Visceral leishmaniasis (VL) is considered an important neglected disease that affects many countries of the world (Desjeux 2004). On the American continent, VL is caused by the protozoan parasite Leishmania chagasi, which is transmitted to humans and other vertebrate hosts (e.g., dogs) through the bite of a female sandfly. Lutzomyia longipalpis is considered to be the main vector for VL in Brazil (Lainson & Rangel 2005).A high proportion of L. chagasi infected persons do not present any clinical symptoms of disease, even after a long incubation period (asymptomatic form) (Evans et al. 1992, Romero et al. 2009). Cohort studies in Brazil have described detection of asymptomatic seroconvertors with a sensitive and specific enzyme linked immunosorbent assay (ELISA) test using crude antigens from promastigotes (Badaró et al. 1986a, c) Malnutrition is considered one of the most important factors associated with the development of clinical symptoms of leishmaniasis (Alvar et al. 2006). The high frequency of Leishmania infection found in human beings, dogs and Lu. longipalpis in previous studies in the municipality of Raposa, state of Maranhão (MA), Brazil, may also be associated with poverty (Caldas et al. 2001(Caldas et al. , 2002.Notably, the current knowledge on the epidemiology of VL is mainly based on studies examining the prevalence of Leishmania infections only among humans. There are few studies that simultaneously examine L. chagasi infection across several known hosts and carriers. Therefore, the aim of the present study was to determine the asymptomatic L. chagasi infection rates in human beings, dogs and the vector Lu. longipalpis in the VL endemic area of Raposa. PATIENTS, MATERIALS AND METHODSThe study was performed from August 2006-July 2008 in Vila Maresia, Vila Marisol and Vila Pantoja; all three neighbourhoods are located in the municipality of Raposa situated in the northern coastal region of MA, approximately 28 km from the state capital, São Luis (Figure).In this study, the inclusion criteria for human subjects were the following: living in an endemic area for more than six months, no signs and symptoms of VL (fever for more than 2 weeks, hepatosplenomegaly, weight loss or mucocutaneous pallor) and no previous history of VL. As exclusion criteria, we considered a history of treatment for VL (including treatment failures and relapses), individuals with known immunodeficiency or currently using immunosuppressants and comorbidities (evidence of other conditions leading to splenomegaly, such as schistosomiasis and malaria).In a preliminary census survey, we found 1,417 inhabitants, 986 (70%) of whom participated in the study. This 30% loss was mainly due to internal and external migrations, as well as refusal to participate in the study. Overall, 986 (69.6%) out of 1,417 inhabitants that lived more than six months in the area and did not exhibit clinical VL symptoms participated in the study. From these, 857 individuals (86.9%) were from Vila Maresia, 77 individuals (7.7%) were from Vila Marisol and 52...

The plasma membrane (PM) H(+)-ATPase has been proposed to play important transport and regulatory roles in plant physiology, including its participation in auxin-induced acidification in coleoptile segments. This enzyme is encoded by a family of genes differing in tissue distribution, regulation, and expression level. A major expressed isoform of the maize PM H(+)-ATPase (MHA2) has been characterized. RNA gel blot analysis indicated that MHA2 is expressed in all maize organs, with highest levels being in the roots. In situ hybridization of sections from maize seedlings indicated enriched expression of MHA2 in stomatal guard cells, phloem cells, and root epidermal cells. MHA2 mRNA was induced threefold when nonvascular parts of the coleoptile segments were treated with auxin. This induction correlates with auxin-triggered proton extrusion by the same part of the segments. The PM H(+)-ATPase in the vascular bundies does not contribute significantly to auxin-induced acidification, is not regulated by auxin, and masks the auxin effect in extracts of whole coleoptile segments. We conclude that auxin-induced acidification in coleoptile segments most often occurs in the nonvascular tissue and is mediated, at least in part, by increased levels of MHA2.

Lutzomyia whitmani (Diptera, Psychodidae) é uma espécie de flebotomíneo incriminada em muitas regiões como principal vetor de espécies de Leishmania causadoras da leishmaniose cutânea americana (LCA) 6 RESUMOO objetivo deste estudo foi determinar as fontes de alimento sanguíneo de fêmeas de Lutzomyia whitmani, espécie de flebotomíneo incriminada no Maranhão como principal vetor da leishmaniose cutânea americana. Para isso, 70 fêmeas desta espécie coletadas no município de Axixá, área com um dos maiores números de casos de leishmaniose cutânea americana em humanos no Maranhão, foram analisadas utilizando a técnica da precipitina. Dos indivíduos analisados, 90% apresentaram reação a algum tipo de antissoro e dentre estes, 73% apresentaram reações do tipo simples com predominância para sangue de galinha (22,2%), roedor (14,3) e humano (12,7%). Nas reações duplas predominaram as combinações galinha/humano (6,3%), galinha/gambá (4,8%), boi/humano e gambá/humano (3,2%). Assim, concluímos que seres humanos, animais domésticos e sinantrópicos constituem fonte alimentar sanguínea para Lutzomyia whitmani podendo desempenhar um papel importante no ciclo de transmissão da leishmaniose cutânea americana explicando os casos da doença em Axixá. Palavras-chaves:Lutzomyia whitmani. Leishmaniose cutânea americana. Alimentação sanguínea. Precipitina. Alimentação sanguínea. Precipitina. ABSTRACTThe aim of this study was to determine the sources of blood meals for females of Lutzomyia whitmani, a phlebotomine species incriminated as the main vector for American cutaneous leishmaniasis in Maranhão. For this, 70 Lutzomyia whitmani females were collected in the municipality of Axixá, an area with one of the greatest numbers of cases of American cutaneous leishmaniasis in humans in Maranhão. They were analyzed using the precipitin technique. Ninety percent of the specimens showed a reaction to some type of antiserum positive immune reaction, among which 73% presented single reactions, with predominance for chicken blood (22%), rodent blood (14.3%) and human blood (12.7%). Among the double reactions, the predominant combinations were chicken/human (6.3%), chicken/opossum (4.8%), ox/human (3.2%) and opossum/human (3.2%). Thus, we conclude that humans and domestic and synanthropic animals are blood meal sources for Lutzomyia whitmani and may play an important role in the transmission cycle for American cutaneous leishmaniasis, thus explaining the cases of this disease in Axixá.Key-words: Lutzomyia whitmani. American cutaneous leishmaniasis. Blood feeding. Precipitin.homem, podemos citar Leishmania braziliensis (Kinetoplastida, Trypanosomatidae), no Nordeste e Sudeste e Leishmania shawi (Kinetoplastida, Trypanosomatidae) na Região Norte 7 . Nos últimos anos, Lutzomyia whitmani vem sendo utilizada freqüentemente em estudos experimentais relacionados à taxa de infecção por Leishmania, o que proporciona um melhor conhecimento desta como vetor 10 . Apesar de Lutzomyia whitmani ser frequentemente encontrada em abrigos de animais domésticos, pou...

Leishmania (L.) amazonensis (Lainson & Shaw, 1972) and Leishmania (Viannia) braziliensis (Vianna, 1911) are the principal causative agents of American tegumentary leishmaniasis (ATL) in Brazil. L. amazonensis also causes diffuse cutaneous leishmaniasis (DCL) vectored principally by Lutzomyia flaviscutellata and secondarily by Lutzomyia whitmani (Antunes & Coutinho, 1939). The latter is the most common phlebotomine in the state of Maranhão, and it is the focal species for potential ATL transmission. For this reason, we tested the ability of L. whitmani to become infected with Lutzomyia parasites. Phlebotomines were derived from a colony maintained in the laboratorial conditions. The first generation, uninfected females were offered a bloodmeal with mice infected with the strains of both parasites. We found that L. whitmani can become infected with both parasite species, with infection rates of 65.2% (L. braziliensis) and 47.4% (L. amazonensis). We conclude that in Maranhão, L. whitmani is likely an important vector in the transmission of ATL and may function as a vector of DCL. This possibility should be further investigated.

The Port Complex of Maranhão (PCM) is the second largest port complex in Brazil, receiving ships with large volumes of ballast water. To evaluate the microbiological quality of its waters, physicochemical parameters (pH and salinity), the number of coliforms (thermotolerants and totals), and the presence of enterobacterias and diarrheagenic Escherichia coli strains were analyzed. In order to identify the presence of E. coli virulence genes target regions of the stx, elt, est, aggR, CVD432, ipaH and eae nucleotide sequences were studied. The presence of totals and thermotolerants coliforms were positive. Analyzing the salinity parameter, a significant increase in total coliforms was observed during the rainy season. We identified the species Escherichia coli, Proteus mirabilis, Citrobacter freundii, Proteus vulgaris, Klebsiella pneumoniae, Klebsiella ozaenae, Morganella morganii, Enterobacter cloacae and Edwardsiella tarda. Out of the 51 E. coli isolated, two were positive for the elt gene and one was positive for the CVD432 sequence, features of enterotoxigenic and enteroaggregative strains, respectively. This study reveals that the PCM is contaminated by enterobacteria and diarrheagenic E.coli thus providing evidence regarding the risk of these bacteria being carried by ships to other countries, and draws attention to the input of fecal bacteria brought by ships in the port waters of Maranhão.