Poster 68 microbiologie


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G/P genotypes of Rotavirus circulating in Tunisia

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Poster 68 microbiologie

  1. 1. G/P genotypes of Rotavirus circulating in Tunisia (2008-2009) Mouna Ben Hadj Fredj, Imène Fodha, Saoussen Kacem, Anissa Chouikha, Abdelhalim Trabelsi UR06SP20, Laboratory of Microbiology, Sahloul University Hospital, 4054 Sousse, Tunisia 2011 Microbiologie Poster 68
  2. 2. <ul><li>Group A rotaviruses are the leading cause of severe diarrhoea in infants and young children worldwide. </li></ul><ul><li>The proteins VP7 and VP4 make up the external viral capsid and present type-specific antigens responsible respectively for rotavirus classification into G and P genotypes. </li></ul><ul><li>The incidence and distribution of human group A rotavirus genotypes varies between geographical areas during a rotavirus season and from one season to the next. </li></ul><ul><li>Aim of the study: </li></ul><ul><li>Characterization of the different genotypes G and P circulating in Tunisia between 2008 and 2009. </li></ul>Introduction
  3. 3. Material and methods <ul><li>Material </li></ul><ul><li>- Period of study: 1 st January 2008 to 31 december 2009. </li></ul><ul><li>- 380 stools conserved at -20°C until use. </li></ul><ul><li>- From infants less than 5 years consulting or hospitalized for acute gastroenteritis in twelve Tunisian hospitals. </li></ul>
  4. 4. Material and methods <ul><li>Methods </li></ul><ul><ul><li>Rotavirus antigen detection: </li></ul></ul><ul><li>An enzyme-linked immunosorbent assay (DAKO, cambridge, United Kingdom) for rotavirus group A was performed on a 10% suspension of fecal material in phosphate buffer. </li></ul><ul><ul><li>Typing VP7/ VP4: </li></ul></ul><ul><li>- dsRNA was extracted and purified using TRIzol® (Gibco) extraction method. </li></ul><ul><li>- The extracted RNA was used for a semi-nested multiplex reverse transcription PCR (RT-PCR) after specific priming with VP7 and VP4 consensus primer pairs [Das et al., 1995, Gentsh et al., 1992 and Iturriza et al., 2000]. </li></ul>
  5. 5. Results <ul><li>Rotavirus antigen detection: </li></ul><ul><li>- The rotavirus group A was found in 87 stools among 380, </li></ul><ul><li>with the prevalence of 23% . </li></ul><ul><li>Tunisia: 1995-1999 : 17% [Trabelsi et al., 2000]. </li></ul><ul><li>2005-2007 : 21% [ Chouikha et al., 2009]. </li></ul><ul><li>Near the results found in Egypt 21% [El Mohamady H et al. , 2006 ] </li></ul><ul><li>and in Libye 26% [Ali MB et al., 2005]. </li></ul><ul><li>Less than results found in Argentine 62% [ Argüelles M.H et al. , </li></ul><ul><li>2000], in Ghana 40,5% [George Aet al., 2003],in Taiwan 55% </li></ul><ul><li>[Yuk-Lan Sung et al., 2004]. </li></ul>
  6. 6. <ul><li>G typing (VP7): </li></ul>58 strains typed: 4 different genotypes - Our study showed inhabituel increase of the prevalence of G3 between 2008-2009 comparing with previous studies in Tunisia where the predominant genotype was G1 [Chouikha et al., 2007]. - As we know, G3 is one of the most common genotypes worldwide but in Tunisia, no any case was detected between 1995 and 1999 [Trabelsi et al., 2000], between 2005-2006, G3 was predominant and in 2007, is unexpected to detect a predominance of G2 [Chouikha et al., 2009, in press]. Results
  7. 7. <ul><li>P typing (VP4): </li></ul>53 strains typed: 2 different genotypes - P[8] and P[4] genotypes were found in Tunisia since 1995 [Trabelsi et al., 2000]. - In this study, the genotype P[6] was totally absent, this genotype was found in the previous tunisian study [Trabelsi et al., 2000]. - P[8] was predominant in Tunisia since 1995 [Trabelsi et al., 2000; Chouikha et al., 2007] and it is one of the most common VP4 types worldwide. Results
  8. 8. <ul><li>It was unexpected to detect a predominance of G3 genotypes during 2008-2009, as the major VP7 genotype usually found in Tunisia from 1995 to 2007 was G1. </li></ul><ul><li>The detection of multiple rotavirus strains in single faecal specimen demonstrates the potential for gene reassortment to occur at high rates in natural rotavirus infections. </li></ul>Discussion-Conclusion These results underline the need for regular surveillance of circulating Tunisian strains