The genetic characteristics of human coronavirus OC43 in cases of severe acute respiratory infection

ABSTRACT

Human coronavirus (HCoV) is one of the important pathogens of human respiratory tract infection. in order to clarify the genetic characteristics of HCoV-0C43 in severe acute respiratory infection (SARI) cases at the molecular level, a total of 374 samples obtained from SARI cases in Henan Province, China, in 2019 were screened for the nucleic acids of HCoV -0C43 by real - time polymerase chain reaction (PCR). Reverse transcription-PCR amplification and sequencing of spike (5) RNA-dependent RNA polymerase (12dRp) and nucleocapsid (N) was carried out in samples with positive detection of the nucleic acids of FICoV-0C43. Upon. combination Of 42 representative sequences obtained from the GenBank database, phylogenetic trees were constructed based on three full-length sequences of S, RdRp and N genes. The FICoV -0C43 strains obtained from SARI cases were genotyped and the genetic characteristics of three target genes were analyzed. Variations in the amino acids of S protein (an important antigen of HCoV-0C43) were also analyzed. Results showed that 15 (4.01%) out of 374 samples from SARI cases were positive for FICoV-0C43, and the full-length sequences of S, RdRp and N genes were obtained from 4 out of 15 samples. Based on the phylogenetic trees of these three target genes, three strains belonged to the U genotype and one strain belonged to the H genotype. Analysis of the amino - acid variations of S protein indicated that there were three special sites of amino - acid variation (L272P, P5165 and 5902A) among the G genotype strains in 2019, including the three strains in our study and USA /MN306041/SC0810/2019. Another special variation in amino acids (N484D) was found among the II genotype strains in 2019, including one strain in our study and USA/MN306043/SC0841/2019. Based on the genotype identification and genetic characteristics of HCoV-0C43 strains from SARI cases in Henan Province in 2019, baseline data for the study of molecular epidemiology of HCoV 0C43 in China have been provided.