Skip to main content

Table 2 Mutation frequencies of plaque-cloned, ribavirin-resistant mutants (RVRp13-P and RVRp22-P) and VR2332-p after 10 passages in MARC-145 cells

From: Effects of ribavirin on the replication and genetic stability of porcine reproductive and respiratory syndrome virus

Sequenced region   VR2332-p RVRp13-p RVRp22-p
nsp2 Total no. of clones sequenceda 15 15 15
Total no. of nucleotides sequenced
(3588 nt per clone)
53820 53820 53820
Total no. of mutations 175 98 51
Total no. of nucleotide deletions
in sequenced length
63 0 6
Mutation rate/103 nt 3.25 1.82* 0.94**
Total no. of amino acids sequenced
(1196 aa per clone)
17940 17940 17940
Total no. of mutations 96 70 24
Total no. of amino acid deletions
in sequenced length
21 0 2
Mutation rate/103 aa 5.35 3.90* 1.33**
ORF5 Total no. of clones sequenced 15 15 15
Total no. of nucleotides sequenced
(603 nt per clone)
9045 9045 9045
Total no. of mutations 51 57 6
Mutation rate/103 nt 5.64 6.30 0.66**
Total no. of amino acids sequenced
(201 aa per clone)
3015 3015 3015
Total no. of mutations 32 29 4
Mutation rate/103 aa 10.61 9.61 1.32**
  1. a: The numbers of nucleotide mutations and amino acid substitutions were determined by sequencing 15 plaque-purified virus clones from cell culture fluids collected at the completion of 10 passages of each virus and comparing those samples to the original viruses not submitted to sequential cell passages.
  2. nt: nucleotide, aa: amino acid, significance levels when comparing a drug-resistant strain with VR2332 are indicated by asterisks: *p < 0.05, **p < 0.001.