Neutralising antibodies for Mayaro virus in Pantanal, Brazil

The Pantanal hosts diverse wildlife species and therefore is a hotspot for arbovirus studies in South America. A serosurvey for Mayaro virus (MAYV), eastern (EEEV), western (WEEV) and Venezuelan (VEEV) equine encephalitis viruses was conducted with 237 sheep, 87 free-ranging caimans and 748 equids, including 37 collected from a ranch where a neurologic disorder outbreak had been recently reported. Sera were tested for specific viral antibodies using plaque-reduction neutralisation test. From a total of 748 equids, of which 264 were immunised with vaccine composed of EEEV and WEEV and 484 had no history of immunisation, 10 (1.3%) were seropositive for MAYV and two (0.3%) for VEEV using criteria of a ≥ 4-fold antibody titre difference. Among the 484 equids without history of immunisation, 48 (9.9%) were seropositive for EEEV and four (0.8%) for WEEV using the same criteria. Among the sheep, five were sero- positive for equine encephalitis alphaviruses, with one (0.4%) for EEEV, one (0.4%) for WEEV and three (1.3%) for VEEV. Regarding free-ranging caimans, one (1.1%) and three (3.4%), respectively, had low titres for neutralising antibodies to VEEV and undetermined alphaviruses. The neurological disorder outbreak could not be linked to the alphaviruses tested. Our findings represent strong evidence that MAYV and all equine encephalitis alphaviruses circulated in the Pantanal.

Whole-genome sequences of influenza A(H3N2) viruses isolated from Brazilian patients with mild illness during the 2014 season

The influenza A(H3N2) virus has circulated worldwide for almost five decades and is the dominant subtype in most seasonal influenza epidemics, as occurred in the 2014 season in South America. In this study we evaluate five whole genome sequences of influenza A(H3N2) viruses detected in patients with mild illness collected from January-March 2014. To sequence the genomes, a new generation sequencing (NGS) protocol was performed using the Ion Torrent PGM platform. In addition to analysing the common genes, haemagglutinin, neuraminidase and matrix, our work also comprised internal genes. This was the first report of a whole genome analysis with Brazilian influenza A(H3N2) samples. Considerable amino acid variability was encountered in all gene segments, demonstrating the importance of studying the internal genes. NGS of whole genomes in this study will facilitate deeper virus characterisation, contributing to the improvement of influenza strain surveillance in Brazil.

Widespread distribution of CTX-M and plasmid-mediated AmpC β-lactamases in Escherichia coli from Brazilian chicken meat

The dissemination of plasmid-mediated antimicrobial resistance genes may pose a substantial public health risk. In the present work, the occurrences ofblaCTX-M and plasmid-mediated ampCand qnrgenes were investigated in Escherichia colifrom 16 chicken carcasses produced by four commercial brands in Brazil. Of the brands tested, three were exporters, including one of organic chicken. Our study assessed 136 E. coli isolates that were grouped into 77 distinct biotypes defined by their origin, resistance profiling, the presence of β-lactamase and plasmid-mediated quinolone resistance genes and enterobacterial repetitive intergenic consensus-polimerase chain reaction typing. TheblaCTX-M-15, blaCTX-M-2 andblaCTX-M-8 genes were detected in one, 17 and eight different biotypes, respectively (45 isolates). Twenty-one biotypes (46 isolates) harboured blaCMY-2.Additionally, blaCMY-2 was identified in isolates that also carried either blaCTX-M-2 orblaCTX-M-8. The qnrB and/orqnrS genes occurred in isolates carrying each of the four types of β-lactamase determinants detected and also in oxyimino-cephalosporin-susceptible strains. Plasmid-mediated extended-spectrum β-lactamase (ESBL) and AmpC determinants were identified in carcasses from the four brands tested. Notably, this is the first description ofblaCTX-M-15 genes in meat or food-producing animals from South America. The blaCTX-M-8, blaCTX-M-15 andblaCMY-2 genes were transferable in conjugation experiments. The findings of the present study indicate that plasmid-mediated ESBL and AmpC-encoding genes are widely distributed in Brazilian chicken meat.

Waiting for chikungunya fever in Argentina: spatio-temporal risk maps

Chikungunya virus (CHIKV) transmission has been detected in America in 2013 and recently reached south up to Bolivia, Brazil and Paraguay, bordering countries of Argentina. The presence of the mosquito Aedes aegyptiin half of the country together with the regional context drove us to make a rapid assessment of transmission risk. Temperature thresholds for vector breeding and for virus transmission, together with adult activity from the literature, were mapped on a monthly basis to estimate risk. Transmission of chikungunya byAe. aegyptiin the world was seen at monthly mean temperatures from 21-34ºC, with the majority occurring between 26-28ºC. In Argentina temperatures above 21ºC are observed since September in the northeast, expanding south until January and retreating back to the northeast in April. The maximum area under risk encompasses more than half the country and around 32 million inhabitants. Vector adult activity was registered where monthly means temperatures exceeded 13ºC, in the northeast all over the year and in the northern half from September-May. The models herein proposed show that conditions for transmission are already present. Considering the regional context and the historic inability to control dengue in the region, chikungunya fever illness seems unavoidable.

A nuclear ribosomal DNA pseudogene in triatomines opens a new research field of fundamental and applied implications in Chagas disease

A pseudogene, designated as "ps(5.8S+ITS-2)", paralogous to the 5.8S gene and internal transcribed spacer (ITS)-2 of the nuclear ribosomal DNA (rDNA), has been recently found in many triatomine species distributed throughout North America, Central America and northern South America. Among characteristics used as criteria for pseudogene verification, secondary structures and free energy are highlighted, showing a lower fit between minimum free energy, partition function and centroid structures, although in given cases the fit only appeared to be slightly lower. The unique characteristics of "ps(5.8S+ITS-2)" as a processed or retrotransposed pseudogenic unit of the ghost type are reviewed, with emphasis on its potential functionality compared to the functionality of genes and spacers of the normal rDNA operon. Besides the technical problem of the risk for erroneous sequence results, the usefulness of "ps(5.8S+ITS-2)" for specimen classification, phylogenetic analyses and systematic/taxonomic studies should be highlighted, based on consistence and retention index values, which in pseudogenic sequence trees were higher than in functional sequence trees. Additionally, intraindividual, interpopulational and interspecific differences in pseudogene amount and the fact that it is a pseudogene in the nuclear rDNA suggests a potential relationships with fitness, behaviour and adaptability of triatomine vectors and consequently its potential utility in Chagas disease epidemiology and control.

Yellow fever impact on brown howler monkeys (Alouatta guariba clamitans) in Argentina: a metamodelling approach based on population viability analysis and epidemiological dynamics

In South America, yellow fever (YF) is an established infectious disease that has been identified outside of its traditional endemic areas, affecting human and nonhuman primate (NHP) populations. In the epidemics that occurred in Argentina between 2007-2009, several outbreaks affecting humans and howler monkeys (Alouatta spp) were reported, highlighting the importance of this disease in the context of conservation medicine and public health policies. Considering the lack of information about YF dynamics in New World NHP, our main goal was to apply modelling tools to better understand YF transmission dynamics among endangered brown howler monkey (Alouatta guariba clamitans) populations in northeastern Argentina. Two complementary modelling tools were used to evaluate brown howler population dynamics in the presence of the disease: Vortex, a stochastic demographic simulation model, and Outbreak, a stochastic disease epidemiology simulation. The baseline model of YF disease epidemiology predicted a very high probability of population decline over the next 100 years. We believe the modelling approach discussed here is a reasonable description of the disease and its effects on the howler monkey population and can be useful to support evidence-based decision-making to guide actions at a regional level.

Sistemática, filogenia e distribuição geográfica das espécies sul-americanas de Centris (Paracentris) Cameron, 1903 e de Centris (Penthemisia) Moure, 1950, incluindo uma análise filogenética do "grupo Centris" sensu Ayala, 1998 (Hymenoptera, Apoidea, Centridini)

Systematics, phylogeny and geographical distribution of the South American species of Centris (Paracentris) Cameron, 1903, and Centris (Penthemisia) Moure, 1950, including a phylogenetic analysis of the "Centris group" sensu Ayala, 1998 (Hymenoptera, Apoidea, Centridini). A cladistic analysis with the objective of testing the hypothesis of monophily of Centris (Paracentris) Cameron, 1903, and of studying its phylogenetic relationships with the other subgenera that belong to the Centris group, sensu Ayala, 1998, and the relationships among the species that occur in South America, is presented. Centris (Paracentris) is a group of New World bees of amphitropical distribution, especially diversified in the Andes and in the xeric areas of South and North America. Thirty-one species were included in the analysis, four considered as outgroup, and 49 characters, all from external morphology and genitalia of adult specimens. Parsimony analyses with equal weights for the characters and successive weighting were performed with the programs NONA and PAUP, and analyses of implied weighting with the program PeeWee. The strict consensus among the trees obtained in all the analyses indicates that C. (Paracentris), as previously recognized, is a paraphyletic group. In order to eliminate that condition, the subgenera C. (Acritocentris), C. (Exallocentris) and C. (Xerocentris), all described by SNELLING (1974) are synonymized under C. (Paracentris). The subgenus C. (Penthemisia) Moure, 1950, previously considered a synonym of C. (Paracentris), is reinstated, but in a more restricted sense than originally proposed and with the following species: Centris brethesi Schrottky, 1902; C. buchholzi Herbst, 1918; C. chilensis (Spinola, 1851), C. mixta mixta Friese, 1904, and C. mixta tamarugalis Toro & Chiappa, 1989. Centris mixta, previously recognized as the only South American species of the subgenus C. (Xerocentris), a group supposedly amphitropical, came out as the sister-species of C. buchholzi. The following South American species were recognized under Centris (Paracentris): Centris burgdorfi Friese, 1901; C. caelebs Friese, 1900; C. cordillerana Roig-Alsina, 2000; C. euphenax Cockerell, 1913; C. flavohirta Friese, 1900; C. garleppi (Schrottky, 1913); C. klugii Friese, 1900; C. lyngbyei Jensen-Haarup, 1908; C. mourei Roig-Alsina, 2000; C. neffi Moure, 2000; C. nigerrima (Spinola, 1851); C. toroi sp. nov.; C. tricolor Friese, 1900; C. unifasciata (Schrottky, 1913), and C. vogeli Roig-Alsina, 2000. The relationships among the subgenera of the "Centris group" were: (Xanthemisia (Penthemisia (Centris s. str. - Paracentris))). Centris xanthomelaena Moure & Castro 2001, an endemic species of the Caatinga and previously considered a C. (Paracentris), came out as the sister group of C. (Centris) s. str. A new species of C. (Paracentris) from Chile is described: Centris toroi sp. nov. Lectotypus designations and redescriptions are presented for Centris burgdorfi, C. caelebs, C. lyngbyei, C. tricolor, C. autrani Vachal, 1904 and C. smithii Friese, 1900. New synonyms proposed: C. buchholzi Herbst, 1918 = Centris wilmattae Cockerell, 1926 syn. nov.; C. caelebs Friese, 1900 = Paracentris fulvohirta Cameron, 1903. The female of C. vogeli Roig-Alsina, 2000 and the male of C. xanthomelaena are described.