Human adenoviruses in respiratory infections: sequencing of the hexon hypervariable region reveals high sequence variability.
BACKGROUND
In respiratory infections, human adenoviruses (hAdV) of species B1 and C are frequently detected, but severe or even fatal disease outbreaks are predominantly caused by only few serotypes. The molecular typing of hAdV hexon sequences can help to speed up the discrimination of serotypes, thus improving on-time epidemiological examinations and patient care.


OBJECTIVE
We aimed to develop a molecular method for the rapid species B1 and C serotype identification in respiratory samples based on sequence generation of the hexon hypervariable region (HVR).


METHODS
We developed two PCR-based genotyping systems for a generic HVR amplification and sequence determination of species B1 and C viruses. The assays were applied to hAdV prototypes and 106 samples.


RESULTS
The primer sets proved to be capable of amplifying all B1 and C serotypes. The viruses detected in clinical samples belong to serotypes 1, 2, 3, 5 and 6. The obtained sequences of serotypes 2, 3 and 5 form 2-3 phylogenetic clusters that are based on the characteristic amino acid changes within the variable HVR sites.


CONCLUSIONS
Our assay can significantly speed up the time-span needed for serotype identification and will improve epidemiological surveillance and patient care. The obtained hexon sequences of field viruses vary significantly and form multiple genetic lineages. The variability is focussed on the HVR sites and can be interpreted as the ongoing evolutionary process. Further research is needed on the hexon sequence variability of other (respiratory) hAdV serotypes.
Robert Koch-Institut, Nationales Referenzzentrum für Influenza, Nordufer 20, 13353 Berlin, Germany. biereb@rki.de
Barbara
B
Biere
Brunhilde
B
Schweiger
D000258:Adenovirus Infections, Human / Q000453:epidemiology / Q000821:virology*; D000260:Adenoviruses, Human / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D036022:Capsid Proteins / Q000235:genetics*; D019411:Clinical Laboratory Techniques / Q000379:methods; D016000:Cluster Analysis; D022801:Complementarity Determining Regions; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D011110:Polymorphism, Genetic; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012703:Serotyping
D036022:Capsid Proteins; D022801:Complementarity Determining Regions; D017931:DNA Primers; D004279:DNA, Viral; C018315:hexon capsid protein, Adenovirus