Phylodynamics of influenza A(H3N2) in South America, 1999–2012

The limited influenza A(H3N2) genetic data available from the Southern Hemisphere (particularly from Africa and Latin America), constrains the accurate reconstruction of viral dissemination dynamics within those regions. Our objective was to describe the spatial dissemination dynamics of influenza A(H3N2) within South America. A total of 469 sequences of the HA1 portion of the hemagglutinin gene (HA) from influenza A(H3N2) viruses sampled in temperate and tropical South American countries between 1999 and 2012 were combined with available contemporary sequences from Australia, Hong Kong, United Kingdom and the United States. Phylogenetic analyses revealed that influenza A(H3N2) sequences from South America were highly intermixed with sequences from other geographical regions, although a clear geographic virus population structure was detected globally. We identified 14 clades mostly (≥ 80%) composed of influenza sequences from South American countries. Bayesian phylogeographic analyses of those clades support a significant role of both temperate and tropical regions in the introduction and dissemination of new influenza A(H3N2) strains within South America and identify an intensive bidirectional viral exchange between different geographical areas. These findings indicate that seasonal influenza A(H3N2) epidemics in South America are seeded by both the continuous importation of viral variants from other geographic regions and the short-term persistence of local lineages. This study also supports a complex metapopulation model of influenza A(H3N2) dissemination in South America, with no preferential direction in viral movement between temperate and tropical regions.     

Molecular genotyping of Toxoplasma gondii from Central and South America revealed high diversity within and between populations

Recent population studies revealed that a few major clonal lineages of Toxoplasma gondii dominate in different geographical regions. The Type II and III lineages are widespread in all continents and dominate in Europe, Africa and North America. In addition, the type 12 lineage is the most common type in wildlife in North America, the Africa 1 and 3 are among the major types in Africa, and ToxoDB PCR-RFLP #9 is the major type in China. Overall the T. gondii strains are more diverse in South America than any other regions. Here, we analyzed 164 T. gondii isolates from three countries in Central America (Guatemala, Nicaragua, Costa Rica), from one country in Caribbean (Grenada) and five countries from South America (Venezuela, Colombia, Peru, Chile, and Argentina). The multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based genotyping of 11 polymorphic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico) were applied to 148 free-range chicken (Gallus domesticus) isolates and 16 isolates from domestic cats (Felis catus) in Colombia; 42 genotypes were identified. Linkage disequilibrium analysis indicated more frequent genetic recombination in populations of Nicaragua and Colombia, and to a lesser degree in populations of Costa Rica and Argentina. Bayesian structural analysis identified at least three genetic clusters, and phylogenetic network analysis identified four major groups. The ToxoDB PCR-RFLP #7, Type III and II were major lineages identified from Central and South America, with high frequencies of the closely related ToxoDB PCR-RFLP #7 and Type III lineages. Taken together, this study revealed high diversity within and between T. gondii populations in Central and South America, and the dominance of Type III and its closely related ToxoDB PCR-RFLP #7 lineages.     

Correlated morphologic and genetic diversity among Lutzomyia longipalpis (Diptera: Psychodidae) collections in Venezuela

Diversity among Lutzomyia longipalpis populations in Venezuela was characterized using 2 methods: larval mouthpart morphology-morphometry and isoenzyme electrophoresis. Analysis of the results suggested the presence of 2 morpho-genotypes. The mentum, maxillary comb, mandibular ventral teeth, and adenylate kinase and hexokinase enzyme-encoding loci suggested that a population from the northwestern Coriano System (Curarigua) is a distinct lineage within the L. longipalpis complex. Three widely separated populations from the Llanos (savanna), Andes, and northcentral Coastal Cordillera showed no significant substructure. These studies provide morphologic markers that are congruent with genetic data and suggest that the morphologic markers may be used to characterize and differentiate populations within this species complex.     

Molecular data supports monophyly of Triatoma dispar complex within genus Triatoma

The genus Triatoma contains numerous species, principal or secondary vectors of Chagas disease, which have been included in the three main lineages of Triatomini tribe based on morphological and biogeographical characteristics: North American, South American, and T. dispar complex. The three members of the T. dispar complex are distributed in Ecuador. This complex has been scarcely studied through molecular approaches, and the taxonomic position of this complex is not confirmed. In this study, we explored the phylogenetic relationships within the genus Triatoma, including five species from North and Central America, six from South America, and the three species belonging to the T. dispar complex. Partial sequences of four mitochondrial genes (Cyt b, COII, 16S-rRNA, 12S-rRNA) and two nuclear genes (18S-rRNA, ITS2) were obtained from 74 specimens. Phylogenetic trees were built with concatenated and single sequences through maximum likelihood (ML), maximum parsimony (MP), and Bayesian methods. The trees built using concatenated sequences showed three main branches (clusters) highly supported by significant bootstrap values; the T. dispar complex appeared as a monophyletic group separate from species of North and Central American origin and South American origin. On the contrary, for each gene tree, the three main clusters were not always significantly supported, mostly because genetic information is dramatically reduced when a single gene is considered. Consequently, concatenation of genes gives relevant results and is highly recommended for further in-depth examination of the relationships of several species and complexes of triatomines that remain unresolved. Moreover, our current molecular data fully revealed the division of genus Triatoma into at least three main genetic groups.     

Hypothesis testing clarifies the systematics of the main Central American Chagas disease vector,Triatoma dimidiata (Latreille, 1811), across its geographic range

The widespread and diverse Triatoma dimidiata is the kissing bug species most important for Chagas disease transmission in Central America and a secondary vector in Mexico and northern South America. Its diversity may contribute to different Chagas disease prevalence in different localities and has led to conflicting systematic hypotheses describing various populations as subspecies or cryptic species. To resolve these conflicting hypotheses, we sequenced a nuclear (internal transcribed spacer 2, ITS-2) and mitochondrial gene (cytochrome b) from an extensive sampling of T. dimidiata across its geographic range. We evaluated the congruence of ITS-2 and cyt b phylogenies and tested the support for the previously proposed subspecies (inferred from ITS-2) by: (1) overlaying the ITS-2 subspecies assignments on a cyt b tree and, (2) assessing the statistical support for a cyt b topology constrained by the subspecies hypothesis. Unconstrained phylogenies inferred from ITS-2 and cyt b are congruent and reveal three clades including two putative cryptic species in addition to T. dimidiata sensu stricto. Neither the cyt b phylogeny nor hypothesis testing support the proposed subspecies inferred from ITS-2. Additionally, the two cryptic species are supported by phylogenies inferred from mitochondrially-encoded genes cytochrome c oxidase I and NADH dehydrogenase 4. In summary, our results reveal two cryptic species. Phylogenetic relationships indicate T. dimidiata sensu stricto is not subdivided into monophyletic clades consistent with subspecies. Based on increased support by hypothesis testing, we propose an updated systematic hypothesis for T. dimidiata based on extensive taxon sampling and analysis of both mitochondrial and nuclear genes.     

The epidemiology of HIV and AIDS among Central American, South American, and Caribbean immigrants to Houston, Texas

A retrospective study with respect to demographics and clinical parameters was conducted of all HIV/AIDS patients born in Central America, South America, and the Caribbean region, presenting to the Harris County Hospital District (public facilities) between 1994 and 1998. The original case definition criteria were fulfilled by 240 patients, 168 (70.0%) of whom were from Central America (including Panama), 42 (17.5%) of whom were from the Caribbean, and 30 (12.5%) of whom were from South America. The Central America group contained the highest proportion of women (37.5% compared with 20.8% among the group from the Caribbean and South America, P = 0.01, chi-square). The mean age was significantly lower among those born in Central America (32.4 vs. 38.8 for those born in the other two areas). The most commonly observed opportunistic infections were toxoplasmosis (14.8%), pneumocystosis (19.9%), and tuberculosis (12.1%). These data confirm the distinct epidemiologic parameters among Central American residents compared to the non-Central American populations as the Central American patients present with HIV infection to our health care system at a younger age and are more often women. The high rate of toxoplasmosis, pneumocystosis, and tuberculosis among those immigrants from the areas assessed in this study are a reminder of the need for intensified prophylaxis against these infections when working with patients from these populations.     

Morphogenetic characterisation,date of divergence,and evolutionary relationships of malaria vectors Anopheles cruzii and Anopheles homunculus

The mosquito species Anopheles cruzii and Anopheles homunculus are co-occurring vectors for etiological agents of malaria in southeastern Brazil, a region known to be a major epidemic spot for malaria outside Amazon region. We sought to better understand the biology of these species in order to contribute to future control efforts by (1) improving species identification, which is complicated by the fact that the females are very similar, (2) investigating genetic composition and morphological differences between the species, (3) inferring their phylogenetic histories in comparison with those of other Anophelinae, and (4) dating the evolutionary divergence of the two species. To characterise the species we used wing geometry and mitochondrial cytochrome oxidase subunit I (COI) gene as morphological and genetic markers, respectively. We also used the genes white, 28S, ITS2, Cytb, and COI in our phylogenetic and dating analyses. A comparative analysis of wing thin-plate splines revealed species-specific wing venation patterns, and the species An. cruzii showed greater morphological diversity (8.74) than An. homunculus (5.58). Concerning the COI gene, An. cruzii was more polymorphic and also showed higher haplotype diversity than An. homunculus, with many rare haplotypes that were displayed by only a few specimens. Phylogenetic analyses revealed that all tree topologies converged and showed [Anopheles bellator + An. homunculus] and [Anopheles laneanus + An. cruzii] as sister clades. Diversification within the subgenus Kerteszia occurred 2–14.2 million years ago. The landmark data associated with wing shape were consistent with the molecular phylogeny, indicating that this character can distinguish higher level phylogenetic relationships within the Anopheles group. Despite their morphological similarities and co-occurrence, An. cruzii and An. homunculus show consistent differences. Phylogenetic analysis revealed that the species are not sister-groups but species that recently diverged within the Kerteszia group, perhaps concomitantly with the radiation of bromeliads in South America or during the Pleistocene climate oscillations.     

Lovesongs and period gene polymorphisms indicate Lutzomyia cruzi (Mangabeira, 1938) as a sibling species of the Lutzomyia longipalpis (Lutz and Neiva, 1912) complex

The sand fly Lutzomyia cruzi (Mangabeira, 1938) is implicated as a vector of American visceral leishmaniasis (AVL) in some areas of Brazil. Lutzomyia cruzi is closely related to Lutzomyia longipalpis s.l. (Lutz and Neiva, 1912) the main Latin American vector of AVL and a species complex. Although females of the two species are identical, the males can be distinguished by differences in the genitalia. Nevertheless, pheromone analysis shows that Lu. cruzi males produce 9-methyl-germacrene-B, which has also been found in a number of Latin American populations of Lu. longipalpis s.l. In addition, analysis of microsatellite loci shows that the level of divergence between Lu. cruzi and Lu. longipalpis s.l. is similar to that observed among the Lu. longipalpis s.l. sibling species. Here we present the lovesongs of Lu. cruzi males which are similar to the Burst-type songs produced by one of the Lu. longipalpis s.l. sibling species. We also present data on the molecular polymorphisms of the period gene of Lu. cruzi that indicate this species as another sibling within the Lu. longipalpis complex. The results highlight the importance of an integrative approach to understand the patterns of genetic and phenotypic divergence among very closely related vector species.     

Phylogeographic analysis on the travel-related introduction of HIV-1 non-B subtypes to Northern Poland

Phylodynamic, sequence data based reconstructions for the surveillance of the geographic spatial spread are a powerful tool in molecular epidemiology. In this study region of origin for the set of 57 partial pol sequences derived from the patients the history of travel-related HIV transmission was analyzed using phylogeographic approach. Maximum likelihood trees based on the sets of country-annotated reference sequences were inferred for identified non-B variants. Region of sequence import was assigned using on the highest approximate likelihood ratios. Import of the A1 clades was traced to the Eastern Europe and associated with immigration from this region. Subtype C infections clustered most frequently with sequences of the South African origin while majority of subtype Ds were similar to the European clades. Subtype G sequences clustered with Portuguese lineage, CRF01_AE with Eastern or South-Eastern Asian. Eastern European, Middle African or Western African lineage was assigned for the CFR02_AG. Rare circulating recombinants originated either from Central Africa (CRF11_cpx – Democratic Republic of Congo, CRF13_cpx – Central African Republic, CRF37_cpx – Cameroon) or South America (CRF28_BF and CRF46_BF - Brazil). Import of the HIV-1 non-B variants, including recombinant forms previously rarely found in Poland and Europe is frequent among travelers. Observed founder events result in the heterosexually-driven introduction of the novel HIV-1 variants into the population.     

Ecological niche and geographic distribution of the Chagas disease vector,Triatoma dimidiata (Reduviidae: Triatominae): Evidence for niche differentiation among cryptic species

The principal vector of Chagas disease in Central America, Triatoma dimidiata, shows considerable diversity of habitat, phenotype, and genotype across its geographic range (central Mexico to southern Ecuador), suggesting that it constitutes a complex of cryptic species. However, no consistent picture of the magnitude of ecological differentiation among populations of this complex has yet been developed. To assess ecological variation across the complex, we broadened the geographic coverage of phylogeographic data and analyses for the complex into Colombia and Mexico, with additional nuclear (ITS-2) and mitochondrial (ND4) DNA sequences. This information allowed us to describe distributions of previously documented clades in greater detail: Group I, from central Guatemala south to Ecuador; Group II, across Mexico south through the Yucatán Peninsula to Belize and northern Guatemala; and Group III, in northern Guatemala, Belize, and the Yucatán Peninsula. Using ecological niche modeling, we assessed ecological niche differentiation among the groups using four hypotheses of accessible areas (M) across the distribution of the complex. Results indicated clear niche divergence of Group I from Group II: the speciation process thus appears to have involved genetic and ecological changes, suggesting divergence in populations in response to environmental conditions.     

Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia

Between the 16th and 18th centuries, Aedes aegypti (Diptera: Culicidae), a mosquito native to Africa, invaded the Americas, where it was successively responsible for the emergence of yellow fever (YF) and dengue (DEN). The species was eradicated from numerous American countries in the mid-20th century, but re-invaded them in the 1970s and 1980s. Little is known about the precise identities of Ae. aegypti populations which successively thrived in South America, or their relation with the epidemiological changes in patterns of YF and DEN. We examined these questions in Bolivia, where Ae. aegypti, eradicated in 1943, re-appeared in the 1980s. We assessed the genetic variability and population genetics of Ae. aegypti samples in order to deduce their genetic structure and likely geographic origin. Using a 21-population set covering Bolivia, we analyzed the polymorphism at nine microsatellite loci and in two mitochondrial DNA regions (COI and ND4). Microsatellite markers revealed a significant genetic structure among geographic populations (F(ST)=0.0627, P<0.0001) in relation with the recent re-expansion of Ae. aegypti in Bolivia. Analysis of mtDNA sequences revealed the existence of two genetic lineages, one dominant lineage recovered throughout Bolivia, and the second restricted to rural localities in South Bolivia. Phylogenic analysis indicated that this minority lineage was related to West African Ae. aegypti specimens. In conclusion, our results suggested a temporal succession of Ae. aegypti populations in Bolivia, that potentially impacted the epidemiology of dengue and yellow fever.     

Insights into the evolution and dispersion of pyrethroid resistance among sylvatic Andean Triatoma infestans from Bolivia

Sylvatic populations of Triatoma infestans represent a challenge to Chagas disease control as they are not targeted by vector control activities and may play a key role in post-spraying house re-infestation. Understanding sylvatic foci distribution and gene flow between sylvatic and domestic populations is crucial to optimize vector control interventions and elucidate the development and spread of insecticide resistance. Herein, the genetic profiles of five Andean T. infestans populations from Bolivia with distinct insecticide susceptibility profiles were compared. Multilocus genotypes based on eight microsatellites and the DNA sequence of a fragment of the cytochrome B (cytB) gene were obtained for 92 individuals. CytB haplotypes were analyzed with previously reported Bolivian T. infestans haplotypes to evaluate putative historical gene flow among populations. Each specimen was also screened for two nucleotide mutations in the sodium channel gene (kdr), related to pyrethroid resistance (L1014 and L9251). Significant genetic differentiation was observed among all populations, although individuals of admixed origin were detected in four of them. Notably, the genetic profiles of adjacent domestic and sylvatic populations of Mataral, characterized by higher levels of insecticide resistance, support their common ancestry. Only one sylvatic individual from Mataral carried the kdr mutation L1014, suggesting that this mechanism is unlikely to cause the altered insecticide susceptibility observed in these populations. However, as the resistance mutation is present in the area, it has the potential to be selected under insecticidal pressure. Genetic comparisons of these populations suggest that insecticide resistance is likely conferred by ancient trait(s) in T. infestans sylvatic populations, which are capable of invading domiciles. These results emphasize the need for stronger entomological surveillance in the region, including early detection of house invasion, particularly post-spraying, monitoring for resistance to pyrethroids and the design of integrative control actions that consider sylvatic foci around domestic settings and their dispersion dynamics.     

Eco-geographical differentiation among Colombian populations of the Chagas disease vector Triatoma dimidiata (Hemiptera: Reduviidae)

Triatoma dimidiata is currently the main vector of Chagas disease in Mexico, most Central American countries and several zones of Ecuador and Colombia. Although this species has been the subject of several recent phylogeographic studies, the relationship among different populations within the species remains unclear. To elucidate the population genetic structure of T. dimidiata in Colombia, we analyzed individuals from distinct geographical locations using the cytochrome c oxidase subunit 1 gene and 7 microsatellite loci. A clear genetic differentiation was observed among specimens from three Colombian eco-geographical regions: Inter Andean Valleys, Caribbean Plains and Sierra Nevada de Santa Marta mountain (SNSM). Additionally, evidence of genetic subdivision was found within the Caribbean Plains region as well as moderate gene flow between the populations from the Caribbean Plains and SNSM regions. The genetic differentiation found among Colombian populations correlates, albeit weakly, with an isolation-by-distance model (IBD). The genetic heterogeneity among Colombian populations correlates with the eco-epidemiological and morphological traits observed in this species across regions within the country. Such genetic and epidemiological diversity should be taken into consideration for the development of vector control strategies and entomological surveillance.     

A new species of tick,Ixodes (Ixodes) mojavensis (Acari: Ixodidae), from the Amargosa Valley of California

Ixodes (Ixodes) mojavensis, n. sp. (Acari: Ixodidae), is described from all parasitic stages collected from the endangered vole Microtus californicus scirpensis Bailey, 1900 (Rodentia: Cricetidae), Mus musculus L. 1758 (Rodentia: Muridae), and Reithrodontomys megalotis (Baird; 1857) (Rodentia: Cricetidae) in the Amargosa Valley of California. When first collected in 2014, this tick was tentatively identified as Ixodes minor Neumann, 1902 because the nucleotide similarity between its 16S rDNA sequence and a homologous GenBank sequence from an I. minor from the eastern U.S. was 99.51%. Nevertheless, adults of I. mojavensis differ morphologically from I. minor by hypostomal dentition, absence of a spur on palpal segment I, and punctation patterns; nymphs by the shapes of basis capituli, auriculae, cervical grooves and external files of hypostomal denticles; and larvae by the length of idiosomal setae and hypostomal dentition. DNA sequencing of fragments of 4 different genes, 12S rDNA, 16S rDNA, cytochrome c oxidase subunit I (COI), and intergenic transcribed spacer 2 (ITS2) of I. mojavensis and of closely related species of Ixodes shows that the mitochondrial gene sequences of the new tick species are almost identical to the I. minor homologous genes. Phylogenetically, the two species do not cluster in mutually exclusive monophyletic clades. However, ITS2 sequences of I. mojavensis and I. minor diverge deeply (≥ 5.74% maximum likelihood divergence) and are as different as homologous genes from other recognized species. The discrepancy between the two sets of genes is suggestive of past mitochondrial introgression or incomplete mitochondrial lineage sorting.     

Molecular homogeneity in diverse geographical populations of Phlebotomus papatasi (Diptera, Psychodidae) inferred from ND4 mtDNA and ITS2 rDNA Epidemiological consequences.

An intraspecific study on Phlebotomus papatasi, the main proven vector of Leishmania major among the members of the subgenus Phlebotomus, was performed. The internal transcribed spacer 2 (ITS 2) of rDNA and the ND4 gene of mt DNA were sequenced from 26 populations from 18 countries (Albania, Algeria, Cyprus, Egypt, Greece, India, Iran, Israel, Italy, Lebanon, Morocco, Saudi Arabia, Spain, Syria, Tunisia, Turkey, Yugoslavia and Yemen), and compared. Samples also included three other species belonging to the subgenus Phlebotomus: P. duboscqi, a proven vector of L. major in the south of Sahara (three populations from Burkina Faso, Kenya and Senegal), P. bergeroti, a suspected vector of L. major (three populations from Oman Sultanate, Iran and Egypt), and one population of P. salehi from Iran. A phylogenetic study was carried out on the subgenus Phlebotomus. Our results confirm the validity of the morphologically characterized taxa. The position of P. salehi is doubtful. Variability in P. papatasi contrasts with that observed within other species having a wide distribution like P. (Paraphlebotomus) sergenti in the Old World or Lutzomyia (Lutzomyia) longipalpis in the New World. Consequently, it could be hypothesized that all populations of P. papatasi over its distribution area have similar vectorial capacities. The limits of the distribution area of L. major are correlated with the distribution of common rodents acting as hosts of the parasites.     

Sandflies (Diptera, Psychodidae) from an endemic leishmaniasis area in the cerrado region of the State of Maranh?o, Brazil]

This article presents a list of ten sandfly species from the genus Lutzomyia Fran?a, 1924 found in the counties of Aldeias Altas, Capinzal do Norte, Caxias, Codó, Coelho Neto, Timbiras, Timon and Tuntum in northeastern Maranh?o, Brazil. Presence of sandflies was associated with cases of visceral and cutaneous leishmaniasis. Some 377 specimens were captured indoors with CDC light traps and 1491 specimens in the peridomicile. The species were: Lutzomyia cortelezii, Lutzomyia evandroi, Lutzomyia goiana, Lutzomyia intermedia, Lutzomyia lenti, Lutzomyia longipalpis, Lutzomyia longipennis, Lutzomyia squamiventris, Lutzomyia termitophila and Lutzomyia whitmani. The most abundant species was L. longipalpis (67. 4% and 70.2%) followed by L. whitmani (31.0% and 24.7%). L. longipalpis was captured both indoors and outdoors in all the months studied.     

成都机场口岸常见媒介蝇类的分子鉴定

目的:建立以线粒体COI基因作为分子标记的蝇类分子鉴定方法。方法:设计COI基因引物对成都双流机场口岸常见4科10属14种卫生蝇类进行PCR扩增和序列测定,并与不同地区蝇类的COI基因片段比较,分析其碱基差异和系统发育关系。结果:部分不同地理来源的种类种内碱基差异变化较大,中国四川与马来西亚棕尾别麻蝇碱基差异为3.4%,中国四川与中国广东巴浦绿蝇碱基差异为3.3%;其他种类种内碱基差异较小(<1.0%)。系统发育分析显示所有种类的COI基因分子鉴定结果和形态学结果相一致。麻蝇科种类聚为一个分支,而丽蝇科、花蝇科和蝇科种类没有聚集形成单系。结论:可以将COI基因片段作为分子标记,建立一种适用于口岸的蝇类种类之间分子鉴定方法。     

Analysis of rotavirus species diversity and evolution including the newly determined full-length genome sequences of rotavirus F and G

Rotaviruses are a leading cause of viral acute gastroenteritis in humans and animals. Eight different rotavirus species (A–H) have been defined based on antigenicity and nucleotide sequence identities of the VP6 gene. Here, the first complete genome sequences of rotavirus F (strain 03V0568) and G (strain 03V0567) with lengths of 18,341 and 18,186 bp, respectively, are described. Both viruses have open reading frames for rotavirus proteins VP1 to VP7 and NSP1 to NSP5 located at the 11 genome segments. Nucleotide sequence identities to other rotaviruses ranged between 29.8% (NSP1 gene) and 61.7% (VP1 gene) for rotavirus F and between 29.3% (NSP1-2 gene) and 65.9% (NSP2 gene) for rotavirus G, thus confirming their classification as separate virus species. Encoded proteins revealed remarkable sequence differences among the rotavirus species. In contrast, the non-coding 5′-terminal sequences of the genome segments are highly conserved among all rotavirus species. Different 3′-terminal consensus sequences are found between rotavirus A/D/F, rotavirus C and rotavirus B/G/H. Phylogenetic analyses indicated a separation of rotaviruses in two major clades consisting of rotavirus A/C/D/F and rotavirus B/G/H. Within these clades, rotavirus F mainly clustered with rotavirus D and rotavirus G with rotavirus B. In addition, differentiation among mammalian and avian rotavirus A strains, host-specific evolution of rotavirus B and C as well as an ancient reassortment event between avian rotavirus A and D are indicated by the phylogenetic data. These results underline the high diversity of rotaviruses as a result of a complex evolutionary history.     

Study of sand flies (Diptera,Psychodidae, Phlebotominae) in the urban area of Campo Grande,Mato Grosso do Sul State,Brazil, from 1999 to 2000

From February 1999 to February 2000, sand flies were captured weekly with CDC light traps at five sites in the urban area of Campo Grande, Mato Grosso do Sul State, Brazil. Traps were placed in 11 different ecotopes in the environment (ground level, tree canopies, and forest edge) and the peridomicile (chicken coops and banana trees). A total of 1,245 sand flies were captured, belonging to 28 species: 4 species from genus Brumptomyia Fran a & Parrot, 1921 and 24 from genus Lutzomyia Fran a, 1924. The species were: B. avellari, B. brumpti, B. galindoi, B. pintoi, L. aragaoi, L. bourrouli, L. campograndensis, L. cerradincola, L. christenseni, L. claustrei, L. cortelezzii, L. corumbaensis, L. cruzi, L. damascenoi, L. flaviscutellata, L. hermanlenti, L. lenti, L. longipalpis, L. longipennis, L. migonei, L. punctigeniculata, L. quinquefer, L. renei, L. shannoni, L. sordellii, L. teratodes, L. termitophila, and L. whitmani. L. longipalpis and L. cruzi, vectors of visceral leishmaniasis, and L. whitmani, L. flaviscutellata and L. migonei, vectors of cutaneous leishmaniasis, were captured in the urban area. The most frequent species were L. termitophila, L. aragaoi, L. lenti, L. longipennis, and L. longipalpis.     

Plasmodium vivax merozoite surface protein PvMSP-3β is radically polymorphic through mutation and large insertions and deletions

Plasmodium vivax causes the majority of malaria outside of sub-Saharan Africa and is an important burden for affected countries. The recent spread of drug-resistant P. vivax strains in these countries has led to renewed pressure for the development of a P. vivax vaccine. The complex life cycle of P. vivax presents many potential vaccine targets, but among the most promising candidates are subunits of the surface coat that surrounds the merozoite, the parasite stage that infects erythrocytes and initiates much of the pathology of malaria. Although the genes for several constituents of the P. vivax surface coat have now been cloned and sequenced, little is known about the extent to which these proteins vary between populations, an important consideration in vaccine development. The merozoite surface protein MSP-3beta is a member of a family of related merozoite surface proteins, all of which contain a central alanine-rich domain that is predicted to form a coiled-coil tertiary structure. We have sequenced the PvMSP-3 beta gene from P. vivax isolates originating in Central and South America, Asia and the Pacific. In this first assessment of PvMSP-3 beta variation between populations, we discovered widespread and significant diversity, mostly within the alanine-rich central region. We observed frequent differences in PvMSP-3 beta gene size, caused by the insertion and/or deletion of several large sequence blocks, as well as numerous single nucleotide polymorphisms and smaller scale insertions and deletions. Despite this high level of sequence diversity, certain physical properties of the encoded protein are maintained, particularly the ability to form coiled-coil tertiary structures, suggesting that although PvMSP-3 beta varies widely, it is under functional constraints. The implications for PvMSP-3 beta function and vaccine development are discussed.