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Table 4 Comparative analysis of the allelic variation in bla locus for MRSA and MSSA strains

From: Evidence for a purifying selection acting on the β-lactamase locus in epidemic clones of methicillin-resistant Staphylococcus aureus

   No. isolates No. alleles Simpson's Unique SNP SNP/allele (average) Mutations per allele (average) dN/dS
     ID CI (95%)    Silent Conserv. Missense Nonsense Average St. dev.
  blaZ 54 11 79.2 69.6-88.8 41 11.4 5.3 1.7 3.7 0.1 0.21 0.11
MRSA blaI 27 7 82.1 74.6-89.5 10 3.9 2.9 0 1.0 0 0.11 0.05
  blaR1 31 10 88.8 83.2-94.4 60 24.4 9.7 5.3 8.0 0 0.24 0.11
  blaZ 24 9 76.1 61.3-90.9 35 14.7 7.1 1.9 4.6 0 0.17 0.04
MSSA blaI 20 6 74.2 60.5-87.9 9 2.5 1.5 0.2 0.8 0 0.08 0.03
  blaR1 17 8 88.2 81.2-95.3 61 24.6 10.4 5.5 7.8 0 0.24 0.10
  blaZ 78 13 81.1 75.0-87.3 43 12.4 5.8 1.8 4.0 0.1 0.20 0.10
All blaI 47 9 78.4 71.0-85.9 13 3.4 2.3 0.1 1.0 0 0.10 0.04
  blaR1 48 12 88.5 84.0-93.0 65 24.8 10.2 5.3 8.1 0 0.25 0.10
  1. ID, index of diversity; CI, confidence interval; SNP, single-nucleotide polymorphism; Conserv., conservative; St. dev., standard deviation