RESUMEN
Numerous, ongoing outbreaks in Brazilian swine herds have been characterized by vesicular lesions in sows and acute losses of neonatal piglets. The complete genome of Seneca Valley virus (SVV) was identified in vesicular fluid and sera of sows, providing evidence of association between SVV and vesicular disease and viraemia in affected animals.
Asunto(s)
Brotes de Enfermedades/veterinaria , Genoma Viral , Infecciones por Picornaviridae/veterinaria , Picornaviridae/genética , Enfermedades de los Porcinos/virología , Animales , Brasil/epidemiología , Femenino , Datos de Secuencia Molecular , Filogenia , Picornaviridae/clasificación , Infecciones por Picornaviridae/genética , ARN Viral/análisis , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/epidemiologíaRESUMEN
Antimicrobial efficacy against Lawsonia intracellularis is difficult to evaluate in vitro, thus, the effects of gallium maltolate's (GaM) were investigated in a rabbit model for equine proliferative enteropathy (EPE). Juvenile (5-6-week-old) does were infected with 3.0 × 10(8) L. intracellularis/rabbit and allocated into three groups (n = 8). One week postinfection, one group was treated with GaM, 50 mg/kg; one, with doxycycline, 5 mg/kg; and one with a sham-treatment (control). Feces and blood were collected daily and weekly, respectively, to verify presence of L. intracellularis fecal shedding using qPCR, and seroconversion using immunoperoxidase monolayer assay. Rabbits were sacrificed after 1 week of treatment to collect intestinal tissues focusing on EPE-affected sections. Intestinal lesions were confirmed via immunohistochemistry. No difference was noted between treatments regarding EPE-lesions in jejunum (P = 0.51), ileum (P = 0.74), and cecum (P = 0.35), or in L. intracellularis fecal shedding (P = 0.64). GaM and doxycycline appear to have similar efficacy against EPE in infected rabbits.
Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Desulfovibrionaceae/veterinaria , Lawsonia (Bacteria)/efectos de los fármacos , Compuestos Organometálicos/uso terapéutico , Pironas/uso terapéutico , Animales , Infecciones por Desulfovibrionaceae/tratamiento farmacológico , Infecciones por Desulfovibrionaceae/microbiología , Infecciones por Desulfovibrionaceae/patología , Modelos Animales de Enfermedad , Femenino , Conejos , Resultado del TratamientoRESUMEN
Oral gallium maltolate (GaM) pharmacokinetics (PK) and intestinal tissue (IT) concentrations of elemental gallium ([Ga]) and iron ([Fe]) were investigated in a rabbit model of equine proliferative enteropathy (EPE). New Zealand white does (uninfected controls and EPE-infected, n = 6/group) were given a single oral GaM dose (50 mg/kg). Serial blood samples were collected from 0 to 216 h post-treatment (PT) and IT samples after euthanasia. Serology, qPCR, and immunohistochemistry confirmed, or excluded, EPE. Blood and IT [Ga] and [Fe] were determined using inductively coupled plasma-mass spectrometry. PK parameters were estimated through noncompartmental approaches. For all statistical comparisons on [Ga] and [Fe] α = 5%. The Ga log-linear terminal phase rate constant was lower in EPE rabbits vs. uninfected controls [0.0116 ± 0.004 (SD) vs. 0.0171 ± 0.0028 per hour; P = 0.03]; but half-life (59.4 ± 24.0 vs. 39.4 ± 10.8 h; P = 0.12); Cmax (0.50 ± 0.21 vs. 0.59 ± 0.42 µg/mL; P = 0.45); tmax (1.75 ± 0.41 vs. 0.9 ± 0.37 h; P = 0.20); and oral clearance (6.743 ± 1.887 vs. 7.208 ± 2.565 L/h; P = 0.74) were not. IT's [Ga] and [Fe] were higher (P < 0.0001) in controls. In conclusion, although infection reduces IT [Ga] and [Fe], a 48 h GaM dosing interval is appropriate for multidose studies in EPE rabbits.
Asunto(s)
Antibacterianos/farmacocinética , Antibacterianos/uso terapéutico , Infecciones por Desulfovibrionaceae/microbiología , Lawsonia (Bacteria) , Compuestos Organometálicos/farmacocinética , Compuestos Organometálicos/uso terapéutico , Pironas/farmacocinética , Pironas/uso terapéutico , Animales , Infecciones por Desulfovibrionaceae/tratamiento farmacológico , Femenino , Semivida , ConejosRESUMEN
Proliferative enteropathy is an infectious disease caused by an obligate intracellular bacterium, Lawsonia intracellularis, and characterized by thickening of the intestinal epithelium due to enterocyte proliferation. The disease is endemic in swine herds and has been occasionally reported in various other species. Furthermore, outbreaks among foals began to be reported on breeding farms worldwide within the past 5 years. Cell proliferation is directly associated with bacterial infection and replication in the intestinal epithelium. As a result, mild to severe diarrhea is the major clinical sign described in infected animals. The dynamics of L. intracellularis infection in vitro and in vivo have been well characterized, but little is known about the genetic basis for the pathogenesis or ecology of this organism. The present review focuses on the recent advances regarding the pathogenesis and host-pathogen interaction of L. intracellularis infections.
Asunto(s)
Infecciones por Desulfovibrionaceae/veterinaria , Genoma Bacteriano/genética , Enfermedades de los Caballos/patología , Interacciones Huésped-Patógeno , Lawsonia (Bacteria)/patogenicidad , Enfermedades de los Porcinos/patología , Animales , Proliferación Celular , Infecciones por Desulfovibrionaceae/inmunología , Infecciones por Desulfovibrionaceae/microbiología , Infecciones por Desulfovibrionaceae/patología , Brotes de Enfermedades , Enterocitos , Enfermedades de los Caballos/inmunología , Enfermedades de los Caballos/microbiología , Caballos , Lawsonia (Bacteria)/genética , Lawsonia (Bacteria)/fisiología , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/microbiologíaRESUMEN
The aim of this study was to investigate whether feces from rabbits experimentally infected with Lawsonia intracellularis were infectious to foals. Two rabbits were infected with L. intracellularis, while two rabbits served as controls. Eight foals received daily feces from either the infected or the control rabbits. All rabbits and foals were monitored daily for clinical signs for the entire study period (21days for rabbits, 42days for foals). Feces and blood were collected for the PCR detection of L. intracellularis and serologic analysis, respectively. None of the infected rabbits or foals developed clinical signs compatible with proliferative enteropathy. All infected rabbits and foals shed L. intracellularis in their feces and all seroconverted. The results support the role of rabbits as asymptomatic amplifiers of L. intracellularis and their role as sources of infection for susceptible foals.