First Record of HAdV-D۲۰ Among Keratoconjunctivitis Patients in Iraq

Background: Human Adenovirus species D (HAdV-D) was common human viral pathogen especially in eye infection, consists of several types of which HAdV-D۸, -D۱۹ and –D۳۷ were common in eye infection. This study includes detection of HAdV-D types implicated in conjunctivitis based on L۲ (Penton protein) gene similarity. Methods: Conjunctival swabs were collected from Keratoconjunctivitis patients as eye infection related to adenovirus. Viral nucleic acids were extracted and specific primer pairs for HAdV-D L۲ gene (encoding for penton base protein) was used to amplify the target gene and only positive samples were sent to sequencing. Results: The results revealed that only ۶ samples give positive results for L۲ gene amplification and then sent for sequencing for L۲ (penton protein) gene-based typing. The results show that ۴ local isolates (S۱, S۲, S۳, S۶) were similar to HAdV-D۸ and ۲ local isolates (S۴, S۵) were similar to HAdVD۲۰. Also the results display that the HAdV-۳۷, prominent HAdV-D type of human eye infection, may be variant of HAdV-D۲۰ due to that six variation were seen in S۴and S۵ local isolates nucleotide sequence in relation to HAdV-D۳۷: T>C at position ۱۴۳۶۴, A>C at position ۱۴۴۱۱, T>C at position ۱۴۴۲۷, C>A at position ۱۴۴۴۸, G>A at position ۱۴۵۴۰ and T>C at position ۱۴۶۱۷, leading to only ۲ amino acid change in resulted penton protein: T (Threonine) instead of K (Lysine) at position ۲۰۴ and N (Asparagine) instead of D (Aspartic acid) at position ۲۴۷. Conclusions: The current study concludes the possibility of implication of HAdV-D۲۰ in eye infections especially conjunctivitis.

Keywords:

HAdV-D۸ , HAdV-D۲۰ , HAdV-D۳۷ , conjunctivitis , Iraq