Comparison of phenotypic and genotypic profiles among caprine and ovine Mycoplasma ovipneumoniae strains.

Mycoplasma ovipneumoniae (Movp) is considered to be one of the most important mycoplasmas causing respiratory disease in small ruminants. Most epidemiologic and characterisation studies have been conducted on strains collected from sheep. Information on the presence and characteristics of Movp in healthy and pneumonic goats is limited. Phenotypic or genotypic differences between sheep and goat isolates have never been studied. The objective of our study was to characterise and compare the similarities and differences between caprine and ovine Movp strains isolated from affected and asymptomatic animals in order to elucidate phenotypic and genotypic variability. Four different techniques were used on a set of 23 Movp isolates. These included SDS-PAGE, Western blotting, random amplified polymorphic DNA and the heat shock protein 70 gene sequence-based method. A high degree of phenotypic and genotypic heterogeneity among Movp strains was demonstrated in this study. Our results demonstrated differences between goat and sheep strains, revealing not only a link between strains and host ruminant species, but by geographical origin as well. However, the finding of immunodominant antigens of molecular masses 36, 38, 40 and 70 kDa (±3 kDa) in Movp isolates from sheep and goats foretells their potential use in the development of serological diagnostic tests and vaccines.

In vitro assessment of the antimicrobial susceptibility of caprine isolates of Mycoplasma mycoides subsp. capri.

The minimum inhibitory concentration (MIC) and minimum mycoplasmacidal concentration (MMC) of 17 antimicrobials against 41 Spanish caprine isolates of Mycoplasma mycoides subsp. capri (Mmc) obtained from different specimens (milk, external auricular canal and semen) were determined using a liquid microdilution method. For half of the isolates, the MIC was also estimated for seven of the antimicrobials using an epsilometric test (ET), in order to compare both methods and assess the validity of ET. Mutations in genes gyrA, gyrB, parC and parE conferring fluoroquinolone resistance, which have been recently described in Mmc, were investigated using PCR. The anatomical origin of the isolate had no effect on its antimicrobial susceptibility. Moxifloxacin and doxycycline had the lowest MIC values. The rest of the fluoroquinolones studied (except norfloxacin), together with tylosin and clindamycin, also had low MIC values, although the MMC obtained for clindamycin was higher than for the other antimicrobials. For all the aminoglycosides, spiramycin and erythromycin, a notable level of resistance was observed. The ET was in close agreement with broth microdilution at low MICs, but not at intermediate or high MICs. The analysis of the genomic sequences revealed the presence of an amino acid substitution in codon 83 of the gene gyrA, which has not been described previously in Mmc.

Sensitivity of two methods to detect Mycoplasma agalactiae in goat milk.

BACKGROUND: Laboratory diagnostic techniques able to detect Mycoplasma agalactiae are essential in contagious agalactia in dairy goats. This study was designed: 1) to determine the detection limits of PCR and culture in goat milk samples, 2) to examine the effects of experimental conditions including the DNA extraction method, PCR technique and storage conditions (fresh versus frozen stored milk samples) on these methods and 3), to establish agreement between PCR and culture techniques using milk samples from goats with mastitis in commercial dairy herds. The study was conducted both on artificially inoculated and field samples. RESULTS: Our findings indicate that culture is able to detect M. agalactiae in goat milk at lower concentrations than PCR. Qualitative detection of M.agalactiae by culture and PCR was not affected by sample freezing, though the DNA extraction method used significantly affected the results of the different PCR protocols. When clinical samples were used, both techniques showed good agreement. CONCLUSIONS: The results from this study indicate that both culture and PCR are able to detect M. agalactiae in clinical goat mastitis samples. However, in bulk tank milk samples with presumably lower M. agalactiae concentrations, culture is recommended within the first 24 h of sample collection due to its lower limit of detection. To improve the diagnostic sensitivity of PCR in milk samples, there is a need to increase the efficiency of extracting DNA from milk samples using protocols including a previous step of enzymatic digestion.

Implicaciones sanitarias del manejo del calostro en el ganado caprino / Sanitary involvements of management of colostrum in caprine herds

El calostro supone la primera fuente de inmunidad para los rumiantes y por tanto determina su resistencia a enfermedades durante las primeras horas de vida. No obstante, la ingesta de calostro puede suponer en sí misma una vía de transmisión de diversas enfermedades, como la paratuberculosis, la artritis-encefalitis caprina o la agalaxia contagiosa. Este riesgo puede evitarse siguiendo un régimen de lactancia artificial con unas adecuadas pautas de manejo del calostro. Entre dichas pautas, el tratamiento del calostro supone un punto crítico. En este sentido, se han empleado los tratamientos térmicos para higienizar el calostro, observándose resultados diversos en la viabilidad de distintos microorganismos. Al mismo tiempo, se debe considerar el efecto negativo del calor sobre la composición nutricional del calostro, principalmente la pérdida de inmunoglobulinas. Como alternativa a los tratamientos térmicos, a nivel experimental, se han empleado métodos como la adición de dodecil sulfato de sodio, capaz de inactivar el virus del síndrome de inmunodeficiencia humana en leche, y otros procesos como la liofilización o el uso de altas presiones. Previamente a la aplicación práctica de las diferentes opciones de tratamiento del calostro se deberá considerar su viabilidad económica y su factibilidad en la explotación (AU)

Colostrum represents the first source of immunity for the ruminants, and thus determines its resistance to disease during the first hours of life. However, colostrum intake could be itself the way of transmition of several diseases, as paratuberculosis, caprine arthritis-encephalytis, or micoplasmosis like contagious agalactia. This risk could be avoided by means of an artificial rearing program which should include correct management practices for colostrum. Between them, the treatment of colostrum represents a critical point. In this sense, thermic treatments have been used to higienitize colostrum, showing different results about microorganism viability. Nevertheless, it should be considered the negative effect of these treatments over nutritional components of colostrum, particularly the loss of immunoglobulines. As an alternative to thermic treatments, there have been experimentally assayed other methods as the addition of sodium dodecyl sulphate, which inactivates AIDS virus in breast milk, and others as liophilization or high pression methods. In this works, apart from the effect of the treatment should be also taken into account its economical viability and on-farm feasibility (AU)

Particularidades etiológicas y epimediológicas de la agalaxia contagiosa ovina: similitudes y diferencias con el caprino / Etiological and epidemiological particularities of ovine contagious agalactia: similarities and differences with goats

Este trabajo describe las diferencias existentes en la presentación de la agalaxia contagiosa, síndrome infectocontagioso causado por varias especies del genero Mycoplasma spp., en el ganado ovino y caprino. Las particularidades etiológicas y epidemiológicas de la infección crónica en la cabra, y la ausencia de datos similares en el ovino, evidencian la necesidad de realizar nuevos trabajos que determinen si las diferencias observadas en referencia a la presencia de portadores auriculares en los rebaños o la participación de los sementales en la difusión de la enfermedad son fruto de la escasez de trabajos científicos o por el contrario, establecen verdaderas diferencias sobre las que desarrollar estrategias dirigidas de control en función de la especie de rumiante afectada (AU)

Contagious agalactia (CA) is an infectious syndrome caused by several species of Mycoplasma spp. which affects small ruminants. The aim of this review is to describe the main differences noted between the disease in sheep and goats, especially with regard to its etiologic and epidemiological peculiarities. Thus, the presence of asymptomatic auricular carriers of CA-causing mycoplasmas and the stud’s role in the transmission of the disease are well known in goats, but scarcely evaluated in sheep. Further studies are needed to determine if these differences are real or if they are due to the shortage of scientific work in this matter (AU)

Short communication: In vitro antimicrobial susceptibility of Mycoplasma agalactiae strains isolated from dairy goats.

This study examined the susceptibility to several antimicrobials of 28 isolates of Mycoplasma agalactiae obtained from goats in a region (southeastern Spain) where contagious agalactia is endemic. For each isolate, the minimum inhibitory concentration (MIC) against 12 antimicrobials of the quinolone, macrolide, aminoglycoside, and tetracycline families was determined. The antimicrobials with the lowest MIC were enrofloxacin, ciprofloxacin, tylosin, and doxycycline, all with MIC90 (concentration at which growth of 90% of the isolates is inhibited) <1 µg/mL. Norfloxacin (a quinolone) showed a wide MIC range (0.1-12.8 µg/mL), suggesting a resistance mechanism toward this antimicrobial that was not elicited by enrofloxacin or ciprofloxacin (the other quinolones tested). Erythromycin showed the highest MIC90 such that its use against Mycoplasma agalactiae is not recommended. Finally, Mycoplasma agalactiae isolates obtained from goat herds with clinical symptoms of contagious agalactia featured higher MIC90 and MIC50 (concentration at which growth of 50% of the isolates is inhibited) values for many of the antimicrobials compared with isolates from asymptomatic animals. The relationship between the extensive use of antimicrobials in herds with clinical contagious agalactia and variations in MIC requires further study.

Lattice dynamics of ß-V2O5: Raman spectroscopic insight into the atomistic structure of a high-pressure vanadium pentoxide polymorph.

We report here the Raman spectrum and lattice dynamics study of a well-crystallized ß-V(2)O(5) material prepared via a high-temperature/high-pressure (HT/HP) route, using α-V(2)O(5) as the precursor. Periodic quantum-chemical density functional theory calculations show good agreement with the experimental results and allow one to assign the observed spectral features to specific vibrational modes in the ß-V(2)O(5) polymorph. Key structure-spectrum relationships are extracted from comparative analysis of the vibrational states of the ß-V(2)O(5) and α-V(2)O(5) structures, and spectral patterns specific to the basic units of the two V(2)O(5) phases are proposed for the first time. Such results open the way for the use of Raman spectroscopy for the structural characterization of vanadium oxide-based host lattices of interest in the field of lithium batteries and help us to greatly understand the atomistic mechanism involved in the α-to-ß phase transition of vanadium pentoxide.

Controlling contagious agalactia in artificial insemination centers for goats and detection of Mycoplasma mycoides subspecies capri in semen.

Many goat artificial insemination (AI) centers in Spain have adopted new measures to control contagious agalactia (CA). To avoid the introduction of male goats carrying mycoplasma organisms subclinically in their external ear canal (auricular carriers) in these centers, two ear swabs and a blood sample are obtained from all candidate animals for polymerase chain reaction (PCR), culture (swabs) and serologic tests to detect the presence of mycoplasmas. In addition, the semen produced at these centers is routinely cultured and PCR tested also to detect the presence of mycoplasmas. One y after the introduction of this program, we tested 48 ear swabs and 24 blood samples from 24 candidates for admission to these AI Centers. Three of these ear swab samples (3/48, 6.25%) scored positive for the presence of mycoplasmas; Mycoplasma agalactiae (Ma) was detected in two samples and Mycoplasma mycoides subsp. capri (Mmc) in one. All animals were serologically negative for Ma. Also, out of 173 semen samples obtained from 137 admitted animals (2 and 3 samples were obtained in 16 and 10 bucks, respectively), one (1/173, 0.56%) was positive for Mmc. Our findings suggest that ear swab and semen samples are useful tools to control CA at AI Centers. The introduction of this program has also resulted in the first detection of Mmc in semen from a naturally infected goat, confirming the ability of this mycoplasma to colonize the reproductive tract of male goats. These results highlight the need to improve control measures in semen producing centers to minimize the risk of CA transmission.

Methanol conversion over a Pd5Cu/Al2O3-CeO2 catalyst: an FT-IR study and reaction mechanism.

A catalyst composed of a Pd(5)Cu mixed oxide supported over Al(2)O(3)-CeO(2) with general formula Pd(5)CuO(x)/Al(2)O(3)-CeO(2) (Al/Ce atomic ratio=1/1) has been prepared by a wet impregnation method and tested in the methanol conversion. The structural and morphological characterization of the catalyst evidences that it is a mesoporous material thermally stable up to 873 K. At that temperature the specific surface area value is 170 m(2)/g, and a CeO(2) cubic phase is identified together with ill-defined diffraction peaks tentatively assigned to Cu-Pd clusters, suggesting that the active phase is well dispersed over the support. Infrared studies prove that methanol conversion takes place over the catalyst to a high extent yielding syngas as main product in the range 473-723 K and methane at higher temperatures. Oxygenated intermediates containing methoxy, carbonile or formiate species are not detected, which evidences that methanol conversion to methane very probably takes place according to a via-carbide mechanism.

Presence of contagious agalactia causing mycoplasmas in Spanish goat artificial insemination centres.

Male goats admitted to artificial insemination centres come from herds that have shown no clinical symptoms of contagious agalactia (CA) for the last 6 mo. However, prior reports suggest that this control measure may not be completely effective. This study was designed to detect the presence of CA-causing mycoplasmas in 9 Spanish centres, comprising 159 goats (147 males and 12 teaser does) of 8 different breeds. A microbiological study was conducted during 8 mo on 448 samples (318 ear swabs, 119 semen samples and 11 milk samples). In 86 samples (84 swabs, 1 semen sample and 1 milk sample), CA-causative mycoplasmas were detected by PCR or culture, and 52 animals (49 goat males and 3 teaser does) tested positive. Most of these positive animals were auricular carriers (n = 50), mainly of Mycoplasma mycoides subsp. capri (Mmc), although some M. agalactiae (Ma) and, interestingly, M. capricolum subsp. capricolum (Mcc) carriers were also identified. At least 1 animal infected by CA-causing mycoplasmas was detected in 8 of the 9 centres (88.8%) although in most (66.7%) no infected animals or only 1 or 2 positive animals were identified. Our results indicate the presence of CA carriers as asymptomatic animals in reproductive programmes. These findings have already prompted efficient measures to detect and avoid the entry of these carriers in Spanish centres. We recommend similar measures for all centres in areas where CA is endemic.

Mycoplasma agalactiae detected in the semen of goat bucks.

Contagious agalactia (CA) is among the most significant diseases affecting small ruminant populations in Mediterranean countries. This study was designed to detect the excretion in semen of CA-causing mycoplasmas in goats (Capra hircus) reared in Spain, where the disease is considered endemic. Culture techniques and PCR were conducted on 147 semen samples collected from 113 goat bucks to detect mycoplasmas. No animal showed clinical symptoms of CA at the moment of the screening. M. agalactiae was identified using both diagnostic methods in three semen samples collected from three different bucks. These animals belonged to a group of animals in which semen had been analyzed twice and only the second sample proved positive, suggesting the possibility of intermittent excretion. This is the first report of the isolation of M. agalactiae from semen collected from naturally infected goats. Future studies should investigate whether semen could be a real source of CA infection by determining if the agent may be transmitted during natural service or when semen is used for artificial insemination.

Simulación numérica de flujo sanguíneo: una herramienta útil en cirugía vascular / The numerical simulation of blood flow: a useful tool in vascular surgery

Objetivos. Revisar el método y las herramientas con las que se trabaja en la simulación numérica aplicada al estudio del flujo sanguíneo y mostrar su utilidad mediante el análisis de una aplicación sencilla en el campo de la cirugía vascular. Desarrollo. Se exponen los pasos que conducen a la construcción del modelo que se va a analizar, los fundamentos físicos y las magnitudes, que se determinan mediante los métodos matemáticos de cálculo. Se analiza una derivación implantada en un tramo arterial con una estenosis del 75% y un injerto de igual diámetro que el de la arteria, se comparan dos opciones posibles con ángulos distintos entre el injerto y la arteria en la anastomosis distal y se evalúan las zonas con flujo retrógrado y tensiones de cizallamiento anormalmente bajas. Se utiliza un modelo geométrico simplificado en dos dimensiones, y el análisis se realiza con los programas informáticos GID y FAUST. Conclusiones. Se pone de manifiesto la utilidad de la simulación numérica en los estudios hemodinámicos. Una de sus posibilidades es la de permitir al cirujano tener un conocimiento aproximado de las condiciones hemodinámicas y mecánicas que se darán tras la implantación de una derivación. En el ejemplo analizado se han detectado dos zonas donde se dan condiciones hemodinámicas favorables a la hiperplasia intimal (HI) durante buena parte del ciclo cardíaco, en buena correspondencia con los datos clínicos que aporta la literatura. Estas condiciones son más favorables a la HI cuanto mayor es el ángulo de incidencia en la anastomosis distal (AU)

Aims. The aim of this paper is to survey the method and the tools used in numerical simulation applied to the study of blood flow and to illustrate their usefulness by analysing a simple application in the field of vascular surgery. Development. We describe the steps that lead to the construction of the model to be analysed, and the physical foundations and the magnitudes, which are determined by mathematical calculations. We analyse a shunt that was implanted in a section of artery with 75% stenosis and a graft with the same diameter as the artery; we compare two possible options with different angles between the graft and the artery in the distal anastomosis; and we assess the areas with a retrograde flow and abnormally low shear stresses. A simplified two-dimensional geometrical model is used, and the analysis is performed using the GID and FAUST computer applications. Conclusions. The value of numerical simulation as a tool for use in haemodynamic studies is clearly demonstrated. One of the possibilities it offers is to enable the surgeon to gain an approximate idea of the haemodynamic and mechanical conditions that will occur after the implantation of a shunt. In the example analysed, two regions were detected in which the haemodynamic conditions were favourable for intimal hyperplasia (IH) throughout the better part of the heart cycle, which coincides well with the clinical data reported in the literature. The greater the angle of incidence in the distal anastomosis is, the more favourable these conditions will be for IH (AU)

Genotypic variation in growth and physiological responses of Finnish hybrid aspen (Populus tremuloides x P. tremula) to elevated tropospheric ozone concentration.

Saplings of six Finnish hybrid aspen (Populus tremuloides Michx. x P. tremula L.) clones were exposed to 0, 50, 100 and 150 ppb ozone (O3) for 32 days in a chamber experiment to determine differences in O3 sensitivity among genotypes. Based on the chamber experiment, three clones with intermediate sensitivity to O3 were selected for a free-air O3 enrichment experiment in which plants were exposed for 2 months to either ambient air (control) or air containing 1.3 x the ambient O3 concentration. We measured stem height and radial growth, number of leaves, dry mass and relative growth rate of leaves, stem and roots, visible leaf injuries, net photosynthesis and stomatal conductance of the clones. There was high clonal variation in susceptibility to O3 in the chamber experiment, indicated by foliar injuries and differential reductions in growth and net photosynthesis. In the free-air O3 enrichment experiment, ozone caused a shift in resource allocation toward stem height growth, thereby altering the shoot to root balance. In both experiments, low O3 concentrations tended to stimulate growth of most clones, whereas 100 and 150 ppb O3 in the chamber experiment impaired growth of most clones. However, growth of the most O3-tolerant clone was not significantly affected by any O3 treatment.

[Use of the laryngeal mask in pediatric surgery]. / Aplicación de la mascarilla laríngea en cirugía pediátrica.

The laryngeal mask is a new method in the control of the airway. In this study we assess the haemodynamic response during the insertion of the laryngeal mask, incidence of complications and recovery from anaesthesia after its use. We also check if the laryngeal mask is easy to place into the patient airway and its versatility in pediatric patients. We have obtain that the use of the laryngeal mask airway is a safe technique, with few complications, easy to learn and with a short recovery time.