Evaluation of qPCR for the Selective Detection of Enteric Adenovirus Followed by Sequence-Based Genetic Characterization of F Strains Circulating in Brazil

Abstract

Human adenovirus (HAdV) F40/41 is an important pathogen in pediatric acute gastroenteritis cases. However, the diversity of study designs and diagnostic methods often leads to misinterpretations of their impact. Our study explored the genetic diversity of HAdV-F40/41 in Brazil using a specific qPCR assay for HAdV species F, combined with a phylogenetic analysis of the partial hexon and fiber genes. Our results demonstrated that HAdV-F41 strains predominated and exhibited higher diversity than HAdV-F40 strains. Based on the hexon gene, Brazilian HAdV-F41 strains were grouped into two genome type clusters (GTC), further divided into subclusters, with most strains clusteringto GTC2. The partial shaft region of the fiber gene exhibited higher conservation among HAdV-F41. The specific qPCR assay for HAdV species F identified HAdV-F in an additional 31.5% (34/108) of previously uncharacterized HAdV-positive samples detected using a non-specific HAdV qPCR assay. Both assays strongly correlated in detecting HAdV-F, and the specific qPCR assay for enteric types can enhance HAdV surveillance, especially when sequencing is not possible. Our study provides novel insights regarding the genetic diversity of HAdV-F species in Brazil.