A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Community-acquired pneumonia(CAP) is one of the leading causes of morbidity and mortality in children worldwide.In this study,we aimed to describe the aetiology of viral infection of pediatric CAP in Chinese mainland.During November2014 to June 2016,the prospective study was conducted in 13 hospitals.The hospitalized children under 18 years old who met the criteria for CAP were enrolled.The throat swabs or nasopharyngeal aspirates(NPAs) were collected which were then screened 18 respiratory viruses using multiplex PCR assay.Viral pathogens were present in 56.6%(1539/2721) of the enrolled cases,with the detection rate of single virus in 39.8% of the cases and multiple viruses in 16.8% of the cases.The most frequently detected virus was respiratory syncytial virus(RSV)(15.2%,414/2721).The highest detection rate of virus was in <6-month-age group(70.7%,292/413).RSV,human metapneumovirus(HMPV),human parainfluenza viruses(HPIVs) and influenza B virus(Flu B) showed the similar prevalence patterns both in north and south China,but HPIVs,Flu A,human bocavirus(HBoV),human adenovirus(HAdV) and human coronaviruses(HCoVs) showed the distinct circulating patterns in north and south China.Human enterovirus/human rhinovirus(HEV/HRV)(27.6%,27/98),HBoV(18.4%,18/98),RSV(16.3%,16/98) and HMPV(14.3%,14/98) were the most commonly detected viruses in severe pneumonia cases with single virus infection.In conclusion,viral pathogens are frequently detected in pediatric CAP cases and may therefore play a vital role in the aetiology of CAP.RSV was the most important virus in hospitalized children with CAP in Chinese mainland.

Evolving strategies for marine enzyme engineering:recent advances on the molecular modification of alginate lyase

Alginate,an acidic polysaccharide,is formed byβ-D-mannuronate(M)andα-L-guluronate(G).As a type of polysaccharide lyase,alginate lyase can efficiently degrade alginate into alginate oligosaccharides,having potential applications in the food,medicine,and agriculture fields.However,the application of alginate lyase has been limited due to its low catalytic efficiency and poor temperature stability.In recent years,various structural features of alginate lyase have been determined,resulting in modification strategies that can increase the applicability of alginate lyase,making it important to summarize and discuss the current evidence.In this review,we summarized the structural features and catalytic mechanisms of alginate lyase.Molecular modification strategies,such as rational design,directed evolution,conserved domain recombination,and non-catalytic domain truncation,are also described in detail.Lastly,the application of alginate lyase is discussed.This comprehensive summary can inform future applications of alginate lyases.