Molecular epidemiology of bovine tuberculosis in wild animals in Spain: a first approach to risk factor analysis

In human tuberculosis (Mycobacterium tuberculosis), molecular epidemiology has accurately indicated the risk factors involved in active transmission of the disease, by comparing individuals whose isolates belong to a cluster with patients whose strains are considered unique. Nevertheless, this application has not been used in bovine tuberculosis (Mycobacterium bovis). Our study describes the integration of epidemiological data into molecular classification data on M. bovis isolates. These were isolated from wild ungulates in Extremadura (western Spain) with the objective of detecting the risk factors linked to the association of strains in clades, which are indicators of the active spread of the disease. The molecular markers used were spoligotyping + VNTR typing (loci: VNTR 2165, VNTR 2461, VNTR 0577, VNTR 0580, VNTR 3192 VNTR 2163a and VNTR 2163b) on a population of 59 M. bovis strains isolated from deer (Cervus elaphus), 112 from wild boar (Sus scrofa), six from bovines, 28 from pigs and 2 from goats (n = 207). Epidemiological variables included the animal species from which the strain was isolated, pathological condition of the host (incipient lesion, early and late generalisation), date of sampling (during or after the reproductive period) and hunting season. Bivariant analysis was used to establish the risk factors connected to the association of strains and later, the variables were evaluated by means of logistic regression. Molecular typing grouped a total of 131 strains (64.21%) in 28 clusters and 76 isolates shows unique profiles. The association of strains was connected to the appearance of macroscopic lesions during the reproductive period (O.R. 4.80; 95% CI 1.09–22.99, P < 0.005), showing a possible higher transmission during the courting period. This happened mainly during the last hunting season analysed (2002–2003, O.R. 3.69; 95% CI 1.27–11.9, P < 0.05), clashing with the time of higher prevalence of the disease in wild ungulates. Active spread was not connected to any species in particular, or to any concrete pathological condition.     

Favus in a fighting cock caused by Microsporum gallinae

The first diagnosis of favus in chickens in Costa Rica was made in a 1-year-old fighting cock that had lesions surrounding the comb. The etiologic agent was isolated and identified as Microsporum gallinae. The rooster recovered during topical treatment with tolnaftate and oral treatment with griseofulvin.     

Serodiagnosis of leptospirosis in pigs using an axial filament enzyme-linked immunosorbent assay.

The axial filament (AF) from Leptospira interrogans serovar canicola was isolated by cesium chloride density gradient centrifugation of 2% sarcosyl treated whole cells. Isolation of AF was confirmed by electron microscopic examination, by protein-A immunogold labelling, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblotting. Analysis by SDS-PAGE of the purified preparation showed relatively weak bands of molecular size 41 kDa and 21 kDa, and strong bands of 35 kDa and 34.5 kDa. Immunoblot analysis using antiserum to the AF against sonicated leptospires of a variety of serovars showed prominent reaction against the 41, 35, and 34.5 kDa protein bands, as well as against minor bands of molecular weight 43, 39, and 37 kDa. Antisera prepared against leptospiral serovars also identified minor bands at 33 and 32 kDa. Immunoblots with antiserum to whole cells of serovar bratislava detected the 35 and 34.5 kDa AF bands of Borrelia burgdorferi moderately and of Treponema hyodysenteriae only slightly in comparison to leptospiral AF. Antibody to B. burgdorferi did not detect the leptospiral AF antigen. Immunoblots with antiserum to T. hyodysenteriae showed a marked reaction with a 41 kDa band of B. burgdorferi but only a very minor reaction with leptospiral AF. The AF was tested in an AF-ELISA against sera from 260 pigs, many of which reacted in the microscopic agglutination test (MAT) against one or more leptospiral serovars. A sensitivity of 97.1% and a specificity of 93.1% was determined in comparison to the MAT. Only moderate correlation was observed between titres detected in the AF-ELISA and the MAT (r = 0.4). When sonicated whole cells (WC) of serovar canicola were used in an ELISA (WC-ELISA), high correlation was observed between AF-ELISA and WC-ELISA (r = 0.97). These findings show that the AF-ELISA can be used effectively as a species-specific antigen for the serological diagnosis of leptospirosis in swine and that sonicated whole cells can substitute excellently for purified AF as the antigen source. These findings may be extrapolated to the use of AF in immunodiagnosis of leptospirosis in other species.     

