Abstract INTRODUCTION Triatomine bugs are hematophagous insects that are extremely important in public health because they are natural vectors of Trypanosoma cruzi, the causative agent of Chagas disease. In this study, we aimed to assess the occurrence of triatomine species and the natural T. cruzi infection in the Guaribas Valley territory, an endemic region for Chagas disease in northeastern Brazil. METHODS Insects were actively captured from July 2017 to October 2019 in the intra- and peridomiciles of 16 municipalities of the Guaribas Valley territory, in the southeast area of Piauí state. Triatomine species were identified following a taxonomic key, and natural infection was investigated through insects’ fresh feces exams. RESULTS A total of 430 triatomines were collected, including 211 nymphs and 219 adults. Of all collected specimens, 39 (9.1%) were from the intradomiciles and 391 (90.9%) from peridomiciles. Nine species, including two subspecies, could be identified: Triatoma brasiliensis brasiliensis, T. brasiliensis macromelasoma, T. pseudomaculata, T. sordida, T. juazeirensis, T. melanocephala, Panstrongylus lutzi, Rhodnius domesticus, R. nasutus, and R. robustus. T. brasiliensis were the most frequently collected bugs, representing 72% of all the identified insects. None of the examined invertebrates presented flagellate forms of T. cruzi. CONCLUSIONS: This is the first report of T. b. macromelasoma and T. juazeirensis in the Guaribas Valley territory. The persistence of triatomine species in the domiciles in an endemic area for Chagas disease emphasizes the relevance of entomological surveillance and vector control measures in the studied area.

Resumo Dois terços da população mundial vivem em áreas infestadas com mosquitos vetores da dengue, especialmente o Aedes aegypti. Este estudo realizou um levantamento de dados sobre casos de dengue no município de Picos, no Estado do Piauí, Brasil, entre os anos de 2007 e 2011, enfatizando alguns fatores envolvidos em sua transmissão. Os dados foram coletados no Centro de Zoonoses de Picos da Secretaria Municipal de Saúde e no Sistema de Informação da Febre Amarela e Dengue (SISFAD) do Programa Nacional do Controle da Dengue (PNCD). Durante os anos de 2007, 2008, 2009, 2010 e 2011, foram visitados, respectivamente, 116.301, 182.024, 181.892, 187.619 e 195.377 imóveis pelos agentes de controle de endemias (ACE). As residências foram os estabelecimentos com maior positividade para focos de larvas de Aedes aegypti (p<0,05). Dentre os depósitos inspecionados, as larvas predominaram em armazenadores de água rebaixados (tambores) e elevados (caixas-d’água). Testes sorológicos confirmaram um total de 85 casos em 2007, 117 em 2008, 221 em 2009, 296 em 2010 e 217 em 2011. A média de casos foi mais expressiva em pacientes com idade entre 20-34 anos (p<0,05). No ano de 2011, foram identificados, pela primeira vez, focos de Aedes albopictus, encontrados principalmente em tambores de água. Portanto, o número de casos vem aumentando, o que sugere que o controle vetorial da transmissão pode sofrer forte impacto a partir da ação de vigilância epidemiológica em âmbito coletivo, uma vez que depósitos de água peri ou intradomiciliares representaram os locais predominantes para a procriação de vetores.

Abstract Two-thirds of the world population live in areas infested with dengue vector mosquitoes, especially Aedes aegypti. This study conducted a survey about dengue cases in Picos (Piauí, Brazil) between 2007 and 2011, emphasizing some transmission factors. Data were collected in the Health Secretary and Municipal Zoonoses Center and in SISFAD Programme (Information System of the National Dengue Control Program). During 2007, 2008, 2009, 2010 and 2011, a total of 116,301; 181,892; 187,619 and 195,377 properties, respectively, were visited by endemic control agents, and presented higher rates of outbreaks for A. aegypti larvae (p<0.05). Among the inspected places, larvae were predominant in lowered (storage tanks) and raised (water tanks) water reservoirs. Serological tests confirmed a total of 85, 117, 221, 296 and 217 cases in 2007, 2008, 2009, 2010 and 2011 and the average number of cases was higher in patients between 20-34 years-old) (p<0.05). In 2011 it was identified, for the first time, Aedes albopictus spots, mainly in storage tanks. Therefore, the number of cases is increasing, suggesting that the transmission vector control may suffer a strong impact by surveillance action based on community contribution, since peri- or household water tanks represented the predominant sites for vectors reproduction.

Three isolates of Klebsiella pneumoniae, collected from the University Hospital in Fortaleza, Brazil, were analyzed to determine their resistance to multiple antibiotics. The results of this study showed that the resistance of the clinically isolated bacteria is associated with the production of extended-spectrum beta-lactamases (ESLBs) and loss of outer membrane proteins.

A análise SDS-PAGE do Cowpea severe mosaic virus (CPSMV) purificado revelou a migração de três frações protéicas estimadas em 43, 23 e 21 kDa, correspondentes às proteínas do capsídeo: denominadas proteína maior (43 kDa) e menor (23 kDa; intacta e 21 kDa; clivada). As proteínas do capsídeo, na sua forma nativa, foram utilizadas na imunização de camundongos pelas vias oral e nasal, durante 10 dias consecutivos. As frações protéicas de 43 e 23 kDa, em sua forma desnaturada, foram utilizadas para imunização subcutânea. A resposta imunológica da mucosa foi avaliada pela proliferação celular das placas de Peyer de camundongos imunizados pela via oral com o CPSMV purificado. Ficou demonstrado que o CPSMV induz resposta imunológica, evidenciada pela síntese de anticorpos séricos, quando administrado na sua forma nativa pelas vias oral e nasal ou através de suas proteínas do capsídeo desnaturadas, pela via subcutânea. Não foi necessário o uso de adjuvantes, quer por via oral quer por via nasal. As frações protéicas de 43 e 23 kDa mostraram-se responsáveis pela imunogenicidade do vírus, como foi evidenciado pela síntese de anticorpos específicos detectados por ELISA. A análise da proliferação celular da placas de Peyer revelou um aumento (r=0,88) do número de leucócitos ao longo de 42 dias após a imunização. Esses resultados reforçam a possibilidade do uso do CPSMV como vetor seguro de antígenos de doenças humanas/animais pouco imunogênicos para produção de vacinas.

SDS-PAGE analysis of purified Cowpea severe mosaic virus (CPSMV) revealed the migration of three protein fractions of 43, 23 and 21 kDa, corresponding to the capsid protein called large protein (43 kDa) and small protein (23 kDa; intact and 21 kDa; cleaved). The capsid proteins, in their native form, were used to immunize mice through oral and nasal routes for ten consecutive days. The denatured form of the 43 and 23 kDa protein fractions were used for subcutaneous immunization. The mucosal immune response was detected by the cellular proliferation of the Peyer's patches of mice immunized by oral route with CPSMV. It was demonstrated that CPSMV induces immune response, evidenced by the synthesis of specific antibodies, when administered in the native form by the oral and nasal routes or with two denatured capsid proteins by the subcutaneous route. The use of adjuvants in the oral and nasal immunizations was not necessary. The 43 and 23 kDa protein fractions were responsible for the immunogenicity of the virus, evidenced by the synthesis of specific antibodies detected by ELISA test. The cellular proliferation analysis of the Peyer's patches revealed an increase (r=0.88) of leucocytes along 42 days after immunization. The results reinforce the possibility of the use of CPSMV as a safe vector of antigens for human/animal diseases of low immunogenicity for the production of vaccines.