Epidemiology and Genetic Variabilities of Human Adenovirus Type 55 Reveal Relative Genome Stability Across Time and Geographic Space in China.

Shi-Ying Chen,Rong Zhou,Yong Chen,Xingui Tian,Wenkuan Liu,Shuyan Qiu,Yun Xu

doi:10.3389/fmicb.2020.606195

Abstract

After the first outbreak in China in 2006, human adenovirus type 55 (HAdV-B55) has become a common pathogen causing life threatening pneumonia in northern China. However, HAdV-B55 infection has been rarely reported in southern China. Here, we collected throat swabs from 3,192 hospitalized children with acute respiratory disease (ARD) from May 2017 to April 2019 in Guangzhou, southern China, tested them for HAdV-B55 infection. Only one of 1,399 patients from May 2017 to April 2018 was HAdV-B55 positive; HAdV-B55 infections significantly increased with 10 of 1,792 patients testing positive since May 2018. HAdV-B55-267, isolated from a case of death, was sequenced for whole genomic analysis. Three other strains, HAdV-B55-Y16, -TY12, and -TY26, isolated earlier in patients from Shanxi, northern China, were also sequenced and analyzed. The four HAdV-B55 strains formed similar plaques, grew to similar titers, and resulted in similar typical cell pathogenic effects. HAdV-B55-267 formed a subclade with the prototype strain QS-DLL; strains HAdV-B55-Y16, -TY12, and -TY26 were closely related to strain QZ01. HAdV-B55 could be divided into two subtypes (HAdV-B55-a and -b) according to the presence or absence of the insertion of “CCATATCCGTGTT”; all strains isolated from China except for strain BJ01 belong to subtype b. HAdV-B55-267 had only one non-synonymous substitution comparing with strain QS-DLL, and all HAdV-B55 strains had highly conserved capsid proteins and few non-synonymous substitutions. This study suggests that HAdV-B55 is an important pathogen associated with ARD in Guangzhou since 2018, exhibiting the relative genome stability across time and geographic space in China.

Highlights

Human adenovirus type 55 (HAdV-B55) is a newly identified adenovirus type that causes severe pneumonia
In 2016, several HAdV-B55 outbreaks were reported in Xizang, Yunnan, and Sichuan (Wang et al, 2017) and Guangdong (Yi et al, 2017), suggesting that this recombinant adenovirus was widely disseminated in China (Figure 4)
We found only one patient was infected by HAdV-B55 during the 12 months prior to May 2018; thereafter, ten HAdV-B55-positive patients were detected in one year in Guangzhou, a central city in southern China

Summary

Introduction

Human adenovirus type 55 (HAdV-B55) is a newly identified adenovirus type that causes severe pneumonia. HAdV-B55 was previously identified as HAdV-B11a, which was first isolated from a military trainee during an outbreak in Spain in 1969 (Hierholzer et al, 1974) It re-emerged in the United States in 1997, of which only the capsid proteins gene sequences have been reported (News From the Centers for Disease Control and Prevention, 1998), and in Egypt in 2001 HAdV-B55 has widely spread among the military and public in many provinces across China and has become one of the important pathogens causing pneumonia in the country (Zhang et al, 2012, 2016; Cao et al, 2014; Li et al, 2014; Lu et al, 2014; Sun et al, 2014; Wang et al, 2017; Yi et al, 2017; Jing et al, 2019). Compared with other types of adenoviral infections, the symptoms of pneumonia caused by HAdV-B55 infection are usually more serious (Cao et al, 2014)

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