Physicochemical changes in the hull of corn grains during their alkaline cooking

The alkaline cooking of corn in a solution of Ca(OH)2 to produce corn-based foods is oriented to make corn proteins available, to incorporate Ca to the cooked grains, and also to remove the corn hull. This process (nixtamalization) is known in Mexico and Guatemala from prehispanic times; however, the effect of the alkaline cooking on the corn hull remains poorly documented. In this work, the physicochemical changes that take place in the corn hull during its cooking in a saturated solution of Ca(OH)2 were studied using infrared, X-ray diffraction, 13C cross-polarization/magic-angle spinning (CP/MAS) NMR, confocal imaging microscopy, differential scanning calorimetry, and thermogravimetry techniques. The main effect of this treatment on the hull is the removal of hemicelluloses and lignin, increasing the hull permeability and, as a consequence, facilitating the entry of the alkaline solution into the corn kernel. No significant changes were observed in the cellulose fiber network, which remains as native cellulose I, with a crystalline index, according to 13C CP/MAS NMR spectra, of 0.60. The alkaline treatment does not allow the cellulose fibers to swell and their regeneration in the form of cellulose(II). It seems any attempt to make use of the Ca binding capacity of the hull to increase the Ca availability in nixtamalized corn-based foods requires a separated treatment for the hull and kernel. On alkaline cooking, the hull hemicellulose fraction dissolves, losing its ability to bind Ca as a way to incorporate this element into foods elaborated from nixtamalized corn.     

Granulomatous giant cell submandibular sialadenitis in a dog

A 4-month-old dog was presented with a progressive swelling of the submandibular area. The history, course, cytological, and sialographic findings were consistent with an aseptic pyogranulomatous sialadenitis with concurrent duct blockage. This rare entity, responsive to medical treatment, appears to be similar to the granulomatous giant cell sialadenitis of humans.     

Seasonal and dietary effects on Vitamin D deficiencies detected in wild boar from mid‐western Spain

Vitamin D (VitD) is involved in important mammalian physiological mechanisms, such as Ca–P metabolism, bone development and immunological response. VitD deficiencies are frequently detected in domestic animals and related to various health problems (e.g., rickets, bone deformation). However, knowledge about the status of VitD in wildlife species, such as the wild boar, is scarce. The aims of this work were to explore VitD status in wild boar populations from mid‐western Spain and to elucidate the influence of daylight exposure and food supplementation in levels of VitD. Serum concentration of VitD (measured as 25‐hydroxivitaminD) was assessed in 276 wild boar from 27 game estates located in mid‐western Spain using a commercial ELISA kit. In 19 out of 27 estates, the staff supplied a specific VitD‐enriched food (2,000 UI/Kg) ad libitum throughout the year, while in the remaining estates (8), no food was supplied. Blood samples were extracted from hunted animals (198) between October and February of hunting seasons 2016/2017 and 2017/2018, and from live wild boar (78) that were captured, sampled and released (March–September of 2017). The percentage of animals with VitD deficiency (<20 ng/ml), VitD insufficiency (20–30 ng/ml) and VitD sufficiency (>30 ng/ml) was estimated, and the relationship of these levels to factors like sex, age and season was assessed using chi‐square tests. Furthermore, associations between daylight exposure and supplemental food with VitD levels were explored using linear models. Of the studied wild boar population, 82.2% showed a VitD deficiency or insufficiency. VitD deficiencies were more frequent in animals sampled in winter and spring. Furthermore, levels of VitD positively correlated with daylight exposure and supplemental food intake. Ad libitum supplementation with VitD‐enriched food was insufficient to prevent VitD deficiencies in wild boar from November to April, probably because food consumption is lower during this period.     

The effect of Saccharomyces cerevisiae on digestion and mortality in the volcano rabbit(Romerolagus diazi)

An experiment was conducted to evaluate whether supplementation with a probiotic could enhance digestion and reduce mortality in the volcano rabbit in captivity. Two enclosures at Chapultepec Zoo, Mexico(114 individuals) were used in a crossover design(two periods of 60 days) with the following treatments: control group and supplementation with Saccharomyces cerevisiae(2×108 CFU/exhibit/day). Supplementation with the probiotic negatively affected(P0.01) the digestibility of dry matter, organic matter, neutral detergent fiber(NDF) and energy. Mortality increased(P0.04) following supplementation with the probiotic(4.26% vs. 8.89%), primarily in the juvenile rabbits. The results indicate that yeast supplementation in the volcano rabbit negatively affects digestion and mortality in captivity.