Recent studies on Schistosoma intercalatum: taxonomic status, puzzling distribution and transmission foci revisited

Schistosoma intercalatum, which causes human rectal schistosomiasis in Africa, still presents a great interest for its imprecise taxonomic status and its puzzling distribution in Africa. Two geographically isolated strains of S. intercalatum are recognized, the Lower Guinea strain and the Congo strain, which differ from each other in a number of morphological, biological and biochemical characteristics. Recent molecular data using RAPD markers indicate high divergence between the two strains, with values of Nei and Li's similarity indice allowing recognition of two genetically distinct taxa: experiments on pre- and post-isolating mechanisms are in progress in order to re-evaluate the taxonomic status of this polytypic species. With regard to its geographical distribution, S. intercalatum is characterized by the existence of two stable endemic areas (localized in Lower Guinea and North East of Democratic Republic of Congo) which correspond to the historical areas of species discovery, and the emergence during the last 15 years of new foci of the Lower Guinea strain outside previously known endemic areas. The absence of local adaptation of the Lower Guinea strain to its intermediate host, supported by experimental studies, may help to facilitate the spread of this strain. Nevertheless, the present restricted distribution of this species remains puzzling, because its potential snail hosts (bulinids) are widely distributed throughout much of Africa. Recent experimental and epidemiological studies suggest that interspecific sexual interactions between human schistosomes could have a role in limiting the distribution of S. intercalatum: the competitive sexual processes acting among human schistosomes show that S. haematobium and S. mansoni are always competitively dominant over S. intercalatum. These epidemiological observations lead the authors to distinguish three kinds of transmission foci for S. intercalatum.

Distribution of the a2, a3, and a5 nicotinic acetylcholine receptor subunits in the chick brain

Nicotinic acetylcholine receptors (nAChRs) are ionotropic receptors comprised of a and ß subunits. These receptors are widely distributed in the central nervous system, and previous studies have revealed specific patterns of localization for some nAChR subunits in the vertebrate brain. In the present study we used immunohistochemical methods and monoclonal antibodies to localize the a2, a3, and a5 nAChR subunits in the chick mesencephalon and diencephalon. We observed a differential distribution of these three subunits in the chick brain, and showed that the somata and neuropil of many central structures contain the a5 nAChR subunit. The a2 and a3 subunits, on the other hand, exhibited a more restricted distribution than a5 and other subunits previously studied, namely a7, a8 and ß2. The patterns of distribution of the different nAChR subunits suggest that neurons in many brain structures may contain several subtypes of nAChRs and that in a few regions one particular subtype may determine the cholinergic nicotinic responses

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite

Introduction The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. Methods The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. Results Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235) of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644) and 13% (83/640), respectively. Thirteen (2%) specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. Conclusions The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified.

Social wasps of two wetland ecosystems in brazilian Amazonia (Hymenoptera, Vespidae, Polistinae)

In Brazilian Amazonia, 20 genera and more than 200 species of polistine wasps are recorded. Local faunas with 70 to 80 species are usually found in non floodable forest environments. However, a variety of wetlands exist in the region, the most expressive in surface area being varzea systems. In this paper, information is presented on polistines from two areas of wetlands in the Brazilian states of Amazonas and Amapá. These are reciprocally compared and also with nearby terra firme locations. Collecting methods consisted of active search for nests, handnetting and automatic trapping of individuals. Forty-six species of 15 genera were collected in Mamirauá, AM, most being widespread common wasps. However, five species deserve special mention in virtue of rarity and/or restricted distribution: Metapolybia rufata, Chartergellus nigerrimus, Chartergellus punctatior, Clypearia duckei, and Clypearia weyrauchi. In Região dos Lagos, AP, 31 species of 9 genera were collected, nearly all being common species with the exception of some Polistes, like P. goeldi and P. occipitalis. Even though less rich than vespid faunas from terra firme habitats, the Mamirauá fauna proved to be quite expressive considering limitations imposed by the hydrological regime. In Região dos Lagos, however, the very low diversity found was below the worst expectations. The virtual absence of otherwise common species in environments like tidal varzea forests along Araguari River is truly remarkable. The causes of low diversity are probably related to isolation and relative immaturity of the region, allied to strong degradation of forested habitats.

