Casos inusuales de colibacilosis septicémica en terneros neonatos de cría para carne

Septicemic colibacillosis is a disease caused by Escherichia coli, and dairy calves are usually affected. The aim of this study was to describe cases of colibacillosis in beef calves. Two calves (cases A and B) aged 4 and 3 days, were born from heifers that suffered dystocia. The herd was grazing maize stubble and a polyphytic pasture with scarce vegetation covering the soil, because of intense rains flooded the field. The clinical signs and lesions were similar in both cases, and included depression, hypopyon, reluctance to move, dehydration, dyspnea, polyarthritis and hyperemia of scleral vessels. Both cases exhibited leukocytosis with neutrophilia, and immature forms (case A). E. coli was isolated from body fluids, liver, spleen and lung after necropsy. Moreover, the synovial fluid revealed an increased volume and fibrin clots (case A). E. coli was also recovered from the whole blood of the other calf (case B). The isolates obtained from different organs (case A) and blood (case B) were susceptible to gentamicin, ciprofloxacin and minocycline. The calf that remained alive (case B) responded favorably to a treatment for 3 days consisting of gentamicin, enrofloxacin, flunixin meglumine and oral rehydrating salts. No similar cases were observed during the calving season. The differential diagnosis of neonatal calf mortality in beef herds should include septicemic colibacillosis, mainly when risk factors mentioned above occur. La colibacilosis septicémica es causada por Escherichia coli y suele afectar a terneros de tambo. El objetivo de este trabajo fue describir casos de colibacilosis en terneros de cría para carne. Las terneras afectadas (casos A y B) tenían 4 y 3 días de vida, eran hijas de vaquillonas y nacieron por parto distócico. El rodeo estaba en un rastrojo de maíz y en una pastura polifítica con escasa cobertura vegetal del suelo, debido al anegamiento por las intensas lluvias. Los signos clínicos y lesiones fueron similares en ambos casos e incluyeron decaimiento, hipopión, dificultad para desplazarse, deshidratación, disnea, poliartritis e hiperemia de vasos esclerales. Ambos animales desarrollaron leucocitosis y neutrofilia, con formas inmaduras en el caso A, en el cual se aisló E. coli de fluidos corporales, hígado, bazo y pulmón, recolectados a la necropsia, observándose aumento del volumen de líquido sinovial, con presencia de coágulos de fibrina. En el caso B se aisló E. coli a partir de sangre entera. Los aislamientos efectuados en diferentes órganos (caso A) y sangre (caso B) fueron sensibles a gentamicina, ciprofloxacina y minociclina. La ternera del caso B respondió favorablemente al tratamiento, durante 3 días, con gentamicina, enrofloxacina, meglumina de flunixin y sales rehidratantes orales. No se volvieron a observar casos similares durante la parición. Esta enfermedad debería considerarse en el diagnóstico diferencial de mortalidad neonatal en terneros de rodeos para carne, fundamentalmente cuando ocurren los factores predisponentes mencionados

Search for the genome of bovine herpesvirus types 1, 4 and 5 in bovine semen

Bovine herpesvirus type 1 (BoHV-1) causes respiratory and reproductive disorders in cattle. Recently, bovine herpesvirus type 5 (BoHV-5) and bovine herpesvirus type 4 (BoHV-4) have been identified to be associated with genital disease. In this study, the presence of the genome of BoHV-1, BoHV-4 and BoHV-5 in bovine semen of Argentinean and international origin was analyzed by PCR assays. The most important finding of this study is the detection of the genome of BoHV-1 and BoHV-4 in semen of bulls maintained at artificial insemination centers. It is particularly relevant that BoHV-1 DNA was also identified in one sample of international origin suggesting the need for extensive quality control measures on international transport of bovine semen.Fil: Moran, P. E.. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias; ArgentinaFil: Favier, P. A.. Ministerio de Ciencia, Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica. Fondo para la Investigación Científica y Tecnológica; ArgentinaFil: Lomonaco, M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Catena, María. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias; ArgentinaFil: Chiapparrone, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias; ArgentinaFil: Odeon, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Verna, Andrea Elizabeth. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Perez, Sandra. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentin

Isolation and characterization of bovine parainfluenza virus type 3 from water buffaloes (Bubalus bulalis) in Argentina

