TABLE 2.

Presence of virulence determinants in MRSA strains and genotypes of the strains representing each combinationa

Group (yr of isolation)bCharacteristics of MRSA strains isolated at each periodGenotypes of chosen MRSA strains as indicated by:No. of tested strains
SCCmec typeRatio (%)Presence of indicated virulent determinantNo. of strains with indicated resultsCoagulase isotypeMLST
PVLCNATSST-1SEHCCSTAllelic profile
A (1979-1985)I (n = 22)22.7++4430302, 2, 2, 2, 6, 3, 22
+7430302, 2, 2, 2, 6, 3, 21
+5430302, 2, 2, 2, 6, 3, 21
6430302, 2, 2, 2, 6, 3, 21
II.1 (IIa) (n = 21)21.6++12551, 4, 1, 4, 12, 1, 101
+202551, 4, 1, 4, 12, 1, 106
IV.1 (IVa) (n = 1)1.0++14NcN2, 2, N, 2, 6, 3, 21
IV.3 (IVc) (n = 37)38.1++30430302, 2, 2, 2, 6, 3, 27
+13883, 3, 1, 1, 4, 4, 31
6
IV.4 (IVd) (n = 10)10.3102551, 4, 1, 4, 12, 1, 101
IV.n (IVn) (n = 4)4.1++1430302, 2, 2, 2, 6, 3, 21
+3430302, 2, 2, 2, 6, 3, 21
Nontypeable (n = 2)1.01
+12551, 4, 1, 4, 12, 1, 101
B (1992)I (n = 1)4.51
II.1 (IIa) (n = 20)91.0+192551, 4, 1, 4, 12, 1, 103
1
IV.3 (IVc) (n = 1)4.51
C (1999)I (n = 1)0.71
II.1 (IIa) (n = 120)91.3+1142551, 4, 1, 4, 12, 1, 106
6
II.n (n = 6)4.3+2
+4
IV.3 (IVc) (n = 6)4.3++471811, 1, 1, 9, 1, 1, 12
2
Nontypeable (n = 5)3.6+5
  • a CNA, collagen adhesion protein; CC, clonal complex; N, nontypeable; SEH, staphylococcal enterotoxin H; ST, sequence type. +, present; −, absent.

  • b For group A (n = 97), the numbers of PVL-positive and TSST-1-positive strains were 44 (45.3) and 23 (23.7%), respectively, for group B (n = 22), the numbers of PVL-positive and TSST-1-positive strains were 0 and 19 (86.3%), respectively, and for group C (n = 138), the numbers of PVL-positive and TSST-1-positive strains were 0 and 123 (89.1%), respectively.

  • c The sequence type of the strains could not be assigned since the glpF gene could not be amplified by PCR.