Cellular and genetic mechanisms involved in the generation of protective and pathogenic immune responses in human Chagas disease

Perhaps one of the most intriguing aspects of human Chagas disease is the complex network of events that underlie the generation of protective versus pathogenic immune responses during the chronic phase of the disease. While most individuals do not develop patent disease, a large percentage may develop severe forms that eventually lead to death. Although many efforts have been devoted to deciphering these mechanisms, there is still much to be learned before we can fully understand the pathogenesis of Chagas disease. It is clear that the host's immune response is decisive in this process. While characteristics of the parasite influence the immune response, it is becoming evident that the host genetic background plays a fundamental role in the establishment of pathogenic versus protective responses. The involvement of three complex organisms, host, parasite and vector, is certainly one of the key aspects that calls for multidisciplinary approaches towards the understanding of Chagas disease. We believe that now, one hundred years after the discovery of Chagas disease, it is imperative to continue with highly interactive research in order to elucidate the immune response associated with disease evolution, which will be essential in designing prophylactic or therapeutic interventions.

Chemical composition and antiprotozoal activities of Colombian Lippia spp essential oils and their major components

The chemical composition and biological activities of 19 essential oils and seven of their major components were tested against free and intracellular forms of Leishmania chagasi and Trypanosoma cruzi parasites as well as Vero and THP-1 mammalian cell lines. The essential oils were obtained from different species of Lippia, a widely distributed genus of Colombian plants. They were extracted by microwave radiation-assisted hydro-distillation and characterised by GC-FID and GC-MS. The major components were geranial, neral, limonene, nerol, carvacrol, p-cymene, γ-terpinene, carvone and thymol. The essential oil of Lippia alba exhibited the highest activity against T. cruzi epimastigotes and intracellular amastigotes with an IC50 of 5.5 μg/mL and 12.2 μg/mL, respectively. The essential oil of Lippia origanoides had an IC50 of 4.4 μg/mL in L. chagasi promastigotes and exhibited no toxicity in mammalian cells. Thymol (IC50 3.2 ± 0.4 μg/mL) and S-carvone (IC50 6.1 ± 2.2 μg/mL), two of the major components of the active essential oils, were active on intracellular amastigotes of T. cruziinfected Vero cells, with a selective index greater than 10. None of the essential oils or major components tested in this study was active on amastigotes of L. chagasi infected THP-1 cells.

Occurrence and composition of class 1 and class 2 integrons in clinical and environmental O1 and non-O1/non-O139 Vibrio cholerae strains from the Brazilian Amazon

This study identified and characterised class 1 and 2 integrons in clinical and environmental Vibrio cholerae O1 and non-O1/non-O139 strains isolated from the Brazilian Amazon. The aadA2 and aadA7 gene cassettes were found in class 1 integrons in two genotypes of environmental V. cholerae non-O1/non-O139. Empty integrons were found in strains from the Brazilian cholera epidemic. A class 2 integron was detected in one strain from the V. cholerae Amazonia lineage harbouring sat1 and aadA1 genes. All isolates were resistant to aminoglycosides, indicating aadA functionality. These findings suggest that environmental bacteria act as cassette reservoirs that favour the emergence of resistant pathogens.

Green propolis phenolic compounds act as vaccine adjuvants, improving humoral and cellular responses in mice inoculated with inactivated vaccines

Adjuvants play an important role in vaccine formulations by increasing their immunogenicity. In this study, the phenolic compound-rich J fraction (JFR) of a Brazilian green propolis methanolic extract stimulated cellular and humoral immune responses when co-administered with an inactivated vaccine against swine herpesvirus type 1 (SuHV-1). When compared to control vaccines that used aluminium hydroxide as an adjuvant, the use of 10 mg/dose of JFR significantly increased (p < 0.05) neutralizing antibody titres against SuHV-1, as well as the percentage of protected animals following SuHV-1 challenge (p < 0.01). Furthermore, addition of phenolic compounds potentiated the performance of the control vaccine, leading to increased cellular and humoral immune responses and enhanced protection of animals after SuHV-1 challenge (p < 0.05). Prenylated compounds such as Artepillin C that are found in large quantities in JFR are likely to be the substances that are responsible for the adjuvant activity.

