L & T Microbiology Research Center, Sankara Nethralaya, Chennai, India.
Indian J Med Res. 2012 Aug;136(2):260-4.
BACKGROUND & OBJECTIVES: Though several viruses are responsible for conjunctivitis, but human adenovirus (HAdV) is by far the most common cause. Epidemic conjunctivitis causes morbidity and early detection of aetiological agent is essential in preventing spread of disease as some of serotypes of adenoviruses cause a severe form of conjunctivitis. This study was undertaken to identify the causative agent of conjunctivitis outbreak in Chennai in 2010.
Conjunctival samples collected from 17 patients with conjunctivitis were subjected to virological investigations. Culture and PCR for detection of adenovirus and enterovirus were carried out. PCR positive products were further subjected for DNA sequencing. The nucleotide sequences of the hexons of isolates were analyzed by comparison with all 51 human adenovirus strains. Phylogenetic tree was constructed using DAMBE software.
Among 17 patients, seven were positive for adenovirus by PCR on the direct specimen, none was positive for enterovirus. Eleven of 30 conjunctival swabs showed cytopathic effect in HEp-2 cell line and were confirmed as HAdV by PCR. The DNA sequence data of the 11 isolates had equal percentage of homology with HAdV 6 and 2 on blast analysis. On phylogenetic analysis with GeneBank data of 51 adenovirus strains, 11 isolates from patients during the outbreak of conjunctivitis formed a separate clade indicating a new variant strain.
INTERPRETATION & CONCLUSIONS: Based on phylogenetic analysis it was concluded that the recent conjunctivitis outbreak that occurred in Chennai was caused by a variant adenovirus strain.
尽管多种病毒可引起结膜炎，但人类腺病毒（HAdV）是目前最常见的病因。流行性角结膜炎会导致发病，尽早检测病原体对于预防疾病传播至关重要，因为某些腺病毒血清型可引起严重形式的结膜炎。本研究旨在确定2010年钦奈结膜炎暴发的病原体。
对17例结膜炎患者采集的结膜样本进行病毒学检测。进行腺病毒和肠道病毒的培养及聚合酶链反应（PCR）检测。PCR阳性产物进一步进行DNA测序。通过与所有51株人类腺病毒菌株比较，分析分离株六邻体的核苷酸序列。使用DAMBE软件构建系统发育树。
17例患者中，直接标本PCR检测7例腺病毒阳性，无肠道病毒阳性。30份结膜拭子中有11份在人喉上皮癌细胞系（HEp-2）中显示细胞病变效应，经PCR确认为HAdV。11株分离株的DNA序列数据在比对分析中与HAdV 6和2具有相同的同源百分比。与51株腺病毒菌株的基因库数据进行系统发育分析时，结膜炎暴发期间患者的11株分离株形成一个单独的分支，表明是一种新的变异株。
基于系统发育分析得出结论，钦奈近期发生的结膜炎暴发是由一种变异腺病毒株引起的。
