Impact of Botryosphaeria,Diplodia and Neofusicoccum species on two Eucalyptus species and a hybrid: From pathogenicity to physiological performance

Species of Botryosphaeriaceae are associated with canker and dieback of Eucalyptus spp. worldwide, but little is known about their effect on the host physiology. The aim of this study was to evaluate the impact of Botryosphaeriaceae isolates from nine species in three genera (Botryosphaeria, Diplodia and Neofusicoccum), previously isolated from eucalypts, on three different Eucalyptus hosts (seedlings of E. nitens, cuttings of E. globulusand of E. globulus× E. cypellocarpa). An approach combining standard pathogenicity trials with evaluation of plant morpho‐physiological parameters was used. The size of the lesions produced revealed differences in fungal aggressiveness and host susceptibility. Isolates of Neofusicoccum kwambonambienseand Diplodia corticolawere the most aggressive, while Botryosphaeria dothidea and Diplodia seriataisolates were the least aggressive. In general, hybrid E. globulus× E. cypellocarpa plants developed smaller lesions, followed by E. nitens and E. globulus. Eucalyptus nitensplants showed minimal modifications on the morpho‐physiological profile when infected, although more severe symptoms and mortality were observed. This is probably due to a more variable genetic background of the plants. However, in general, no direct association between putative fungal aggressiveness and plant physiological disorders could be found. Results suggested that under optimal growth conditions plants manage to cope with pathogen attack and maintain their physiological performance.     

Pseudomonas associated with Bursaphelenchus xylophilus,its insect vector and the host tree: A role in pine wilt disease?

In this study, we characterized the diversity of Pseudomonas associated with Bursaphelenchus xylophilus, its insect vector (Monochamus galloprovincialis) and its host (Pinus pinaster), by a culture‐independent approach using rpoD clone libraries. Clone libraries of Pseudomonas rpoD were obtained from B. xylophilus, M. galloprovincialis and infected P. pinaster. Most M. galloprovincialis and B. xylophilus sequences grouped together in the P. fluorescens group. Genes related to xenobiotics degradation and phenylacetate synthesis were present in the genomes of the type strains closely related to sequences retrieved from the nematode libraries. Results demonstrated that the nematode, during its life stages inside the tree, maintains a diverse Pseudomonas community that is closely related to the one associated with the insect vector. These bacteria might contribute to degradation of xenobiotics and tree weakening during the nematode tree infection.     

Extracts of Peels and Seeds of Five Varieties of Brazilian Jabuticaba Present High Capacity to Deactivate Reactive Species of Oxygen and Nitrogen

Plant Foods for Human Nutrition - Jabuticaba has a high concentration of phenolic compounds, which have a significant antioxidant capacity. Methodologies have been developed to evaluate the ability...     

Structural Analysis of Tillandsia usneoides L. Exposed to Air Pollutants in São Paulo City–Brazil

Bioindicators plants are important for the evaluation of air quality and Tillandsia usneoides L., an atmospheric epiphyte bromeliad, has been used for this purpose. The present study aims at evaluate the structural pattern of the leaf of this species when exposed to urban air pollutants, and determining whether the leaves present structural parameters that could be used as indicators of such pollutants. Samples of T. usneoides were exposed in São Paulo, the biggest city of Brazil, for 8, 16 and 24 weeks, and compared with others kept in a rural area. The urban pollution of São Paulo affected the structure of the leaves of T. usneoides causing alterations, especially in the scales, density of stomata and epidermis thickness. Qualitative alterations in the mesophyll were not observed in plants exposed at the polluted sites. These structural characteristics of T. usneoides seem to account for its high tolerance to heavy metal accumulation. The percentage of anomalous scales may potentially be used as an alternative bioindicator parameter.     

