RESUMO
Worldwide rotaviruses A (RVA) are responsible for approximately 215,000 deaths annually among children aged <5â¯years. RVA G1P[8] remains associated with >50% of gastroenteritis cases in this age group. The aim of this study was to assess the genetic variability of G1P[8] strains detected in children with severe diarrhea in Belém, Pará, Brazil, during the post-rotavirus vaccine introduction era. Phylogenetic analysis clustered the VP4 and VP7 genes of 40 samples selected between 2009 and 2011 into lineages found to be different from the Rotarix® vaccine strain. A detailed investigation of their complete genotype constellations identified 2 reassortant viruses (5%), resulting from reassortments between the genogroups Wa-like and DS-1-like (G1-P[8]-I1-R2-C1-M1-A1-N1-T2-E1-H1) and Wa-like and AU-1-like (G1-P[8]-I1-R3-C1-M1-A1-N1-T1-E1-H1) genotype constellations. A comparison of the amino acid residues presents in the antigenic epitopes of VP7 and VP4, showed differences in the electrostatic charges distribution, between wild type Brazilian strains and the Rotarix® and RotaTeq® vaccine strains. These findings reflect the structural analyses of the antigenic regions of VP7 and VP4 of the RVA G1P[8] in children with gastroenteritis in Northern Brazil raising the hypothesis that structural modifications at these sites over time may account for the emergence of new strains that could possibly pose a challenge to current vaccines.
Assuntos
Diarreia/epidemiologia , Diarreia/virologia , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/classificação , Rotavirus/genética , Antígenos Virais/química , Antígenos Virais/genética , Antígenos Virais/imunologia , Brasil/epidemiologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Diarreia/prevenção & controle , Variação Genética , Genoma Viral , Humanos , Filogenia , Vírus Reordenados/genética , Vírus Reordenados/imunologia , Rotavirus/imunologia , Infecções por Rotavirus/prevenção & controle , Análise de Sequência de DNARESUMO
Biomphalaria amazonica is a planorbid species considered a potential host of Schistosoma mansoni. It is widely distributed in the Neotropical zone, particularly in the North and Centre-West of Brazil and in the North of Bolivia. The aim of the present study was to determine the host-parasite relationship between B. amazonica and S. mansoni (BH and SJ strains). Specimens of B. amazonica and their snail-conditioned water were examined in terms of their ability to attract miracidia. The infectivity of the mollusks was determined by exposing them to 20 miracidia of both strains. Sporocyst development and amebocyte reactions were studied after each mollusk specimen was exposed to 100 miracidia. Although no cercariae were eliminated, specimens of B. amazonica proved capable of attracting 77% of the miracidia they were exposed to. Viable sporocysts with no amebocyte reaction were found 96 hours after the exposure to miracidia. These results indicate the susceptibility of B. amazonica to the BH and SJ strains of S. mansoni, and therefore demonstrate the importance of this planorbid species as a potential vector of the trematode in the areas where it occurs.(AU)
Biomphalaria amazonica é uma espécie de planorbídeo considerada vetora potencial do Schistosoma mansoni. É amplamente distribuída na zona neotropical, especialmente no Norte e Centro-Oeste do Brasil e Norte da Bolívia. O presente trabalho teve por objetivo estudar a relação parasito-hospedeiro entre B. amazonica e S. mansoni (linhagens BH e SJ). Espécimes de B. amazonica e sua água de condicionamento foram examinados em relação à sua capacidade de atração miraxonal. A infectividade dos moluscos foi testada expondo-os a 20 miracídios de ambas as linhagens. A viabilidade dos esporocistos e o desenvolvimento de reações amebocitárias foram estudados após cada molusco ser exposto a 100 miracídios. Apesar de não eliminarem cercárias, B. amazonica provou ser capaz de atrair 77% dos miracídios a que foram expostos. Esporocistos viáveis sem reação amebócitaria foram encontrados 96 horas após a exposição aos miracídios. Esses resultados indicam a suscetibilidade de B. amazonica às linhagens BH e SJ de S. mansoni e, portanto, demonstram a importância desta espécie de planorbídeo como um vetor potencial do trematodeo na área onde ele ocorre.(AU)
Assuntos
Biomphalaria/parasitologia , Schistosoma mansoni/fisiologia , Interações Hospedeiro-Parasita , Estudos EpidemiológicosRESUMO
Abstract Biomphalaria amazonica is a planorbid species considered a potential host of Schistosoma mansoni. It is widely distributed in the Neotropical zone, particularly in the North and Centre-West of Brazil and in the North of Bolivia. The aim of the present study was to determine the host-parasite relationship between B. amazonica and S. mansoni (BH and SJ strains). Specimens of B. amazonica and their snail-conditioned water were examined in terms of their ability to attract miracidia. The infectivity of the mollusks was determined by exposing them to 20 miracidia of both strains. Sporocyst development and amebocyte reactions were studied after each mollusk specimen was exposed to 100 miracidia. Although no cercariae were eliminated, specimens of B. amazonica proved capable of attracting 77% of the miracidia they were exposed to. Viable sporocysts with no amebocyte reaction were found 96 hours after the exposure to miracidia. These results indicate the susceptibility of B. amazonica to the BH and SJ strains of S. mansoni, and therefore demonstrate the importance of this planorbid species as a potential vector of the trematode in the areas where it occurs.
Resumo Biomphalaria amazonica é uma espécie de planorbídeo considerada vetora potencial do Schistosoma mansoni. É amplamente distribuída na zona neotropical, especialmente no Norte e Centro-Oeste do Brasil e Norte da Bolívia. O presente trabalho teve por objetivo estudar a relação parasito-hospedeiro entre B. amazonica e S. mansoni (linhagens BH e SJ). Espécimes de B. amazonica e sua água de condicionamento foram examinados em relação à sua capacidade de atração miraxonal. A infectividade dos moluscos foi testada expondo-os a 20 miracídios de ambas as linhagens. A viabilidade dos esporocistos e o desenvolvimento de reações amebocitárias foram estudados após cada molusco ser exposto a 100 miracídios. Apesar de não eliminarem cercárias, B. amazonica provou ser capaz de atrair 77% dos miracídios a que foram expostos. Esporocistos viáveis sem reação amebócitaria foram encontrados 96 horas após a exposição aos miracídios. Esses resultados indicam a suscetibilidade de B. amazonica às linhagens BH e SJ de S. mansoni e, portanto, demonstram a importância desta espécie de planorbídeo como um vetor potencial do trematodeo na área onde ele ocorre.
Assuntos
Animais , Schistosoma mansoni/fisiologia , Biomphalaria/parasitologia , Interações Hospedeiro-Parasita , Schistosoma mansoni/crescimento & desenvolvimento , Brasil , Quimiotaxia , Oocistos/crescimento & desenvolvimento , Oocistos/fisiologia , Cercárias/crescimento & desenvolvimento , Cercárias/fisiologiaRESUMO
Biomphalaria amazonica is a planorbid species considered a potential host of Schistosoma mansoni. It is widely distributed in the Neotropical zone, particularly in the North and Centre-West of Brazil and in the North of Bolivia. The aim of the present study was to determine the host-parasite relationship between B. amazonica and S. mansoni (BH and SJ strains). Specimens of B. amazonica and their snail-conditioned water were examined in terms of their ability to attract miracidia. The infectivity of the mollusks was determined by exposing them to 20 miracidia of both strains. Sporocyst development and amebocyte reactions were studied after each mollusk specimen was exposed to 100 miracidia. Although no cercariae were eliminated, specimens of B. amazonica proved capable of attracting 77% of the miracidia they were exposed to. Viable sporocysts with no amebocyte reaction were found 96 hours after the exposure to miracidia. These results indicate the susceptibility of B. amazonica to the BH and SJ strains of S. mansoni, and therefore demonstrate the importance of this planorbid species as a potential vector of the trematode in the areas where it occurs.
Assuntos
Biomphalaria/parasitologia , Interações Hospedeiro-Parasita , Schistosoma mansoni/fisiologia , Animais , Brasil , Cercárias/crescimento & desenvolvimento , Cercárias/fisiologia , Quimiotaxia , Oocistos/crescimento & desenvolvimento , Oocistos/fisiologia , Schistosoma mansoni/crescimento & desenvolvimentoRESUMO
Chrysomya megacephala (F.) and Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae) are considered of forensic, medical, and veterinary importance in Brazil because of their necrophagous and synanthropic behaviour. The development of flies can be influenced by temperature, and species from the same genus usually have different responses to external variables. The egg development of blow fly can be a useful complementary technique to estimate the minimum postmortem interval. Thus, this study aimed to compare the egg developmental time and survival of C. megacephala and C. putoria at different temperatures to determine the optimal temperature for egg development and the linear regression for developmental time and temperature, thereby determining the minimum threshold (t) and thermal summation constant (K) for each species. Adults of both species were collected in the region of Campinas city, São Paulo state, Brazil. Eggs were incubated at eight constant temperatures between 05 ± 1°C and 35 ± 1°C and the egg developmental time and survival were evaluated. There was no egg survival at 5 and 10°C. The K for C. megacephala and C. putoria were 179.41 HD and 189.94 HD, respectively. The regression slopes and t (10°C) were similar for both species. The optimal temperature for egg survival was between 25 and 35°C, for C. megacephala and 20 and 30°C, for C. putoria. The present data were similar to most data available in the literature, but differences in the same species are a possibility.
Assuntos
Dípteros/crescimento & desenvolvimento , Dípteros/fisiologia , Estágios do Ciclo de Vida/fisiologia , Animais , Brasil , Modelos Lineares , TemperaturaRESUMO
A method of extracting membranes from red blood cells (RBCs) is described, which were in turn used to assay acetylcholinesterase (AChE) activity. The evidence for the enzyme activity was established by selective inhibition using 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide, tetraisopropyl pyrophosphoramide and neostigmine. Blood samples were exposed to three organophosphorus (dichlorvos, chlorpyrifos and diazinon) and two carbamate (carbaryl and carbofuran) pesticides. Afterwards AChE activities in RBC membranes were determined. The concentrations capable to inhibit the enzyme activity by 50% (IC50) for the pesticides were 10.66 µM (dichlorvos), 21.42 µM (chlorpyrifos), 109.98 µM (carbaryl) and 5.44 µM (carbofuran). The results related to 20% enzyme inhibition (level used in the estimation of threshold limits for anticholinesterase compounds) were below those acceptable daily intake values enacted by relevant national and international regulations. These results suggest that the proposed AChE extraction from RBC and assay could be a suitable method for monitoring occupational exposure to pesticides.
Assuntos
Acetilcolinesterase/metabolismo , Bioensaio/métodos , Inibidores da Colinesterase/toxicidade , Eritrócitos/efeitos dos fármacos , Praguicidas/toxicidade , Células Cultivadas , Eritrócitos/enzimologia , HumanosRESUMO
AIM: To verify the in vitro cytocompatibility of iRoot BP Plus (iRoot) and to compare it with White ProRoot MTA (MTA). METHODOLOGY: Thirty-six human maxillary incisor root canals were prepared using a step-back flaring technique. The apical 3 mm was resected perpendicular to the long axis at the roots, and root-end cavities were prepared with the aid of an ultrasonic device plus a diamond retrotip with continuous irrigation using water, producing standardized preparations. After that, the root-end cavities were filled with iRoot or MTA, and each root was exposed to cell culture media for 24 or 48 h. Human osteoblast cells were exposed to the extracts thus obtained, and a multiparametric cell viability assay was performed, evaluating mitochondrial activity, membrane integrity and cell density. The results were analysed by one-way analysis of variance, complemented with the Duncan post-test (P < 0.05). RESULTS: Cells exposed to MTA revealed a cytocompatibility pattern similar to the untreated cells (negative control), at both experimental times (P > 0.05). iRoot, however, promoted a significantly poorer viability than MTA and the control, after 48 h of exposure (P < 0.001). Nevertheless, iRoot did not induce critical cytotoxic effects because cell viability remained higher than 70% of the control group in most tests performed. CONCLUSION: iRoot and MTA were biocompatible and did not induce critical cytotoxic effects.
Assuntos
Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Osteoblastos/efeitos dos fármacos , Cimento de Silicato/farmacologia , Silicatos/farmacologia , Compostos de Alumínio/farmacologia , Contagem de Células , Técnicas de Cultura de Células , Membrana Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados , Combinação de Medicamentos , Humanos , Mitocôndrias/efeitos dos fármacos , Óxidos/farmacologia , Obturação Retrógrada/métodos , Preparo de Canal Radicular/métodos , Fatores de Tempo , Técnicas de Cultura de Tecidos , Cimento de Óxido de Zinco e Eugenol/toxicidadeRESUMO
Insects are the most important components of the terrestrial fauna associated with carrion because they recycle organic matter back into the ecosystem. They can be classified into four ecological categories comprising: necrophages; parasites and predators of necrophagous species; omnivores, and incidentals. To determine the composition and temporal succession of necrophagous and predator beetles on pig carrion, four experiments, one in each season, were carried out during 2004 in a rural area of Cordoba, central Argentina. Two pigs (Sus scrofa L.), weighing approximately 8 kg each, were used in each of the four experiments. The animals were killed by a sharp blow to the head and immediately placed in an appropriate trap. One pig was placed in the shade and the other in direct sunlight. Beetle fauna were collected daily during the first 4 weeks and thereafter every 2 or 3 days. Five stages of decomposition were observed and a total of 1586 adults and 4309 immatures of Coleoptera belonging to the Staphylinidae, Nitidulidae, Cleridae, Dermestidae, Histeridae, Anthicidae and Trogidae families were collected during the four experiments. The necrophagous community was represented by Dermestes maculates (De Geer), nitidulid species and members of the Trox genus. Staphylinidae, Cleridae and Histeridae species were considered to be the main predators of the necrophagous species.
Assuntos
Besouros/classificação , Ciências Forenses/métodos , Animais , Argentina , Biota , Cadáver , Besouros/crescimento & desenvolvimento , Meio Ambiente , Larva/classificação , Larva/crescimento & desenvolvimento , Mudanças Depois da Morte , Estações do Ano , Especificidade da Espécie , Sus scrofaRESUMO
Necrophagous insects are valuable tools for postmortem interval (PMI) estimation or for determining the cause of death. Due to the increase in deaths related to drug abuse, it is crucial to know how these substances affect the development of flies that feed on corpses, to avoid errors in the PMI estimates. This study evaluated the effect of nandrolone decanoate, an anabolic androgenic steroid, on the development ofimmatures of Chrysomya megacephala (F.), Chrysomya putoria (Wiedemann), and Chrysomya albiceps (Wiedemann) (Diptera:Calliphoridae) when added to an artificial rearing diet. Four experimental groups were delineated: three of them were given diets containing 4.5, 22.5, or 45 mg/kg nandrolone decanoate; and a drug-free control group. Weights were recorded at 12-h intervals from larval eclosion to pupation. No statistically significant differences were observed in mean larval weights, emergence interval, or emergence rates for all groups. However, differences in the three species were observed during the larval development. Initially, C. putoria reared in the highest concentration of decanoate showed greater weight gain. However, at older ages, immatures reached lower mean weights than the control group. For C. albiceps, the highest concentration of decanoate contributed to an effective lack of weight gain during almost the entire course of larval development. Therefore, the influence of any drug on development should always be considered.
Assuntos
Anabolizantes/farmacologia , Dípteros/efeitos dos fármacos , Nandrolona/análogos & derivados , Animais , Cadáver , Dípteros/crescimento & desenvolvimento , Ciências Forenses , Crescimento/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Nandrolona/farmacologia , Decanoato de Nandrolona , Especificidade da EspécieRESUMO
BACKGROUND: An epidemic of acute gastroenteritis occurred in Rio Branco City, Acre State, in Brazil's Amazon region in 2005. An investigation was conducted to confirm the etiology and identify possible risk factors for death. METHODS: Rio Branco municipality surveillance data for the period May to October 2005 were reviewed. In a case-control study, children who died following acute gastroenteritis were compared to age-matched controls with acute gastroenteritis who survived. Rotavirus A (RV-A) was investigated in 799 stool samples and genotyped by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The cumulative incidence of diarrhea in children aged <5 years was 21%. A fatal outcome was significantly associated with uncovered household water storage containers. RV-A was identified in 88% of samples and G9 was the prevalent genotype (71%). CONCLUSIONS: Oral rehydration solution and boiling or chlorinating drinking water likely limited mortality. This epidemic was caused by RV-A genotype G9. After the outbreak, a rotavirus vaccine was introduced into the official childhood immunization schedule in Brazil.
Assuntos
Surtos de Doenças , Gastroenterite/epidemiologia , Infecções por Rotavirus/epidemiologia , Rotavirus/isolamento & purificação , Doença Aguda , Brasil/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Gastroenterite/mortalidade , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Fatores de Risco , Rotavirus/genética , Infecções por Rotavirus/mortalidade , Infecções por Rotavirus/virologiaRESUMO
Data on the insect species associated with corpse decomposition are particularly important for estimation of the post-mortem interval (PMI) in forensic science because the PMI is based on the lifecycle and behaviour of necrophagous insects, among other measures. To determine the dipteran succession on pig carrion, four experiments, one in each season, were carried out during 2004 in a rural area of Córdoba, central Argentina. Two pigs (Sus scrofa L.) were used in each of the four experiments. At each time-point one pig was placed in the shade and the other under direct sunlight. Insects were collected daily during the first 4 weeks and thereafter every 2 or 3 days. Five stages of decomposition were observed and a total of 24 710 adult specimens were collected, belonging to the following eight families of Diptera: Calliphoridae; Muscidae; Sarcophagidae; Phoridae; Piophilidae; Fanniidae; Sphaeroceridae, and Anthomyiidae. All Calliphoridae collected in this study were considered to be of potential forensic importance because of their necrophagous behaviour and because their immature stages use carrion as a food source. Other species, such as Musca domestica L. and Ophyra aenescens (Wiedemann), were also considered to represent potential forensic indicators.
Assuntos
Cadáver , Dípteros/crescimento & desenvolvimento , Ciências Forenses/métodos , Suínos , Animais , Argentina , Feminino , Masculino , População Rural , Estações do AnoRESUMO
The attraction exerted by Biomphalaria glabrata infected with Angiostrongylus costaricensis on Schistosoma mansoni miracidia of the BH strain was tested, using a glass apparatus composed by two circular chambers connected to a channel. One mollusk or a sample of a snail conditioning water (SCW) was placed in one of the chambers, randomly selected, and the remaining of the apparatus was filled with chlorine-free water. Ten miracidia were placed in the centre of the channel and their behaviour was observed for 15 minutes. Ten replicates were made for each treatment (snail or SCW), using different specimens of mollusks or different samples of SCW. Mollusks infected with A. costaricensis attracted significantly less S. mansoni miracidia than non-infected B. glabrata. In addition, miracidia were also significantly more attracted to SCW from mollusks infected with A. costaricensis.
Assuntos
Angiostrongylus , Biomphalaria/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Schistosoma mansoni/fisiologia , Animais , Larva/fisiologiaRESUMO
The association between rotavirus serotypes and severity is not well established. Analysis of a clinical trial conducted in Latin America points at more-severe disease associated with serotype G9. Thus, demonstration of efficacy against G9 will be an important asset of any rotavirus vaccine to be introduced into a Latin American country or any country where G9 has been shown to be prevalent.
Assuntos
Infecções por Rotavirus/virologia , Rotavirus/classificação , Diarreia Infantil/virologia , Feminino , Gastroenterite/virologia , Humanos , Lactente , América Latina/epidemiologia , Masculino , Prevalência , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Sorotipagem , Índice de Gravidade de DoençaRESUMO
Some terrestrial mollusks are natural hosts of Angiostrongylus costaricensis. In the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of Schistosoma mansoni. Mollusks can be infected with Angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. In this work we assessed the ability of Biomphalaria glabrata to attract first-stage larvae of A. costaricensis. Movement of the nematode larvae towards the mollusks was observed after 15 min, 30 min and 1 h. B. glabrata did not attract the first-stage larvae of A. costaricensis in any of the three intervals. The susceptibility of two populations of Biomphalaria tenagophila to infection by A. costaricensis was also determined. One population was genetically selected for the susceptibility to S. mansoni while the other was not. Third-stage larvae were recovered from the snails 30 days after exposure of the two populations to 120 first-stage larvae. All the mollusks were infected. However, a significantly higher number of third-stage larvae were recovered in mollusks not genetically selected.
Assuntos
Angiostrongylus/fisiologia , Animais Geneticamente Modificados/parasitologia , Biomphalaria/genética , Animais , Comportamento Animal/fisiologia , Biomphalaria/parasitologia , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Larva/fisiologia , Fatores de TempoRESUMO
Alguns moluscos terrestres são hospedeiros naturais do Angiostrongylus costaricensis. No laboratório, esse nematódeo pode ser mantido em planorbídeos, que são moluscos aquáticos e hospedeiros intermediários do Schistosoma mansoni. Os moluscos podem ser infectados com A. costaricensis por ingestão ou por penetração ativa de larvas de primeiro estágio. Neste trabalho, testamos a habilidade de Biomphalaria glabrata em atrair larvas de primeiro estágio de A. costaricensis. A movimentação das larvas do nematódeo em direção aos moluscos foi observada após 15 minutos, 30 minutos e 1 hora. B. glabrata não atraiu as larvas de primeiro estágio de A. costaricensis nos três intervalos de tempo. Verificamos também a suscetibilidade de duas populações de Biomphalaria tenagophila à infecção por A. costaricensis. Uma população era selecionada geneticamente para a susceptibilidade ao S. mansoni, enquanto a outra não o era. Larvas de terceiro estágio foram recuperadas dos moluscos 30 dias após a exposição das duas populações a 120 larvas de primeiro estágio. Todos os moluscos estavam infectados. Entretanto, um número significativamente maior de larvas de terceiro estágio foi recuperado em moluscos não geneticamente selecionados.
Assuntos
Animais , Angiostrongylus/fisiologia , Animais Geneticamente Modificados/parasitologia , Comportamento Animal/fisiologia , Biomphalaria/genética , Biomphalaria/parasitologia , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Larva/fisiologia , Fatores de TempoRESUMO
An oral, human-derived monovalent (G1P1A) rotavirus vaccine, strain RIX4414, has been developed by GlaxoSmithKline, Rixensart, Belgium. The safety, immunogenicity and efficacy of this vaccine were evaluated in a randomized, double-blind, placebo-controlled, phase IIb trial conducted in Brazil, Mexico and Venezuela. Healthy infants were given two doses of vaccine (104.7, 105.2 or 105.8 ffu) or placebo at age 2 and 4 months, with routine DTPw-HBV and Hib vaccines. OPV was given separately, at least 2 weeks before or after administration of the study vaccine. A total of 2155 infants were enrolled, of whom 1618 received one of the three vaccine viral concentrations and 537 were given placebo. Analysis of efficacy included diarrheal episodes occurring from 2 weeks after second dose until one year of age. Efficacy rates against any rotavirus gastroenteritis, severe rotavirus gastroenteritis and hospitalizations for rotavirus disease were as high as 70% (46-84%; 95%CI), 86% (63-96%; 95%CI), and 93% (54-100%; 95%CI), respectively. For non-G1 (mainly G9) serotypes, RIX4414 vaccine conferred protection as high as 83% (40-97%; 95%CI) against severe gastroenteritis. A decrease was noted in the incidence of severe rotavirus-related gastroenteritis after first dose. It is demonstrated that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis and hospitalization, including disease caused by non-G1 strains, namely G9 serotypes.
Assuntos
Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus , Vacinas Atenuadas , Administração Oral , Brasil , Método Duplo-Cego , Gastroenterite/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Lactente , México , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/efeitos adversos , Vacinas contra Rotavirus/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , VenezuelaRESUMO
Some terrestrial mollusks are natural hosts of Angiostrongylus costaricensis. In the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of Schistosoma mansoni. Mollusks can be infected with Angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. In this work we assessed the ability of Biomphalaria glabrata to attract first-stage larvae of A. costaricensis. Movement of the nematode larvae towards the mollusks was observed after 15 min, 30 min and 1 h. B. glabrata did not attract the first-stage larvae of A. costaricensis in any of the three intervals. The susceptibility of two populations of Biomphalaria tenagophila to infection by A. costaricensis was also determined. One population was genetically selected for the susceptibility to S. mansoni while the other was not. Third-stage larvae were recovered from the snails 30 days after exposure of the two populations to 120 first-stage larvae. All the mollusks were infected. However, a significantly higher number of third-stage larvae were recovered in mollusks not genetically selected.
Alguns moluscos terrestres são hospedeiros naturais do Angiostrongylus costaricensis. No laboratório, esse nematódeo pode ser mantido em planorbídeos, que são moluscos aquáticos e hospedeiros intermediários do Schistosoma mansoni. Os moluscos podem ser infectados com A. costaricensis por ingestão ou por penetração ativa de larvas de primeiro estágio. Neste trabalho, testamos a habilidade de Biomphalaria glabrata em atrair larvas de primeiro estágio de A. costaricensis. A movimentação das larvas do nematódeo em direção aos moluscos foi observada após 15 minutos, 30 minutos e 1 hora. B. glabrata não atraiu as larvas de primeiro estágio de A. costaricensis nos três intervalos de tempo. Verificamos também a suscetibilidade de duas populações de Biomphalaria tenagophila à infecção por A. costaricensis. Uma população era selecionada geneticamente para a susceptibilidade ao S. mansoni, enquanto a outra não o era. Larvas de terceiro estágio foram recuperadas dos moluscos 30 dias após a exposição das duas populações a 120 larvas de primeiro estágio. Todos os moluscos estavam infectados. Entretanto, um número significativamente maior de larvas de terceiro estágio foi recuperado em moluscos não geneticamente selecionados.
RESUMO
Some terrestrial mollusks are natural hosts of Angiostrongylus costaricensis. In the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of Schistosoma mansoni. Mollusks can be infected with Angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. In this work we assessed the ability of Biomphalaria glabrata to attract first-stage larvae of A. costaricensis. Movement of the nematode larvae towards the mollusks was observed after 15 min, 30 min and 1 h. B. glabrata did not attract the first-stage larvae of A. costaricensis in any of the three intervals. The susceptibility of two populations of Biomphalaria tenagophila to infection by A. costaricensis was also determined. One population was genetically selected for the susceptibility to S. mansoni while the other was not. Third-stage larvae were recovered from the snails 30 days after exposure of the two populations to 120 first-stage larvae. All the mollusks were infected. However, a significantly higher number of third-stage larvae were recovered in mollusks not genetically selected.
Alguns moluscos terrestres são hospedeiros naturais do Angiostrongylus costaricensis. No laboratório, esse nematódeo pode ser mantido em planorbídeos, que são moluscos aquáticos e hospedeiros intermediários do Schistosoma mansoni. Os moluscos podem ser infectados com A. costaricensis por ingestão ou por penetração ativa de larvas de primeiro estágio. Neste trabalho, testamos a habilidade de Biomphalaria glabrata em atrair larvas de primeiro estágio de A. costaricensis. A movimentação das larvas do nematódeo em direção aos moluscos foi observada após 15 minutos, 30 minutos e 1 hora. B. glabrata não atraiu as larvas de primeiro estágio de A. costaricensis nos três intervalos de tempo. Verificamos também a suscetibilidade de duas populações de Biomphalaria tenagophila à infecção por A. costaricensis. Uma população era selecionada geneticamente para a susceptibilidade ao S. mansoni, enquanto a outra não o era. Larvas de terceiro estágio foram recuperadas dos moluscos 30 dias após a exposição das duas populações a 120 larvas de primeiro estágio. Todos os moluscos estavam infectados. Entretanto, um número significativamente maior de larvas de terceiro estágio foi recuperado em moluscos não geneticamente selecionados.
RESUMO
An actinomycete strain, isolated from a Mata Atlântica soil sample, showing cellulolytic activity was subjected to polyphasic taxonomic characterization to determine its identity. Strain M7aT presented morphological and chemotaxonomic characteristics consistent with its assignment to the genus Streptomyces. Phylogenetic analysis of its 16S rDNA sequence revealed that the strain differed from described streptomycetes available in the public databases; the most closely related species was Streptomyces laceyi, with 98.4% nucleotide similarity. It also differed from other cellulolytic strains in its phenotypic characteristics. It is therefore proposed that strain M7aT, a cellulolytic strain with biotechnological potential, represents a novel species, named Streptomyces drozdowiczii sp. nov. The type strain is M7aT (=CBMAI 0498T=CIP 107837T=NRRL B-24297T).
Assuntos
Celulose/metabolismo , Microbiologia do Solo , Streptomyces/classificação , Streptomyces/isolamento & purificação , Aminoácidos/análise , Técnicas de Tipagem Bacteriana , Brasil , Parede Celular/química , DNA Bacteriano/química , DNA Ribossômico/química , Ácidos Graxos/análise , Genes de RNAr , Dados de Sequência Molecular , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência , Streptomyces/citologia , Streptomyces/metabolismoRESUMO
Different biomaterials have been used as scaffolds for bone tissue engineering. Here we characterize a biomaterial composed of sintered (1100 degrees C) and powdered hydroxyapatite (HA) and type I collagen (Coll), both of bovine origin, designed for osteoconductive and osteoinductive scaffolds. Coll/HA proportions were 1/2.6 and 1/1 (wet weight), and particles sizes varied from 200 to 400 microm. Vv (volume density) and Sv (surface to volume density) for the HA particles in the composite ranged from 0.48 +/- 0.06 to 0.55 +/- 0.02 and 5.090 +/- 0.545 to 6.366 +/- 0.289 microm(-1), respectively. Due to the relatively small changes in Vv and Sv, a macroporosity could be characterized for the biocomposite. X-ray diffraction and infrared spectroscopy showed that the sintered bone was composed essentially of HA with minimum additional groups such as surface calcium hydroxide, surface and crystal water, free carbon dioxide and possibly brushite. Mass spectrometry detected carbonates at A and B sites of HA, and weakly bound to the structure. Human osteoblasts adhered and spread on both the HA particle surface and the collagen fibers, which seemed to guide cells between adjacent particles. The biocomposite studied has several characteristics considered as ideal for its use as a scaffold for osteoconduction and osteoinduction.