Genetic characterization of rabies viruses isolated from frugivorous bat (Artibeus spp.) in Brazil

In Latin America, rabies cases related to frugivorous bats have been reported since 1930's. Recently, two viruses isolated from Artibeus lituratus were proved to be vampire bat variants by monoclonal antibodies panels [2], but their genetic information is not well known. In this report, four rabies viruses were isolated from frugivorous bats (Artibeus spp.) in Brazil and their nucleoprotein gene sequences were determined. These isolates were found to be genotype 1 of lyssavirus and showed the maximum nucleotide sequence homology of 97.6-99.4% with vampire bat-related viruses in Brazil [6]. These results indicate that the Brazilian frugivorous bat rabies viruses in this study are closely related to vampire bat-related viruses that play a main role in rabies virus transmission to livestock in Brazil.     

Usefulness of an early diagnosis for the favorable prognosis of fibrocartilaginous embolism diagnosed by magnetic resonance imaging in 10 Small- to Middle-Sized Dogs

Fibrocartilaginous embolism (FCE), a disorder of rapid onset featured by nonprogressive paralysis and paresis of four legs, shows clinical symptoms very similar to those of other disorders, e.g., disk herniation. We examined 10 animals diagnosed with FCE based on clinical symptoms and magnetic resonance imaging (MRI) findings in a retrospective study to examine the relationship between onset-to-diagnosis/treatment initiation time and prognosis of FCE. Statistical procedures, including Fisher’s exact probability test, were conducted. All animals in a group, in which the diagnosis was made and treatment was initiated after an elapse of <15 days after onset, showed improved symptoms; the group showed a positive correlation (r = 0.76) between “onset-to-symptom improvement time” and “onset-to-diagnosis/treatment initiation time”. Furthermore, the mean onset-to-diagnosis/ treatment initiation times were 2.67 days and 10.25 days in groups without and with sequelae, respectively; the time was significantly (P < 0.02) shorter in the group without sequelae. A significant difference was found between the groups in early diagnosis and treatment initiation. Our study indicates that the early precise diagnosis for acutely developed paralysis and paresis of four legs through testings including MRI, as well as the early onset of their treatment are important to obtain a favorable prognosis.     

The survival of pathogenic bacteria and plant growth promoting bacteria during mesophilic anaerobic digestion in full‐scale biogas plants

The introduction of biogas plants is a promising way to recycle organic wastes with renewable energy production and reducing greenhouse gas. Application of anaerobic digestate as a fertilizer reduces the consumption of chemical fertilizers. In this study, the survival of pathogenic bacteria and plant growth promoting bacteria (PGPB) in two full‐scale biogas plants operated at mesophilic condition were investigated. Feedstock and anaerobic digestate samples were collected from biogas plants and bacteria load in samples were detected using standard dilution plate method. Pathogenic bacteria were reduced to not detected level through mesophilic digestion tank except for Campylobacter. However, it could be reduced by 98.7% through a sterilization tank. Bacillus was detected at 8.00 and 7.81 log₁₀ CFU/g dry matter in anaerobic digestates, and it was also resistant to sterilization tank. Bacillus spp. is considered to be the safe bacteria that hold remarkable abilities for promoting plant growth. The results showed that treatment at biogas plants is effective to reduce pathogenic bacteria in dairy manure, and sterilization could further reduce the sanitary risks of pathogenic bacteria relating to anaerobic digestate application. Anaerobic digestates could also be utilized as bio‐fertilizer as the high load of plant growth promoting bacteria.     

Cutaneous mastocytosis with a mutation in the juxtamembrane domain of c-kit in a young laboratory beagle dog

Cutaneous mastocytosis, which resembles a subset of urticaria pigmentosa in humans, is rare in dogs. We herein report unrepresentative neoplastic proliferation of mast cells in ventral skin removed routinely from a nine-month-old female laboratory beagle dog at necropsy. A histological examination revealed diffuse extensive cellular infiltration from the superficial to deep dermis in most parts of the skin around the fourth and fifth mammary papilla without nodule formation. Tumor cells were fairly monomorphic, well-differentiated mast cells with round nuclei of small distinct nucleoli and moderate to abundant, slightly eosinophilic and granular cytoplasm. A perivascular arrangement of mast cells was noted at the margin of the lesions. Infiltration of eosinophils and degeneration of collagen were not observed in the dermis. Cutaneous mastocytosis was diagnosed based on these features. A sequence analysis of lesions revealed the deletion of Gln₅₅₅ to Ile₅₇₀ within the juxtamembrane domain of c-kit (exon 11).     