Floristic composition and similarity analysis of an Atlantic rain forest fragment in Cananéia, São Paulo State, Brazil

The aim of this study is to investigate the floristic composition of an Atlantic rain forest fragment located in Cananéia, São Paulo, Brazil, and to contribute to the knowledge on Atlantic forest through the comparative analysis of this and other floristic surveys both on the southern and southeastern Brazil, in different soil and relief types. We surveyed 215 species in 132 genera and 51 families. Classification and ordination analysis were applied to a binary matrix in order to analyze the similarity among 24 surveys, including the present one, of Atlantic forest from the south and southeast coast of Brazil. Higher floristic similarity was observed among this area and the ones where there was marine influence and more rugged relief. The surveys in areas with greater marine influence (sandy soil) were separated from those in other conditions, possibly indicating a species replacement gradient from the steep slopes towards the lowland and were probably related to different edaphic conditions. A latitudinal gradient was found among the surveys apparently confirming a continuous species replacement along the Atlantic forest, related to a restricted distribution of the species. This suggests that it is essential to preserve areas from the whole Atlantic coast. Atlantic forest distribution is quite complex and its composition cannot be adequately represented by small localized areas.

DISTRIBUTION OF DERMATOPHYTES FROM SOILS OF URBAN AND RURAL AREAS OF CITIES OF PARAIBA STATE, BRAZIL

SUMMARYThe dermatophytes, keratinophilic fungi, represent important microorganisms of the soil microbiota, where there are cosmopolitan species and others with restricted geographic distribution. The aim of this study was to broaden the knowledge about the presence of dermatophytes in soils of urban (empty lots, schools, slums, squares, beaches and homes) and rural areas and about the evolution of their prevalence in soils of varying pH in cities of the four mesoregions of Paraiba State, Brazil. Soil samples were collected from 31 cities of Paraiba State. Of 212 samples, 62% showed fungal growth, particularly those from the Mata Paraibana mesoregion (43.5%), which has a tropical climate, hot and humid. Soil pH varied from 4.65 to 9.06, with 71% of the growth of dermatophytes occurring at alkaline pH (7.02 - 9.06) (ρ = 0.000). Of 131 strains isolated, 57.3% were geophilic species, particularly Trichophyton terrestre(31.3%) and Mycrosporum gypseum(21.4%). M. nanum and T. ajelloi were isolated for the first time in Paraiba State. The zoophilic species identified were T. mentagrophytes var.mentagrophytes (31.3 %) and T. verrucosum (7.6 %), and T. tonsurans was isolated as an anthropophilic species. The soils of urban areas including empty lots, schools, slums and squares of cities in the mesoregions of Paraiba State were found to be the most suitable reservoirs for almost all dermatophytes; their growth may have been influenced by environmental factors, soils with residues of human and/or animal keratin and alkaline pH.

DISTRIBUTION AND FEEDING ECOLOGY OF THE AFRICAN TILAPIA Oreochromis mossambicus (TELEOSTEI, PERCIFORMES, CICHLIDAE) IN SURINAME (SOUTH AMERICA) WITH COMMENTS ON THE TILAPIA-KWIKWI (Hoplosternum littorale) (TELEOSTEI, SILURIFORMEs, CALLICHTHYIDAE) INTERACTION

The geographical distribution of the African Tilapia Oreochromis mossambicusin Suriname is restricted to a narrow strip of land along the Atlantic coast. Within the coastal plain, O. mossambicusoccurs in brackish lagoons, oligohaline canals, and shell-sand pit lakes. Physico-chemical characteristics and phytoplankton composition of representative Tilapia water bodies are described. Blue-green algae and fine flocculent detritus are dominant food items in the diet of the Tilapia, while Rotifera and microcrustacea are also important in the diet of larvae and juveniles. Intraspecific diet overlap among ontogenetic stages of the Tilapia did not differ significantly from 1, which means that these diets showed complete overlap. Interspecific diet overlap between the Tilapia and the indigenous armoured catfish Hoplosternum littoralewere moderate or low. The results are discussed in relation to recent developments in the Surinamese fisheries and aquaculture sector.

Spatial and temporal distribution of a tiger beetle guild (Coleoptera: Carabidae: Cicindelinae) along a 105m long transect in the reserva florestal A. Ducke near Manaus (Central Amazonia)

The spatial and temporal distribution of a guild of eight diurnal tiger beetle species was studied on a 105 m long transect near the field station of the Reserva Florestal A. Ducke near Manaus (AM), Brazil. The transect followed a path that included both shaded and an open areas. Five of the species, restricted to primary forest, occurrred only in shaded areas of the transect, and three species occurred in open areas. Of all eight species only two of the open habitat species showed no clear seasonality in adult activity. In six species the activity of adults was limited to the rainy season. The most pronounced annual rhythm was found in Pentacomia ventralis, an open habitat species. Activity of adults was limited to October/November. First in-star larvae appeared shortly thereafter. Larval development mainly took place from January to May. The third instar larva entered a dormancy which lasted up to 10 months, and which enabled the synchronisation of emerging adults with annual seasons.

Ecology of sandflies Diptera: Psychodidae) in a restricted focus of cutaneous leishmaniasis in Northern Venezuela: IV. Sandfly monthly fluctuation and leishmaniasis incidence relationship

An attempt has been made to correlate the monthly incidence of human leishmaniasis with the temporal distribution of sandfly species at San Esteban, Northern Venezuela. Upon statistical analysis, the seasonal fluctuation of L. ovallesi population correlated strongly with the human disease, while the dynamics of L. panamensis, generally believed to be the vector in the Central area of the country, showed only a very weak correlation. These findings support the hypothesis that L. panamensis might not be the main or unique species responsible for the transmission in this area and that L. ovallesi and additionally L. olmeca bicolor might be involved in the epidemiology of the disease.

Phlebotominae spatial distribution asssociated with a focus of tegumentary leishmaniasis in Las Lomitas, Formosa, Argentina, 2002

Las Lomitas, Formosa, Argentina, reported 96 cases of tegumentary leishmaniasis during 2002. The urban transmission was suggested although previous outbreaks were related with floods of the Bermejo river (BR) 50 km from the village. Phlebotomine collections were performed during March 2002 to define the spatial distribution of risk, together with satellite imaginery. The phlebotomine/trap obtained was 1679.5 in the southern BR shore, 1.1 in the periruban-rural environment and 2.3 in the northern Pilcomayo river marshes. Lutzomyia neivai was the prevalent species (91.1%) among the 2393 phlebotomine captured, and it was only found in the BR traps. The other species were L. migonei (7.9%), L. cortelezzii (0.9%), and Brumptomyia guimaraesi (0.1%). The satellite images analysis indicates that the fishing spots at the BR were significantlyoverflowed during the transmission peak, consistent with fishermen recollections. This spatial restricted flood might concentrate vectors, reservoirs, and humans in high places. Therefore, both the spatial distribution of vectors and the sensor remoting data suggests that in Las Lomitas area the higher transmission risk it is still related with the gallery forest of the BR, despite of the urban residence of the cases. The surveillance and control implications of these results are discussed.

Distribution of phlebotomine fauna (Diptera: Psychodidae) across an urban-rural gradient in an area of endemic visceral leishmaniasis in northern Brazil

The number of visceral leishmaniasis (VL) cases has increased over the past 10 years in Brazil, especially in the North and Northeast regions of the country. The aim of this study was to evaluate the urbanisation of VL vectors in Barcarena, Pará, an area in northern Brazil where VL is endemic. Sandflies were captured using Centers for Disease Control (CDC) light traps along an urban-rural gradient. The CDC traps were installed inside hen houses at a height of 150 cm. A total of 5,089 sandflies were collected and 11 species were identified. The predominant species was Lutzomyia longipalpis (rate of 95.15%), which suggests its participation in the transmission of VL. A total of 1,451 Lu. longipalpis females were dissected and no Leishmania infections were detected. Most of the sandflies were captured at the border of a forest (88.25%) and no flies were captured in the urban area, which suggests that transmission is still restricted to rural sites. However, the fact that a specimen was collected in an intermediate area indicates that urbanisation is a real possibility and that vector monitoring is important.

