title: Identification of resistance-associated HCMV UL97- and UL54-mutations and a UL97-polymporphism with impact on phenotypic drug-resistance.
abstract: Human cytomegalovirus (HCMV) drug-resistance remains of high clinical importance. While UL97-mutations can confer ganciclovir-resistance, UL54-mutations can be associated with resistance to ganciclovir, foscarnet and/or cidofovir.
  
  
  
  Three UL97-mutations (A619V, P468Q, del597-599), three UL54-mutations (V715A, A492D, L516W) and two UL97/UL54-mutation combinations (A594TUL97+V715MUL54; A591VUL97+D515EUL54, L516MUL54, I521TUL54) were characterised phenotypically. All mutations were introduced into the bacterial artificial chromosome (BAC) TB40-BACKL7-UL32EGFP. A revertant of HCMV-TB40-BACKL7-UL32EGFP/A591VUL97+D515EUL54, L516MUL54, I521TUL54 was generated.
  
  
  
  The UL97-mutation del597-599 showed GCV-resistance while A619V and P468Q were drug-sensitive. The UL54-mutation V715A was FOS-resistant/CDV-hypersensitive and L516W was GCV/CDV cross-resistant. Mutation A594TUL97+V715MUL54 showed GCV/FOS cross-resistance. HCMV-BACKL7-UL32EGFP/A591VUL97+D515EUL54,L516MUL54, I521TUL54 was GCV/CDV cross-resistant with a remarkably increased GCV-ratio compared to a strain where only the UL54-mutations D515E+L516M+I521T were present. Since the revertant was drug-sensitive again, the increased drug-ratio is supposed to be due to the UL97-polymorphism A591V.
  
  
  
  Phenotypic characterisation of newly detected mutations in UL97 and UL54 remain of high importance. Only mutations with a confirmed phenotype allow reliable interpretation of genotypic methods. Here, we provide the first description of a UL97-polymorphism that contributes to the overall drug-resistance when combined with resistance-associated UL54-mutations. The finding shows the high importance to look at mutations in the context of their genetic background.
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Fischer
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany.
authors.forename: Eike
authors.initials: E
authors.lastname: Imrich
authors.affiliation: Institute of Virology, University Hospital Ulm, 89081 Ulm, Germany.
authors.forename: Kerstin Laib
authors.initials: KL
authors.lastname: Sampaio
authors.affiliation: Institute of Medical Virology, Charité University Hospital, 10117 Berlin, Germany; Labor Berlin, Charité-Vivantes GmbH, 13353 Berlin, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Hofmann
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Jahn
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hamprecht
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, 72076 Tübingen, Germany. Electronic address: katharina.goehring@med.uni-tuebingen.de.
authors.forename: Katharina
authors.initials: K
authors.lastname: Göhring
mesh_terms: D000293:Adolescent; D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology*; D002648:Child; D022202:Chromosomes, Artificial, Bacterial; D000077404:Cidofovir; D003587:Cytomegalovirus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D003586:Cytomegalovirus Infections / Q000151:congenital / Q000821:virology; D003596:Cytosine / Q000031:analogs & derivatives / Q000494:pharmacology; D004279:DNA, Viral; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D024882:Drug Resistance, Viral / Q000235:genetics*; D017245:Foscarnet / Q000494:pharmacology; D015774:Ganciclovir / Q000494:pharmacology; D005838:Genotype; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D008875:Middle Aged; D009154:Mutation; D063065:Organophosphonates / Q000494:pharmacology; D010641:Phenotype; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D011110:Polymorphism, Genetic; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D063065:Organophosphonates; C109367:UL54 protein, Human herpesvirus 5; D014764:Viral Proteins; D017245:Foscarnet; D003596:Cytosine; D017853:Phosphotransferases (Alcohol Group Acceptor); C075365:ganciclovir kinase; D004259:DNA-Directed DNA Polymerase; D000077404:Cidofovir; D015774:Ganciclovir
keywords: Antiviral drug-resistance; Cytomegalovirus; Infections in immunocompromised patients; Polymorphisms with phenotypic impact