Inhibitory effects of green tea polyphenols on the production of a virulence factor of the periodontal-disease-causing anaerobic bacterium Porphyromonas gingivalis

The effect of polyphenolic compounds isolated from green tea (Camellia sinensis) on the production of toxic end metabolites of Porphyromonas gingivalis was investigated. Green tea polyphenols completely inhibited the production of n-butyric acid and propionic acid at a concentration of 1.0-2.0 mg/mL in general anaerobic medium (GAM). (-)-Epigallocatechin gallate (EGCg), which is a major component of tea polyphenols also inhibited the production of phenylacetic acid at 0.5 mg/mL in GAM broth. In the experiment using resting cells of P. gingivalis, phenylacetic acid was produced from l-phenylalanine and phenylpyruvic acid, but this reaction was also inhibited by EGCg, (-)-epicatechin gallate, and (-)-gallocatechin gallate. However, (+)-catechin, (+)-gallocatechin, (-)-epicatechin, and (-)-epigallocatechin did not inhibit those reactions. These results indicate that the inhibitory effect on the production of toxic end metabolites of P. gingivalis can be attributed to the presence of the galloyl moiety, which is ester-linked with the 3-OH of the catechin moiety in the polyphenolic compounds. This study shows that continuous application of tea polyphenols on a daily basis can be considered as a useful and practical method for the prevention of periodontal diseases.     

Effects of exogenous application of proline and betaine on the growth of tobacco cultured cells under saline conditions

The effects of the application of exogenous proline and betaine on the growth of tobacco cultured cells subjected to salt stress were investigated. Both proline and betaine mitigated the inhibition of growth of tobacco cells under saline conditions, but the harmful effect of salinity was less reduced by betaine than by proline. The amount of intracellular betaine in tobacco cells cultured in the NaCI medium supplemented with 20 mm betaine was larger than that of intracellular proline in the NaCI medium with 20 mm proline. The 1,1-diphenyl2-picrylhydrazyl (DPPH) experiments showed that proline displayed an antioxidant activity and that the antioxidant activity of betaine was not detectable. The malondialdehyde (MDA) assay demonstrated that exogenous proline but not betaine decreased the amount of MDA in salt-stressed tobacco cells. These results suggest that the difference in the mitigation effects between proline and betaine may be responsible for the difference in the antioxidant activity.     

Importance of cucurbits in the epidemiology of Papaya ringspot virus type P

Papaya ringspot virus type P (PRSV‐P) systemically infects Carica papaya and species belonging to the family Cucurbitaceae. Attempts to recover PRSV‐P from naturally infected cucurbit plants grown near or among diseased papaya trees have shown conflicting results worldwide. This study aimed to evaluate the natural infection of cucurbit species grown among and near papaya trees infected with PRSV‐P in Brazil. Natural infection of cucurbits with PRSV‐P occurred in zucchini squash but not in watermelon and cucumber. However, several attempts to recover PRSV‐P from numerous Cucurbita pepo cv. Caserta (zucchini squash) plants grown 5–80 m from diseased papaya trees in the field failed. Mechanical inoculations of Cucurbita pepo cv. Caserta, Cucurbita maxima cv. Exposição (pumpkin), Cucumis sativus cv. Primepack Plus (cucumber) and Citrullus lanatus cv. Crimson Sweet (watermelon) with five Brazilian PRSV‐P isolates showed that zucchini squash was the most susceptible species followed by watermelon and cucumber, while pumpkin was not infected. The results confirmed the variable susceptibility of cucurbit species to experimental and natural PRSV‐P infection. Given these facts, the control of the disease through roguing should focus mainly on diseased papaya plants, as has been practised successfully in Brazil for many years, and on those cucurbits particularly known to be susceptible to natural infection with PRSV‐P.     

Infection-inhibition activity of avenacin saponins against the fungal pathogens Blumeria graminis f. sp. hordei, Bipolaris oryzae, and Magnaporthe oryzae

Triterpenoid saponins are sugar-modified triterpene derivatives. Cereals and other grasses are generally deficient in these secondary metabolites with the exception of oat. Oat accumulates antimicrobial triterpenoid saponins in its roots. These oat-root-derived compounds, called avenacins, confer broad-spectrum resistance to soil-borne pathogens. Here, we tested the effect of avenacins on the development of infection structures of fungal pathogens Blumeria graminis f. sp. hordei and Bipolaris oryzae and Magnaporthe oryzae. We show that avenacins are able to inhibit the infection process of these phytopathogens on plant hosts.     

H2O2 production by copper amine oxidase, a component of the ecto-apyrase (ATPase)-containing protein complex(es) in the pea cell wall, is regulated by an elicitor and a suppressor from Mycosphaerella pinodes

Blue native PAGE analysis for cell wall proteins from pea epicotyls demonstrated that cell wall-associated ecto-apyrase (ATPase) formed a large protein complex(es) ranging from 450 to 900?kDa; one of the components of the complex was copper amine oxidase (CuAO), which catalyzes the oxidation of amines with the subsequent generation of ammonia and hydrogen peroxide. CuAO activity was coordinately regulated in vitro with ATP-hydrolyzing activity by an elicitor and a suppressor from Mycosphaerella pinodes. Moreover, treatment of cell wall proteins with the suppressor caused the appearance of the apyrase monomer. On the basis of these results, M. pinodes may target the apyrase-containing protein complex(es) of the host to attenuate cell wall-based, extracellular defense(s) including the production of hydrogen peroxide.