Swine influenza: clinical, serological, pathological, and virological cross-sectional studies in nine farms in Argentina

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.Facultad de Ciencias Veterinaria

Canine alopecic diseases with adnexal involvement. Retrospective study (1998-2007)

Los trastornos dermatológicos en los caninos constituyen un alto porcentaje de consulta por parte de los propietarios. La alopecía de distintos orígenes, acompañada o no de otros signos, se convierte, muchas veces, en un desafío de diagnóstico para el clínico. Las enfermedades que involucran a los anexos pueden presentar signos similares. El estudio histopatológico de la piel constituye un método complementario de diagnóstico de suma utilidad en la caracterización de este tipo de procesos dermatológicos. La alopecía se define como la pérdida de pelo y puede variar de parcial a completa. Puede ser primaria, como la alopecía de los trastornos endocrinos o las displasias foliculares, o secundaria a traumatismos o inflamación. El prurito puede o no estar presente. El objetivo de este trabajo fue presentar datos sobre las enfermedades alopécicas con compromiso de los anexos en caninos, diagnosticados en el Servicio de Anatomía Patológica de la Cátedra de Patología Especial de la FCV de UNLP entre los años 1998 y 2007.Facultad de Ciencias Veterinaria

Galactomannan as a potential modulator of intestinal ischemia–reperfusion injury

Background: Galactomannan (GAL), a polysaccharide present on the cell wall of several fungi, has shown an ability to modulate inflammatory responses through the dectin-1 receptor in human macrophages. However, studies evaluating the modulatory properties of this polysaccharide in in vivo inflammatory scenarios are scarce. We hypothesized that GAL pretreatment would modulate local and remote damage related to intestinal reperfusion after an ischemic insult. Materials and methods: Adult male Balb/c mice were subjected to intestinal ischemia–reperfusion injury by reversible occlusion of the superior mesenteric artery, consisting of 45 min of ischemia followed by 3 or 24 h of reperfusion. Intragastric GAL (70 mg/kg) was administered 12 h before ischemia, and saline solution was used in the control animals. Jejunum, lung, and blood samples were taken for the analysis of histology, gene expression, plasma cytokine levels, and nitrosative stress. Results: Intestinal and lung histologic alterations were attenuated by GAL pretreatment, showing significant differences compared with nontreated animals. Interleukin 1β, monocyte chemoattractant protein 1, and IL-6 messenger RNA expression were considerably downregulated in the small intestine of the GAL group. In addition, GAL treatment significantly prevented plasma interleukin 6 and monocyte chemoattractant protein 1 upregulation and diminished nitrate and nitrite levels after 3 h of intestinal reperfusion. Conclusions: GAL pretreatment constitutes a novel and promising therapy to reduce local and remote damage triggered by intestinal ischemia–reperfusion injury. Further in vivo and in vitro studies to understand GAL's modulatory effects are warranted.Fil: Stringa, Pablo. Hospital Universitario la Paz; EspañaFil: Toledano, Victor. Hospital Universitario la Paz; EspañaFil: Papa Gobbi, Rodrigo. Hospital Universitario la Paz; EspañaFil: Arreola, Miguel. Hospital Universitario la Paz; EspañaFil: Largo, Carlota. Hospital Universitario la Paz; EspañaFil: Machuca, Mariana. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Aguirre, Luis A.. Hospital Universitario la Paz; EspañaFil: Rumbo, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: López Collazo, Eduardo. Hospital Universitario la Paz; EspañaFil: Hernández Oliveros, Francisco. Hospital Universitario la Paz; Españ

Hemagglutinating Encephalomyelitis Coronavirus Infection in Pigs, Argentina

We describe an outbreak of vomiting, wasting, and encephalomyelitis syndrome in piglets in Argentina, caused by porcine hemagglutinating encephalomyelitis coronavirus (PHE-CoV) infection. Diagnosis was made by epidemiologic factors, pathologic features, immunohistochemistry, reverse transcription–PCR, and genomic sequencing. This study documents PHE-CoV infection in South America

Comparison between inmunohistochemestry and PCR for porcine circo virus type 2 detection in linfonodes

El síndrome multisistémico de adelgazamiento postdestete (SMAP) se caracteriza clínicamente por adelgazamiento progresivo, linfoadenomegalia, diarrea, disnea, palidez cutánea e ictericia. La presencia de circovirus porcino tipo 2 (PCV-2) es uno de los factores determinantes para la presentación de SMAP. Las lesiones macroscópicas son agrandamiento de linfonódulos, focos blancos en riñón, hepatomegalia, ulcera gástrica, consolidación pulmonar con edema interlobulillar. Las lesiones microscópicas características son depleción en tejido linfoide e infiltración granulomatosa, nefritis intersticial y neumonía.Facultad de Ciencias Veterinaria

Porcine dermatitis and nephropathy syndrome: a review on epidemiology, pathology and etiology

El síndrome de dermatitis y nefropatía porcino (SDNP) es una entidad exclusiva de los cerdos que afecta, en general, a animales de desarrollo y engorde. Su presentación suele ser esporádica con una prevalencia en las granjas afectadas menor al 1% y una letalidad entre el 50 y 100% que varia según la edad. Se caracteriza por la aparición súbita de lesiones multifocales rojo-violáceas en piel y riñones pálidos que se cubren de hemorragias petequiales. La lesión microscópica típica consiste en una vasculitis generalizada y glomérulonefritis sugestivas de una reacción de hipersensibilidad tipo III, mediada por inmunocomplejos. Si bien su etiología no es conocida, distintos trabajos asocian al SDNP con la infección por circovirus porcino tipo 2 (PCV-2) basados en ciertas evidencias epidemiológicas, las características de algunas de las lesiones microscópicas y, aún cuando inconstante, la detección de antígeno y/o ácido nucleico de PCV-2 en tejidos de animales enfermos. En el presente trabajo se describen las principales características de la enfermedad desde el punto de vista de su epidemiología, patología y etiología, incluyendo datos sobre la situación en la Argentina.Porcine dermatitis and nephropathy syndrome (PDNS) is a disease that affects growing and finishing pigs characterized by a sporadic presentation, prevalence lower than 1 % and variable lethality. PDNS affected pigs shows acute multifocal red-to-purple skin lesions and enlarged tan kidneys with petechial hemorrhages. The hallmark microscopic lesions of PDNS are a generalized vasculitis and glomerulonephritis that suggest a type III hypersensitivity reaction. Although the etiology remains unknown, different works have showed the association between porcine circovirus type 2 (PCV-2) and PDNS based on epidemiological evidences, microscopic lesions and, the inconstant detection of PCV-2 antigen and / or nucleic acid in affected tissues. In this article the main characteristics of the disease from an epidemiological, pathological and etiological standpoint are described. Information about national situation is also included.Facultad de Ciencias Veterinaria

Salmonella enterica Subclinical Infection: Bacteriological, Serological, Pulsed-Field Gel Electrophoresis, and Antimicrobial Resistance Profiles-Longitudinal Study in a Three-Site Farrow-to-Finish Farm

Fil: Vigo, German B. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Cappuccio, J. A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Pineyro, Pablo E. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Salve, Angela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Machuca, Mariana A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Quiroga, Maria A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Moredo, Fabiana. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Giacoboni, Gabriel. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Cancer, Jose L. Private practitioner; Argentina.Fil: Caffer, María Ines. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Binsztein, Norma. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Pichel, Mariana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Perfumo, Carlos J. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.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 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

Salmonella enterica Subclinical Infection: Bacteriological, Serological, Pulsed-Field Gel Electrophoresis, and Antimicrobial Resistance Profiles-Longitudinal Study in a Three-Site Farrow-to-Finish Farm

Fil: Vigo, German B. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Cappuccio, J. A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Pineyro, Pablo E. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Salve, Angela. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Machuca, Mariana A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Quiroga, Maria A. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.Fil: Moredo, Fabiana. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Giacoboni, Gabriel. Universidad Nacional de La Plata. Laboratorio de Diagnóstico e Investigaciones Bacteriológicas; Argentina.Fil: Cancer, Jose L. Private practitioner; Argentina.Fil: Caffer, María Ines. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Binsztein, Norma. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Pichel, Mariana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología; Argentina.Fil: Perfumo, Carlos J. Universidad Nacional de La Plata. Cátedra de Patología Especial; Argentina.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 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

Outbreak of swine influenza in Argentina reveals a non-contemporary human H3N2 virus highly transmissible among pigs

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 96-98% with H3N2 IAVs that circulated in humans from 2000 to 2003. Antigenically, sera from experimentally inoculated animals cross-reacted mainly with noncontemporary 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.Facultad de Ciencias Veterinaria

Outbreak of swine influenza in Argentina reveals a non-contemporary human H3N2 virus highly transmissible among pigs

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 96-98% with H3N2 IAVs that circulated in humans from 2000 to 2003. Antigenically, sera from experimentally inoculated animals cross-reacted mainly with noncontemporary 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.Facultad de Ciencias Veterinaria