Orientadora: Profª Drª Helena Beatriz de Carvalho Ruthner Batista / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, 2017. / Apesar de ser uma das doenças mais antigas que se tem registro a raiva ainda é um desafio para a Saúde Pública. Esta zoonose acomete o sistema nervoso central (SNC) de todos os mamíferos sendo considerada fatal, porém foram registrados casos de cura no mundo que impulsionaram pesquisas na busca por potenciais mecanismos antivirais que atuem contra o vírus da raiva (RABV). O objetivo deste trabalho foi avaliar o efeito antiviral do extrato vegetal hidroetanólico derivado de Dalbergia variabilis contra diferentes linhagens do RABV. Inicialmente, foi determinada a concentração máxima tolerada (CMT) do extrato vegetal em células de neuroblastoma de murino (N2a), sendo 1,56 mg/ml identificada como CMT. A atividade antiviral do extrato vegetal derivado da Dalbergia variabilis foi avaliada pela diferença no título viral infeccioso expresso em doses infectantes em 50% do cultivo celular (DICC50), na presença e na ausência do extrato frente a quatro amostras de RABV (IP4005 - amostra de RABV com linhagem genética característica de morcego hematófago Desmodus rotundus, IP964 - amostra de RABV com linhagem genética característica de morcego insetívoro Eptesicus furinalis, IP4871 - amostra de RABV com linhagem genética característica de cachorro do mato Cerdocyon thous e amostra padrão do vírus da raiva "Pasteur vírus" - PV). Uma vez que houve diferença no título viral infeccioso entre as amostras de RABV analisadas na presença e na ausência do extrato vegetal, foram realizados experimentos subsequentes a fim de compreender melhor a forma de atuação deste extrato vegetal frente ao RABV. Foi possível identificar ação antiviral do extrato vegetal derivado de Dalbergia variabilis frente a amostras de RABV analisadas, através dos resultados obtidos, sendo que a interferência na replicação viral foi mais significativa frente a amostras de RABV com linhagem genética de morcegos. / Despite its status as one of the oldest registered diseases, rabies remains a public health challenge. This zoonosis affects the central nervous system (CNS) of all mammals and is usually considered fatal. However, some cases in which the disease was reportedly cured have been registered worldwide, leading to renewed interest in researching potential antiviral mechanisms against the rabies virus (RABV). The aim of this work was to evaluate the antiviral activity of the hydroethanolic plant extract Dalbergia variabilis against different genetic lineages of RABV. In the first step, the maximum tolerated concentration (MTC) of plant extract in murine neuroblastoma cells (N2a) was determined to be 1.56 mg/ml. The antiviral activity of plant extract Dalbergia variabilis was evaluated to determine the difference presence and absence of the plant extract in four samples of RABV (IP4005- sample of RABV with the genetic lineage characteristic of haematophagous bat, Desmodus rotundus; IP964- sample of RABV with the genetic lineage characteristic of insectivorous bat, Eptesicus furinalis; IP4871- sample of RABV with the genetic lineage characteristic of wild dog, Cerdocyon thous; and a standard sample of RABV, "Pasteur vírus" - PV). Since there was a difference in the infectious viral titer between the RABV samples analysed in the presence of the plant extract, subsequent experiments were carried out to better understand the performance of this plant extract against RABV. The antiviral activity of plant extract Dalbergia variabilis against samples of RABV was analysed, and the interference in viral replication was more significant against samples of RABV with genetic lineage characteristic of bats.

A study of the life history and ecology of Camelobaetidius variabilis was conducted in Honey Creek, OK from February 2003-April 2004. Nymph development was assessed using changes in external morphology. Laboratory reared nymphs were used to calculate number of degree days to complete development (772 degree days at 20.8° C ±.38° C), which was used to determine voltinism. Field collected nymph microhabitat distribution was used in assessing microhabitat distribution. Nymphal thermoregulation was assessed during the winter and spring by comparing nymphal numbers present in shaded and un-shaded habitats. Camelobaetidius variabilis nymphs showed preference for algal microhabitats during the spring and leaf packs in the winter. Nymphs inhabited leaf packs to increase metabolic rate during the winter. Increased temperatures aid in development of nymphs. Camelobaetidius variabilis exhibited a multivoltine life cycle with six overlapping generations.