BACKGROUND: Parainfluenza virus type 3 (PIV3) was isolated from dairy buffaloes (Bubalus bubalis) naturally affected with respiratory and reproductive clinical conditions. RESULTS: Examination of nasal and vaginal swabs collected from 12 diseased buffaloes led to the isolation of three paramyxovirus isolates from two animals. Antigenic, morphological and biological characteristics of these three isolates were essentially similar to those of members of the Paramyxoviridae family. Antigenic analysis by direct immunofluorescence and cross neutralization test placed these isolates together with bovine parainfluenza virus type 3 (BPIV3). Nucleotide and amino acid phylogenetic analysis of partial matrix gene sequences of the buffalo isolates and six field BPIV3 isolates from bovines in Argentina were studied. Buffalo isolates were similar to genotype B (BPIV3b) while the six BPIV3 isolates were similar to genotypes A (BPIV3a) and C (BPIV3c). CONCLUSIONS: This is the first characterization of BPIV3 in water buffalo. According to the samples analyzed, in Argentina, the genotype B was found in buffalo and the genotypes A and C were found in cattle

Latent infection by bovine herpesvirus type-5 in experimentally infected rabbits: virus reactivation, shedding and recrudescence of neurological disease

Abstract Latent infection with bovine herpesvirus type-5 (BHV-5) was established in rabbits inoculated with two South American isolates (EVI-88 and 613) by intranasal or conjunctival routes. Nine rabbits (613, 8/27; EVI-88, 1/34) developed neurological disease and died during acute infection and other three (613, n ¼ 2; EVI-88, n ¼ 1) developed a delayed neurological disease, at days 34, 41 and 56 post-inoculation (p.i.). Between days 56 and 62 p.i., the remaining rabbits were submitted to five daily administrations of dexamethasone (Dx) to reactivate the infection. Twenty-five out of 44 rabbits (56.8%) shed virus in nasal or ocular secretions after Dx treatment. Virus shedding was first detected at day two post-Dx and lasted from one to 11 days. The highest frequencies of virus reactivation were observed in rabbits inoculated conjunctivally (10/15 versus 15/29); and among rabbits infected with isolate 613 (12/16 versus 13/28). Virus reactivation upon Dx treatment was accompanied by neurological disease in nine rabbits (20.4%), resulting in six deaths (13.6%). Virus in moderate titers and mild to moderate non-suppurative inflammatory changes in the brain characterized the neurological infection. Three other rabbits showed severe neurological signs followed by death after 31 to 54 days of Dx treatment. Virus, viral nucleic acids and inflammatory changes were detected in their brains. The late-onset neurological disease, after acute infection or Dx treatment, was probably a consequence of spontaneous virus reactivation. These results demonstrate that BHV-5 does establish a latent infection in rabbits and that clinical recrudescence may occur upon reactivation.

A descriptive Study of lectin histochemistry of the placenta in cattle following inoculation of Neospora caninum.

The aim of this study was to describe the lectin-binding pattern in the placentas of cows infected experimentally with Neospora caninum. Four cows were inoculated intravenously with 1 × 108 tachyzoites of the NC-1 strain of N. caninum at 150 ± 7 days of pregnancy. Two control cows were administered a placebo. An indirect fluorescence antibody test (IFAT) was performed on serum samples obtained before and after the inoculation. The cows were killed at 30 and 37 days post inoculation. Samples of placenta were taken for histopathology and lectin histochemistry. Fetal tissues and fluids were collected for histopathology and IFAT, respectively. All infected cows had high antibody titres. All fetuses had characteristic histopathological lesions, including non-suppurative meningoencephalitis, myocarditis, hepatitis and myositis, suggesting N. caninum infection. Only two infected fetuses developed specific antibodies. Mild non-suppurative inflammatory infiltrates were recorded in the placentae. Differences in the lectin-binding pattern were observed between infected animals and controls in the glycocalyx (CON-A and WGA) and apical cytoplasm (RCA-I and CON-A) of the trophoblastic cells; giant trophoblastic cells (CON-A and DBA); glycocalyx (PNA, WGA) and apical cytoplasm (CON-A, WGA, PNA, DBA and RCA-I) of endometrial cells; trophoblast of the interplacentomal region (WGA); endothelium (CON-A, SBA, RCA-1 and WGA); and finally, mesenchyme (CON-A, RCA-1, SBA, PNA and DBA). These findings indicate that there is a distinctive pattern of lectin binding in the placenta of cattle infected with N. caninum. The direct effect of the presence of the protozoa as well as the altered expression of cytokines could explain these changes in the maternofetal interface.EEA BalcarceFil: Dorsch, Matias A. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: de Yañiz, María Guadalupe. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina.Fil: Fiorani, Franco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Barbeito, Claudio G. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Moore, Dadín Prando. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina