Elucidating in vitro and in vivo phenotypic behaviour of L. infantum/L. major natural hybrids.

The clinical manifestation and course of Leishmania infections depend on factors such as species, virulence and host-immunity. Although trypanosomatids are considered to have clonal propagation, genetic hybridization has produced successful natural hybrid lineages. Hybrids displaying strong selective advantages may have an impact on pathogenesis and the eco-epidemiology of leishmaniasis. Thus, characterization of phenotypic properties of Leishmania hybrids could bring significant insight into the biology, infectivity, pathogenicity and transmission dynamics of these atypical strains. The present study focuses on phenotypic features and survival capacity of Leishmania infantum/Leishmania major hybrid isolates as compared with representative putative parental species, L. infantum and L. major. In vitro assays (growth kinetics, susceptibility to different conditions) and in vivo infection (parasite detection and histopathological alterations) showed that hybrids present higher growth capacity and decreased susceptibility to reactive oxygen species. Furthermore, evaluation of infected spleen tissue suggests that hybrids induce a stronger immune reaction than their putative parents, leading to the development of white pulp hyperplasia in B-lymphocyte compartments. Overall, these hybrids have shown high plasticity in terms of their general behaviour within the different phenotypic parameters, suggesting that they might have acquired genetic features conferring different mechanisms to evade host cells.

Identification of QTLs of resistance to white mold in common bean from multiple markers by using Bayesian analysis.

In this study, we identified simple sequence repeat, ampli-fied fragment length polymorphism, and sequence-related amplified poly-morphism markers linked to quantitative trait loci (QTLs) for resistance to white mold disease in common bean progenies derived from a cross between lines CNFC 9506 and RP-2, evaluated using the oxalic acid test and using Bayesian analysis. DNA was extracted from 186 F2 plants and their parental lines for molecular analysis. Fifteen experiments were car-ried out for phenotypic analysis, which included 186 F2:4 progenies, the F1 generation, the F2 generation, and the lines CNFC 9506, RP-2, and G122 as common treatments. A completely randomized experimental design with 3 replications was used in controlled environments. The adjusted means for the F2:4 generation were to identify QTLs by Bayesian shrink-age analysis. Significant differences were observed among the progenies for the reaction to white mold. The moving away method under the Bayes-ian approach was effective for identifying QTLs when it was not possible to obtain a genetic map because of low marker density. Using the Wald test, 25 markers identified QTLs for resistance to white mold, as well as 16 simple sequence repeats, 7 amplified fragment length polymorphisms, and 2 sequence-related amplified polymorphisms. The markers BM184, BM211, and PV-gaat001 showed low distances from QTLs related white mold resistance. In addition, these markers showed, signal effects with increasing resistance to white mold and high heritability in the analysis with oxalic acid, and thus, are promising for marker-assisted selection.

Reaction of common bean lines and aggressiveness of Sclerotinia sclerotiorum isolates.

The aims of this study were to evaluate the reaction of common bean lines to white mold, the aggressiveness of different Sclerotinia sclerotiorum isolates from various common bean production areas in Brazil, and comparison of the diallel and GGE (genotype main effect plus genotype-by-environment interaction) biplot analysis procedures via study of the line-by-isolate interaction. Eleven common bean (Phaseolus vulgaris) lines derived from 3 backcross populations were used. Field experiments were performed in the experimental area of the Departamento de Biologia of the Universidade Federal de Lavras, Lavras, MG, Brazil, in the 2011 and 2012 dry crop season and 2011 winter crop season through a randomized block design with 3 replications. This study was also set up in a greenhouse. Inoculations were performed 28 days after sowing by means of the straw test method. The reaction of the bean lines to white mold was assessed according to a diagrammatic scale from 1 (plant without symptoms) to 9 (dead plant). Estimations of general reaction capacity (lines) and general aggressiveness capacity (isolates) indicated different horizontal levels of resistance in the lines and levels of aggressiveness in the isolates. Therefore, it was possible to select more resistant lines and foresee those crosses that are the most promising for increasing the level of resistance. It was also possible to identify the most aggressive isolates that were more efficient in distinguishing the lines. Both diallel and GGE biplot analyses were useful in identifying the genotypic values of lines and isolates.

Oral myiasis caused by sarcophagidae in an extraction wound.

Oral myiasis (infestation by the larvae of Diptera flies) has only rarely been reported in the English-language literature. This article records a case of wound myiasis caused by flies of the family Sarcophagidae that affected a tooth-extraction site, and was a painful complication of the extraction.