animales , Diarrea/veterinaria , Edematosis Porcina/microbiología , Escherichia coli Enterotoxigénica/genética , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Genes Bacterianos , Escherichia coli Shiga-Toxigénica/genética , Enfermedades de los Porcinos/microbiología , Adhesinas de Escherichia coli/genética , Argentina/epidemiología , Diarrea/epidemiología , Diarrea/microbiología , Brotes de Enfermedades , Edematosis Porcina/epidemiología , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Genotipo , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Sus scrofa , Porcinos , Enfermedades de los Porcinos/epidemiología , DesteteRESUMEN
El objetivo del trabajo fue caracterizar mediante PCR 47 aislamientos de Escheríchia coli recuperados de 32 cerdos con diagnóstico clínico de diarrea posdestete (DPD) y de 3 cerdos con enfermedad de los edemas (ED). Sobre 44 aislamientos provenientes de cerdos con DPD, 42 (95,5 %) fueron caracterizados como E. coli enterotoxigénicos (ETEC) y 2 (4,5 %) como E. coli productores de toxina Shiga (STEC). Catorce aislamientos de ETEC (33,3 %) fueron positivos para los genes estl/estlI/fedA. El genotipo más complejo fue eltA/estll/east1/faeG/aidA. Los aislamientos provenientes de cerdos con ED se clasificaron como STEC porcinos y fueron portadores de stxJaidA. Once aislamientos (25 %) fueron portadores del gen que codifica la expresión de la adhesina AIDA-I. Sin embargo, en ningún aislamiento se detectaron los genes que codifican la expresión de las adhesinas F5, F6, F41, de intimina y de "Paa". La prevención de la DPD y de la ED podría realizarse mediante el desarrollo de vacunas que generen anticuerpos contra las adhesinas de las cepas de E. coli prevalentes en la Argentina.
The purpose of this work was to characterize 47 Escherichia coli strains isolated from 32 pigs diagnosed with postweaning diarrhea and tree pigs with edema disease by PCR. Forty two (95.5 %) of the strains isolated from diarrheic pigs were characterized as enterotoxigenic E. coli (ETEC) and 2 (4.5 %) as Shiga toxin-producing E. coli (STEC). Fourteen (33.3 %) ETEC strains were positive for est/estll/fedA genes. The most complex genotype was eltA/estl/faeG/aidA. Strains isolated from pigs with ED were classified as porcine STEC and were stxjaidA carriers. Eleven (25 %) strains carried the gene encoding adhesln protein AIDA-I. However, genes coding for F5, F6, F41, intimin and Paa were not detected. The development of vaccines generating antibodies against prevalent E. coli adhesins in Argentina could be useful for the prevention of PWD and ED.
Asunto(s)
Animales , Diarrea/veterinaria , Edematosis Porcina/microbiología , Escherichia coli Enterotoxigénica/genética , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Genes Bacterianos , Escherichia coli Shiga-Toxigénica/genética , Enfermedades de los Porcinos/microbiología , Adhesinas de Escherichia coli/genética , Argentina/epidemiología , Brotes de Enfermedades , Diarrea/epidemiología , Diarrea/microbiología , Edematosis Porcina/epidemiología , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Genotipo , Sus scrofa , Porcinos , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , DesteteRESUMEN
An outbreak of proliferative hemorrhagic enteropathy in a commercial pig farm, characterized by granulomatous enteritis, was studied by slaughter checks and by histopathological, histochemical and immunohistochemical studies. Six of the postmortem examined pigs (117-122-day-old) with diagnosis of porcine proliferative enteropathy (PPE) showed granulomatous enteritis and 4.3% of the 465 slaughtered pigs showed gross lesions of PPE. A total of 33 of the 66 ileum samples had histopathological changes, whereas 17 of them had granulomatous enteritis and PPE lesions. Lawsonia intracellularis was immunolabeled in 52 of the ileum samples in epithelial cells and within granulomatous inflammation in Peyer´s patches and in 28 samples of mesenteric lymph nodes. Porcine circovirus type 2 was only detected by immunohistochemistry in 4 ileum samples and in 5 mesenteric lymph nodes. Since there was a strong statistically significant association between granulomatous enteritis and L. intracellularis infection, granulomatous enteritis could be considered as a part of the PPE complex.(AU)
Asunto(s)
Animales , Porcinos , Enfermedad de Crohn/veterinaria , Gastroenteritis/veterinaria , Ileítis/veterinaria , Inmunohistoquímica , Lawsonia (Bacteria) , Infecciones por Desulfovibrionaceae , Enfermedades Intestinales/veterinariaRESUMEN
An outbreak of proliferative hemorrhagic enteropathy in a commercial pig farm, characterized by granulomatous enteritis, was studied by slaughter checks and by histopathological, histochemical and immunohistochemical studies. Six of the postmortem examined pigs (117-122-day-old) with diagnosis of porcine proliferative enteropathy (PPE) showed granulomatous enteritis and 4.3% of the 465 slaughtered pigs showed gross lesions of PPE. A total of 33 of the 66 ileum samples had histopathological changes, whereas 17 of them had granulomatous enteritis and PPE lesions. Lawsonia intracellularis was immunolabeled in 52 of the ileum samples in epithelial cells and within granulomatous inflammation in Peyer´s patches and in 28 samples of mesenteric lymph nodes. Porcine circovirus type 2 was only detected by immunohistochemistry in 4 ileum samples and in 5 mesenteric lymph nodes. Since there was a strong statistically significant association between granulomatous enteritis and L. intracellularis infection, granulomatous enteritis could be considered as a part of the PPE complex.
