title: Detecting human cytomegalovirus drug resistant mutations and monitoring the emergence of resistant strains using real-time PCR.
abstract: BACKGROUND
  Antiviral resistance development is a serious complication of human cytomegalovirus virostatic therapy caused by mutations in UL 97 and/or UL54 genes.
  
  
  OBJECTIVE
  To determinate the presence of sensitive and resistant strains in patients developing antiviral resistance.
  
  
  METHODS
  We used three different molecular biological methods for mutation analysis-restriction fragment length polymorphism, sequencing and real-time PCR approach.
  
  
  RESULTS
  We describe three allogeneic hematopoietic stem cell transplant patients developing the GCV resistant HCMV strains manifested by virostatic treatment failure. In these patients we identified UL97 mutations L595S, A594V and A594T and monitored the dynamics of coexisted sensitive/resistant strains. We confirmed the presence of mixed HCMV populations and in two patients a phenomenon of sensitive strain repopulation which occurred after 6.5 months and 1 month after removing GCV pressure.
  
  
  CONCLUSIONS
  Our results show changes in proportions of sensitive/resistant subpopulations over time but other studies would be required to demonstrate the beneficial impact of their monitoring on clinical outcome.
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic. Electronic address: pvolfova@fnbrno.cz.
authors.forename: Pavlina
authors.initials: P
authors.lastname: Volfova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic; Faculty of Medicine, Masaryk University, Brno, Czech Republic; CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Lengerova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Lochmanova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic; Faculty of Medicine, Masaryk University, Brno, Czech Republic; CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Dana
authors.initials: D
authors.lastname: Dvorakova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic.
authors.forename: Dita
authors.initials: D
authors.lastname: Ricna
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Palackova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic.
authors.forename: Barbora
authors.initials: B
authors.lastname: Weinbergerova
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic; Faculty of Medicine, Masaryk University, Brno, Czech Republic; CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Mayer
authors.affiliation: Department of Internal Medicine-Hematology and Oncology, University Hospital Brno, Brno, Czech Republic; Faculty of Medicine, Masaryk University, Brno, Czech Republic; CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Racil
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D003587:Cytomegalovirus / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000188:drug therapy / Q000821:virology; D024882:Drug Resistance, Viral; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D020125:Mutation, Missense; D012150:Polymorphism, Restriction Fragment Length; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D017422:Sequence Analysis, DNA; D014184:Transplantation, Homologous / Q000009:adverse effects; D017211:Treatment Failure
chemical_list: D000998:Antiviral Agents
keywords: HCMV resistance; Real-time PCR; Repopulation; Sensitive/resistant strain