An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens

Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs) to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.

Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD) [standard M27 A3 (with neutral and acid pH), ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test). Trailing growth, detection of cell-associated secreted aspartic proteases (Saps) and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC) values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100% of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels.

The overexpression of the trypanosomatid-exclusive TcRBP19 RNA-binding protein affects cellular infection by Trypanosoma cruzi

To characterise the trypanosomatid-exclusive RNA-binding protein TcRBP19, we analysed the phenotypic changes caused by its overexpression. Although no evident changes were observed when TcRBP19 was ectopically expressed in epimastigotes, the metacyclogenesis process was affected. Notably, TcRBP19 overexpression also led to a decrease in the number of infected mammalian cells. These findings suggest that TcRBP19 may be involved in the life cycle progression of the Trypanosoma cruzi parasite.

Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae) in coffee agroecosystems

The composition and seasonal occurrence of sandflies were investigated in coffee agroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling was performed on three plantations located at different altitudes: Finca Guadalupe Zajú [1,000 m above sea level (a.s.l.)], Finca Argovia (613 m a.s.l.) and Teotihuacán del Valle (429 m a.s.l.). Sandflies were sampled monthly from August 2007-July 2008 using three sampling methods: Shannon traps, CDC miniature light traps and Disney traps. Sampling was conducted for 3 h during three consecutive nights, beginning at sunset. A total of 4,387 sandflies were collected during the course of the study: 2,718 individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacán del Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDC light traps and Disney traps captured 4.9% and 0.8%, respectively. More females than males were collected at all sites. While the number of sandflies captured was positively correlated with temperature and relative humidity, a negative correlation was observed between sandfly numbers and rainfall. Five species of sandflies were captured: Lutzomyia cruciata , Lutzomyia texana , Lutzomyia ovallesi , Lutzomyia cratifer / undulata and Brumptomyia sp. Lu. cruciata , constituting 98.8% of the total, was the most abundant species. None of the captured sandflies was infected with Leishmaniaspp.

Anthropophilic Anopheles species composition and malaria in Tierradentro, Córdoba, Colombia

Malaria is still a primary health problem in Colombia. The locality of Tierradentro is situated in the municipality of Montelíbano, Córdoba, in the northwest of Colombia, and has one of the highest annual parasite index of malaria nationwide. However, the vectors involved in malaria transmission in this locality have not yet been identified. In this study, the local anthropophilic Anopheles composition and natural infectivity with Plasmodium were investigated. In August 2009, 927 female Anopheles mosquitoes were collected in eight localities using the human landing catch method and identified based on their morphology. Cryptic species were determined by restriction fragment length polymorphism-internal transcribed spacer (ITS)2 molecular analysis. Eight species [Anopheles nuneztovari s.l. (92.8%), Anopheles darlingi (5.1%), Anopheles triannulatus s.l. (1.8%), Anopheles pseudopunctipennis s.l. (0.2%), Anopheles punctimacula s.l. (0.2%), Anopheles apicimacula (0.1%), Anopheles albimanus (0.1%) and Anopheles rangeli (0.1%)] were identified and species identity was confirmed by ITS2 sequencing. This is the first report of An. albimanus, An. rangeli and An. apicimacula in Tierradentro. Natural infectivity with Plasmodium was determined by ELISA. None of the mosquitoes was infectious for Plasmodium. An. nuneztovari s.l. was the predominant species and is considered the primary malaria vector; An. darlingi and An. triannulatus s.l. could serve as secondary vectors.

Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia

Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

Composition of the electrocautery smoke: integrative literature review

Abstract OBJECTIVE To identify the composition of the smoke produced by electrocautery use during surgery. METHOD Integrative review with search for primary studies conducted in the databases of the US National Library of Medicine National Institutes of Health, Cumulative Index to Nursing and Allied Health Literature, and Latin American and Caribbean Health Sciences, covering the studies published between 2004 and 2014. RESULTS The final sample consisted of 14 studies grouped into three categories, namely; polycyclic aromatic hydrocarbons, volatile compounds and volatile organic compounds. CONCLUSION There is scientific evidence that electrocautery smoke has volatile toxic, carcinogenic and mutagenic compounds, and its inhalation constitutes a potential chemical risk to the health of workers involved in surgeries.

Hesperiidae (Lepidoptera, Hesperioidea) from Ponta Grossa, Paraná, Brazil: 70 years of records with special reference to faunal composition of Vila Velha State Park

Hesperiidae (Lepidoptera, Hesperioidea) de Ponta Grossa, Paraná, Brazil: 70 anos de registros com especial referência à composição faunística do Parque Estadual de Vila Velha. O município de Ponta Grossa se destaca por apresentar originalmente uma paisagem peculiar onde capões isolados de Floresta Ombrófila Mista são interligados por grandes extensões de fitofisionomias estépicas, também denominadas campos. No entanto, ambos os ecossistemas atualmente se encontram altamente ameaçados pela ocupação humana, restando na região o Parque Estadual de Vila Velha, cuja composição florística tem sido recentemente relacionada com o bioma Cerrado. Poucos trabalhos são dedicados à caracterização da fauna dos campos e sua relação com outras fitofisionomias estépicas brasileiras, motivo que suscitou a realização deste estudo. Após reunir informações de coletas realizadas por mais de 70 anos, são listadas 225 espécies de Hesperiidae (Lepidoptera, Hesperioidea) presentes no município, entre elas 162 indicadoras de ambientes florestais e 53 de áreas abertas. O Parque Estadual de Vila Velha contribui para a conservação de 65% delas enquanto sua composição se mostra intimamente relacionada tanto aos Pampas como ao Cerrado, em detrimento de hábitats florestais. Tal relação é dada provavelmente pela localização geográfica de Vila Velha, visto que a similaridade da fauna de Hesperiidae se encontrou influenciada pelas distâncias geográficas das amostras no presente estudo. A flora de Vila Velha também deve afetar diretamente a composição observada de Hesperiidae, uma vez que uma grande parte de suas espécies são também encontradas em áreas de Cerrado. No entanto, estudos em ambientes campestres brasileiros ainda se fazem necessários, especialmente em enclaves de Cerrado no Paraná e em São Paulo, para que se adquira um melhor entendimento da dinâmica de suas comunidades.

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil

Temporal variation in the composition of ant assemblages (Hymenoptera, Formicidae) on trees in the Pantanal floodplain, Mato Grosso do Sul, Brazil. In this paper we investigate how seasonal flooding influences the composition of assemblages of ants foraging on trees in the Pantanal of Mato Grosso do Sul. During the flood in the Pantanal, a large area is covered by floods that are the main forces that regulate the pattern of diversity in these areas. However, the effects of such natural disturbances in the ant communities are poorly known. In this sense, the objective of this study was to evaluate the effect of temporal variation in assemblages of ants foraging on trees in the Pantanal of Miranda. Samples were collected during a year in two adjacent areas, one who suffered flooding during the wet period and another that did not suffer flooding throughout the year. In 10 sites for each evaluated habitat, five pitfall traps were installed at random in trees 25 m apart from each other. In the habitat with flooding, the highest richness was observed during the flooding period, while there was no significant change in richness in the area that does not suffer flooding. The diversity of species between the two evaluated habitats varied significantly during the two seasons. Most ants sampled belong to species that forage and nest in soil. This suggests that during the flood in flooded habitats, ants that did not migrate to higher areas without flooding adopt the strategy to search for resources in the tree canopy.

The genus Lycoderides Sakakibara, stat. nov., its composition and descriptions of new species (Hemiptera, Membracidae, Stegaspidinae)

The genus Lycoderides Sakakibara, stat. nov. , its composition and descriptions of new species (Hemiptera, Membracidae, Stegaspidinae).The subgenus Lycoderes (Lycoderides) Sakakibara, 1972 is raised to the genus category - Lycoderides stat. nov.. - : and it now includes: Lycoderides amazonicus (Sakakibara, 1991), comb. nov. , Lycoderides brevilobus (Sakakibara, 1972), comb. nov. , Lycoderides burmeisteri (Fairmaire, 1846), comb. nov. , Lycoderides cultratus (Sakakibara, 1991), comb. nov. , Lycoderides fernandezi (Strümpel, 1988), comb. nov. , Lycoderides fuscus (Amyot & Serville, 1843), comb. nov. , Lycoderides gradatus (Sakakibara, 1972), comb. nov. , Lycoderides hippocampus (Fabricius, 1803), comb. nov. , Lycoderides luteus (Funkhouser, 1940), comb. nov. , Lycoderides marginalis (Walker, 1851), comb. nov. , Lycoderides nathanieli (Cryan, 1999), comb. nov. , Lycoderides obtusus (Sakakibara, 1991), comb. nov. , Lycoderides pennyi (Sakakibara, 1991), comb. nov. , Lycoderides phasianus (Fowler, 1896), comb. nov. (= Enchenopa minamen Buckton, 1901,SYN. NOV: ), Lycoderides protensus (Sakakibara, 1991), comb. nov. , Lycoderides serraticornis (Fowler, 1896), comb. nov. , and Lycoderides strumpeli (Sakakibara, 1991), comb. nov. The following new species are described: Lycoderides abditus, sp. nov. , Lycoderides brulei,SP. NOV. (: both from French Guiana), Lycoderides capixaba, sp. nov. (from Brazil, Espírito Santo), Lycoderides cavichiolii, sp. nov. (from Brazil, Rio de Janeiro), Lycoderides meloi, sp. nov. (from Brazil, Bahia), and Lycoderides oliviae, sp. nov. (from Brazil, Minas Gerais). Other nomenclatural change: Stegaspis bracteata (Fabricius, 1787) = Lycoderes capitata Buckton, 1903, syn. nov. New records of geographical distribution and a key to the species are provided.

Mosquito community composition in dynamic landscapes from the Atlantic Forest biome (Diptera, Culicidae)

Mosquito community composition in dynamic landscapes from the Atlantic Forest biome (Diptera, Culicidae). Considering that some species of Culicidae are vectors of pathogens, both the knowledge of the diversity of the mosquito fauna and how some environment factors influence in it, are important subjects. In order to address the composition of Culicidae species in a forest reserve in southern Atlantic Forest, we compared biotic and abiotic environmental determinants and how they were associated with the occurrence of species between sunset and sunrise. The level of conservation of the area was also considered. The investigation was carried out at Reserva Natural do Morro da Mina, in Antonina, state of Paraná, Brazil. We performed sixteen mosquito collections employing Shannon traps at three-hour intervals, from July 2008 to June 2009. The characterization of the area was determined using ecological indices of diversity, evenness, dominance and similarity. We compared the frequency of specimens with abiotic variables, i.e., temperature, relative humidity and pluviosity. Seven thousand four hundred ten mosquito females were captured. They belong to 48 species of 12 genera. The most abundant genera were Anopheles, Culex, Coquillettidia, Aedes and Runchomyia. Among the species, the most abundant was Anopheles cruzii, the primary vector of Plasmodium spp. in the Atlantic Forest. Results of the analyses showed that the abiotic variables we tested did not influence the occurrence of species, although certain values suggested that there was an optimum range for the occurrence of culicid species. It was possible to detect the presence of species of Culicidae with different epidemiologic profiles and habitat preference.