RESUMEN
Sporadic outbreaks of human H3N2 influenza A virus (IAV) infections in swine populations have been reported in Asia, Europe and North America since 1970. In South America, serological surveys in pigs indicate that IAVs of the H3 and H1 subtypes are currently in circulation; however, neither virus isolation nor characterization has been reported. In November 2008, an outbreak of respiratory disease in pigs consistent with swine influenza virus (SIV) infection was detected in Argentina. The current study describes the clinical epidemiology, pathology, and molecular and biological characteristics of the virus. Phylogenetic analysis revealed that the virus isolate shared nucleotide identities of 96-98â% with H3N2 IAVs that circulated in humans from 2000 to 2003. Antigenically, sera from experimentally inoculated animals cross-reacted mainly with non-contemporary human-origin H3N2 influenza viruses. In an experimental infection in a commercial swine breed, the virus was of low virulence but was transmitted efficiently to contact pigs and caused severe disease when an infected animal acquired a secondary bacterial infection. This is the first report of a wholly human H3N2 IAV associated with clinical disease in pigs in South America. These studies highlight the importance of two-way transmission of IAVs and SIVs between pigs and humans, and call for enhanced influenza surveillance in the pig population worldwide.
Asunto(s)
Subtipo H3N2 del Virus de la Influenza A/patogenicidad , Gripe Humana/transmisión , Gripe Humana/virología , Infecciones por Orthomyxoviridae/transmisión , Infecciones por Orthomyxoviridae/veterinaria , Animales , Argentina/epidemiología , Brotes de Enfermedades , Humanos , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Datos de Secuencia Molecular , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/virología , Filogenia , Filogeografía , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/transmisión , Enfermedades de los Porcinos/virología , Replicación ViralRESUMEN
In this report, we describe the occurrence of two novel swine influenza viruses (SIVs) in pigs in Argentina. These viruses are the result of two independent reassortment events between the H1N1 pandemic influenza virus (H1N1pdm) and human-like SIVs, showing the constant evolution of influenza viruses at the human-swine interface and the potential health risk of H1N1pdm as it appears to be maintained in the swine population. It must be noted that because of the lack of information regarding the circulation of SIVs in South America, we cannot discard the possibility that ancestors of the H1N1pdm or other SIVs have been present in this part of the world. More importantly, these findings suggest an ever-expanding geographic range of potential epicenters of influenza emergence with public health risks.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/veterinaria , Virus Reordenados/aislamiento & purificación , Enfermedades de los Porcinos/virología , Animales , Argentina , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/virología , Pandemias , Virus Reordenados/clasificación , Virus Reordenados/genética , Virus Reordenados/fisiología , PorcinosRESUMEN
Porcine circovirus type 2 (PCV-2) has been associated with syndromes grouped by the term porcine circovirus associated diseases (PCVAD). The PCV-2 isolates have been grouped into two major groups or genotypes according to their nucleotide sequence of whole genomes and/or ORF-2: PCV-2b, which have, in turn, been subdivided into three clusters (1A-1C), and PCV-2a, which has been subdivided into five clusters (2A-2E). In the present study, we obtained 16 sequences of PCV-2 from different farms from 2003 to 2008, from animals with confirmatory diagnosis of PCVAD. Since results showed an identity of 99.8% among them, they were grouped within a common cluster 1A-B. This preliminary study suggests a stable circulation of PCV-2b among the Argentinean pig population.
RESUMEN
In June-July 2009, an outbreak of pandemic (H1N1) 2009 infection occurred on a pig farm in Argentina. Molecular analysis indicated that the virus was genetically related to the pandemic (H1N1) 2009 influenza virus strain. The outbreak presumably resulted from direct human-to-pig transmission.
