Local infection associated with vascular bundles: the colonization of coconut palm leaflets by two <Emphasis Type="Italic">Camarotella</Emphasis> species

Two Camarotella (Phyllachoraceae) species, C. torrendiella and C. acrocomiae are the causative agents of small (SV) and large verrucosis (LV), respectively, which are important diseases affecting Brazilian coconut palms. The small verrucosis produces necrotic lesions in coconut palm leaflets, whereas LV just produces chlorosis. Semi-thin sections of asymptomatic leaflets and of leaves presenting stromata in different development stages were compared through light microscopy in order to characterize the colonization process of these two coconut palm verrucosis agents. Camarotella torrendiella initially colonized the adaxial epidermal cells and the cells underlying the epidermis close to the vascular bundles. In latter colonization stages, the hyphae of C. torrendiella remained limited to the underlying necrotic tissue adjacent to the mature stromata, mostly in the intracellular spaces and in the collapsing cells of necrotized tissues around the vascular bundles. This species does not colonize intracellular intact fiber cells, xylem vessels or phloem sieve tube elements. In contrast, C. acrocomiae presented a typical biotrophic parasitism model such as that of some gramineous Phyllachora spp. High densities of C. acrocomiae hyphae were found inside intact sieve tube elements; however, with no evidence of cellular death. The extensive hyphal colonization by C. acrocomiae within sieve tube elements was also observed in tertiary and quaternary bundles, as well as in anastomosing vascular bundles. The dependence of both species on the colonization sites associated with vascular bundles indicates the need for additional studies about these intricate host-pathogen relationships. These studies could be important to define new strategies to control coconut palm verrucosis diseases.     

Development of a bioacoustic sensor for the early detection of Red Palm Weevil (Rhynchophorus ferrugineus Olivier)

The Red Palm Weevil (Rhynchophorus ferrugineus Olivier) is one of the worst pests for palms, since it can completely destroy the plant. Its early detection is very difficult and when the action of the pest is discovered, normally it is too late for recovering the plant. Bioacoustic sensors provide a good alternative for early detection of this pest because larvae activity is audible while they excavate tunnels to feed. This work describes the different stages for the development of an original electronic device based on acoustic sensors for early detection of Red Palm Weevil larvae in the interior of palms. This device is based on characteristic frequencies possibly related to their feeding activity. The performed tests have demonstrated that is possible to detect two week old larvae activity studying the sound intensity around 2250 Hz in palms infested only with 5 individuals under controlled environmental conditions. The activity of other insects artificially situated in the interior of palms did not affect the response of the device, possibly because they produce different frequencies (in the range 5–7 kHz). Future work will be aimed at assessing the infestation levels.     

Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle

Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle.     

Quality and aromatic sensory descriptors (mainly fresh and dry fruit character) of Spanish red wines can be predicted from their aroma-active chemical composition

A satisfactory model explaining quality could be built in a set of 25 high quality Spanish red wines, by aroma-active chemical composition. The quality of the wines was positively correlated with the wine content in fruity esters, acids, enolones, and wood derived compounds, and negatively with phenylacetaldehyde, acetic acid, methional, and 4-ethylphenol. Wine fruitiness was demonstrated to be positively related not only to the wine content on fruity esters and enolones, but to wine volatile fatty acids. Fruitiness is strongly suppressed by 4-ethylphenol, acetic acid, phenylacetaldehyde, and methional, this involved in the perception of dry-fruit notes. Sensory effects were more intense in the presence of β-damascenone and β-ionone. A satisfactory model explaining animal notes could be built. Finally, the vegetal character of this set of wines could be related to the combined effect of dimethylsulfide (DMS), 1-hexanol, and methanethiol.     

Analysis of the spatial variation of Bovine tuberculosis disease risk in Spain (2006-2009)

In this study we explored the spatial variation of Bovine tuberculosis (BTB) risk of being positive, new positive or persistently positive, as well as the risk of eliminating BTB in positive herds throughout Spain from 2006 to 2009 by means of hierarchical Bayesian models. The results of the models showed that the risk of infection (positive or new positive herds), persistence and elimination was lower in counties located in north and north-eastern of Spain, and in the Balearic and Canary islands than in the rest of the country. In some counties the risk of positivity was high during the four years of study, whereas there were others where the risk of positivity was high only in some of the years. With regard to the risk of persistence of BTB positive herds, counties located in the central, western and south-western part of the country had a higher risk in the three studied periods. This study has identified some specific areas of increased BTB risk in Spain, information that is useful for disease management.     

