Phylogenetic analysis of human coronavirus NL63 circulating in Italy.
BACKGROUND
Five known human coronaviruses infect the human respiratory tract: HCoV-OC43, HCoV-229E, SARS-CoV, HCoV-NL63 and HCoV-HKU1.


OBJECTIVE
To evaluate the prevalence of HCoV-NL63 in hospitalized adult patients and to perform molecular characterization of Italian strains.


METHODS
HCoV-NL63 was sought by RT-PCR in 510 consecutive lower respiratory tract (LRT) samples, collected from 433 Central-Southern Italy patients over a 1-year period. Phylogenetic analysis was performed by partial sequencing of S and ORF1a. Additional S sequences from Northern Italy were included in the phylogenetic trees.


RESULTS
HCoV-NL63 was detected in 10 patients (2.0%) with symptomatic respiratory diseases, mainly during winter. Phylogenetic analysis indicated a certain degree of heterogeneity in Italian isolates. The ORF1a gene clustering in phylogenetic trees did not match with that of the S gene.


CONCLUSIONS
As observed by others, HCoV-NL63 is often associated with another virus. Phylogenetic characterization of HCoV-NL63 circulating in Italy indicates that this virus circulates as a mixture of variant strains, as observed in other countries.
Minosse
C
C
Laboratory of Virology, National Institute for Infectious Diseases L. Spallanzani, Via Portuense 292, 00149 Rome, Italy.
Selleri
M
M
Zaniratti
M S
MS
Cappiello
G
G
Spanò
A
A
Schifano
E
E
Lauria
F N
FN
Gualano
G
G
Puro
V
V
Campanini
G
G
Gerna
G
G
Capobianchi
M R
MR
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017934:Coronavirus / Q000145:classification* / Q000235:genetics*; D018352:Coronavirus Infections / Q000453:epidemiology / Q000821:virology*; D005260:Female; D005814:Genes, Viral; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins