Molecular cloning of components of protective antigenic preparations has suggested that related parasite fatty acid-binding proteins could form the basis of the protective immune crossreactivity between the parasitic trematode worms Fasciola hepatica and Schistosoma mansoni. Molecular models of the two parasite proteins showed that both molecules adopt the same basic three-dimensional structure, consisting of a barrel-shaped molecule formed by 10 antiparallel (8-pleated strands joined by short loops, and revealed the likely presence of crossreactive, discontinuous epitopes principally derived from amino acids in the C-terminal portions of the molecules. A recombinant form of the S. mansoni antigen, rSml4, protected outbred Swiss mice by up to 67% against challenge with S. mansoni cercariae in the absence of adjuvant and without provoking any observable autoimmune response. The same antigen also provided complete protection against challenge with F. hepatica metacercariae in the same animal model. The results suggest that it may be possible to produce a single vaccine that would be effective against at least two parasites, F. hepatica and S. mansoni, of veterinary and human importance, respectively. Schistosomiasis, caused principally by Schistosoma mansoni, S. haematobium, and S. japonicum, afflicts some 200 million individuals in tropical regions of the world. Fascioliasis caused by Fasciola hepatica is an economically important disease of cattle and sheep in Europe, the Americas, Australia, and New Zealand. There are no vaccines against Schistosoma or Fasciola species; however, there is evidence for protective immune crossreactivity between S. mansoni and F. hepatica. Hillyer and coworkers (1-3) have isolated a low molecular weight F. hepatica fraction that protects against both S. mansoni and F. hepatica infections. A component of this fraction is an antigen with homology to mammalian fatty acid-binding proteins that is termed Fhl5 (4). A similar antigen, Sm14, was cloned from S. mansoni following studies of a protective saline extract of adult worms, SE (5). These results suggested that the pair of similar parasite proteins could mediate immune crossreaction and represent the basis of a subunit vaccine effective against both species. We have investigated the molecular relationship of Fhl5, Sml4, and mammalian fatty acid-binding proteins (FABPs) (6) (9), and rat intestine (10) were obtained directly from the Brookhaven Protein Data Bank (accession codes 2HMB, 1ALB, and 2IFB, respectively). Sequences of known crystal structure were aligned by leastsquares superposition of the molecules using C' coordinates alone, and the remaining sequences were subsequently incorporated into the alignment by the method of Barton and Sternberg (11) as implemented in the AMPS package.For the construction of the Sm14 model, the backbone of the 10 (3-strands and three a-helices was based on that of 1ALB. (3-Turn types were determined on the basis of the position of glycine and/or asparagine and aspartic residues within ...

This paper describes patterns of infestation with

Ticks were obtained from dogs from February to September of 1999 at weekly intervals, in the County of Piraí, State of Rio de Janeiro. Four hundred seventy four ixodids were taxonomically identified, 103 Amblyomma cajennense, seven Amblyomma ovale, 209 Rhipicephalus sanguineus, and 155 Amblyomma sp. An hemolymph test associated with Giemsa's stain revealed two specimens in 163 ticks tested (R. sanguineus and Amblyomma sp), containing rickettsia-like organisms. Direct immunofluorescence verified the presence of spotted fever group rickettsia in one specimen of R. sanguineus. Considering the limited information on rickettsiosis in Brazil, principally in relation to the vectors involved in perpetuating it in foci, these preliminary results give us an idea on the importance of infection in ticks, allowing to expand our knowledge on this zoonosis.

Human occupation for several centuries was recorded in the archaeological layers of "Place d'Armes

We describe the isolation of a novel flavivirus, isolated from a pool of mosquitoes identified as Culex (Culex) chidesteri collected in 2010 in the Pantanal region of west-central Brazil. The virus is herein designated Nhumirim virus (NHUV) after the name of the ranch from which the mosquito pool was collected. Flavivirus RNA was detected by real-time RT-PCR of homogenized mosquitoes and from the corresponding C6/36 culture supernatant. Based on full-genome sequencing, the virus isolate was genetically distinct from but most closely related to Barkedji virus (BJV), a newly described flavivirus from Senegal. Phylogenetic analysis demonstrated that NHUV grouped with mosquito-borne flaviviruses forming a clade with BJV. This clade may be genetically intermediate between the Culex-borne flaviviruses amplified by birds and the insect-only flaviviruses.

The eco-epidemiological scenario of spotted fever (SF), a tick-borne disease that affects humans and other animals in several countries around the world, was analyzed in Rio de Janeiro (RJ) State, Brazil. During the last 34 years, 990 SF cases were reported in RJ (the Brazilian state with the highest population density), including 116 cases confirmed by serology (RIFI) or PCR, among 42.39% of the municipalities with reported cases of SF. The epidemiologic dynamics of SF in RJ State are very heterogeneous in time and space, with outbreaks, high mortality rates and periods of epidemiological silence (no SF cases reported). Furthermore, it exhibited a changing epidemiological profile from being rural to becoming an urban disease. This study identified arthropods infected with Rickettsia felis, R. bellii and R. rickettsii, and found that the abundance of ectoparasites was associated with specific hosts. The R. rickettsii-vector-host relationship was most evident in species-specific parasitism. This suggests that the association between dogs, cattle, horses, capybaras and their main ectoparasites, Rhipicephalus sanguineus and Ctenocephalides felis, Rhipicephalus microplus, Dermacentor nitens, and Amblyomma dubitatum, respectively, has a key role in the dynamics of R. rickettsii transmission in enzootic cycles and the maintenance of carrier ectoparasites, thus facilitating the existence of endemic areas with the ability to produce epidemic outbreaks of SF in RJ. This study found confirmed human infections for only the R. rickettsii carrier Amblyomma sculptum, which reinforces the importance of this species as a vector of the pathogen in Brazil. This study can be adapted to different eco-epidemiological scenarios of spotted fever throughout the Americas.

The result of a survey of ectoparasites infesting bats in southeastern Brazil is presented. Of 181 bats belonging to 16 species, 10 (34.1%) were infested by streblid flies (Streblidae), nine (33.5%) by spinturnicid mites (Spinturnicidae), and five (8.3%) by macronyssid mites (Macronyssidae). One species of the families Trombiculidae and Myobiidae was found. A total of 195 streblids, 178 spinturnicids, and 76 macronyssids was collected. Paratrichobius longicrus was the most abundant bat fly species (50 specimens). The spinturnicid mite Periglischrus iheringi was the most abundant ectoparasite species (159 specimens) and was recorded on three different bat species; Radfordiella desmodi was the most numerous macronyssid (69 specimens).

In this study, the oviposition behavior of mosquito species exhibiting acrodendrophilic habits was investigated. The study was conducted near the Simplicio Hydroelectic Reservoir (SHR) located on the border of the states of Minas Gerais and Rio de Janeiro, Brazil. Samples were collected using oviposition traps installed in forest vegetation cover between 1.70 and 4.30 m above ground level during the months of April, June, August, October, and December of 2011. Haemagogus janthinomys (Dyar), Haemagogus leucocelaenus (Dyar and Shannon), Aedes albopictus (Skuse), and Aedes terrens (Walker) specimens were present among the collected samples, the first two of which being proven vectors of sylvatic yellow fever (SYF) in Brazil and the latter is a vector of dengue in mainland Asia. As the data set was zero-inflated, a specific Poisson-based model was used for the statistical analysis. When all four species were considered in the model, only heights used for egg laying and months of sampling were explaining the distribution. However, grouping the species under the genera Haemagogus Williston and Aedes Meigen showed a significant preference for higher traps of the former. Considering the local working population of SHR is very large, fluctuating, and potentially exposed to SYF, and that this virus occurs in almost all Brazilian states, monitoring of Culicidae in Brazil is essential for assessing the risk of transmission of this arbovirus.