ABSTRACT
Objective@#To understand the epidemiological characteristics of outbreaks and analyze the genetic characteristics of the whole genome of influenza H3N2 virus among avian-human-swine, and to elaborate the source of influenza virus.@*Methods@#The epidemic information was collected using the case investigation, the pharyngeal swab samples from influenza-like-illness cases were detected by real-time PCR and virus isolation. The phylogeny and molecular features of whole-genome were analyzed with EditSeq and MEGA 5.05 software.@*Results@#The prevalence rate of this outbreak was 34.88%, 15 samples of throat swabs were collected, the positive rate of nucleic acid detection was 73.33%, 5 strains of seasonal influenza A (H3N2) influenza viruses were isolated. The phylogenetic analysis showed the eight gene segments of the isolated influenza viruses belonged to the same cluster with 2015-2016 influenza vaccine strain A/Switzerland/9715293/2013(H3N2), and no recombination was found. Compared with vaccine strain, 14 variant amino acids of protein of HA were identified, and 8 of them were located in antigenic sites. All strains were sensitive to neuraminidase inhibitors while they showed resistance to blockers of M2 ion channel. The glycosylation sites analysis showed that two new glycosylation sites NRT151-153 and NAT245-247were added.@*Conclusions@#The outbreak was caused by seasonal influenza A (H3N2) virus which had an antigenic drift and no genetic avian-human-swine recombination was found.
ABSTRACT
Quantitative calibration strategy as an essential issue in laser ablation ICP-MS plays an important role for the guarantee of analytical accuracy.In this study, uncertainties of reference values in current available glass certified reference materials (NIST, MPI-DING and USGS) as well as the matrix effect among them were systematically evaluated.The results illustrated that NIST610 was better than other reference materials from aspect of reference value uncertainty.The matrix effect among NIST, MPI-DING and USGS reference materials was insignificant under our experimental conditions.A quantification strategy based on two reference materials (NIST610 and StHs6/80-G) and normalization to 100% (w/w) was proposed to avoid the insufficiency of single reference material strategy, which suffered the very low content and large uncertainty for some elements.The comparision of ML3B-G results obtained from three quantification strategies (single reference material NIST610, single reference material StHs6/80-G and two refterence materials) illustrated that the proposed strategy improved the analytical accuracy.Three reference materials (BCR-2G, CGSG-2 and KL-2G) were quantified with the proposed strategy, and almost all data matched well with reference value, meanwhile the data reported here could supplement the reference value database.