Trypanosomatids (Protozoa: Kinetoplastida) in three species of Armored Catfish from Mogi-Guaçu river, Pirassununga, São Paulo, Brazil / Tripanossomatídeos (Protozoa: Kinetoplastida) em três espécies de cascudos do rio Mogi-Guaçu, Pirassununga, São Paulo, Brasil

Abstract Trypanosome infections have been reported in several species of fish, in majority of cases described on the basis of morphological characteristics. Trypanosomes in fish are heteroxenous and transmitted by hirudineans. This study aims to evaluate the prevalence and density of infections by Trypanosoma sp. in blood from three species of catfish, Hypostomus regani, H. strigaticeps, H. albopunctatus, from the Mogi Guaçu River, Pirassununga, São Paulo, Brazil. Further, this study intends to characterize the Trypanosoma specimens found in the blood of these fish by morphological and molecular techniques. The trypanosomes overall prevalence observed was 47.6% with a general average density of 0.75 parasites/µl of blood. Hypostomus regani and Hypostomus strigaticeps showed a significant difference in prevalence. The average densities of parasites were not significantly different among the three fish species. Similar findings were observed for the monthly variations in densities. The parasites found in the three species of catfish studied showed similar morphological characteristics. The morphological data and the statistical analyses used in this study didn’t show the formation of groups. The analyses provided evidence of the presence of pleomorphisms in the trypanosomes found in the three studied fish.

Resumo Infecções por tripanossomas foram descritas em diversas espécies de peixes, sendo a maioria das descrições baseada nas características morfológicas. Tripanossomas de peixes são heteroxenos e transmitidos por hirudíneos. Este estudo tem como objetivo a avaliação da prevalência e densidade da infecção por Trypanosoma sp. no sangue de três espécies de cascudos, Hypostomus regani, H.strigaticeps, H.albopunctatus, do Rio Mogi-Guaçu, Pirassununga, São Paulo, Brasil. Além disso, pretende-se a caracterização das espécies de Trypanosoma encontradas no sangue desses peixes, por meio da utilização de técnicas morfólogicas e moleculares. A prevalência total de tripanossomas foi de 47,6%, e a densidade média foi de 0,75 parasitas/ µl de sangue. Hypostomus regani e Hypostomus strigaticeps apresentaram diferenças significativas em prevalência. As médias das densidades dos parasitas não apresentaram diferenças significativas entre as três espécies de peixes estudadas. O mesmo foi observado com a variação mensal das densidades. Os parasitas encontrados nas três espécies de cascudo possuíam características morfológicas semelhantes. As análises morfológicas e estatísticas obtidas neste estudo não mostraram a formação de grupos. As análises evidenciaram a presença de pleomorfismo dos tripanossomas encontrados nas três espécies de peixes estudados.

Alcohol dehydrogenase activities and ethanol tolerance in Anastrepha (Diptera, Tephritidae) fruit-fly species and their hybrids

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits.

Ultra morphology of the digestive system of Anastrepha fraterculus AND Ceratitis capitata (DIPTERA TEPHRITIDAE)

Anastrepha fraterculus and Ceratitis capitata are widely distributed fruit flies that cause significant damageto fruit crops in tropical and temperate regions. The economic importance of these flies has resulted innumerous studies of their biology, with particular emphasis on their control and management. However,various aspects of the biology of these species are still poorly understood. In this work, we used scanningelectron microscopy (SEM) to examine the external anatomy and organization of the digestive system inthese two species. Adult males and females of A. fraterculus and females of C. capitata were dissected inphysiological saline solution, and the digestive tracts were removed and prepared for microscopy. SEMshowed that the crop was covered by a strong muscular layer that consisted of circular fibers connected bylongitudinal fibers; this arrangement was probably related to the post-feeding behavior of these flies in whichthe crop contents are regurgitated and reingested. The size of the rectum varied and was probably related tothe different body sizes of the two species.

Biological and genetic characteristics of uropathogenic Escherichia coli strains

The aim of the present study was to determine biological characteristics such as expression of fimbriae, Congo red binding, production of hemolysin and aerobactin, adhesion to HeLa and uroepithelial cells and invasion of HeLa cells by Escherichia coli isolates obtained from patients showing clinical signs of urinary tract infection (UTI). Also, the presence of genes (apa, afa, spa) for fimbria expression and cytotoxic necrotizing factors (CNF1, CNF2) was assayed using specific primers in PCR. The data obtained were compared with the clonal relationships obtained by analysis of multilocus enzyme electrophoresis (MLEE), restriction fragment length polymorphism (RFLP) of the rDNA (ribotyping) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). All isolates but one presented a combination of at least two of the characteristics studied, a fact suggesting the presence of pathogenicity islands (PAIs). Diffuse adherence type to HeLa cells was observed to occur in most of the strains, but adhesion to uroepithelial cells seems to be a more reliable test to verify pathogenicity. Although four strains seemed to be able to invade HeLa cells when assayed by light microscopy, electron microscopy studies demonstrated that these strains were not invasive. MLEE, RFLP and ERIC-PCR were able to group the isolates differently into main clusters that were not correlated with the presence of pathogenic traits

Evolutionary trends of alcohol dehydrogenase isozymes in some species of tephritid flies

Com a finalidade de se caracterizar o padräo de evoluçäo das desidrogenases alcoolicas de tefritídeos foram realizados diversos tipos de análise. Através de eletroforese em gel de amido, foram analisadas as ADHs de larvas de alguns tefritídeos e de famílias relacionadas (drosofilídeos e otitídeos). Esta análise revelou uma grande variaçäo quanto ao número de locos que produzem este tipo de enzima. Em Tomoplagia rudolfi, näo se observou qualquer atividade de ADH. Em Acinia fucata, Rachiptera limbata, Rhagoletis nova e R. conversa observou-se apenas um loco, sendo que nas duas primeiras espécies, a enzima correspondente apresentou migraçäo anódica e atividade fortemente preferencial em alcoois de cadeia longa. Esta enzima corresponde ao loco Adh-2 e apresenta comportamento semelhante ao da enzima produzida pelo loco Odh de Drosophila melanogaster. Nas duas espécies estudadas do gênero Rhagoletis, a enzima produzida pelo loco que foi denominado Adh-1 apresentou migraçäo catódica e menor especialidade por substratos alcoólicos, mas ativa principalmente em alcoois de cadeia curta, similar ao observado nas enzimas produzidas pelo loco Adh de Drosophila melanogaster. As larvas de Euxesta eluta (Otitidae)) apresentaram uma ADH que se comportava de modo similar àquela produzida pelas larvas das espécies estudadas de Rhagoletis. Em Ceratitis capitata, Anastrepha grandis, A. fraterculus e A. striata foram observados dois locos, com as características dos locos Adh-1 e Adh-2 já comentadas, mas com especificidade de substrato bem menos pronunciada. Em A. obliqua, A. serpentina e A. bistrigata, foram observados, além destes dois locos, um terceiro (Adh-3), produzindo enzimas com características de migraçäo e especificidade de substrato semelhantes às das enzimas produzidas pelo loco Adh-2. Em A. bistrigata, foi detectado, em parte dos indivíduos o que seria uma enzima correspondente a um quarto loco, com características semelhantes às da enzima produzida pelo loco Odh de D. melanogaster. Medidas de atividade específica de ADH e do conteudo de etanol (principal alcool encontrado) nos frutos hospedeiros de espécies de Anastrepha mostraram haver uma correlaçäo positiva e estatisticamente signioficante entre estes parâmetros