Prevalence and risk factors for anti-Toxoplasma gondii antibodies in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil

The prevalence and risk factors for anti-Toxoplasma gondii antibodies were investigated in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil. Three hundred and sixty-six blood samples from goats collected by jugular venopuncture were used. For the serologic diagnosis of Toxoplasma gondii infection, the indirect fluorescent-antibody test (IFAT) with cut-off value 1:64 was carried out. The prevalence of anti-T. gondii antibodies was 30.6% [95% CI=25.9-35.6%] with titers ranging from 1:64 to 1:16,384. The multivariate logistic regression analysis showed that the risk factors associated to anti-T. gondii antibodies were presence of cats in the herd, extensive/semi-intensive management systems and lack of mineral supplementation.     

Diagnosis of canine visceral leishmaniasis: biotechnological advances

Human visceral leishmaniasis (HVL) is endemic in the tropical and sub-tropical regions of Africa, Asia, the Mediterranean, Southern Europe and South and Central America, with approximately 500,000 new cases reported annually. As dogs are considered to be the major reservoirs for HVL, the accurate diagnosis of disease in these animals is important. Diagnosis of canine visceral leishmaniasis (CVL) is performed mainly by direct parasitological methods that can yield false-negative results, either because of the very low number of Leishmania spp. organisms in clinical samples (bone marrow and lymph nodes) or because morphological identification is difficult. In addition, these methods are invasive. Conventional serological techniques are limited by cross-reactivity with other parasitic diseases and because several technical procedures have not been standardised. The development of polymerase chain reaction based approaches and immunoassays based on the use of recombinant antigens aimed at improving the sensitivity and specificity of CVL diagnosis is discussed.     

Strategies of the control of an outbreak of leptospiral infection in dairy cattle in Northeastern Brazil

The aim of the present study was to describe the strategies of the control of an outbreak of leptospiral infection in dairy cattle in Maranhão State, Northeastern Brazil. In the period from January to July 2015, 18 (17%) out of 106 cows presented abortion, six (5.7%) stillbirth, and 12 (11.3%) repeated estrus, totaling 24 animals with reproductive problems. The diagnosis of leptospirosis was based on serology (microscopic agglutination test—MAT), bacteriological culture, and polymerase chain reaction (PCR). Antibiotic therapy, vaccination protocols, and changes in management practices were suggested as control measures. Of all animals on the farm (n?=?280), 136 (48.6%) were seropositive for at least one serovar of Leptospira sp. No pure leptospiral culture was obtained. Eight of the animals with reproductive problems yielded positive PCR results (vaginal fluid of seven animals and urine and vaginal fluid of one animal). Genetic sequencing of a vaginal fluid/urine PCR-positive sample revealed Leptospira borgpetersenii. One year after the adoption of control measures, no reproductive problems were observed. Thus, leptospirosis probably caused the reproductive failures in the herd, and the control and prevention measures implemented were efficient in controlling the disease.

     

Characterization of the LH peak after short and long fixed‐time artificial insemination protocols in sheep raised in the tropics

The aim of this study was to evaluate the peak in luteinizing hormone (LH) and the pregnancy rate of sheep (Texel × Santa Inês) in the tropics using short‐ (6 days) and long‐term (12 days) progesterone protocols followed by artificial insemination (AI) both in and out of the breeding season. Experiment 1 was conducted within (IN) the breeding season (autumn, n = 36), and experiment 2 was conducted outside (OUT) of the breeding season (spring, n = 43). In each experiment, the sheep were divided into two groups (6 or 12 days) according to the duration of treatment with a single‐use progesterone release vaginal device (CIDR^®, Pfizer, São Paulo, SP, Brazil), and blood samples were collected from 10 animals per group every 4 hr to measure the LH and progesterone concentrations. In the spring, the characteristics of the LH peak did not differ between groups; but in the autumn, there were differences between groups at the beginning (G‐6 IN: 36.44 ± 5.46 hr; G‐12 IN: 26.57 ± 4.99 hr) and end of the LH peak (G‐6 IN: 46.22 ± 7.51 hr; G‐12 IN: 34.86 ± 8.86 hr). The results showed alterations in the LH peak during the breeding season only in the sheep undergoing the short‐term protocol.