Irreversible block of the mycelial-to-yeast phase transition of Histoplasma capsulatum

p-Chloromercuriphenylsulfonic acid (PCMS), a sulfhydryl inhibitor, prevented the mycelial-to-yeast transition of the dimorphic fungal pathogen, Histoplasma capsulatum. The effect of PCMS was specific for the mycelial-to-yeast transformation; it had no effect on growth of either the yeast or mycelial forms or on the yeast-to-mycelial transition. The failure of PCMS-treated mycelia to transform to yeast was permanent and irreversible. PCMS-treated mycelia could not infect mice but could stimulate resistance to infection by a pathogenic strain of Histoplasma capsulatum. These results suggest a new general strategy for vaccine development in diseases caused by dimorphic pathogens.     

Simple confirmatory method for the determination of erythromycin residues in trout: a fast liquid-liquid extraction followed by liquid chromatography-tandem mass spectrometry

In recent years, erythromycin has received considerable attention for its therapeutic efficacy against some bacterial kidney diseases in aquaculture and, therefore, suitable and sensitive analytical methods to monitor erythromycin residues in fish are required. A fast sample treatment followed by an LC-ESI-MS/MS method is described for the purification, identification, and quantification of erythromycin A residues in fish. After two extractions with acetonitrile, samples were defatted with n-hexane, filtered, and analyzed by tandem mass spectrometry. Three characteristic transition reactions (m/z 734 --> 716, 734 --> 576, and 734 --> 558) in multiple reaction monitoring were tested for the determination and confirmation of erythromycin A. The method was in-house validated through the determination of precision, accuracy, specificity, stability, calibration curve, decision limit (CCalpha), and detection capability (CCbeta), in accordance with European Commission Decision 657/2002. The coefficients of variation ranged from 1.8 to 9.4% and from 7.5 to 10.9% for intra- and interday repeatability, respectively. Recovery data were also satisfactory, with values varying from 85 to 97%. The method was specific, stable, and robust enough for the required purposes. The calibration curve showed a good linearity in the whole range of the tested concentrations (0-1000 microg kg(-1)) with a correlation coefficient (r2) equal to 0.9956. CCalpha and CCbeta were found to be 220 and 238 microg kg(-1), respectively.     

Interactions between Soil,Leaves and Beans Nutrient Status and Dry Biomass of Beans and Pod Husk of Forastero Cacao: An Exploratory Study

ABSTRACT

In cacao crop the understanding of the multiple relationships between bean and pod husk dry biomass and mineral nutrition in the soil-plant system is scarce. The main objective of this work is to verify the linear, bivariate and multivariate correlations between the mineral nutrient concentrations in the soil, leaves and beans of 53 cacao trees with known dry biomass of cacao beans and pod husk, and further graphically identifying the consistency of these information. For this study, soil samples, leaves and fruits (pod husk and beans) were collected from each cacao trees, for the analysis of nitrogen-N, phosphorous-P, potassium-K, calcium-Ca, magnesium-Mg, iron-Fe, manganese-Mn, zinc-Zn and cooper-Cu mineral nutrient concentrations. The interpretation of the results by the exploratory analysis technique linked to the linear correlation analysis proved to be an essential tool to support studies related to mineral nutrition in the soil-plant system. Foliar N concentration were directly related to the high and very high dry biomass classes of cacao beans. Levels of exchangeable Ca and Mg in the soil were inversely correlated with the dry biomass of cacao pod husk (DBCH), in contrast to results with the positive correlations of these nutrients in the leaves and cacao beans data sets. The foliar concentrations of Zn, Mn, Fe and Cu are shown to be more positively associated with DBCH than dry biomass classes of cacao beans. The concentrations of Fe, Mn and Cu in dry cacao beans show such similar pattern of association with dry biomass of pod husk and beans.     

Molecular survey of selected viruses in Pudus (Pudu puda) in Chile revealing first identification of caprine herpesvirus—2 (CpHV-2) in South American ungulates

Viral diseases jeopardize the health of wildlife in Chile. However, this country lacks health surveillance programs that allow for defining preventive measures to tackle such diseases. The objective of this study was to determine the occurrence and the genetic diversity of pestivirus, herpesvirus and adenovirus in pudus from Chile. Blood samples from wild (n=34) and captive (n=32) pudus were collected between 2011 and 2019 and analyzed through consensus PCR. All the samples were negative to pestivirus and adenovirus. Herpesvirus was confirmed in four captive, and one wild pudu. All four zoo animals share the same sequence for both polymerase and glycoprotein genes. Both sequences share a 100% identity with caprine herpesvirus-2, classifying them in the same cluster as the Macavirus group. In turn, novel sequences of the polymerase and glycoprotein B genes were obtained from the wild pudu. Our study reports the first evidence of CpHV-2 infection in Chile and South American ungulate populations. Further research will be necessary to assess the pathogenicity of CpHV-2 in this species. It is also urgently recommended that molecular, serological and pathological screening should be conducted in Chilean wild and captive pudus to understand the impact of the herpesvirus on their populations.     

Brucellosis: a short review of the disease situation in Paraguay

A short review of the brucellosis situation, its control and eradication programs are presented. Data from over 1.2 milliom samples collected from more than 50,718 groups of cattle over a period of over 20 years (1979–2000) illustrates that over the last few years the number of individual reactors remain constant at around 3–4%. The percentage of reactive groups of animals decreased over these years, reflecting a better disease management and possibly an improved general education, handling of information on the immune (vaccination) status of animals and testing practices. Reported zoonotic cases are presented, as well as control and eradication programs, including utilization of vaccines.     

Production characters of primiparous females of a five-breed diallel

Data included pubertal, reproductive and lactation records of primiparous females produced in a diallel of Angus, Brahman, Hereford, Holstein and Jersey. Brahman heifers were oldest, tallest and heaviest at puberty, while Jersey heifers were youngest, shortest and lightest. Crossbred heifers were 22 d younger (P less than .01) at puberty than straightbred heifers; no significant differences were detected between the two groups for weight or height at puberty. Dairy heifers (Holstein and Jersey) required fewer services (P less than .05) to conception than beef heifers. The difference between straightbred and crossbred heifers for number of services to conception was small and nonsignificant. Rank of straightbreds for age at conception was similar to their rank for age at puberty except that Holstein required 1.2 fewer services and were younger at conception than Jersey. Crossbreds were 41 d younger (P less than .05) at conception than straightbreds. Brahman had the longest gestation length and were oldest at first calving; Jersey had the shortest gestation length and Holstein were youngest at first calving. Straightbred heifers gestated 1.3 d longer and were 45 d older (P less than .05) at first calving than crossbred heifers. Dairy females had greater peak and total milk yield than beef females (P less than .01). Overall straightbred and crossbred means for peak milk yield and total milk yield did not differ significantly.     

Ribotyping and restriction endonuclease analysis reveal a novel clone of Bordetella bronchiseptica in seals.

The goal of the present study was to characterize, by ribotyping and restriction endonuclease analysis (REA), 35 phocine Bordetella bronchiseptica isolates and to ascertain their relationship to one another and to isolates acquired from other host species. Thirty-four isolates were obtained in Scotland during a 10-year period encompassing the 1988 epizootic; the remaining isolate was obtained independently in Denmark. All phocine isolates had an identical Pvu II ribotype unique from the 18 ribotypes previously detected in strains from heterologous hosts. Alternative restriction enzymes, useful for subgrouping strains within Pvu II ribotypes, also failed to discriminate among isolates from seals. The exclusive occurrence of a single ribotype of B. bronchiseptica in a particular host species has not been previously observed. Similarly, REA based on either HinfI or Dde I profiles did not reveal detectable polymorphisms, although unique patterns were readily distinguished among a limited number of isolates from other host species. This is the first report demonstrating the utility of REA using frequently cutting enzymes for discrimination of B. bronchiseptica strains. These data suggest that B. bronchiseptica-induced respiratory disease in seals along the Scottish shore may be due to the circulation of a single, unique clone.     

Grain,pellet and wax block bait take by the house mouse (Mus musculus) and non‐target species: implications for mouse eradications on coral cay islands

Introduced rodents have been eradicated from large numbers of offshore islands using toxic baits; however, toxic baits have been linked with negative impacts on non‐target species. The present study assessed the bait take of target (house mouse, Mus musculus) and non‐target (buff banded rail, Rallus philippensis) animals on Northwest and Heron Islands in the Great Barrier Reef. Three non‐toxic bait formulations (wax block, pellet and grain) were tested and each was applied at 1 kg ha^?1 in six treatment grids. The tracks of animals visiting the baits were identified using 30 tracking stations per treatment grid. A tracking station consisted of a track‐board placed in the centre of a sand‐pad. Mean bait take differed significantly between the formulations: birds took more grain bait than wax block bait; mice took more wax block than grain bait. Both mice and birds were equally selective of pellet bait. Thus, the findings indicate that wax blocks are the most suitable formulation for future baiting programs to eradicate mice on these and other islands.