Publications by authors named "Marta S Contigiani"

23 Publications

  • Page 1 of 1

Phylogeography and evolutionary history of hepatitis E virus genotype 3 in Argentina.

Trans R Soc Trop Med Hyg 2021 Mar 19. Epub 2021 Mar 19.

Instituto de Virología 'Dr J. M. Vanella', Facultad de Ciencias Médicas, Universidad Nacional de Córdoba. Enfermera Gordillo Gómez s/n. CP: 5016. Córdoba, Argentina.

Background: Few studies about the evolutionary history of the hepatitis E virus (HEV) have been conducted. The aim of our work was to investigate and make inferences about the origin and routes of dispersion of HEV-3 in Argentina.

Methods: Phylogenetic, coalescent and phylogeographic analyses were performed using a 322-bp ORF2 genomic fragment of all HEV-3 sequences with known date and place of isolation published at GenBank until May 2018 (n=926), including 16 Argentinian sequences (isolated from pigs, water and humans).

Results: Phylogenetic analysis revealed two clades within HEV-3: abchij and efg. All Argentinian samples were grouped intermingled within clade 3abchij. The coalescent analysis showed that the most recent common ancestor for the clade 3abchij would have existed around the year 1967 (95% highest posterior density (HPD): 1963-1970). The estimated substitution rate was 1.01×10-2 (95%HPD: 9.3×10-3-1.09×10-2) substitutions/site/y, comparable with the rate previously described. The phylogeographic approach revealed a correspondence between phylogeny and place of origin for Argentinian samples, suggesting many HEV introductions in the country, probably from Europe and Japan.

Conclusions: This is the first evolutionary inference of HEV-3 that includes Argentinian strains, showing the circulation of many HEV-3 subtypes, obtained from different sources and places, with recent diversification processes.

Accession Numbers: [KX812460], [KX812461], [KX812462], [KX812465], [KX812466], [KX812467], [KX812468], [KX812469].
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http://dx.doi.org/10.1093/trstmh/trab044DOI Listing
March 2021

Inactivation of Herpes Simplex Virus by Photosensitizing Anthraquinones Isolated from Heterophyllaea pustulata.

Planta Med 2021 Feb 23. Epub 2021 Feb 23.

Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas, Córdoba, Argentina.

is a phototoxic plant from Argentina. Aerial parts extracts, high in photosensitizing anthraquinones, have shown antiviral activity. The purpose of this study was to study the antiherpetic activity of the main purified anthraquinones, even evaluating their competence as photodynamic sensitizers to photo-stimulate the antiviral effect. antiviral activity against Herpes Simplex virus type I and the photo-inactivation of viral particle were studied by the Neutral Red uptake test and observation of the cytopathic effect. Rubiadin 1-methyl ether and 5,5'-bisoranjidiol produced a significant effect (≥ 80% inhibition) with minimal damage to host cells (subtoxic concentration). Anthraquinones with poor antiherpetic activity at its maximum noncytotoxic concentration showed an important photo-stimulated effect, such is the case of soranjidiol and 5,5'-bisoranjidiol (28.0 ± 6.3 81.8 ± 2.1% and 15.5 ± 0.3 89.8 ± 1.7%, respectively). The study also proved the decrease of viral particles, necessary to reduce infection. Therefore, photosensitizing anthraquinones from natural resources could be proposed to develop new treatments for localized viral lesions with antimicrobial photodynamic therapy.
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http://dx.doi.org/10.1055/a-1345-6831DOI Listing
February 2021

Autochthonous circulation of Saint Louis encephalitis and West Nile viruses in the Province of La Rioja, Argentina.

Rev Argent Microbiol 2021 Apr-Jun;53(2):154-161. Epub 2020 Nov 8.

Universidad Nacional de Córdoba, Centro de Investigaciones Entomológicas de Córdoba,Facultad de Ciencias Exactas, Físicas y Naturales, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Biológicas y Tecnológicas, Córdoba, Argentina; Instituto de Biología de la Conservación y Paleobiología (IBiCoPa), Centro de Investigación e Innovación Tecnológica (CENIIT), Universidad Nacional de la Rioja, La Rioja, Argentina. Electronic address:

St. Louis encephalitis (SLEV) and West Nile (WNV) arboviruses, which circulate in Argentina, are maintained in enzootic transmission cycles involving Culex mosquitoes (vectors) and birds belonging to orders Passeriformes and Columbiformes (amplifier hosts). The objective of this work was to determine the circulation of both viruses among wild birds in a semiarid ecosystem in the Province of La Rioja through a serologic survey. During spring 2013 and fall 2014, a total of 326 wild birds belonging to 41 species were captured in areas close to the cities of La Rioja and Chilecito, in the Province of La Rioja. While exposure to SLEV and WNV was analyzed in birds' serum through neutralizing antibody detection, viral circulation was estimated through apparent seroprevalence of neutralizing antibodies. The exposure of the avian community to viruses was 3.02% for SLEV and 1.89% for WNV, while 1.19% corresponded to coinfections. Our study confirms for the first time the circulation of SLEV and WNV in wild birds in the Province of La Rioja. Moreover, it is the first study to register neutralizing antibodies for flavivirus in the species Leptotila verreauxi (White-tipped Dove) (WNV) and Melanerpes cactorum (White-fronted Woodpecker) (SLEV). These results suggest that in semiarid ecosystems from northwestern Argentina the requirements and conditions for amplification and enzootic maintenance of SLEV and WNV would be present.
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http://dx.doi.org/10.1016/j.ram.2020.09.001DOI Listing
November 2020

Culex interfor and Culex saltanensis (Diptera: Culicidae) are susceptible and competent to transmit St. Louis encephalitis virus (Flavivirus: Flaviviridae) in central Argentina.

Trans R Soc Trop Med Hyg 2020 10;114(10):725-729

Laboratorio de Arbovirus y Arenavirus, Instituto de Virología "Dr J. M. Vanella", CONICET, Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina.

Background: St. Louis encephalitis virus (SLEV) is endemic and autochthonous on the American continent. Culex pipiens quinquefasciatus is a vector of SLEV; however, Culex interfor and Culex saltanensis have also been found to be naturally infected with SLEV. The aim of this study was to determine the vector competence of C. interfor and C. saltanensis for SLEV from Argentina compared with C. p. quinquefasciatus.

Methods: Female of the Culex species were orally infected by feeding on viraemic chicks that had been inoculated with SLEV. Abdomens, legs and saliva blood-fed mosquitoes were analysed by viral plaque assay.

Results: Mosquitoes were susceptible to orally acquired infection, dissemination and transmission of SLEV in the saliva.

Conclusions: Our results demonstrate that C. saltanensis and C. interfor are susceptible to SLEV and competent for its transmission.
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http://dx.doi.org/10.1093/trstmh/traa058DOI Listing
October 2020

Genomic characterization of orthobunyavirus of veterinary importance in America.

Infect Genet Evol 2019 09 30;73:205-209. Epub 2019 Apr 30.

Instituto de Virologia "Dr J. M. Vanella", Facultad de Ciencias Medicas, Universidad Nacional, Ciudad Universitária, X5016 GRA Córdoba, Argentina.

During 2013, in Argentina, three new isolates of serogroup Bunyamwera virus (genus Orthobunyavirus, family Peribunyaviridae) were recovered from two horses with encephalitis, and from an aborted equine fetus. In the present study, we report the complete genome sequence, genetic characterization, and phylogenetic analysis of three new strains isolated in Argentina to clarifying their relationship within the Bunyamwera serogroup virus and to investigate the evolutionary history of viruses with segmented genomes.
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http://dx.doi.org/10.1016/j.meegid.2019.04.030DOI Listing
September 2019

Neuronal Degeneration in Mice Induced by an Epidemic Strain of Saint Louis Encephalitis Virus Isolated in Argentina.

Front Microbiol 2018 7;9:1181. Epub 2018 Jun 7.

Inmunología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

Saint Louis encephalitis virus (SLEV) is a neglected flavivirus that causes severe neurological disorders. The epidemic strain of SLEV, CbaAr-4005, isolated during an outbreak in Córdoba city (Argentina), causes meningitis and encephalitis associated with neurological symptoms in a murine experimental model. Here, we identified the affected brain areas and the damage triggered by this neurotropic arbovirus. We performed a detailed analysis of brain neurodegeneration associated with CbaAr-4005 SLEV infection in mice. The motor cortex, corpus striatum and cerebellum were the most affected structures. Neurodegeneration was also found in the olfactory bulb, thalamus, hypothalamus, hippocampus, and hindbrain. SLEV infection triggered brain cell apoptosis as well as somatodendritic and terminal degeneration. In addition, we observed massive excitotoxic-like degeneration in many cortical structures. Apoptosis was also detected in the neuroblastoma cell line N2a cultured with SLEV. The results evidenced that SLEV CbaAr-4005 infection induced severe degenerative alterations within the central nervous system of infected mice, providing new information about the targets of this flavivirus infection.
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http://dx.doi.org/10.3389/fmicb.2018.01181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6000731PMC
June 2018

Evaluation of Argentinean Bird Species as Amplifying Hosts for St. Louis Encephalitis Virus (Flavivirus, Flaviviridae).

Am J Trop Med Hyg 2018 07 10;99(1):216-221. Epub 2018 May 10.

Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella," Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

St.Louis encephalitis virus (SLEV) is an emerging human pathogen flavivirus in Argentina. Recently, it has reemerged in the United States. We evaluated the role as amplifying host of six resident bird species and analyzed their capacity as host during the 2005 encephalitis outbreak of SLEV in Córdoba. Eared Dove, Picui Ground Dove, and House Sparrow were the three species with highest host competence index. At a city level, Eared Dove and Picui Ground Dove were the most important amplifying hosts during the 2005 SLEV human outbreak in Córdoba city. This finding highlighted important differences in the SLEV ecology between Argentina and the United States. Characterizing and evaluating the SLEV hosts contribute to our knowledge about its ecology and could help us to understand the causes that promote its emergence as a human pathogen in South America.
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http://dx.doi.org/10.4269/ajtmh.17-0856DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6085794PMC
July 2018

Exploring Genomic, Geographic and Virulence Interactions among Epidemic and Non-Epidemic St. Louis Encephalitis Virus (Flavivirus) Strains.

PLoS One 2015 27;10(8):e0136316. Epub 2015 Aug 27.

Laboratorio de Arbovirus, Instituto de Virología ''Dr. J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

St. Louis encephalitis virus (SLEV) is a re-emerging arbovirus in South America. In 2005, an encephalitis outbreak caused by SLEV was reported in Argentina. The reason for the outbreak remains unknown, but may have been related to virological factors, changes in vectors populations, avian amplifying hosts, and/or environmental conditions. The main goal of this study was to characterize the complete genome of epidemic and non-epidemic SLEV strains from Argentina. Seventeen amino acid changes were detected; ten were non-conservative and located in proteins E, NS1, NS3 and NS5. Phylogenetic analysis showed two major clades based on geography: the North America and northern Central America (NAnCA) clade and the South America and southern Central America (SAsCA) clade. Interestingly, the presence of SAsCA genotype V SLEV strains in the NAnCA clade was reported in California, Florida and Texas, overlapping with known bird migration flyways. This work represents the first step in understanding the molecular mechanisms underlying virulence and biological variation among SLEV strains.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136316PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4552378PMC
May 2016

First isolation of Bunyamwera virus (Bunyaviridae family) from horses with neurological disease and an abortion in Argentina.

Vet J 2015 Oct 25;206(1):111-4. Epub 2015 Jun 25.

Laboratorio de Arbovirus, Instituto de Virología Dr. J.M. Vanella, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Enfermera Gordillo Gómez s/n, CP: X5016 GRA Ciudad Universitaria, Córdoba, Argentina.

Bunyamwera virus (BUNV) is the prototype virus for both the Orthobunyavirus genus and the Bunyaviridae family. Different strains of BUNV have been associated with clinical diseases in domestic animals, mainly ruminants. During 2013, in Argentina's Santa Fe Province, three new isolates of BUNV were recovered from the brain and spleen of two horses with encephalitis, and from the brain of an aborted equine fetus. This isolation of BUNV from domestic animals provided the first association of BUNV infection with disease of the central nervous system and abortion in equines in Argentina.
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http://dx.doi.org/10.1016/j.tvjl.2015.06.013DOI Listing
October 2015

St. Louis Encephalitis virus mosquito vectors dynamics in three different environments in relation to remotely sensed environmental conditions.

Acta Trop 2015 Jun 16;146:53-9. Epub 2015 Mar 16.

Centro de Investigaciones Entomológicas de Córdoba, Instituto de Investigaciones Biológicas y Tecnológicas, CONICET-Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales. Av. Vélez Sarsfield 1611, Ciudad Universitaria, CP X5016GCA Córdoba, Argentina.

In Argentina the St. Louis Encephalitis virus (SLEV) is an endemic and widely distributed pathogen transmitted by the cosmopolitan mosquito Culex quinquefasciatus. During two outbreaks in Córdoba city, in 2005 and 2010, Culex interfor was also found infected, but its role as vector of SLEV is poorly known. This mosquito species is distributed from central Argentina to southern Brazil. The primary aim of this study was to analyze the population dynamic of Cx. interfor and Cx. quinquefasciatus in three different environments (urban, suburban and non-urban) in relation to remotely sensed environmental data for vegetation (NDVI and NDWI) and temperature (brightness temperature). Cx. quinquefasciatus and Cx. interfor were found at the three sampled sites, being both the most abundant Culex species, with peaks in early and midsummer. Temporal distribution patterns of both mosquito species were highly correlated in a non-urban area of high SLEV risk transmission. Cx. quinquefasciatus and Cx. interfor were associated with the most urbanized site and the non-urban environment, respectively; high significant correlations were detected between vegetation indices and abundance of both mosquito species confirming these associations. These data provide a foundation for building density maps of these two SLEV mosquito vectors using remotely sensed data to help inform vector control programs.
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http://dx.doi.org/10.1016/j.actatropica.2015.03.009DOI Listing
June 2015

Ticks (Acari: Ixodidae) on wild birds in north-central Argentina.

Ticks Tick Borne Dis 2014 Oct 7;5(6):715-21. Epub 2014 Aug 7.

Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, Consejo Nacional de Investigaciones Científicas y Técnicas, CC 22, CP 2300 Rafaela, Santa Fe, Argentina.

Ixodid ticks were collected from wild birds in five ecoregions in north-central Argentina, namely: Selva de las Yungas, Esteros del Iberá, Delta e Islas del Paraná, Selva Paranaense and Chaco Seco. A total of 2199 birds belonging to 139 species, 106 genera, 31 families and 11 orders were captured, but ticks were collected only from 121 birds (prevalence=5.5%) belonging to 39 species (28.1%) and three Orders: Tinamiformes (Tinamidae) and Falconiformes (Falconidae) in Selva de las Yungas and Passeriformes (Conopophagidae, Corvidae, Emberizidae, Furnariidae, Icteridae, Parulidae, Thamnophilidae, Thraupidae, Troglodytidae, Turdidae) for all ecoregions. The following tick species were found: Haemaphysalis juxtakochi, Haemaphysalis leporispalustris, Ixodes pararicinus plus Amblyomma sp. and Haemaphysalis sp. in Selva de las Yungas; Amblyomma triste and Ixodes auritulus in Delta e Islas del Paraná; Amblyomma dubitatum, A. triste and Amblyomma sp. in Esteros del Iberá; Amblyomma ovale and Amblyomma sp. in Selva Paranaense, and Amblyomma tigrinum in Chaco Seco. Amblyomma dubitatum was found for the first time on Passeriformes, while the records of A. ovale on avian hosts are the first for Argentina. Birds are also new hosts for I. pararicinus females. Besides 2 larvae and 1 nymph, and 1 larvae found on Tinamidae (Tinamiformes) and Falconidae (Falconiformes), respectively, all other ticks (691 larvae, 74 nymphs and 2 females) were found on Passeriformes with a relevant contribution of the family Turdidae. Birds are important hosts for I. pararicinus as shown by a prevalence of 45% while all others prevalence were below 15%. All the species of Amblyomma and Haemaphysalis found on birds in Argentina have been also detected on humans and are proven or potential vectors for human diseases. Therefore, their avian hosts are probable reservoirs of human pathogens in Argentina.
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http://dx.doi.org/10.1016/j.ttbdis.2014.05.004DOI Listing
October 2014

West Nile and st. Louis encephalitis viruses antibodies surveillance in captive and free-ranging birds of prey from Argentina.

Ecohealth 2014 Dec 9;11(4):603-9. Epub 2014 Aug 9.

Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

We evaluated the prevalence of WNV and SLEV neutralizing antibodies in captive and free-ranging raptors from Argentina by plaque-reduction neutralization test. Eighty plasma samples from 12 species were analyzed. Only one captive adult Crowned Eagle (Harpyhaliaetus coronatus) was WNV seropositive (prevalence: 1.25%; antibody titer of 1:80). Two captive Crowned Eagles were SLEV seropositive (prevalence: 2.50%; antibody titers: 1:80 and 1:40).These findings expand the geographic distribution of WNV and SLEV and confirm their activity in central and northeastern Argentina. West Nile virus activity in Argentina may represent a potential threat to Crowned Eagles and other endangered raptors in this country.
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http://dx.doi.org/10.1007/s10393-014-0956-5DOI Listing
December 2014

Intertwined arbovirus transmission activity: reassessing the transmission cycle paradigm.

Front Physiol 2012 11;3:493. Epub 2013 Jan 11.

Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba Córdoba, Argentina ; Instituto de Investigaciones Biológicas y Tecnológicas, Consejo Nacional de Investigaciones Científicas y Técnicas (IIByT-CONICET) Córdoba, Argentina ; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ministerio de Ciencia y Tecnología Córdoba, Argentina.

Arboviruses are emerging/reemerging infectious agents worldwide. The factors within this scenario include vector and host population fluctuations, climatic changes, anthropogenic activities that disturb ecosystems, an increase in international flights, human mobility, and genetic mutations that allow spill-over phenomenon. Arboviruses are maintained by biologic transmission among vectors and hosts. Sometimes this biological transmission is specific and includes one vector and host species such as Chikungunya (CHIKV), Dengue (DENV), and urban Yellow Fever (YFV). However, most of the arboviruses are generalist and they use many vectors and hosts species. From this perspective, arboviruses are maintained through a transmission network rather than a transmission cycle. This allows us to understand the complexity and dynamics of the transmission and maintenance of arboviruses in the ecosystems. The old perspective that arboviruses are maintained in close and stable transmission cycles should be modified by a new more integrative and dynamic idea, representing the real scenario where biological interactions have a much broader representation, indicating the constant adaptability of the biological entities.
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http://dx.doi.org/10.3389/fphys.2012.00493DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3542535PMC
January 2013

In vitro antiviral activity of Heterophyllaea pustulata extracts.

Nat Prod Commun 2012 Aug;7(8):1025-8

Pharmacognosy, Department of Pharmacy, School of Chemistry, National University of Córdoba, IMBIV-CONICET, Edificio Ciencias II, Ciudad Universitaria, 5016 Córdoba, Argentina.

The antiviral activity was tested of different polarity extracts, with differing chemical composition, obtained from aerial parts of Heterophyllaea pustulata Hook f. (Rubiaceae) against Herpes Simplex Virus Type I (HSV-1) and Saint Louis Encephalitis Virus (SLEV). The Vero cell line was employed as a host cell for the antiviral assessment of benzene (Ben), ethyl acetate (EtOAc) and ethanol (EtOH) extracts by means of the Neutral Red uptake assay and plaque reduction test. None of the extracts showed antiviral activity against SLEV. Only the extracts (Ben and EtOAc) with a high content of anthraquinones (AQs) inhibited HSV-1 replication, exhibiting Selectivity Index (SI) values of 2.7 and 2.4, respectively. Therefore, these extracts could be good candidates as natural sources for antiviral drug development against HSV-1.
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August 2012

Mapping environmental susceptibility to Saint Louis encephalitis virus, based on a decision tree model of remotely-sensed data.

Geospat Health 2011 Nov;6(1):85-94

Instituto de Altos Estudios Espaciales Mario Gulich, Comisión Nacional de Actividades Espaciales, Centro Espacial Teófilo Tabanera, Córdoba, Argentina.

In response to the first human outbreak (January May 2005) of Saint Louis encephalitis (SLE) virus in Córdoba province, Argentina, we developed an environmental SLE virus risk map for the capital, i.e. Córdoba city. The aim was to provide a map capable of detecting macro-environmental factors associated with the spatial distribution of SLE cases, based on remotely sensed data and a geographical information system. Vegetation, soil brightness, humidity status, distances to water-bodies and areas covered by vegetation were assessed based on pre-outbreak images provided by the Landsat 5TM satellite. A strong inverse relationship between the number of humans infected by SLEV and distance to high-vigor vegetation was noted. A statistical non-hierarchic decision tree model was constructed, based on environmental variables representing the areas surrounding patient residences. From this point of view, 18% of the city could be classified as being at high risk for SLEV infection, while 34% carried a low risk, or none at all. Taking the whole 2005 epidemic into account, 80% of the cases came from areas classified by the model as medium-high or high risk. Almost 46% of the cases were registered in high-risk areas, while there were no cases (0%) in areas affirmed as risk free.
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http://dx.doi.org/10.4081/gh.2011.160DOI Listing
November 2011

Evaluation of cytogenotoxic effects of cold aqueous extract from Achyrocline satureioides by Allium cepa L test.

Nat Prod Commun 2011 Jul;6(7):995-8

Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.

Achyrocline satureioides ("marcela del campo") is native to America. Numerous investigations have reported several bioactive properties such as anti-inflammatory, hepatoprotective, immunomodulatory, antimicrobial and antiviral. Nowadays, few medicinal plants have been scientifically evaluated to test its safety, efficacy and potential benefits, despite the great public interest in these herbs. The aim of this work was to evaluate the cytotoxic and genotoxic activities of cold aqueous extract obtained from A. satureioides using Allium cepa L test. The results demonstrated the absence of genotoxicity of the extract. Only higher concentrations induced cytotoxicity but interestingly this effect was reversible and was not associated with mutagenicity. The contribution of this research provides assurance of safety in the application of Achyrocline satureioides in treatment of microbial diseases and other pathologies helping to define selective toxicity.
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July 2011

Viral diversity of Junín virus field strains.

Virus Res 2011 Sep 13;160(1-2):150-8. Epub 2011 Jun 13.

Laboratorio de Ingeniería Genética y Biología Celular y Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, B1876BXD, Bernal, Buenos Aires, Argentina.

The Argentine Hemorrhagic Fever, an endemic disease present in a much of Argentina, is caused by the Junín virus (JUNV). Currently, there are sequences available from several strains of this virus, like those belonging to the vaccine lineage (XJ13, XJ#44 and Candid#1), as well as MC2 (rodent isolate) and IV4454 (human isolate). In this article, we report sequence information on two fragments of genomic segment S of viral isolates from the endemic area. A Nested-RT-PCR was used to amplify discrete genomic regions of 13 isolates of rodent and human origin. The bioinformatics studies revealed a great homogeneity of sequences among the JUNV isolates. The phylogenetic classification showed greater evolutionary distance between the old world arenaviruses (Lassa and LCM virus) than between the new world arenaviruses (JUNV and Machupo virus).
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http://dx.doi.org/10.1016/j.virusres.2011.06.004DOI Listing
September 2011

Comparison of argentinean saint louis encephalitis virus non-epidemic and epidemic strain infections in an avian model.

PLoS Negl Trop Dis 2011 May 24;5(5):e1177. Epub 2011 May 24.

Laboratorio Arbovirus, Instituto de Virología Dr. J. M. Vanella, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

St. Louis encephalitis virus (SLEV, Flavivirus, Flaviviridae) is an emerging mosquito-borne pathogen in South America, with human SLEV encephalitis cases reported in Argentina and Brazil. Genotype III strains of SLEV were isolated from Culex quinquefasciatus mosquitoes in Cordoba, Argentina in 2005, during the largest SLEV outbreak ever reported in South America. The present study tested the hypothesis that the recent, epidemic SLEV strain exhibits greater virulence in birds as compared with a non-epidemic genotype III strain isolated from mosquitoes in Santa Fe Province 27 years earlier. The observed differences in infection parameters between adult House sparrows (Passer domesticus) that were needle-inoculated with either the epidemic or historic SLEV strain were not statistically significant. However, only the House sparrows that were infected with the epidemic strain achieved infectious-level viremia titers sufficient to infect Cx. spp. mosquitoes vectors. Furthermore, the vertebrate reservoir competence index values indicated an approximately 3-fold increase in amplification potential of House sparrows infected with the epidemic strain when pre-existing flavivirus-reactive antibodies were present, suggesting the possibility that antibody-dependent enhancement may increase the risk of avian-amplified transmission of SLEV in South America.
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http://dx.doi.org/10.1371/journal.pntd.0001177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3101189PMC
May 2011

Phylodynamics of hepatitis C virus subtype 2c in the province of Córdoba, Argentina.

PLoS One 2011 18;6(5):e19471. Epub 2011 May 18.

Facultad de Ciencias Médicas, Instituto de Virología, Universidad de Córdoba, Córdoba, Argentina.

The Hepatitis C Virus Genotype 2 subtype 2c (HCV-2c) is detected as a low prevalence subtype in many countries, except in Southern Europe and Western Africa. The current epidemiology of HCV in Argentina, a low-prevalence country, shows the expected low prevalence for this subtype. However, this subtype is the most prevalent in the central province of Córdoba. Cruz del Eje (CdE), a small rural city of this province, shows a prevalence for HCV infections of 5%, being 90% of the samples classified as HCV-2c. In other locations of Córdoba Province (OLC) with lower prevalence for HCV, HCV-2c was recorded in about 50% of the samples. The phylogenetic analysis of samples from Córdoba Province consistently conformed a monophyletic group with HCV-2c sequences from all the countries where HCV-2c has been sequenced. The phylogeographic analysis showed an overall association between geographical traits and phylogeny, being these associations significant (α = 0.05) for Italy, France, Argentina (places other than Córdoba), Martinique, CdE and OLC. The coalescence analysis for samples from CdE, OLC and France yielded a Time for the Most Common Recent Ancestor of about 140 years, whereas its demographic reconstruction showed a "lag" phase in the viral population until 1880 and then an exponential growth until 1940. These results were also obtained when each geographical area was analyzed separately, suggesting that HCV-2c came into Córdoba province during the migration process, mainly from Europe, which is compatible with the history of Argentina of the early 20th century. This also suggests that the spread of HCV-2c occurred in Europe and South America almost simultaneously, possibly as a result of the advances in medicine technology of the first half of the 20th century.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019471PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3097208PMC
September 2011

First detection of human infection by Cache Valley and Kairi viruses (Orthobunyavirus) in Argentina.

Trans R Soc Trop Med Hyg 2009 Feb 18;103(2):197-9. Epub 2008 Oct 18.

Laboratorio de Arbovirus y Arenavirus, Instituto de Virología Dr J. M. Vanella, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, 5016 Córdoba, Argentina.

Human sera samples from Córdoba Province, Argentina were analyzed by reduction neutralization test for Cache Valley (CVV) and Kairi (KRIV) viruses. A 5.72% (27/472) prevalence of neutralizing antibodies for CVV and 5.92% (31/524) for KRIV was detected in Córdoba City, whereas the prevalences in Jesús María and Colonia Caroya suburban cities was 7.83% (13/166) and 5.42% (9/166) for CVV and KRIV, respectively. The neutralizing antibody titers ranged between 1/20 and >or=1/160. Our results report the first known infection by CVV and KRIV in human inhabitants from temperate areas of Argentina.
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http://dx.doi.org/10.1016/j.trstmh.2008.09.004DOI Listing
February 2009

Eared dove (Zenaida auriculata, Columbidae) as host for St. Louis encephalitis virus (Flaviviridae, Flavivirus).

Vector Borne Zoonotic Dis 2008 Apr;8(2):277-82

Laboratorio Arbovirus, Instituto de Virología Dr JM Vanella, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.

St. Louis encephalitis virus (SLEV) is an emerging Flavivirus in South American countries. Its ecology and biological transmission cycles are scarcely known. Eared doves (Zenaida auriculata) have frequently been found infected by SLEV, and therefore, could be suspected as SLEV hosts. Thirty post-hatch-year eared doves were subcutaneously inoculated with the genotype V SLEV 78V-6507 viral strain and subsequently bled. No deaths or clinical signs of illness were observed in the inoculated doves. The viremia titers ranged from 2 to 5.5 log(10) plaque-forming units (PFU)/mL during 1-7 days postinoculation (dpi), the highest being observed on the 4th dpi. Mosquitoes were collected using can traps baited with chicken and eared doves for comparison. A total of 2792 mosquitoes belonging to 5 species were collected. Ninety percent of the mosquitoes collected in eared dove-baited can traps were Culex quinquefasciatus. Statistical differences were not observed in either Cx. quinquefasciatus (Chi(2) = 0.86; df = 1; p = 0.354) or in Cx. interfor (Chi(2) = 0.63; df = 1; p = 0.426) mosquitoes collected in both chicken- and eared dove-baited can traps. Considering that eared doves were frequently found naturally infected by SLEV, that they developed viremia titers higher than the minimum infection threshold needed to infect Cx. quinquefasciatus, and that these mosquitoes also fed on eared doves, they could be considered competent hosts for SLEV.
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http://dx.doi.org/10.1089/vbz.2007.0168DOI Listing
April 2008
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