José Rivero

Publications (4)5.28 Total impact

• Article: Population genetic structure of the dengue mosquito Aedes aegypti in Venezuela.

  Flor Herrera, Ludmel Urdaneta, José Rivero, Normig Zoghbi, Johanny Ruiz, Gabriela Carrasquel, José Antonio Martínez, Martha Pernalete, Patricia Villegas, Ana Montoya, Yasmin Rubio-Palis, Elina Rojas
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  ABSTRACT: The mosquito Aedes aegypti is the main vector of dengue in Venezuela. The genetic structure of this vector was investigated in 24 samples collected from eight geographic regions separated by up to 1160 km. We examined the distribution of a 359-basepair region of the NADH dehydrogenase subunit 4 mitochondrial gene among 1144 Ae. aegypti from eight collections. This gene was amplified by the polymerase chain reaction and tested for variation using single strand conformation polymorphism analysis. Seven haplotypes were detected throughout Venezuela and these were sorted into two clades. Significant differentiation was detected among collections and these were genetically isolated by distance.
  Memórias do Instituto Oswaldo Cruz 10/2006; 101(6):625-33. · 2.15 Impact Factor
• Article: Detection of dengue viruses in field-caught Aedes aegypti (Diptera: Culicidae) in Maracay, Aragua state, Venezuela by type-specific polymerase chain reaction.

  Ludmel Urdaneta, Flor Herrera, Martha Pernalete, Normig Zoghbi, Yasmín Rubio-Palis, Roybel Barrios, José Rivero, Guillermo Comach, Matilde Jiménez, Maria Salcedo
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  ABSTRACT: Virological surveillance of dengue viruses in Aedes aegypti populations constitutes a powerful tool for early prediction of dengue outbreaks. We have standardized a protocol for viral RNA extraction from individual and pools of mosquitoes that permits a sensitive detection of dengue virus without RNA degradation or PCR inhibition when we apply a semi-nested RT-PCR. The limit of detection for each dengue serotype was 0.1 PFU. In a prospective field study conducted from November 2000 to December 2001, adult female A. aegypti mosquitoes from several municipalities with high dengue transmission in Maracay, Aragua State, Venezuela were collected and screened for dengue viruses using RT-PCR. We analyzed a total of 296 A. aegypti pools (1,632 mosquitoes); of these, 154 pools (469 mosquitoes) were collected from houses with persons with clinical diagnosis of dengue (dengue houses), and 142 pools (1,163 mosquitoes) from adjacent residences (neighbour houses). From the dengue houses, eight mosquito pools (5.2%) were positive for DENV-1 (0.7%), DENV-3 (3.2%) and DENV-4 (1.3%) viruses. From the neighbour houses, 18 mosquito pools (12.7%) were positive for DENV-3 (12%) and DENV-4 (0.7%) viruses. From these 26 RT-PCR positive mosquito pools (containing 1-25 mosquitoes each), 22 pools (84.6%) were positive for DENV-3. The most prevalent serotype in the 2001 dengue outbreak was also DENV-3. The minimum infection rate in both A. aegypti collections, from dengue houses and neighbour houses was 17 and 15 per 1,000, respectively. The relevance of these results for dengue surveillance is discussed.
  Infection Genetics and Evolution 04/2005; 5(2):177-84. · 3.13 Impact Factor
• Article: Optimization of extraction procedure for mosquito DNA suitable for PCR-based techniques

  José Rivero, Ludmel Urdaneta, Normig Zoghbi, Martha Pernalete, Yasmin Rubio-Palis, Flor Herrera
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  ABSTRACT: A modified technique to extract intact DNA from Aedes aegypti and Anopheles darlingi mosquitoes is presented. The samples were treated initially with proteinase K to digest all proteinaceous matter. For both vectors, the optimum temperature for the protease treatment was 55°C and the best pre-incubation time was 4 h. RNA contamination was eliminated with RNAse treatment. The purity of the DNA was high since the A260/A280 ratio averaged >1.80 for all samples and the quantity of DNA extracted was >1.6 times higher than that using the unmodified procedure. The DNA obtained displayed clear random amplified polymorphic DNA (RAPD) profiles, which indicates that it can be used for polymerase chain reaction (PCR)-based techniques.
  International Journal of Tropical Insect Science 08/2004; 24(03):266 - 269.
• Source

  Available from: Glenda Velasquez

  Article: Evaluación de vectores para el virus West Nile en Venezuela, utilizando VecTestTM para el diagnóstico rápido de mosquitos infectados

  Francisco Alfonso, Humberto Montañez, José Rivero, Flor Herrera, Glenda Velásquez, Nicholas Komar
  Entomotrópica: Revista internacional para el estudio de la entomología tropical, ISSN 1317-5262, Vol. 23, Nº. 2, 2008, pags. 167-172.