Oocysts of Hepatozoon canis in Rhipicephalus (Boophilus) microplus collected from a naturally infected dog

Canine hepatozoonosis is a tick-borne disease caused by protozoans of the genus Hepatozoon. Several tick species have been implicated as potential vectors. Therefore, extensive studies are needed to determine the 'natural' endemic cycle of this parasite. This paper presents the first report of the presence of Hepatozoon canis oocysts in Rhipicephalus (Boophilus) microplus collected from an infected dog.     

Use of crude, FML and rK39 antigens in ELISA to detect anti-Leishmania spp. antibodies in Felis catus

Visceral leishmaniasis is a disease caused by Leishmania (Leishmania) chagasi and represents a serious public health problem. The dog is the main urban reservoir of the disease; however, investigations regarding the occurrence and epidemiological importance of leishmaniasis in cats have recently been initiated. This study aimed to detect cats seropositive for Leishmania spp. using different antigens. Additional studies were performed using sera from cats with Toxoplasma gondii (n=15) to evaluate cross-reactivity. Serum samples (n=113) from cats living in the town of Ara?atuba, State of S?o Paulo, Brazil, an endemic area for human and canine visceral leishmaniasis, were tested by indirect ELISA using different antigens: crude (CAG-ELISA), fucose-mannose ligand (FML-ELISA) and K39 (rK39-ELISA). Anti-Leishmania spp. antibodies were detected in 23.0% of samples evaluated by CAG-ELISA, 13.3% by FML-ELISA and 15.9% by RK39-ELISA. Only reactive sera in all three tests were considered truly positive. No disagreement occurred among the tests (p<0.05). Serum samples seropositive for toxoplasmosis tested by CAG-ELISA were negative, but one sample (6.7%) was positive for FML-ELISA and rK39-ELISA suggesting a cross-reaction between these antigens and anti-T. gondii antibodies. These findings indicate the occurrence of feline leishmaniasis in Ara?atuba. Further studies are required to clarify the role of cats in the epidemiological cycle of leishmaniasis.     

Leishmania chagasi infection in cats with dermatologic lesions from an endemic area of visceral leishmaniosis in Brazil

Although dogs are considered the main domestic reservoirs for Visceral Leishmaniosis (VL), which is caused in the Americas by Leishmania chagasi, infected cats have also been recently found in endemic areas of several countries and became a public health concern. Accordingly, the purpose of this study was to evaluate cats with dermatologic lesions from an endemic area of VL and the natural infection of L. chagasi. A total of 55 cats were selected between April 2008 and November 2009 from two major animal shelters of Ara?atuba, Southeastern Brazil. All cats underwent general and dermatologic examinations, followed by direct parasitological examination of lymphoid organs, immunosorbent assay (ELISA) and indirect immunofluorescence (IFAT). In addition, detection of amastigotes was performed by immunohistochemistry (IHC) in skin lesions of all cats. VL was diagnosed in 27/55 (49.1%) cats with dermatological problems. Amastigotes were found in lymphoid organs of 10/27 (37.0%) cats; serology of 14/27 (51.9%), 6/27 (22.2%) and 5/27 (18.5%) cats was positive for ELISA, IFAT and both, respectively. The IHC identified 9/27 (33.3%) cats; 5/27 (18.5%) were positive only for IHC and therefore increased the overall sensitivity. Specific FIV antibodies were found in 6/55 (10.9%) cats, of which 5/6 (83.3%) had leishmaniosis. Real time PCR followed by amplicon sequencing successfully confirmed L. chagasi infection. In conclusion, dermatological lesions in cats from endemic areas was highly associated to visceral leishmaniosis, and therefore skin IHC and differential diagnosis of LV should be always conducted in dermatological patients in such areas.     

Changes in amino acid and organic acid composition in tomato and cucumber plants in relation to salinity and nitrogen nutrition

Under conditions of salt stress, plants show qualitative and quantitative alterations in various organic compounds, such as nitrogen (N) compounds and organic acids. In this work, the effect of different saline levels as well as various N levels, supplied as nitrate (NO₃) or as ammonium (NH₄)+NO₃ on the concentration of amino acids and organic acids in the leaves of tomato and cucumber plants has been studied. The effect of the source of N on individual amino acid contents varied with plant species. Most of the amino acids increased when the concentration of N in the nutrient solution was increased, except when N was added as NH₄+NO₃ for tomato. The effect of salt stress depended on which amino acid was considered. The data also indicate that the effect of salinity on each particular amino acid was greatly dependent on the plant species and N source. Organic acids were differently affected by salinity and by the N source, depending on the plant species. In tomato, the concentrations of short‐chain organic acids were 2–3 times higher in NO₃‐supplied plants than in those grown with NH₄+NO₃. Finally, in cucumber, malic acid concentration increased as a function of the saline level in the medium.