Behavioural responses to human skin extracts and antennal phenotypes of sylvatic first filial generation and long rearing laboratory colony Rhodnius prolixus

Chagas disease is a major public health issue and is mainly spread by Triatominae insects (Hemiptera: Reduviidae). Rhodnius prolixus is the main vector species in Northern South America. Host-seeking behaviour in R. prolixus is mediated by different compounds that are produced by and emanate from the host or microbiota on the host's skin. We tested the behavioural responses of sylvatic first filial generation (F1) and colony insects to extracts of human skin with a dual choice olfactometer. In addition, we compared the antennal phenotypes in both populations. No statistical differences were found between the two populations at the behavioural level. Both showed a preference for face and feet extracts and this effect was abolished for face extracts after treatment with an antibacterial gel. The observation of the antennal phenotype showed that there were differences between both groups in the total length, total surface area and number and density of bristles. However, the number and density of chemoreceptive sensilla (basiconic and thin and thick-walled trichoids) and the total density of sensilla did not show statistically significant differences. These results demonstrate that colony insects, which have only been fed with living hens for the last 30 years, are attracted by human skin extracts in a similar way as F1 sylvatic insects.

Formas de exclusión al derecho de propiedad de la población campesina indígena en Argentina: una aproximación al pensamiento de Michael Foucault

En septiembre del año 2010, el Movimiento Nacional Campesino Indígena celebraba su Primer Congreso. Bajo el lema “Somos tierra para alimentar a los pueblos” compartieron y debatieron durante tres días. De este modo, reafirmaron su lucha por la Reforma Agraria Integral y la Soberanía Alimentaria. Se manifestaron por las calles de Buenos Aires para hacer visible “el otro campo”: el de los marginados, ocultados, los pobres, los excluidos del imaginario social, nacional, y también del acceso a los bienes necesarios para el desarrollo una vida digna

DNA multigene sequencing of topotypic specimens of the fascioliasis vector Lymnaea diaphana and phylogenetic analysis of the genus Pectinidens (Gastropoda)

Freshwater lymnaeid snails are crucial in defining transmission and epidemiology of fascioliasis. In South America, human endemic areas are related to high altitudes in Andean regions. The species Lymnaea diaphana has, however, been involved in low altitude areas of Chile, Argentina and Peru where human infection also occurs. Complete nuclear ribosomal DNA 18S, internal transcribed spacer (ITS)-2 and ITS-1 and fragments of mitochondrial DNA 16S and cytochrome c oxidase (cox)1 genes of L. diaphana specimens from its type locality offered 1,848, 495, 520, 424 and 672 bp long sequences. Comparisons with New and Old World Galba/Fossaria, Palaearctic stagnicolines, Nearctic stagnicolines, Old World Radix and Pseudosuccinea allowed to conclude that (i) L. diaphana shows sequences very different from all other lymnaeids, (ii) each marker allows its differentiation, except cox1 amino acid sequence, and (iii) L. diaphana is not a fossarine lymnaeid, but rather an archaic relict form derived from the oldest North American stagnicoline ancestors. Phylogeny and large genetic distances support the genus Pectinidens as the first stagnicoline representative in the southern hemisphere, including colonization of extreme world regions, as most southern Patagonia, long time ago. The phylogenetic link of L. diaphana with the stagnicoline group may give light to the aforementioned peculiar low altitude epidemiological scenario of fascioliasis.

Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil

Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America.

Leishmania aethiopica field isolates bearing an endosymbiontic dsRNA virus induce pro-inflammatory cytokine response.

BACKGROUND: Infection with Leishmania parasites causes mainly cutaneous lesions at the site of the sand fly bite. Inflammatory metastatic forms have been reported with Leishmania species such as L. braziliensis, guyanensis and aethiopica. Little is known about the factors underlying such exacerbated clinical presentations. Leishmania RNA virus (LRV) is mainly found within South American Leishmania braziliensis and guyanensis. In a mouse model of L. guyanensis infection, its presence is responsible for an hyper-inflammatory response driven by the recognition of the viral dsRNA genome by the host Toll-like Receptor 3 leading to an exacerbation of the disease. In one instance, LRV was reported outside of South America, namely in the L. major ASKH strain from Turkmenistan, suggesting that LRV appeared before the divergence of Leishmania subgenera. LRV presence inside Leishmania parasites could be one of the factors implicated in disease severity, providing rationale for LRV screening in L. aethiopica. METHODOLOGY/PRINCIPAL FINDINGS: A new LRV member was identified in four L. aethiopica strains (LRV-Lae). Three LRV-Lae genomes were sequenced and compared to L. guyanensis LRV1 and L. major LRV2. LRV-Lae more closely resembled LRV2. Despite their similar genomic organization, a notable difference was observed in the region where the capsid protein and viral polymerase open reading frames overlap, with a unique -1 situation in LRV-Lae. In vitro infection of murine macrophages showed that LRV-Lae induced a TLR3-dependent inflammatory response as previously observed for LRV1. CONCLUSIONS/SIGNIFICANCE: In this study, we report the presence of an immunogenic dsRNA virus in L. aethiopica human isolates. This is the first observation of LRV in Africa, and together with the unique description of LRV2 in Turkmenistan, it confirmed that LRV was present before the divergence of the L. (Leishmania) and (Viannia) subgenera. The potential implication of LRV-Lae on disease severity due to L. aethiopica infections is discussed.

The residual efficacy of a cypermethrin pour-on formulation applied on goats on the mortality and blood intake of Triatoma infestans

Triatoma infestans is the main vector of Trypanosoma cruzi, the aetiological agent of Chagas disease in the Gran Chaco region of South America. As a frequent blood meal source for triatomine bugs, domestic goats play a key role in the eco-epidemiology of Chagas disease. The aim of this study was to evaluate the mortality and blood intake of T. infestans fed on goats that had been treated with different doses of pour-on insecticide. Third-instar nymphs were fed on goats that had been treated with 0 cc, 5 cc, 10 cc or 15 cc of a pour-on formulation of cypermethrin. The exposure of T. infestans to animals treated at different post-application intervals revealed a residual activity of the insecticide. The mortality rate in the treated groups was higher than in the control groups until 30 days post-insecticide application (p = 0.03), except in the group treated with 5 cc, in which no mortality was detected after seven days of insecticide application. Rainfall affected the triatomicide effect, reducing the time of residual activity. The cypermethrin pour-on treatment decreased the blood intake of T. infestans. Thirty days after the cypermethrin application, nymph mortality was 16% (± 13) with both doses (10 cc and 15 cc). The 15 cc dose did not result in higher insect mortality or increased persistence compared to the 10 cc dose.

Anaphylaxis caused by imported red fire ant stings in Málaga, Spain.

A 27-year-old woman suffered from anaphylaxis after being stung by Solenopsis invicta ants while she was handling wood from South America. The patient reported no previous adverse reactions to stings by other hymenopteran species. Intradermal skin tests with hymenoptera venom (Vespula vulgaris, Polistes species, Apis melifera) were negative. Serum specific immunoglobulin (Ig) E yielded positive results for S invicta (5.28 kU/L) and negative results for A melifera, Ves v 5 and Pol a 5. Immunodetection assays showed the presence of serum IgE against the Sol i 2 allergen. The patient had probably been stung previously although inadvertently by red fire ants while she handled infested wood from South America, and precautionary measures are thus advisable when this material is to be handled. To our knowledge this is the first case of anaphylaxis from red fire ant stings reported in Europe.

Severity of tegumentary leishmaniasis is not exclusively associated with Leishmania RNA virus 1 infection in Brazil

Leishmania RNA virus (LRV) has been shown to be a symbiotic component of Leishmania parasites in South America. Nested retro-transcription polymerase chain reaction was employed to investigate LRV1 presence in leishmaniasis lesions from Brazil. In endemic areas of Rio de Janeiro (RJ), no LRV1 infection was observed even with mucosal involvement. LRV1 was only detected in Leishmania (V.) guyanensis cutaneous lesions from the northern region, which were obtained from patients presenting with disease reactivation after clinical cure of their primary lesions. Our results indicated that the severity of leishmaniasis in some areas of RJ, where Leishmania (V.) brazi-liensis is the primary etiological agent, was not associated with Leishmania LRV1 infection.