Abundance and temporal distribution of Gonioterma exquisita Duckworth (Lepidoptera, Elachistidae, Stenomatinae) on Byrsonima pachyphylla Griseb. (Malpighiaceae) in the Brazilian Cerrado

The seasonal characteristics of the Cerrado region strongly influence food resource predictability and vegetal tissue nutritional content. The aims of this work were to record the abundance and temporal distribution of Gonioterma exquisita Duckworth, 1964 (Lepidoptera, Elachistidae) and its relation with phenological, physical, and chemical traits of the host plant Byrsonima pachyphylla Griseb. (Malpighiaceae). Four nutritional quality parameters were determined for new and mature leaves: gross protein and nitrogen content, dry matter, and in vitro digestibility. We inspected 200 plants per month, searching for G. exquisita caterpillars. About 35.8% of the 2,400 plants inspected presented caterpillars, with an abundance peak in the wet season. Caterpillar abundance was positively correlated with mature leaf availability, their food resource. Although mature leaves presented lower gross protein and nitrogen contents than new leaves, this difference was small during the abundance peak of G. exquisita.

Description of the male of Eburella pinima Martins and notes on the geographical distribution of Eburodacrys aenigma Galileo & Martins and Eburodacrys lanei Zajciw (Coleoptera, Cerambycidae)

Description of the male of Eburella pinima Martins and notes on the geographical distribution of Eburodacrys aenigma Galileo & Martins and Eburodacrys lanei Zajciw (Coleoptera, Cerambycidae). The male of Eburella pinima Martins, 1997 is described and illustrated for the first time. Information on Eburodacrys aenigma Galileo & Martins, 2006, previously known only from the female holotype, which lacked locality label, is herein complemented. This species is recorded from Brazil and the male is depicted for the first time. The geographical distribution of Eburodacrys lanei Zajciw, 1958 is further restricted here as some previous records are confirmed to result from misidentifications of E. aenigma.

Dexamethasone-induced reactivation of bovine herpesvirus type 5 latent infection in experimentally infected rabbits results in a broader distribution of latent viral DNA in the brain

Bovine herpesvirus type 5 (BHV-5) is a major agent of meningoencephalitis in cattle and establishes latent infections mainly in sensory nerve ganglia. The distribution of latent BHV-5 DNA in the brain of rabbits prior to and after virus reactivation was studied using a nested PCR. Fifteen rabbits inoculated intranasally with BHV-5 were euthanized 60 days post-inoculation (group A, N = 8) or submitted to dexamethasone treatment (2.6 mg kg-1 day-1, im, for 5 days) and euthanized 60 days later (group B, N = 7) for tissue examination. Two groups of BHV-1-infected rabbits (C, N = 3 and D, N = 3) submitted to each treatment were used as controls. Viral DNA of group A rabbits was consistently detected in trigeminal ganglia (8/8), frequently in cerebellum (5/8), anterior cerebral cortex and pons-medulla (3/8) and occasionally in dorsolateral (2/8), ventrolateral and posterior cerebral cortices, midbrain and thalamus (1/8). Viral DNA of group B rabbits showed a broader distribution, being detected at higher frequency in ventrolateral (6/7) and posterior cerebral cortices (5/7), pons-medulla (6/7), thalamus (4/7), and midbrain (3/7). In contrast, rabbits inoculated with BHV-1 harbored viral DNA almost completely restricted to trigeminal ganglia and the distribution did not change post-reactivation. These results demonstrate that latency by BHV-5 is established in several areas of the rabbit's brain and that virus reactivation leads to a broader distribution of latent viral DNA. Spread of virus from trigeminal ganglia and other areas of the brain likely contributes to this dissemination and may contribute to the recrudescence of neurological disease frequently observed upon BHV-5 reactivation.

Uniformity of liquid distribution in the canopy of the bean plant, using the spectrophotometric analysis

Fungal diseases are important factors limiting common bean yield. White mold is one of the main diseases caused by soil pathogens. The objective of this study was to quantify the distribution of a fungicide solution sprayed into the canopy of bean plants by spectrophotometry, using a boom sprayer with and without air assistance. The experiment was arranged in a 2 x 2 x 2 factorial (two types of nozzles, two application rates, and air assistance on and off) randomized block design with four replications. Air assistance influenced the deposition of solution on the bean plant and yield increased significantly with the increased rate of application and air assistance in the boom sprayer.