title: Amantadine resistance among porcine H1N1, H1N2, and H3N2 influenza A viruses isolated in Germany between 1981 and 2001.
abstract: This study was designed to gain insight into amantadine susceptibility of porcine influenza A viruses isolated in Germany between 1981 and 2001. The 12 studied H1N1, H1N2, and H3N2 porcine influenza virus strains were isolated in chicken eggs and passaged once in MDCK cells. Plaque reduction assays were applied to examine virus susceptibility to amantadine. Genotyping was used to confirm drug resistance. In the results of these antiviral studies, only 3 of the 12 isolates were shown to be amantadine-susceptible. All resistant strains contained the AA substitutions G16E, S31N, and R77Q in the membrane protein 2 (M2). Additionally, L27A was detected in two H1N1 strains. S31N and/or L27A are well-known amino acid substitutions in M2 that confer amantadine resistance. The role of the pig as an intermediate host of avian and human influenza A viruses, the possible involvement of genetic reassortment, and the high incidence of naturally amantadine-resistant porcine influenza A viruses suggest a real risk of emergence of amantadine resistant human viruses. Therefore, drug susceptibility monitoring appears to be warranted for effective application of those drugs.
authors.affiliation: Institute of Virology and Antiviral Therapy, Medical Centre of the Friedrich Schiller University Jena, Jena, Germany. michaela.schmidtke@med.uni-jena.de
authors.forename: Michaela
authors.initials: M
authors.lastname: Schmidtke
authors.forename: Roland
authors.initials: R
authors.lastname: Zell
authors.forename: Katja
authors.initials: K
authors.lastname: Bauer
authors.forename: Andi
authors.initials: A
authors.lastname: Krumbholz
authors.forename: Christina
authors.initials: C
authors.lastname: Schrader
authors.forename: Jochen
authors.initials: J
authors.lastname: Suess
authors.forename: Peter
authors.initials: P
authors.lastname: Wutzler
mesh_terms: D000547:Amantadine / Q000494:pharmacology*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D002642:Chick Embryo; D024882:Drug Resistance, Viral / Q000235:genetics; D005814:Genes, Viral; D005858:Germany; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects / Q000235:genetics; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects; D029521:Alphainfluenzavirus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D016415:Sequence Alignment; D013552:Swine; D013553:Swine Diseases / Q000821:virology*; D014763:Viral Matrix Proteins / Q000235:genetics; D010948:Viral Plaque Assay; D000086082:Viroporin Proteins
chemical_list: D000547:Amantadine; D000998:Antiviral Agents; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins