Leishmania (Viannia) lainsoni (Kinetoplastida: Trypanosomatidae), a divergent Leishmania of the Viannia subgenus: a mini review

Leishmania (Viannia) lainsoni is the Leishmania species that presents the most distinct biological (morphology, growth in axenic culture medium), biochemical (enzymatic electrophoresis profile), and molecular biology characteristics, when compared to other species of the Viannia subgenus. Development of promastigote forms of this parasite attached to the wall of the pyloric and hind gut regions of sand fly vectors is a solid characteristic that allows its positioning in the Viannia subgenus. However, taxonomic data from biochemical and molecular techniques on this Leishmania species are still not conclusive. It is evident the difficulty in taxonomically positioning this borderline Leishmania species. In this review we present the data accumulated since L. (Viannia) lainsoni has been described and we discuss its position in the Viannia subgenus.

Ingestion of saliva during carbohydrate feeding by Lutzomyia longipalpis (Diptera; Psychodidae)

The aim of this study was to obtain experimental evidence that phlebotomine saliva is actually ingested during the carbohydrate ingestion phase (before and after blood digestion). The ingestion of carbohydrate was simulated as it occurs in the field by offering the insects balls of cotton soaked in sucrose, sucrose crystals or orange juice cells. The results obtained here showed that ingestion occurred under each condition investigated, as indicated by the presence of apyrase, an enzyme used as a marker to detect saliva in the insect gut and/or carbohydrate sources. Saliva ingestion by phlebotomine during the carbohydrate ingestion phase is important to explain how it could promote starch digestion and to trigger Leishmania promastigotes to follow a differentiation pathway as proposed previously by some authors.

Single and concomitant experimental infectionsby Endotrypanum spp. and Leishmania (Viannia) guyanensis (Kinetoplastida: Trypanosomatidae) in the Neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae)

Lutzomyia longipalpis females received single and mixed infections with Endotrypanum and Leishmania. Two biological parameters were analyzed: the percentage of infected females and the distribution of flagellates in the gut of the females. The principal comparisons were performed between (1) two strains of Endotrypanum, (2) cloned versus primary sample of one strain of Endotrypanum, (3) Endotrypanum versus Leishmania guyanensis, and (4) the pattern of flagellates behaviour by optical microscopy in females with single or mixed infection versus the identification of parasites isolated from digestive tracts by isoenzyme electrophoresis. Flagellates of Endotrypanum showed distinct patterns of infection suggesting that there is variation between and within strains. The distribution of Endotrypanum and L. guyanensis differed significantly in relation to the colonization of the stomodeal valve. In co-infection with L. guyanensis, a large number of flagellates were seen to be plentifully infecting the stomodeal valve in significantly more specimens than in females infected by Endotrypanum only. However, the electrophoretic profiles of isoenzymes of parasites recovered from all co-infected specimens corresponded to Endotrypanum. This suggests that the mere correlation sand fly infection-biochemical analysis of isolates may induce parasitological incorrect consideration.

The effects of drugs, ions, and poly-l-lysine on the excretory system of Schistosoma mansoni

We have been able to label the excretory system of cercariae and all forms of schistosomula, immature and adult worms with the highly fluorescent dye resorufin. We have shown that the accumulation of the resorufin into the excretory tubules and collecting ducts of the male adult worm depends on the presence of extracellular calcium and phosphate ions. In the adult male worms, praziquantel (PZQ) prevents this accumulation in RPMI medium and disperses resorufin from tubules which have been prelabelled. Female worms and all other developmental stages are much less affected either by the presence of calcium and phosphate ions, or the disruption caused by PZQ. The male can inhibit the excretory system in paired female. Fluorescent PZQ localises in the posterior gut (intestine) region of the male adult worm, but not in the excretory system, except for the anionic carboxy fluorescein derivative of PZQ, which may be excreted by this route. All stages of the parasite can recover from damage by PZQ treatment in vitro. The excretory system is highly sensitive to damage to the surface membrane and may be involved in vesicle movement and damage repair processes. In vivo the adult parasite does not recover from PZQ treatment, but what is inhibiting recovery is unknown, but likely to be related to immune effector molecules.

Early Cretaceous trypanosomatids associated with fossil sand fly larvae in Burmese amber

Early Cretaceous flagellates with characters typical of trypanosomatids were found in the gut of sand fly larvae, as well as in surrounding debris, in Burmese amber. This discovery supports a hypothesis in which free-living trypanosomatids could have been acquired by sand fly larvae in their feeding environment and then carried transtadially into the adult stage. At some point in time, specific genera were introduced into vertebrates, thus establishing a dixenous life cycle.

Isolation and molecular identification of Leishmania ( Viannia ) peruviana from naturally infected Lutzomyia peruensis (Diptera: Psychodidae) in the Peruvian Andes

Leishmania (Viannia) peruviana was isolated from 1/75 Lutzomyia peruensis captured during May 2006 in an endemic cutaneous leishmaniasis region of the Peruvian Andes (Chaute, Huarochiri, Lima, Peru). Sand fly gut with promastigotes was inoculated into a hamster and the remaining body was fixed in ethanol. L. (Viannia) sp. was determined by polymerase chain reaction (PCR), and Leishmania species through molecular genotyping by PCR-restriction fragment length polymorphism analyses targeting the genes cpb and hsp70, resulting L. (V.) peruviana. The infected sand fly appeared 15 days after the rains finished, time expected and useful real time data for interventions when transmission is occurring.

Immune homeostasis to microorganisms in the guts of triatomines (Reduviidae): a review

Bacteria, fungi and parasites are in constant contact with the insect gut environment and can influence different aspects of the host gut physiology. Usually, some of these microorganisms develop and survive in the digestive tract. Therefore, the gut environment must be able to tolerate certain populations of these organisms for the establishment of interactions between non-pathogenic bacteria, parasites and the gut. This review provides a brief overview of the biological and molecular mechanisms that microorganisms use to interact with the gut epithelia in mosquitoes and speculates on their significances for the development of bacteria and Trypanosoma cruzi in the guts of triatomines.

Treatment of an Aedes aegypti colony with the Cry11Aa toxin for 54 generations results in the development of resistance

To study the potential for the emergence of resistance in Aedes aegypti populations, a wild colony was subjected to selective pressure with Cry11Aa, one of four endotoxins that compose the Bacillus thuringiensis serovar israelensis toxin. This bacterium is the base component of the most important biopesticide used in the control of mosquitoes worldwide. After 54 generations of selection, significant resistance levels were observed. At the beginning of the selection experiment, the half lethal concentration was 26.3 ng/mL and had risen to 345.6 ng/mL by generation 54. The highest rate of resistance, 13.1, was detected in the 54th generation. Because digestive proteases play a key role in the processing and activation of B. thuringiensis toxin, we analysed the involvement of insect gut proteases in resistance to the Cry11Aa B. thuringiensis serovar israelensis toxin. The protease activity from larval gut extracts from the Cry11Aa resistant population was lower than that of the B. thuringiensisserovar israelensis susceptible colony. We suggest that differences in protoxin proteolysis could contribute to the resistance of this Ae. aegypti colony.

A Microtus fortisprotein, serum albumin, is a novel inhibitor of Schistosoma japonicumschistosomula

Schistosomiasis is an endemic parasite disease and praziquantel is the only drug currently in use to control this disease. Experimental and epidemiological evidence strongly suggests that Microtus fortis( Mf) is a naturally resistant vertebrate host of Schistosoma japonicum. In the present study, we found that Mfserum albumin ( Mf-albumin) and the conditioned medium of pcDNA3.1- Mf-albumin caused 46.2% and 38.7% schistosomula death rates in 96 h, respectively, which were significantly higher than that of the negative control (p < 0.05). We also found that mice injected with Mf-albumin had a 43.5% reduction in worm burden and a 48.1% reduction in liver eggs per gram (p < 0.05) in comparison to the control animals. To characterise the mechanisms involved in clearance, schistosomula were incubated with fluorescein isothiocyanate-labelled Mf-albumin and fluorescent enrichment effects were found in the gut lumen of schistosomula after 48 h of incubation. Next, digestive tract excretions from schistosomula were collected and the sensitivity of Mf-albumin to digestive tract excretions was evaluated. The results indicated that schistosomula digestive tract excretions showed indigestibility of Mf-albumin. The death of schistosomula could be partially attributed to the lack of digestion of Mf-albumin by digestive tract excretions during the development of the schistosomula stage. Therefore, these data indicate the potential of Mf-albumin as one of the major selective forces for schistosomiasis.

Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

The small species of Belostoma Latreille (Heteroptera, Belostomatidae). III. A revision of oxyurum group, with a new species from Brazil and description of the male of B. noualhieri Montandon

Species of the oxyurum group (sensu Lauck) consist of five extant Neotropical small species, whose lengths range 15.0 to 20.0 mm. The anterior interocular width about 1.5 times the width of an eye and ventral diverticulum of phallus flattened, circular, and large are, in combination, diagnostic. The small species of the oxyurum group were included in the Lauck´s key to the identification of the species groups, without dealing with the species included in it because many of them are very similar in appearance. Therefore here we redescribe and key the Belostoma species of the oxyurum group. Belostoma oxyurum (Dufour) is newly recorded from Brazil (Paraná and Rio Grande do Sul). Holotype and lectotype are designated for B. oxyurum and B. sanctulum Montandon, respectively. The aspect of the prosternal keel, the ratio between the width of the ventral diverticulum of phallus and its length in ventral view, and the aspect of dorsal arms of ventral diverticulum have proven useful for better species delimitation. Based on specimens from Pará State (N. Brazil), Belostoma carajaensis Ribeiro & Estévez, sp. nov. is described and illustrated. This new species differs from B. sanctulum in having anteoculus shorter than interoculus and the dorsal arms of ventral diverticulum divergent and large. A male specimen of B. noualhieri Montandon was collected in São Paulo State and based mainly on features of male genitalia, this species is here also included under oxyurum group.

First record of larvae of Chironomidae (Insecta, Diptera) as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae), an ectosymbiont on larvae of Corydalidae (Megaloptera)

First record of larvae of Chironomidae (Insecta, Diptera) as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae), an ectosymbiont on larvae of Corydalidae (Megaloptera). This study constitutes the first record of Temnocephala Blanchard, an ectosymbiont on Corydalidae, as a possible predator of chironomid larvae. Twenty-eight Corydalidae larvae (Corydalus and Protochauliodes) were examined under stereomicroscopic in search for Temnocephala and Chironomidae larvae, of which five megalopteran larvae had 24 Temnocephala sp. associated. Furthermore, eight of these Temnocephala worms had chironomid larvae in their gut contents, an interaction previously unknown. Gut content analyses revealed Corynoneura as the commonest chironomid, but larvae of Larsia, Rheotanytarsus and Tanytarsus were recorded as well. This study included Corydalus and Protochauliodes as hosts for Temnocephala, which might be important for this worm dispersion and population dynamics.

Gestão da biblioteca escolar: metodologias, enfoques e aplicação de ferramentas de gestão e serviços de biblioteca

Este artigo apresenta a gestão da biblioteca escolar com enfoque na aplicação de ferramentas de gestão para avaliação da qualidade dos serviços oferecidos. Aborda as questões de qualidade e de administração como gestão garantindo aos serviços as características das expectativas e necessidades dos usuários da biblioteca escolar. O bibliotecário, como gestor dos serviços prestados na tomada de decisão, tem competência para utilizar as ferramentas que auxiliam a avaliar seus serviços, como brainstorming, diagrama de causa e efeito, diagrama de Pareto, histograma, matriz de priorização GUT, ciclo PDCA, fluxograma e 5W2H. Apresenta ainda algumas situações de problemas e dificuldades no âmbito da biblioteca escolar exemplificadas na utilização das ferramentas e a aplicação da junção de três ferramentas (fluxograma, PDCA e 5W2H) para avaliação dos serviços.

Why should we care about soil fauna?

The reasons why we care about soil fauna are related to their intrinsic, utilitarian and functional values. The intrinsic values embrace aesthetic or moral reasons for conserving below-ground biodiversity. Unfortunately, the protection of soil invertebrates has rarely been a criterion for avoiding changes in land use and management. Utilitarian, or direct use values, have been investigated more extensively for fungi, bacteria and marine invertebrates than for soil fauna. However, some traditional remedies, novel enzymes and pharmaceutical compounds have been derived from earthworms, termites and other groups, and gut symbionts may provide microbial strains with interesting properties for biotechnology. The functional importance of soil invertebrates in ecosystem processes has been a major focus of research in recent decades. It is suggested herein that it is rarely possible to identify the role of soil invertebrates as rate determinants of soil processes at plot and ecosystem scales of hectares and above because other biophysical controls override their effects. There are situations, however, where the activities of functional groups of soil animals, even of species, are synchronised in space or time by plant events, resource inputs, seasonality or other perturbations to the system, and their emergent effects are detectable as higher order controls.

Bilateral Killian-Jamieson diverticula demonstrated by videofluoroscopic swallowing study: case report

The authors report the case of a 56-year-old male patient complaining of dysphagia for solids and food impaction, submitted to videofluoroscopic swallowing study that demonstrated the presence of two esophageal diverticula. The videofluoroscopic swallowing study was critical in the identification and diagnosis of the diverticula, an esophageal cause of dysphagia.