Ce projet de recherche porte sur l’étude de la contamination de la côte libanaise par les composés organiques (HAP, DDE) et par les éléments-trace métalliques (Hg, Pb principalement). Les travaux sur les compartiments sédimentaires et biologiques de la côte libanaise constituent deux parties aux problématiques et aux approches distinctes autour desquelles s’articule cette thèse. Dans la première partie, l’analyse d’une carotte sédimentaire datée prélevée sur le plateau continental du Sud du Liban a permis de reconstituer l’historique de contamination dans le bassin Levantin. Les analyses de contaminants dans les sédiments de la carotte C1 combinés à la datation aux 210Pb et 137Cs ont permis d’obtenir un enregistrement fiable des variations du dépôt de mercure, de plomb et de HAP sur le plateau continental libanais, dans le bassin Levantin. Bien que les concentrations et les flux soient relativement faibles, une augmentation en deux phases des concentrations est bien mise en évidence par le profil sédimentaire de C1. Le charbon est identifié comme source principale de Pb, de Hg et de HAP dans le bassin Levantin entre la moitié du 19ème siècle et la moitié du 20ème siècle. Les résultats des ratios isotopiques du Pb et des ratios diagnostiques de HAP appuient ce constat. Les archives sédimentaires dans la carotte C1 fournissent un signal du dépôt de contaminants à l’échelle globale probablement lié aux sources d’émissions atmosphériques en provenance d’Europe Centrale et de l’Est. Dans la seconde partie, une étude de la contamination par les HAP du littoral libanais est menée suite à la marée noire résultant du conflit armé israélo-libanais en 2006. Une approche de biomonitoring sur trois ans utilisant l’espèce de moules invasives Brachidontes variabilis a été développée. Les résultats indiquent une décroissance progressive des concentrations de HAP dans l’écosystème intertidal du littoral libanais. La contamination par les HAP du fioul en zone subtidale en 2007 est nettement plus faible. Cependant la signature des HAP dans les tissus de moules prélevées trois ans après la marée noire indique toujours la présence des composés du fioul de Jiyeh. La contamination est particulièrement persistante dans certaines zones fortement touchées par la nappe de fioul en 2006. Il apparaît que l’état initial pré-marée noire n’a pas été atteint, même trois ans après la marée noire de Jiyeh. L’examen détaillé de l’évolution spatiale et temporelle de la contamination par les HAP de l’environnement intertidal est présenté dans ce volet de notre étude. / This research project aims at the study of the contamination of the Lebanese coast by PAHs, DDE, Hg and Pb. The research work is divided into two distinct parts concerning two environmental compartments (sedimentary and biological) and it addresses different questions and approaches. In the first part, the study of a dated sediment core raised from the continental shelf in southern Lebanese coast allowed reconstructing the contamination history in the Levantine basin. The contaminants’ analysis as well as 210Pb and 137Cs datation allowed obtaining a reliable record of mercury, lead and PAHs sedimentary deposition in the Lebanese continental margin in the Levantine basin. Although concentrations and fluxes are relatively low, a two-phase increase of concentration is found using C1 core sedimentary profiles. Coal was identified as the main source of Pb, Hg and PAHs in the Levantine basin between the mid 19th and the mid 20th century. Ratios of Pb stable isotopes and PAH diagnostic ratios support this assumption. The studied sedimentary archives provide also information on the deposition of contaminants on a global scale possibly related to atmospheric emissions mainly from Central and Eastern Europe. In the second part of the thesis, the study of contamination by PAHs of the Lebanese coast was undertaken following an oil spill in the south of Lebanon, which occurred after the bombardment by the Israeli military of the electric power plant in Jiyeh in 2006. We have set-up a biomonitoring program with an invasive mussel specie Brachidontes variabilis over a three-year study. Results indicate a progressive decrease of PAH concentrations in the intertidal ecosystem of the Lebanese coast. Contamination of the subtidal zone in 2007 by Jiyeh fuel oil was significantly lower. However, Jiyeh fuel oil signature was still detectable in mussel tissues even three years after the oil spill. Contamination was found to be particularly persistent in some of the highly oiled sites. It appears that pre-spill state was still not reached even three years following the oil spill. Detailed investigation of spatio-temporal changes of intertidal mussels contamination by PAH is also presented in this part of the thesis.

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Little is understood about off-host behavior and ecology of immature Amblyomma maculatum Koch (Gulf Coast tick). A more complete understanding of this tick is essential to protect human and animal health. My research focused on seasonality and distribution of immatures in Mississippi, potential suitability of some insect and human hosts to larvae, and aspects of nymphal questing behavior. A single larva was collected (third off-host collection reported) when sampling A. maculatum habitat using a novel device. Collection of this larva in November expands the stage’s known seasonality and confirmed a prediction concerning seasonality of larval A. maculatum. Low frequency of immatures (8.3%) confirmed that they’re incredibly difficult to collect off-host. Nymphal collections peaked in March, and known seasonality was extended for both nymphs and adults. I examined known records, elucidating seasonality and distribution of A. maculatum in Mississippi. Either multiple generations per year or diapause are responsible for observed bi-modal distribution of immature collections. Additionally, I compiled the most extensive host record of immature A. maculatum in Mississippi and investigated seasonality patterns using USDA plant hardiness zones. I compiled the most complete record of ticks found on arthropods. Amblyomma americanum and A. maculatum were both confirmed to crawl onto arthropods, giving support to occasional, unintentional dispersal by phoresy. There was no conclusive evidence that larval A. maculatum feed on arthropods, however data supported feeding by larval A. americanum. These results have interesting implications regarding evolution of pathogens/endosymbionts. I provided the first evidence that larval A. maculatum can attach to humans. Rickettsia parkeri, a human pathogen transmitted by this species has recently been shown to be capable of transovarial transmission. Therefore, larval A. maculatum may provide another avenue of transmission. I have demonstrated that A. maculatum are difficult to collect off-host in part because they prefer to quest low to the ground. In choice studies, 5-cm-tall stems were most likely to be occupied by nymphs released into an array of stems. Low vapor pressure deficit encouraged questing, while higher VPD and warmer temperature increased questing height. These results may have implications in understanding host-seeking behavior in other tick species as well.