ABSTRACT
Protozoan parasites, such as Leishmania spp., are the causative agents of many insect-borne infectious diseases with medical and veterinary importance. Leishmaniasis, caused by Leishmania spp., is transmitted by female phlebotomine sand flies. In the Alentejo region of Portugal, located at the north of Algarve, cases of human and canine leishmaniasis caused by Leishmania infantum have been notified. However, no recent studies regarding the sand fly fauna in the region are available. We therefore aimed to explore the phlebotomine sand fly species found in both, Évora and Beja Districts, to gain an insight about the leishmaniasis epidemiology in these areas. After the identification of the insect species, PCR molecular tests were used to assess L. infantum infection rate in the sand fly captured females, together with the analysis of blood meal sources of the insect vectors. One Sergentomyia minuta female was positive for L. infantum infection and another for human blood as a meal source. The occurrence of this phlebotomine species infected with L. infantum may suggest that, in the Mediterranean basin, leishmaniasis epidemiology is changing. Also, if the importance of S. minuta for the zoonotic and anthroponotic cycle of leishmaniasis is later proven, the strategies to control its vector will inevitably to be rethought.
Subject(s)
Dog Diseases/parasitology , Insect Vectors/parasitology , Leishmania infantum/isolation & purification , Leishmaniasis/veterinary , Phlebotomus/parasitology , Animals , Dog Diseases/epidemiology , Dogs , Female , Humans , Leishmania infantum/genetics , Leishmaniasis/epidemiology , Leishmaniasis/parasitology , Leishmaniasis/transmission , Polymerase Chain Reaction , Portugal/epidemiology , Psychodidae/parasitologyABSTRACT
The sand fly Lutzomyia (Lutzomyia) elizabethrangelae sp. nov. is described and illustrated based on the morphological characters of male and female specimens captured in sandstone caves in the municipality of Palmeirópolis, in the southern region of Tocantins state. The samples were collected as part of an entomological vector-monitoring project during the construction of the Peixe Angical Hydroelectric Plant. Based on the morphological characters of the new species, we believe this species can be included in the subgenus Lutzomyia. This species is closely related to two others, Lutzomyia forattinii Galati et al. 1985 and Lutzomyia almerioi Galati and Nunes 1999. The new species can be distinguished from Lutzomyia forattinii and Lutzomyia almerioi by the morphological characteristics of the male genitalia and the female cibarium.
Subject(s)
Psychodidae/anatomy & histology , Psychodidae/classification , Animals , Brazil , Caves , Female , MaleABSTRACT
The immunization of vertebrate hosts with vector components may be an alternative for the control of diseases transmitted by insects. In the present study we evaluated the effects of anti-sandfly antibodies on some of the biological parameters of female Lutzomyia longipalpis, a vector of visceral leishmaniasis. Rabbits were immunized with extracts of gut from blood-fed (GB) or sugar-fed (GS) females, carcass of sugar-fed (CS) or blood-fed (CB) females, and with repeated sandfly bites (BITE). Immune sera showed increased antibody titers compared to pre-immunized animals, and specific bands were detected by Western Blot. An analysis of biological parameters revealed a decline in fecundity in the group of females fed on rabbits immunized with GB and BITE. Longevity and mortality were studied in females with oviposition (parous) and without oviposition (nulliparous). Nulliparous females that fed on rabbits immunized with bites died in the highest percentage. A mortality analysis after egg laying revealed a peak on the fifth day in all the groups, but females fed on rabbit subjected to repeated bites showed a shift towards the third day.
Subject(s)
Antibodies/immunology , Immune Sera/pharmacology , Insect Vectors/immunology , Psychodidae/immunology , Animals , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Female , Fertility , Longevity , RabbitsABSTRACT
A imunização de hospedeiros vertebrados com componentes derivados de vetores pode se constituir numa estratégia alternativa para o controle de doenças transmitidas por insetos. No presente estudo avaliamos o efeito de anticorpos antiflebótomos sobre alguns parâmetros biológicos de fêmeas de Lutzomyia longipalpis, vetor de leishmaniose visceral. Coelhos foram imunizados com extratos de tubos digestivos de fêmeas alimentadas com açúcar (GS), fêmeas alimentadas com sangue (GB), carcaças de fêmeas alimentadas com açúcar (CS) ou carcaças de fêmeas alimentadas com sangue (CB), e coelho imunizado por repetidas picadas de fêmeas de flebótomos (BITE). Os soros imunes de coelhos apresentaram títulos aumentados quando comparados com os soros pré-imunes, e bandas específicas foram detectadas por meio de Western Blot. A análise dos parâmetros biológicos revelou um decréscimo na fecundidade no grupo de fêmeas alimentadas em coelho imunizado com GB e BITE. A longevidade e a mortalidade foram estudadas em fêmeas com postura (paridas) e fêmeas sem postura (nulíparas). Fêmeas nulíparas que se alimentaram em coelho imunizado por repetidas picadas morreram em maior percentual. A análise da mortalidade, após a postura dos ovos, revelou um pico no quinto dia em todos os grupos, mas em fêmeas que se alimentaram em coelho submetido a repetidas picadas, foi antecipada para o terceiro dia.
