Year of isolation (no. of isolates; % of isolates)* | penA alteration (% of isolates) | mtrR alteration† | PorB1b (penB alteration) | MIC (mg/l) range‡ | |||
Mosaic allele | |||||||
Alteration of A501 in PBP2§ | Promoter region | Coding region | G101 | A102 | Cefixime | Ceftriaxone | |
1998 (0; 0%), 1999 (2; 2%), 2000 (0; 0%), 2001 (2; 1%), 2005 (32; 6%) | None | – | – | – | – | – | – |
None | – | – | – | – | – | – | |
2002 (21; 17%)¶ | 6 (5.0)¶ | 6 | 6 | 6 | 6 | 0.25–0.5 | 0.064–0.125 |
None | – | – | – | – | – | – | |
2003 (27; 21%)¶ | 5 (3.8)¶ | 5 | None | 5 | 5 | 0.25–0.5 | 0.125 |
3 (2.3) | None | 3 | 3 | 3 | 0.064–0.094 | 0.064–0.125 | |
2004 (17; 11%) | None | – | – | – | – | – | – |
3 (2.0) | 1 | 2 | 3 | 3 | 0.032–0.064 | 0.064–0.125 | |
2006 (49; 11%) | 2 (0.5) | 2 | None | 2 | 2 | 0.047–0.094 | 0.064–0.125 |
3 (0.7) | 3 | None | 2 | 3 | 0.032–0.047 | 0.064 | |
2007 (43; 9%) | 10 (2.1) | 10 | None | 10 | 10 | 0.032–0.25 | 0.032–0.125 |
9 (1.8) | 5 | 6 | 9 | 9 | 0.016–0.047 | 0.032–0.064 | |
2008 (81; 15%) | 20 (3.8) | 20 | None | 19 | 19 | 0.023–0.25 | 0.023–0.25 |
12 (2.3) | 11 | None | 12 | 10 | 0.023–0.19 | 0.023–0.125 | |
2009 (57; 13%) | 35 (8.1) | 33 | None | 34 | 34 | 0.032–0.38 | 0.008–0.125 |
7 (1.6) | 6 | None | 7 | 7 | 0.023–0.064 | 0.023–0.094 |
↵* The selection of isolates with increased MICs of cefixime and ceftriaxone was performed from a collection of 348 (1998), 85 (1999), 131 (2000), 141 (2001), 120 (2002), 130 (2003), 149 (2004), 486 (2005), 431 (2006), 487 (2007), 523 (2008) and 434 (2009) isolates.
↵† Number of isolates that contained the characteristic single nucleotide (A) deletion in the inverted repeat of the promoter region and alteration of G45 in MtrR, respectively.
↵‡ MIC values for isolates that possessed a penA mosaic allele or an alteration of A501 in PBP2.
↵§ The alterations of A501 in PBP2 were A501V (n=33) and A501T (n=4).
↵¶ Eight of the 11 isolates with decreased susceptibility and also a penA mosaic allele in 2002 (n=6) and 2003 (n=5) were received from the USA (n=5) and UK (n=3) for a specific study regarding ESC decreased susceptibility.
MIC, minimum inhibitory concentration.