The objective of the study was to determine Mycoplasma hyopneumoniae infection and the presence of swine enzootic pneumonia (SEP) in pigs of herds from Mendoza province. In each of five herds, 18 to 20-week-old pigs were observed looking for non-productive cough and 20 of these pigs were sampled for PCR (nasal swab). The pigs were slaughtered at abattoir, where their lungs were inspected looking for SEP-compatible macroscopic lesions. Prevalence of lung lesions, percentage of affected area, and pneumonia index were calculated. In addition, 20 lung samples were collected for histopathology and bronchoalveolar lavage (BAL) for PCR. The presence of the agent in BAL samples (20% - 90%) was observed in all herds, as well as a high percentage of macroscopic (57% - 97%) and microscopic (10% - 40%) lung SEP-compatible lesions and non-productive cough (6% - 25%). The results obtained in the present study would indicate that more than half of 50- 500 sow herds in Mendoza province are infected with M. hyopneumoniae and that the impact of the NEP is important in these herds.

El objetivo del trabajo fue determinar la infección por Mycoplasma hyopneumoniae y la presencia de neumonía enzoótica porcina (NEP) en cerdos de granjas porcinas de la provincia de Mendoza. En cada una de cinco granjas, cerdos de 18-20 semanas de edad fueron observados en busca de tos no productiva y 20 de ellos muestreados para PCR (hisopado nasal). Los cerdos fueron faenados en frigorífico, donde se inspeccionaron sus pulmones en busca de lesiones macroscópicas compatibles con NEP y se calculó la prevalencia de lesiones, el área pulmonar afectada y el índice de neumonía. Además se tomó de 20 animales muestra de lesión para histopatología y de lavado broncoalveolar (LBA) para PCR. Se observó la presencia del agente en muestras de LBA (20% - 90%) en todas las granjas, así como también un alto porcentaje de lesiones pulmonares macroscópicas (57% - 97%) y microscópicas (10% - 40%) compatibles con NEP y tos no productiva (6% - 25%). Los resultados obtenidos indicarían que más de la mitad de las piaras de entre 50 y 500 madres de la provincia de Mendoza están infectadas con M. hyopneumoniae y que el impacto de la NEP es importante en estas piaras.

It is important to identify distinct Mycoplasma hyopneumoniae genotypes to improve the study and understanding of some epidemiological aspects of the disease it produces. MLVA (Multiple-Locus Variable-number tandem-repeats Analysis) methodology would be the most adequate for typing this pathogen from clinical samples. The objective of the present study was to design nested PCR assays for VNTR (Variable Number of Tandem Repeats) loci P97, H4, and H5 with the aim to obtain a high analytical sensitivity. To evaluate them, DNA samples positive for M. hyopneumoniae were analyzed by the nested PCR assays in parallel to conventional PCR assays, and the proportion of positive results with each approach were compared. Taking into account the higher sensitivity of the PCR assays developed in this study, it was concluded that the recommended approach to type M. hyopneumoniae from clinical samples - even when they contain a low load of the agent- is to perform nested PCR assays for these loci, along with the other one previously informed for P146.

Identificar distintos genotipos de Mycoplasma hyopneumoniae es importante para estudiar y entender mejor algunos aspectos epidemiológicos de la enfermedad que éste produce. La metodología de MLVA (Multiple-Locus Variable-number tandem-repeats Analysis) sería la más adecuada para la tipificación del patógeno a partir de muestras clínicas. El objetivo del presente trabajo fue diseñar PCR anidadas para los loci VNTR (Variable Number of Tandem Repeats) P97, H4 y H5 con la finalidad de obtener pruebas de mayor sensibilidad analítica. Para evaluarlas se analizaron muestras de ADN positivas para M. hyopneumoniae en paralelo con una PCR convencional para cada locus y se compararon las proporciones de positivos con cada formato. Dada la mayor sensibilidad de las reacciones desarrolladas en el presente estudio, se recomienda utilizar reacciones anidadas de estos loci para la tipificación de M. hyopneumoniae en muestras clínicas, y realizarlas en conjunto con la PCR anidada para el locus P146 previamente informada

Control of swine enzootic pneumonia (EP), a disease caused by Mycoplasma hyopneumoniae, is mainly through vaccination. Three herds with different vaccination schedules against this agent were studied in order to determine the infection dynamics. A group of 250 pigs from each herd were followed over time from weaning to slaughter, measuring daily weight gain and percentage of cough (at the end of weaning and finishing stages). Thirty pigs were sampled from each group at 9, 15 and 23 weeks of age to determine the percentage of seropositives. In addition, 30 pigs from the different groups were sacrificed at 6 and 12 weeks of age, respectively, to detect the presence of the agent by PCR in nasal swab (NS) and broncho-alveolar lavage (BAL) samples and for macroscopic and microscopic lung lesions evaluation. In each group, the lungs of the remaining animals were inspected at slaughter for the same purpose. Lung affected area and proportion of PCR positives were significantly higher (p <0.05) at slaughter. Proportion of PCR positives was significantly higher (p <0.05) in BAL vs HN samples. Different serological profiles were found on each herd. It was concluded that the dynamics of infection in each farm should be evaluated before M. hyopneumoniae vaccination.

Una de las maneras de controlar la Neumonía enzoótica porcina (NEP), enfermedad causada por Mycoplasma hyopneumoniae, es la vacunación. Se trabajó en 3 granjas similares con distintos esquemas de vacunación contra NEP con el objetivo de analizar la dinámica de la infección. Un grupo de 250 cerdos de cada granja fueron seguidos en el tiempo desde el destete hasta el frigorífico midiendo ganancia diaria de peso y porcentaje de tos (al final de las etapas de recría y terminación). De cada grupo fueron muestreados 30 cerdos a las 9, 15 y 23 semanas de edad para determinar el porcentaje de seropositivos. Además, de esos grupos, 30 cerdos fueron sacrificados a las 6 y 12 semanas de edad, respectivamente, para determinar la presencia del agente mediante PCR en muestras de hisopado nasal (HN) y lavado bronquio-alveolar (LBA) y para la evaluación de lesiones pulmonares macroscópicas y microscópicas. De cada grupo, los pulmones de los animales remanentes fueron inspeccionados en frigorífico con el mismo fin. El área pulmonar afectada y la proporción de PCR positivos fue significativamente mayor (p<0,05) en el muestreo de frigorífico respecto a los otros muestreos. La proporción de PCR positivos fue significativamente mayor (p<0,05) en muestras de LBA vs HN. Se encontraron distintos perfiles serológicos en cada granja. Se concluyó que la dinámica de infección en cada granja debería ser evaluada antes de vacunar.

Mycoplasma bovis is the most important cause of mycoplasmal mastitis in dairy cows and has been diagnosed in our country and worldwide. MLVA analysis seems to be a suitable tool to type this pathogen, for epidemiological studies of outbreaks. In the present work, 7 strains of M. bovis were analyzed. They had been obtained from 2 different herds (milk samples from bulk tank milk and mammary quarters of cows with and without mastitis´s clinical signs) and had been previously identified. Four tandem repeat regions (TR) were studied. Among the TR loci studied, variability was found in only one of them (TR52), in which 2 possible alleles were observed in samples from cows with clinical mastitis. According to the author´s knowledge this is the first report of the use of MLVA for the genetic subtyping of M. bovis strains in Argentina.

Mycoplasma bovis es el mycoplasma causante de mastitis más importante en vacas lecheras y ha sido diagnosticado en nuestro país así como a nivel mundial. Para realizar estudios epidemiológicos de brotes, el análisis por MLVA parece ser una herramienta adecuada para la tipificación genética del patógeno. En el presente trabajo se analizaron 7 cepas de M. bovis provenientes de 2 tambos distintos (muestras de leche de tanque de enfriado, y cuartos mamarios de vacas con y sin signos de mastitis) que habían sido previamente identificadas. Se estudiaron por PCR 4 regiones que comprenden secuencias repetidas en tándem (TR). Dentro de los loci TR analizados, sólo se encontró variabilidad en TR 52, en el cual se observaron 2 posibles alelos en muestras que provenían de vacas con mastitis clínica. Según el conocimiento de los autores es la primera vez que se informa la utilización del análisis MLVA para detectar subtipos genéticos entre cepas de M. bovis en Argentina

Mycoplasma hyopneumoniae is the etiological agent of porcine enzootic pneumonia (EP), one of the respiratory diseases with higher impact on the swine industry. Knowledge of M. hyopneumoniae genetic diversity is useful for epidemiological and pathogenesis studies to develop effective control strategies. In this work, 39 DNA samples from nasal swabs and bronchial lavages, that previously rendered positive for this pathogen by nPCR, were analyzed. They corresponded to pigs of different ages, belonging to seven farms. For M. hyopneumoniae typing using DNA from nasal swabs, a nPCR assay was developed to amplify the region coding for the serine tandem repeat domain of p146 gene. For samples from bronchial lavages, the same region was amplified by PCR, along with other VNTRs (variable number tandem repeats) from other loci. With this approach, that proved to be useful for the direct analysis of clinical samples without prior isolation of the pathogen, the genetic diversity of M. hyopneumoniae strains circulating in our country could be evidenced. Different genotypes were found among farms and also among animals from a same farm, but there were also animals (from a different or a same farm) that harbored a same M. hyopneumoniae genotype.

El Mycoplasma hyopneumoniae es el agente causal de la neumonía enzoótica porcina (NEP), una de las enfermedades respiratorias de mayor impacto en la industria porcina. Conocer su diversidad genética permite el desarrollo de estudios epidemiológicos y de patogénesis para desarrollar estrategias de control más efectivas. En este trabajo se analizaron 39 muestras de ADN de hisopado nasal y lavado bronquial de cerdos de distintas edades, provenientes de siete orígenes diferentes, que habían sido positivas a la detección de M. hyopneumoniae por nPCR. Para tipificar este patógeno en las muestras provenientes de hisopados nasales, se diseñó una nPCR que amplifica en el gen p146 una región que codifica serinas repetidas en tándem. Para las muestras de lavados bronquiales, se amplificó esa región mediante PCR, así como también otros VNTRs (variable number tandem repeats), localizados en otros genes. Las metodologías empleadas, que permiten el análisis a partir de muestras clínicas sin el aislamiento previo del patógeno, determinaron que existe diversidad genética entre las cepas de M. hyopneumoniae que se encuentran en nuestro país. Se detectaron diferentes genotipos de este patógeno tanto entre granjas como entre animales de un mismo establecimiento, así como genotipos compartidos entre diferentes granjas o animales.

The aim of this study was to determine the colonization and serologic state of piglets and sows of different ordinal number of farrowings. Between 78 and 81 sows, multiple-vaccinated against Mycoplasma hyopneumoniae (Mh), were sampled (from 1st to 9th parity) at day 0 of gestation, 8 weeks of pre-farrowing and post-farrowing, and 163 piglets at two weeks old, taking blood samples (for enzime-linked immunosorbent assay test, ELISA) and nasal swabs (for polymerase chain reaction, PCR). In addition to the percentages of seropositive and PCR positive, other values were obtained to determine the concentration of antibodies and to analyze the dynamics of antibodies in sows and piglets. The percentage of seropositive sows and title values were both high. The same was observed in piglets, allowing to conclude that the multiple vaccinations of the first ones guarantees a high level of antibodies in their offspring, but not 100%. The sows of intermediate parity number showed a higher variability in those values that reflected concentration of antibodies; at day zero of gestation the sows of first farrowing showed these lower values. At post-farrowing, younger sows and their offspring showed the highest percentage of nPCR positive. Sows (and piglets) showed a higher concentration of antibodies when increasing the number of ordinal farrows, although this can be due to vaccination and the repeated exposure of the animals to Mh under field conditions.

Para determinar el estado de colonización y el estado serológico de lechones y de cerdas de diferente número ordinal de partos, entre 78 y 81 hembras vacunadas de manera múltiple contra Mycoplasma hyopneumoniae (Mh) fueron muestreadas (de 1er a 9no parto) al día 0 de gestación, a las 8 semanas de preparto y al postparto y 163 lechones a las dos semanas de edad, tomando muestras de sangre (para enzimoinmuno ensayo, ELISA) e hisopados nasales (para reacción en cadena de polimerasa, PCR). Además de los porcentajes de seropositivos y PCR positivos, se calcularon otros valores para determinar la concentración de anticuerpos y así analizar la dinámica de los anticuerpos en hembras y lechones. El porcentaje de cerdas seropositivas fue alto, al igual que los valores de título. Lo mismo se observó en los lechones, por lo que se concluyó que la múltiple vacunación de las primeras garantiza un alto nivel de anticuerpos en sus crías, aunque no es del 100%. Las cerdas de intermedio número de partos presentaron una mayor variabilidad en aquellos valores que reflejan la concentración de anticuerpos; siendo al día cero de gestación las hembras de primer parto las que mostraron estos valores más bajos. Al postparto las hembras más jóvenes y su descendencia mostraron los mayores porcentajes de nPCR positivos. Si bien las cerdas (y los lechones), al aumentar el número ordinal de partos, presentaron una mayor concentración de anticuerpos, esto puede deberse tanto a la vacunación como a la exposición repetida de los animales al Mh en condiciones de campo.

The diagnosis of tuberculosis in live animals is carried out using primarily by the tuberculin test (TT), however only few reports only show the results of this diagnostic test in swine. The objective of this study was to compare the TT with pathological and microbiological findings in swine. A total of 307 sows were injected with avium PPD and bovine PPD following the standard technique. Tissues samples for bacteriological tests and histological exams were collected from 171 animals after slaughter. The following results were obtained: 14.4% (44) tested positive to avium PPD, 1.9% (6) to bovine PPD, 3.9% (12) to both PPD and 79.8% (245) were negatives. Only 4 samples were culture positives typified by Mycobacterium bovis, M. avium, M. fl avescens y M. scrofulaceum. Neither macroscopic nor histological examinations revealed lesions compatible with TB.

El diagnóstico de tuberculosis en animales vivos se realiza casi exclusivamente mediante la prueba intradérmica tuberculínica (IDR), aunque en los porcinos son escasos los reportes de resultados utilizando dicha técnica. El objetivo de este trabajo fue comparar resultados obtenidos realizando la IDR en porcinos con hallazgos patológicos y microbiológicos. Se tuberculinizaron 307 hembras con DPP aviar y DPP bovino. Del total, 171 se inspeccionaron a la faena tomando muestras para exámenes bacteriológicos e histopatológicos. Los resultados de la IDR fueron: 14.4% (44) positivos a DPP aviar, 1.9% (6) a DPP bovino, 3.9% (12) a ambos DPP y 79.8% (245) negativos. Cuatro muestras fueron positivas al cultivo, tipificándose como Mycobacterium bovis, M. avium, M. flavescens y M. scrofulaceum. En la observación macroscópica e histopatológica no se hallaron lesiones compatibles. Concluimos que la IDR sería útil para indicar una infección predial aunque tendría limitaciones en el diagnóstico individual y en el estudio comparativo con la presencia de lesiones y aislamiento del agente.

Determinou-se, por meio de um sistema de monitoramento de suínos em fase de crescimento e em matadouro, a presença de patologias como indicadoras de problemas na população de referência. O estudo foi realizado em uma criação intensiva de ciclo completo, durante nove semanas. Foram determinadas as prevalências dos diagnósticos clínico-patológicos obtidos durante um período de nove semanas. Utilizaram-se cinco grupos de 43 leitões, com pesos de até 19kg, considerados de baixa performance. Estimaram-se, por intervalos de confiança de 95%, as prevalências acumuladas em cada monitoramento. Obteve-se correlação de 0,99 (P<0,0001) entre as prevalências anuais com as nove semanas de estudo, mostrando correspondência com o achado em matadouro. Amostras em semanas alternadas de três grupos de 43 animais são bons indicadores das patologias que afetam os suínos em crescimento, mesmo aquelas de baixa freqüência ou muito letais.

The prevalence of different pathologies as an indicator of health problems in a particular population by means of slaughterhouse monitoring of growing pigs was determined. The work was carried out in an indoor intensive farrow to finish swine farm during 9 weeks. The prevalence of diseases was determined by means of clinical and pathological diagnosis. For the slaughterhouse inspection, five groups of 43 pigs each weighting up to 19kg, considered as poor performers, were put together. These animals were sent to the slaughterhouse and were observed for the presence or absence of skin and joint lesions of arms and legs and also lesions of serous membranes and parenchimal organs. An estimative with a confidence interval level of 95% was performed on cumulated prevalence in each monitoring session for 43, 86, 129, 172 and 215 animals. Annual prevalence from clinical and pathological diagnosis and 9-week-period had correlations (r=0.99; P<0.0001) and correspondence with slaughterhouse observations. In conclusion, samplings in alternate weeks of three groups of 43 pigs seem to be a good indicator of pathologies affecting growing swines, even those of very low prevalence or highly lethal.

The goal of this work was to find a process to extract and separate carotene from natural sources using supercritical carbon dioxide. A high pressure extraction process was compared with a combined extraction-adsorption process. The experiments were performed with a pilot plant which can be operated up to 50 MPa and 100ºC. A technique using an on-line photometer, was used to estimate the concentration of carotenoids in the fluid phase, to monitor the different steps of the process. During the extraction of paprika powder, a time fractionation of pigments was observed: a low concentration fraction of free carotenoids at the beginning of the process and an enriched esterified carotenoid fraction at the end. With the combined extraction-adsorption process, using silica gel as adsorbent, a selective adsorption occurred. Red pigments (mainly esterified carotenoid) were adsorbed but the yellow ones (mainly free carotenoid) remained in supercritical phase which were collected in a separation step at lower pressure.

Supercritical CO2 extraction has shown great potential in separating vegetable oils as well as removing undesirable oil residuals from natural products. The influence of process parameters, such as pressure, temperature, mass flow and particle size, on the mass transfer kinetics of different natural products has been studied by many authors. However, few publications have focused on specific features of the raw material (moisture, mechanical pretreatment, bed compressibility, etc.), which could play an important role, particularly in the scale-up of extraction processes. A review of the influence of both process parameters and specific features of the material on oilseed extraction is given in Eggers (1996). Mechanical pretreatment has been commonly used in order to facilitate mass transfer from the material into the supercritical fluid. However, small particle sizes, especially when combined with high moisture contents, may lead to inefficient extraction results. This paper focuses on the problems that appear during scale-up in processes on a lab to pilot or industrial plant scale related to the pretreatment of material, the control of initial water content and vessel shape. Two applications were studied: deoiling of wheat gluten with supercritical carbon dioxide to produce a totally oil-free (< 0.1 % oil) powder (wheat gluten) and the extraction of oil from rose hip seeds. Different ways of pretreating the feed material were successfully tested in order to develop an industrial-scale gluten deoiling process. The influence of shape and size of the fixed bed on the extraction results was also studied. In the case of rose hip seeds, the present work discusses the influence of pretreatment of the seeds prior to the extraction process on extraction kinetics.