title: Phenotypic characteristics of novel swine-origin influenza A/California/07/2009 (H1N1) virus.
abstract: BACKGROUND
  The 2009 novel A(H1N1) virus appears to be of swine origin. This strain causing the current outbreaks is a new virus that has not been seen previously either in humans or animals. We have previously reported that viruses causing pandemics or large outbreaks were able to grow at a temperature above the normal physiological range (temperature resistance, non-ts phenotype), were found to be inhibitor resistant and restricted in replication at suboptimal temperature (sensitivity to grow at low temperature, non-ca phenotype). In this study, we performed phenotypic analysis of novel A(H1N1) virus to evaluate its pandemic potential and its suitability for use in developing a live attenuated influenza vaccine.
  
  
  OBJECTIVE
  The goal of this study is to identify phenotypic properties of novel A(H1N1) influenza virus.
  
  
  METHODS
  A/California/07/2009 (H1N1) swine-origin influenza virus was studied in comparison with some influenza A viruses isolated in different years with respect to their ability to grow at non-permissive temperatures. We also analyzed its sensitivity to gamma-inhibitors of animal sera and its ability to agglutinate chicken, human and guinea pig erythrocytes.
  
  
  RESULTS
  Swine-origin A/California/07/2009 (H1N1) virus was found to be non-ts and inhibitor resistant and was not able to grow at 25 degrees C (non-ca). We did not find any difference in the ability of the hemagglutinin of A/California/07/2009 (H1N1) virus to bind to erythrocytes of different origin.
  
  
  CONCLUSIONS
  The novel swine-origin A(H1N1) virus displays a phenotype typical of the past pandemic and epidemic viruses. This finding suggests that this virus might be a good wild type parental prototype for live vaccine for potential use for controlling pandemic influenza.
authors.affiliation: Institute of Experimental Medicine RAMS, St. Petersburg, Russia. irina.v.kiseleva@mail.ru
authors.forename: Irina
authors.initials: I
authors.lastname: Kiseleva
authors.forename: Natalie
authors.initials: N
authors.lastname: Larionova
authors.forename: Vasily
authors.initials: V
authors.lastname: Kuznetsov
authors.forename: Larisa
authors.initials: L
authors.lastname: Rudenko
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D002140:California / Q000453:epidemiology; D002645:Chickens; D004196:Disease Outbreaks; D024882:Drug Resistance, Viral; D006168:Guinea Pigs; D006387:Hemagglutination, Viral; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification* / Q000187:drug effects / Q000502:physiology*; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D009500:Neutralization Tests; D009976:Orthomyxoviridae Infections / Q000821:virology; D012712:Serum Globulins / Q000276:immunology; D013552:Swine / Q000821:virology; D013696:Temperature
chemical_list: D007252:Influenza Vaccines; D012712:Serum Globulins