First Report of Powdery Mildew Caused by Erysiphe platani on Platanus × acerifolia in Rio Grande do Sul, Brazil.

Platanus × acerifolia (Aiton) Willd. (London planetree) is a tree commonly used as an ornamental and in the furniture industry. In the summer of 2013, powdery mildew was observed on shoots of P. × acerifolia plants in the cities of Pelotas and Canela (State of Rio Grande do Sul, Brazil). Voucher specimens (n = 2) were deposited in the Phytopathological Museum Manoel Alves Oliveira at Federal University of Pelotas. Dense white powdery masses of conidia and mycelium were observed on leaves (abaxial and adaxial surfaces), petioles, and young stems. Leaves with high disease severities (≥70%) were deformed with curved edges to the adaxial side, and they often died. Mycelia were superficial with lobed appressoria. Conidiophores were straight, sometimes curved at the base, unbranched, cylindrical, 98 to 236 µm long (137.3 ± 41.2 µm) and composed of a cylindrical foot cell 49 to 102 µm long (66.9 ± 19.5 µm) and 4.4 to 6.4 µm wide (5.3 ± 0.8 µm) followed by two to four cells. Conidia were produced singly or in short chains (two to three), without distinct fibrosin bodies, ellipsoid to ovoid and measuring 24 to 37 µm long (29.5 ± 3.2 µm) and 12 to 19 µm wide (15.2 ± 1.4 µm), often with a wrinkled appearance. Primary conidia had truncate bases and rounded apex while both base and apex were truncated in secondary conidia. Germ tubes were produced apically (pseudoidium type). Chasmothecia were not observed. Genomic DNA was used to amplify the internal transcribed spacer (ITS) region using the ITS1 and ITS4 primers. The resulting sequence (602 bp) was deposited (Accession No. KF499270) in GenBank. BLASTn searches revealed similarity of 100 and 99% with Erysiphe platani from P. orientalis L. (Accession No. JQ365943.1) and P. occidentalis L. (Accession No. JX997805.1), respectively. Phylogenetic analysis placed our sequence in a clade (99% bootstrap support) which included only other E. plantani sequences. In short, morphological and molecular approaches allowed us to identify the infecting fungus as E. platani. For Koch's postulates, 10 detached leaves were inoculated (10 to 15 conidia cm2) on their adaxial surface using an eyelash brush. Non-inoculated leaves served as control. All leaves were kept inside trays with petiole immersed in humidified cotton and maintained at 25 ± 1°C. Symptoms identical to those of the original leaves were observed 6 to 8 days after inoculation, whereas the control leaves remained symptomless. Although E. platani has been previously reported on P. × acerifolia in the city of Poços de Calda, state of Minas Gerais, Brazil (1) and on P. occidentalis in Korea (2), to our knowledge, this is the first record of E. platani on P. × acerifolia in Rio Grande do Sul, Brazil. References: (1) E. M. Inokuti et al. New Dis. Rep. 15:38, 2007. (2) Y. J. La and H. D. Shin. Plant Dis. 97:843, 2013.

[Effect of glucidic and fat total parenteral nutrition on macrophage phagocytosis in rats]. / Influência da nutrição parenteral total em regime glicídico e lipídico sobre a fagocitose de macrófagos de ratos.

Fat lipid emulsions in Total Parenteral Nutrition (TPN) have been associated to Mononuclear Phagocytary System (MPS) changes. Intravenous lipid emulsions may alter macrophage membrane composition but there are controversies about their effects on MPS function. The aim of the present investigation was to assess the influence of fat free TPN and fat emulsions TPN on the macrophage phagocytosis. Wistar rats (70) with external jugular vein canulation were divided in seven groups. The rats received, intravenously (i.v.) different isocaloric (1.16 kcal/mL), isonitrogenous (1.5 g/mL), and isolipidic (30 to 32% of non-proteic caloric value) TPN regimens or oral diet: 1) Group OS: oral diet with i.v. infusion of saline; 2) Group GLU: fat-free TPN; 3) Group LCT: TPN with 10% long chain triglecide emulsion (TCL); 6) Group MCT: TPN with 10% lipid emulsion with medium chain triglycerides (TCM-50%) and TCL (50%). After 96 hours of TPN or saline infusion, colloidal carbon was i.v. injected at 1.0 mL/kg body weight. The rats were sacrificed after three hours. Liver, spleen and lung were weighted and studied by immunohistochemistry by the avidine-biotine method. Under light microscopy the total macrophage number (MT) and colloidal carbon phagocytic macrophages number (MF) were established. Phagocytic index was MT/MF x 100. The results were statistically analysed (p < 0.05). The group under oral diet (OS) was the only one to gain weight. There were no differences in organ weight in any group. There were changes in MT, MF and phagocytic index in all TPN groups. Fat free TPN inhibited liver, spleen and lung macrophage phagocytosis. Fat TPN with TCL inhibited liver and lung macrophage phagocytosis. At conclusion fat free TPN or with long chain tryglicerides may inhibit MPS phagocytosis. Further studies are necessary to estabilish the effect of TPN on other MPS function.

House construction, triatomine distribution, and household distribution of seroreactivity to Trypanosoma cruzi in a rural community in northeast Brazil.

Household distribution of seroreactivity to Trypanosoma cruzi in inhabitants was analyzed in relation to house construction and the distribution of Panstrongylus megistus, the principal domestic vector of Chagas' disease in a rural area in northeast Brazil. No children residing in mud-brick houses were seroreactive to T. cruzi. The highest rates of seroreactivity occurred in residents of unplastered mud-stick houses, and were twice as high as those found in persons living in mud-brick houses or plastered mud-stick houses. Two-thirds of seroreactive children in this area resided in unplastered mud-stick houses. Over 90% of the P. megistus infestations were found in mud-stick houses. Mud-brick houses had the lowest infestation rates of P. megistus and the lowest household rates of seroreactivity to T. cruzi.