Asunto(s)
Bronquiolitis Viral/veterinaria , Brotes de Enfermedades/veterinaria , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/transmisión , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/epidemiología , Crianza de Animales Domésticos , Animales , Argentina/epidemiología , Bronquiolitis Viral/epidemiología , Bronquiolitis Viral/patología , Humanos , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/patología , Sus scrofa , Enfermedades de los Porcinos/patología , Enfermedades de los Porcinos/virologíaRESUMEN
The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time course of serological response in farrow-to-finish reared pigs from a subclinically infected farm. Antimicrobial resistance profile, molecular subtyping, and the relationship among the isolates were determined by pulsed-field gel electrophoresis (PFGE). A farrow-to-finish farm of 6000 sows, with a history of Salmonella Typhimurium septicemia, was selected. A longitudinal bacteriological and serological study was conducted in 25 sows before farrowing (M/S1) and in 50 offspring at 21 (M/S2), 35 (M/S3), 65 (M/S4), 86 (M/S5), 128 (M/S6), and 165 (M/S7) days of age. Serum antibodies were tested using Herdcheck((R)) Swine Salmonella antibody test kit (Idexx Laboratories, ME). Bacteria were isolated from pooled fecal samples. Suspected isolates were confirmed by conventional biochemical assays, and those identified as Salmonella spp. were serotyped. A variation between seropositive percentages and positive fecal samples was observed. Serologically positive pigs decreased from S1 to S4, and subsequently increased from S4 to S7. The percentages of fecal positive culture increased from M1 to M3, and then declined in M4, increased in M5, and were negative in M6 and M7. In the study three serovars, Salmonella 3,10:e,h:-, Salmonella Muenster, and Salmonella Bovismorbificans, were identified with low pathogenicity for swine. Three multidrug resistance strains (one belonged to Salmonella 3,10:e,h:- and two belonged to Salmonella Muenster) were found. PFGE results showed three different but closely related patterns among the 13 isolates of Salmonella Bovismorbificans, and two patterns for the three Salmonella Muenster and Salmonella 3,10:e,h:- isolates. This longitudinal study established critical points of Salmonella spp. infection in the farm and the production stages, where appropriate control measures must be taken. PFGE showed clonal relationships in each serovar. Antibiotic resistance profiles should be periodically included due to public health concerns.
Asunto(s)
Farmacorresistencia Bacteriana/genética , Salmonelosis Animal/microbiología , Salmonella enterica , Enfermedades de los Porcinos/microbiología , Envejecimiento , Crianza de Animales Domésticos/métodos , Animales , Argentina/epidemiología , Derrame de Bacterias , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Electroforesis en Gel de Campo Pulsado/veterinaria , Heces/microbiología , Femenino , Variación Genética , Estudios Longitudinales , Masculino , Filogenia , Recto/microbiología , Salmonelosis Animal/epidemiología , Salmonelosis Animal/prevención & control , Salmonella enterica/clasificación , Estudios Seroepidemiológicos , Serotipificación/veterinaria , Porcinos , Enfermedades de los Porcinos/epidemiología , Factores de TiempoRESUMEN
Clostridium difficile is a Gram-positive opportunistic anaerobic bacterium found in the soil, water as well as the digestive tract of several species of mammals. Currently in high-health herds and not related with antibiotic treatment, C. difficile has been emerged in association with neonatal catarrhal, fibrinouspurulent colitis in 2 to 7 day-old piglets. Mesocolon edema and colitis with a volcano lesion are pathological key marks of C. difficile infection. In farm 1, the prevalence of neonatal piglet mesocolon edema and colitis was evaluated in an extensive study of postmortem preweaning mortality. Lectinhistochemistry pattern of normal colon and colon with edema and colitis were analyzed in order to provide more accurate information related with pathogenesis of C.difficile infection. In farm 2, a clinical description of an outbreak of neonatal colitis in piglets due to C. difficile infection was reported. A total 820 piglets were post-mortem examined, from them, 8 cases were classified as suspected of C. difficile infection (0.1%). Age of affected piglets varied between 3 to 14 days. In all of them, the key mark was the severe mesocolon edema and 2 cases were characterized by focal necrosis and loss of epithelial cells associated with a focal infiltration of neutrophils and macrophages in the lamina propria and lumen like erupted volcano. Lectins SBA and DBA that has aff
RESUMEN
The objectives of this work were: 1) to investigate L. intracellularis antibodies in grower-finisher pigs from 30 herds by immunofluorescent antibody test (IFAT) 2) To evaluate the porcine proliferative enterophaty (PPE) lesions by histopathology, histochemistry (Warthin Starry) and immunohistochemistry (IHC) in ileum samples obtained at slaughterhouse from 10 ed herds, 9 seropositive and 1 control seronegative. At each farm, 30 grower-finisher pigs (18 to 20 weeks old pigs) were randomly ed for blood sampling. The sera were analyzed with a commercial IFAT kit (IleiTest, Elanco Animal Health). The overall percentage of positive pigs was 31.2% (281/900), whereas the percentage of positive farms was 76.7% (23/30). The within-herd mean percentage of positive sera ranged from 27.5 to 53.6%. Only 1 out of the 10 ed farms showed characteristic gross and histopathological lesions at slaughterhouse. On the other hand, 4 farms were positive by immunohistochemistry . In conclusion L. intracellularis infection is widespread among Argentinean farms even though the within-herd percentage was quite variable. Slaughter pigs without microscopic lesions showed immunoreactivity to L. intracellularis.