Subject(s)
Rabbits , Animals , Female , Antibodies/immunology , Immune Sera/pharmacology , Insect Vectors/immunology , Psychodidae/immunology , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Fertility , LongevityABSTRACT
During two consecutive years, studies on the sand fly fauna in Poço das Antas and Fazenda Bom Retiro, two Atlantic Rain Forest Reserves from the State of Rio de Janeiro, were performed using Shannon traps, CDC light traps and human bait collections. Eleven species were identified; Lutzomyia longipalpis, L. migonei, L. edwardsi, L. intermedia, L. whitmani, L. fischeri, L. shannoni, L. ayrozai, L. hirsuta, L. monticola and L. misionensis (first occurrence in the State of Rio de Janeiro). L. intermedia and L. whitmani were the predominant anthropophilic species around houses, while L. hirsuta predominated in the forest.
Subject(s)
Ecosystem , Psychodidae/classification , Trees , Animals , Brazil , Female , Humans , Male , SeasonsABSTRACT
Molecular studies of insect disease vectors are of paramount importance for understanding parasite-vector relationship. Advances in this area have led to important findings regarding changes in vectors' physiology upon blood feeding and parasite infection. Mechanisms for interfering with the vectorial capacity of insects responsible for the transmission of diseases such as malaria, Chagas disease and dengue fever are being devised with the ultimate goal of developing transgenic insects. A primary necessity for this goal is information on gene expression and control in the target insect. Our group is investigating molecular aspects of the interaction between Leishmania parasites and Lutzomyia sand flies. As an initial step in our studies we have used random sequencing of cDNA clones from two expression libraries made from head/thorax and abdomen of sugar fed L. longipalpis for the identification of expressed sequence tags (EST). We applied differential display reverse transcriptase-PCR and randomly amplified polymorphic DNA-PCR to characterize differentially expressed mRNA from sugar and blood fed insects, and, in one case, from a L. (V.) braziliensis-infected L. longipalpis. We identified 37 cDNAs that have shown homology to known sequences from GeneBank. Of these, 32 cDNAs code for constitutive proteins such as zinc finger protein, glutamine synthetase, G binding protein, ubiquitin conjugating enzyme. Three are putative differentially expressed cDNAs from blood fed and Leishmania-infected midgut, a chitinase, a V-ATPase and a MAP kinase. Finally, two sequences are homologous to Drosophila melanogaster gene products recently discovered through the Drosophila genome initiative.
Subject(s)
Expressed Sequence Tags , Gene Expression Profiling/methods , Psychodidae/genetics , RNA, Messenger/genetics , Random Amplified Polymorphic DNA Technique/methods , Animals , Female , Genetic Variation/genetics , Insect Vectors/geneticsABSTRACT
There are very few reports on the microbiota of the digestive tract of sand flies, an important omission considering that blood is not the only meal ingested. Male and female sand flies obtain sugar meals from several sources, thereby increasing their chance of infection with microorganisms. Chances of contamination are higher when insects are bred in the laboratory, and this may affect the development of Leishmania spp. From the digestive tract of 300 sand fly females separated in two groups we isolated 10 species of bacteria in group 1 and 8 species in group 2. In group 1, Enterobacteriaceae of the following genera were identified: Serratia, Enterobacter, and Yokenella and the non-fermenters: Pseudomonas, Acinetobacter, and Stenotrophomonas. In group 2, the Enterobacteriaceae Enterobacter and Serratia were identified as well as the non-fermenters Acinetobacter, Stenotrophomonas, Burkolderia, and Pseudomonas.
Subject(s)
Digestive System/microbiology , Malpighian Tubules/microbiology , Psychodidae/microbiology , Animals , Blood , Carbohydrates , Female , FoodSubject(s)
Psychodidae/growth & development , Animals , Entomology/methods , Female , Food , Larva , MaleABSTRACT
The municipality of Ilhéus, State of Bahia, has a focus of cutaneous leishmaniasis where entomological studies were carried out to determine the sand fly species and their habits. Lutzomyia migonei, L. sallesi, L. tupynambai, L. schreiberi, L. intermedia, L. whitmani, L. yuilli yuilli, L. fischeri, L. pessoai, L. shannoni and L. misionensis were identified. Lutzomyia whitmani was the predominant species. Specimens were collected indoors, at peridomestic sites, in the cocoa plantations and in other types of collections. Females fed readily on humans and were attracted to domestic animals. Our evidence suggests that L. whitmani is a probable vector.
Subject(s)
Leishmania braziliensis/physiology , Leishmaniasis, Cutaneous/parasitology , Psychodidae/parasitology , Animals , Brazil , Insect VectorsABSTRACT
Schneider's Drosophila medium, a complex amino acid rich medium was tested alone and with seven different sugars for some aspects of the biology of Lutzomyia longipalpis. Statistically significant results were obtained when sucrose was used alone, indicating that among the sugars tested, this is still the most suitable and practical one for the maintenance of L. longipalpis colonies. However, the addition of Schneider's medium to a pool of different sugars, was suggested to be related with the acceptance of the first and second blood meals and to longevity, these being, obviously, quite relevant aspects when transmission experiments are contemplated.
Subject(s)
Psychodidae/physiology , Amino Acids/blood , Animals , Carbohydrates/blood , Feeding Behavior , Female , Longevity/physiology , Oviposition/physiologySubject(s)
Food Preferences , Psychodidae/physiology , Animals , Brazil , Chickens , Dogs , Ecology , Humans , PerissodactylaABSTRACT
Sao relatados os resultados obtidos de uma pesquisa de anticorpos anti-mielina nos soros e liquidos cefalorraquianos de 11 pacientes com doencas neurologicas supostamente desmielizantes. A tecnica utilizada foi de imunofluorescencia indireta usando-se como marcadores soro de cabra anti-imunoglobulina (IgG, IgA e IgM) e de coelho anti-IgM humano
