Genotypic characterization of toxigenic Escherichia coli isolated from pigs with postweaning diarrhea (PWD) and edema disease (ED)

El objetivo del trabajo fue caracterizar mediante PCR 47 aislamientos de Escherichia 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 estI/estII/fedA. El genotipo más complejo fue eltA/estII/east1/faeG/aidA. Los aislamientos provenientes de cerdos con ED se clasificaron como STEC porcinos y fueron portadores de stx2e aidA. 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 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/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.Fil: Moredo, Fabiana Alicia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Cappuccio, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Insarralde, Lucas. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Perfumo, Carlos Juan. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Quiroga, María A.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

Diarrea en lechones lactantes y posdestete de cuatro criaderos intensivos de la provincia de Buenos Aires, Argentina: identificación e índice de detección de partículas virales en materia fecal por microscopía electrónica

The aim of this pilot study was to identify and to determine the detection rate of viral particles in faecal specimens recovered from suckling and postweaning piglets with diarrhoea from 4 pigherds situated in Buenos Aires Province, Argentina. We used the negative staining for electron microscopy (NSEM) technique, which has been applied for decades because of its simplicity, rapidness and sensitivity. One hundred and forty six samples were collected during one year from suckling (50) and postweaning (96) young pigs. Viral particles were identified in 58% and 53.1% of the suckling and postweaning faecal samples, respectively. Rotavirus-like, coronavirus-like, adenovirus- like, parvovirus-like and small round viruses (SRV) were detected in 32% and 34.4%, 18% and 16.7%, 10% and 9.4%, 4% and 3.1% and, 2% and 1% of suckling and postweaning faecal samples, respectively. Viral combinations were observed in 8% and 10.4% of suckling and postweaning samples, respectively. Rotavirus-like and coronavirus-like particles was the most frequent combination in both categories. The present study identified the presence of several viruses known to be linked to diarrhoea in young pigs. Apart from rotavirus, the detected viruses had never been reported previously in Argentina. The NSEM technique demonstrated to be adequate as a screening test to identify viral particles in faecal specimens. However, more specific tests are needed to confirm the presence of these viruses and also to determine the group or variant of the identified viruses.El presente estudio preliminar tuvo como objetivo identificar y determinar el índice de detección de partículas virales en heces diarreicas de lechones de 4 establecimientos intensivos de la Provincia de Buenos Aires, Argentina, empleando la técnica de tinción negativa en microscopía electrónica (TNME). Esta técnica ha venido empleándose durante décadas por su rapidez, sencillez y sensibilidad. Se estudiaron un total de 146 muestras pertenecientes a lechones lactantes (50) y a lechones posdestete (96), detectándose partículas virales en un 58% y en un 53,1% de las heces, respectivamente. Se identificaron partículas virales compatibles con rotavirus, coronavirus, adenovirus, parvovirus y pequeños virus redondos en 32% y 34,4%, 18% y 16,7%, 10% y 9,4%, 4 y 3,1% y 2 y 1% de las muestras de lechones lactantes y posdestete, respectivamente. Se observaron combinaciones virales en un 8% y en un 10,4% de las muestras, respectivamente. En ambas categorías, la combinación más frecuente fue de partículas compatibles con rotavirus y coronavirus. El presente estudio permitió la identificación de diversos géneros de virus considerados agentes causales de diarrea en lechones y que, a excepción de rotavirus, no habían sido previamente descriptos en nuestro país. La técnica de TNME demuestra ser un método adecuado como prueba tamiz para identificar partículas virales en materia fecal; sin embargo, necesita de otras pruebas de mayor especificidad para confirmar los resultados obtenidos y también para determinar a qué grupo o variante pertenecen los virus identificados

Directed microbial biosynthesis of deuterated biosurfactants and potential future application to other bioactive molecules

Deuterated rhamnolipids were produced using strain AD7 of Pseudomonas aeruginosa, which was progressively adapted to increasing levels of deuterium in D2O and carbon substrates. Fourteen different deuterated rhamnolipid structures, including structural isomers, were produced which is similar to normal protonated structures. There were two main products monorhamnolipid Rha-C-10-C-10 and dirhamnolipid Rha(2)-C-10-C-10. The levels of deuteration varied from 16% with 25% D2O + h-glycerol to 90% with 100% D2O + d-glycerol. When d-tetradecane was used with H2O, virtually all the deuterium appeared in the lipid chains while using h-tetradecane + D2O led to the majority of deuterium in the sugars. The adaptation to growth in deuterium appeared to be metabolic since no genetic changes could be found in the key rhamnolipid biosynthetic genes, the rhamnosyl transferases RhlB and RhlC. Deuterated sophorolipids were similarly produced using Candida bombicola and Candida apicola although in this case, no adaptation process was necessary. Up to 40 different sophorolipids were produced by these yeasts. However, unlike the rhamnolipids, use of D2O did not lead to any deuteration of the lipid chains, but direct incorporation into the lipid was achieved using d-isostearic acid. The results from these experiments show the feasibility of producing deuterated bioactive compounds from microorganisms coupled with the possibility of manipulating the pattern of labelling through judicious use of different deuterated substrates

Biosecurity assessment of Argentinian pig farms

The pig industry is growing very fast in Argentina with an increasing need for replacement animals, feedstuff and transportation of animals. One of the main competitive advantages of the Argentinian pig industry is its being free of most major pig diseases. Within this context, applying measures aimed to reduce the risk of introduction and spread of pathogens is critical. The aim of the present study was to assess the biosecurity of Argentinian pig farms. Two types of farms were assessed: firstly, all official suppliers of high-genetic-value (n = 110) and secondly, a sample from commercial farms (n = 192). Data on the external and internal biosecurity practices applied on the farms was collected with a questionnaire. Data was analysed using a correspondence analysis and a hierarchical clustering analysis, which allowed identification of types of farms with regard to the biosecurity measures applied. Key variables characterizing the clusters were identified through an indicator value analysis. In addition, the external biosecurity of the farms was evaluated by using risk assessment tools with respect to the potential introduction of porcine epidemic diarrhoea virus. Results made evident three clusters: the first one which, amongst other measures, applied several barriers to prevent the entry of people, trucks and other vehicles, and could be considered as a group of high biosecurity, and the two other groups which applied a lower number of external and internal biosecurity measures. The results of the risk assessment showed that the routes with the highest risk of disease introduction were: replacement animals, vehicles transporting feed or animals, and visitors. The assessment of the external biosecurity showed that most Argentinian farms were not prepared for the contingency of a pathogen such as porcine epidemic diarrhoea virus. Special efforts should be made in official suppliers of high-genetic-value farms with poor biosecurity scores since they are at the top of the pig production chain and can be key for the spread of diseases.info:eu-repo/semantics/acceptedVersio

Toxoplasmosis in domestic rabbit

Se describe un brote de Toxoplasmosis en conejos domésticos, desde el punto de vista clínico y anatomopatológicos macro y microscópico, el diagnóstico se realizó exclusivamente en base al estudio histopatológico. Se relatan las formas de presentación en otras especies domésticas, ciclo evolutivo y epidemiología del parásito y los antecedentes en veterinaria en nuestro país.An outbreak of Toxoplasmosis in domestic rabbits is described clinically and anatomopathologically.Diagnosis was performed under hlstologlc studies carried out with hematoxylin and eosin stains and other special techniques. Its occurrence in other domestic animals, biological cycle and epidemiology are also described as well as the antecedents in veterinary in our country.Facultad de Ciencias Veterinaria

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