Abstract
Purpose::
Adenovirus type 37 (Ad37) is a major cause of epidemic keratoconjunctivitis (EKC), considered one of the most common eye infections. We sequenced the genome of Ad37 and compared it to another subgroup D adenovirus (Ad17) not commonly associated with ocular infection.
Methods::
PCR amplification and sequencing primers were designed using the previously sequenced Ad17. Ad37-specific primers designed from newly acquired sequence were then used to close the sequence and improve sequence quality. The ends of the linear viral genome were sequenced using a whole virus genome approach adopted from previous work. Annotation was performed with NCBI software. Ad37 and Ad17 genome sequences were compared by mVISTA LAGAN software, and predicted protein sequences were compared using MEGA and JvirGel software.
Results::
A 35,213 base pair genome sequence was determined and analyzed. The GC content was 56.40 %, slightly lower than that of Ad17. Through annotation, we located 36 classical protein coding sequences. Further analysis comparing Ad37 sequence with that of Ad17 revealed a 94.8% sequence similarity. By predicted amino acid sequence, and as analyzed by virtual 2D gel migration, major differences were found in viral capsid proteins that mediate viral attachment and internalization, and in the E3 region, known to be responsible for immune modulation.
Conclusions::
Except for proteins that directly mediate viral infectivity and immune regulation, the Ad37 genome is similar in most respects to that of Ad17, a virus not typically associated with eye infections. Further analysis will be necessary to determine the existence of other possible pathogenesis traits uniquely present in the Ad37 genome.
Keywords: adenovirus • keratitis • gene mapping