Browsing by Author "Godoy, Paula"

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    Anaplasma platys in dogs, Chile
    (CENTER DISEASE CONTROL, 2007) Abarca, Katia; Lopez, Javier; Perret, Cecilia; Guerrero, Javier; Godoy, Paula; Veloz, Ana; Valiente Echeverria, Fernando; Leon, Ursula; Gutjahr, Constanza; Azocar, Teresa
    We conducted a 16S rRNA nested PCR for the genus Ehrlichia and Ehrlichia spp. with blood samples from 30 ill dogs in Chile. Phylogenetic analysis was performed by using groESL gene amplification. We identified Anaplasma platys as 1 of the etiologic agents of canine ehrlichiosis.
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    Andes Virus Antigens Are Shed in Urine of Patients with Acute Hantavirus Cardiopulmonary Syndrome
    (AMER SOC MICROBIOLOGY, 2009) Godoy, Paula; Marsac, Delphine; Stefas, Elias; Ferrer, Pablo; Tischler, Nicole D.; Pino, Karla; Ramdohr, Pablo; Vial, Pablo; Valenzuela, Pablo D. T.; Ferres, Marcela; Veas, Francisco; Lopez Lastra, Marcelo
    Hantavirus cardiopulmonary syndrome (HCPS) is a highly pathogenic emerging disease (40% case fatality rate) caused by New World hantaviruses. Hantavirus infections are transmitted to humans mainly by inhalation of virus-contaminated aerosol particles of rodent excreta and secretions. At present, there are no antiviral drugs or immunotherapeutic agents available for the treatment of hantaviral infection, and the survival rates for infected patients hinge largely on early virus recognition and hospital admission and aggressive pulmonary and hemodynamic support. In this study, we show that Andes virus (ANDV) interacts with human apolipoprotein H (ApoH) and that ApoH-coated magnetic beads or ApoH-coated enzyme-linked immunosorbent assay plates can be used to capture and concentrate the virus from complex biological mixtures, such as serum and urine, allowing it to be detected by both immunological and molecular approaches. In addition, we report that ANDV-antigens and infectious virus are shed in urine of HCPS patients.
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    Development and Characterization of a Highly Specific and Sensitive SYBR Green Reverse Transcriptase PCR Assay for Detection of the 2009 Pandemic H1N1 Influenza Virus on the Basis of Sequence Signatures
    (AMER SOC MICROBIOLOGY, 2011) Medina, Rafael A.; Rojas, Mark; Tuin, Astrid; Huff, Stephen; Ferres, Marcela; Martinez Valdebenito, Constanza; Godoy, Paula; Garcia Sastre, Adolfo; Fofanov, Yuriy; SantaLucia, John, Jr.
    The emergence and rapid spread of the 2009 H1N1 pandemic influenza virus showed that many diagnostic tests were unsuitable for detecting the novel virus isolates. In most countries the probe-based TaqMan assay developed by the U.S. Centers for Disease Control and Prevention was used for diagnostic purposes. The substantial sequence data that became available during the course of the pandemic created the opportunity to utilize bioinformatics tools to evaluate the unique sequence properties of this virus for the development of diagnostic tests. We used a comprehensive computational approach to examine conserved 2009 H1N1 sequence signatures that are at least 20 nucleotides long and contain at least two mismatches compared to any other known H1N1 genome. We found that the hemagglutinin (HA) and neuraminidase (NA) genes contained sequence signatures that are highly conserved among 2009 H1N1 isolates. Based on the NA gene signatures, we used Visual-OMP to design primers with optimal hybridization affinity and we used ThermoBLAST to minimize amplification artifacts. This procedure resulted in a highly sensitive and discriminatory 2009 H1N1 detection assay. Importantly, we found that the primer set can be used reliably in both a conventional TaqMan and a SYBR green reverse transcriptase (RT)-PCR assay with no loss of specificity or sensitivity. We validated the diagnostic accuracy of the NA SYBR green assay with 125 clinical specimens obtained between May and August 2009 in Chile, and we showed diagnostic efficacy comparable to the CDC assay. Our approach highlights the use of systematic computational approaches to develop robust diagnostic tests during a viral pandemic.
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    Oral polio vaccine in infants does not interfere in detection of enterovirus in blood
    (SOC CHILENA INFECTOLOGIA, 2013) Gonzalez, Marcela; Sandoval, Carmen; Valenzuela, Patricia; Montecinos, Luisa; Martinez, Constanza; Godoy, Paula; Abarca, Katia
    Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with prevaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.
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    Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae) in Patagonian Chile, and first record of Hantavirus in the region
    (2009) Belmar-Lucero, Sebastian; Godoy, Paula; Ferres, Marcela; Vial, Pablo; Eduardo Palma, R.
    At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae) are recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes. Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832: "colilargo" or the long-tailed pygmy rice rat: 2n = 56), which ranges from 27 degrees to approximately 51 degrees S, and O. magellanicus (Bennet, 1 836 Magellanic pygmy rice rate 2n = 54), south of 51 degrees S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the southern Patagonia of Chile. we report the results Of small mammal samplings in six localities. We karyotyped 28 specimens and we also sequenced the hypervariable mtDNA region I in 22 individuals. aligning these sequences With an Under development phylogeny of O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of antibodies to Andes virus (ANDV) through Strip Immunoblot Assay (SIA), and of viral genome by RT-PCR. The results consistently showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatusand that individuals from this area (to not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs S of a single specimen of Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south of 51 degrees S correspond to Oligoryzomys longicaudatus thus expanding the distribution of this speciei from 51 degrees to at least 55 degrees S. The results also extended the distribution of the Andes strain of Hantavirus to Southernmost Patagonia.