Molecular Characterization of an Adenovirus 3-16 Intertypic Recombinant Isolated in Argentina from an Infant Hospitalized with Acute Respiratory Infection

Abstract

An intertypic recombinant adenovirus with a serotype 3-like hexon gene and a serotype 16-like fiber (99% identical to that of the prototype strain of human adenovirus 16 [HAdV-16], Ch79) was isolated in Argentina from an infant admitted to the hospital with acute respiratory disease. Consistent with the results of molecular characterization, strain Arg827/04 was designated H3-F16. CASE REPORTIn January 2004, a 3-month-old male infant with a diagnosis of myoclonic epilepsy and severe developmental delay was admitted to the Juan P. Garrahan Hospital in Buenos Aires, Argentina, with fever, conjunctivitis, and bronchiolitis (disseminated rales in both lung fields, wheezing, and hypoxemia). The chest X ray showed atelectasis of the right upper lobe, which disappeared in 2 days. The patient was treated with amoxicillin and nebulized albuterol. A nasopharyngeal aspirate (NPA) collected on admission was positive for human adenovirus (HAdV) by indirect immunofluorescence. He was discharged after 13 days and followed up in the neurology department. His medical record shows two readmissions to the hospital over the following 10 months, with similar respiratory symptoms. However, blood samples taken during these episodes were negative for bacterial infection, and the new NPAs were negative for respiratory viruses. After discharge, his follow-up was discontinued.

Molecular characterization of adenovirus from clinical samples through analysis of the hexon and fiber genes

“…Both the hexon and the fiber genes are considered 'hot spots' for base mutations and recombination, which are important driving forces for AdV serotype evolution (Darr et al, 2009;Kajon et al, 2010a;Lukashev et al, 2008;Yang et al, 2009). Together with the hexon protein, the fiber protein, which enables the virus to attach to the cellular receptor, is responsible for the serotype specificity of AdV strains.…”

Random sampling of the Central European bat fauna reveals the existence of numerous hitherto unknown adenoviruses

“…Nonetheless, the appearance of recombinant virus types, a frequent finding among human AdVs (Kajon et al, 2010), cannot be excluded until the full genome sequence is available for analysis. Such data or at least the hexon sequences would also be essential for the unambiguous confirmation of the new BtAdV types.…”

Molecular evolution of human species D adenoviruses

“…However, it is not clear to what extent near sequence identity can be used to predict the results of serologic tests. Serology can suggest possible recombinant viruses in the natural population; so-called “intermediate” or “intertypic” strains are identified when the two principal serological tests provide contradictory results, seeming to indicate two different HAdV types (Adrian et al, 1985; Adrian and Wigand, 1986; Adrian et al, 1987; Hierholzer et al, 1988a; Hierholzer et al, 1980; Kajon et al, 2010; Kim et al, 1985; Matumoto et al, 1958; Norby, 1968; Parks et al, 1967; Wigand, 1987; Wigand and Fliedner, 1968). As these terms imply a „temporary’ state, they should be replaced with “putative recombinant”.…”