Comparative clinical study of different multiplex real time PCR strategies for the simultaneous differential diagnosis between extrapulmonary tuberculosis and focal complications of brucellosis

Background: Both brucellosis and tuberculosis are chronic-debilitating systemic granulomatous diseases with a high incidence in many countries in Africa, Central and South America, the Middle East and the Indian subcontinent. Certain focal complications of brucellosis and extrapulmonary tuberculosis are very difficult to differentiate clinically, biologically and radiologically. As the conventional microbiological methods for the diagnosis of the two diseases have many limitations, as well as being time-consuming, multiplex real time PCR (M RT-PCR) could be a promising and practical approach to hasten the differential diagnosis and improve prognosis. Methodology/Principal Findings: We designed a SYBR Green single-tube multiplex real-time PCR protocol targeting bcsp31 and the IS711 sequence detecting all pathogenic species and biovars of Brucella genus, the IS6110 sequence detecting Mycobacterium genus, and the intergenic region senX3-regX3 specifically detecting Mycobacterium tuberculosis complex. The diagnostic yield of the M RT-PCR with the three pairs of resultant amplicons was then analyzed in 91 clinical samples corresponding to 30 patients with focal complications of brucellosis, 24 patients with extrapulmonary tuberculosis, and 36 patients (Control Group) with different infectious, autoimmune or neoplastic diseases. Thirty-five patients had vertebral osteomyelitis, 21 subacute or chronic meningitis or meningoencephalitis, 13 liver or splenic abscess, eight orchiepididymitis, seven subacute or chronic arthritis, and the remaining seven samples were from different locations. Of the three pairs of amplicons (senX3-regX3+ bcsp3, senX3-regX3+ IS711 and IS6110+ IS711) only senX3-regX3+ IS711 was 100% specific for both the Brucella genus and M. tuberculosis complex. For all the clinical samples studied, the overall sensitivity, specificity, and positive and negative predictive values of the M RT-PCR assay were 89.1%, 100%, 85.7% and 100%, respectively, with an accuracy of 93.4%, (95% CI, 88.3—96.5%). Conclusions/Significance: In this study, a M RT-PCR strategy with species-specific primers based on senX3-regX3+IS711 sequences proved to be a sensitive and specific test, useful for the highly efficient detection of M. tuberculosis and Brucella spp in very different clinical samples. It thus represents an advance in the differential diagnosis between some forms of extrapulmonary tuberculosis and focal complications of brucellosis.

Molecular findings from influenza A(H1N1)pdm09 detected in patients from a Brazilian equatorial region during the pandemic period

After the World Health Organization officially declared the end of the first pandemic of the XXI century in August 2010, the influenza A(H1N1)pdm09 virus has been disseminated in the human population. In spite of its sustained circulation, very little on phylogenetic data or oseltamivir (OST) resistance is available for the virus in equatorial regions of South America. In order to shed more light on this topic, we analysed the haemagglutinin (HA) and neuraminidase (NA) genes of influenza A(H1N1)pdm09 positive samples collected during the pandemic period in the Pernambuco (PE), a northeastern Brazilian state. Complete HA sequences were compared and amino acid changes were related to clinical outcome. In addition, the H275Y substitution in NA, associated with OST resistance, was investigated by pyrosequencing. Samples from PE were grouped in phylogenetic clades 6 and 7, being clustered together with sequences from South and Southeast Brazil. The D222N/G HA gene mutation, associated with severity, was found in one deceased patient that was pregnant. Additionally, the HA mutation K308E, which appeared in Brazil in 2010 and was only detected worldwide the following year, was identified in samples from hospitalised cases. The resistance marker H275Y was not identified in samples tested. However, broader studies are needed to establish the real frequency of resistance in this Brazilian region.

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.