Table 1

Neisseria gonorrhoeae displaying increased MICs of cefixime and/or ceftriaxone (≥0.032 mg/l) isolated in Sweden (n=331), 1998–2009

Year of isolation (no. of isolates; % of isolates)*penA alteration (% of isolates)mtrR alterationPorB1b (penB alteration)MIC (mg/l) range
Mosaic allele
Alteration of A501 in PBP2§Promoter regionCoding regionG101A102CefiximeCeftriaxone
1998 (0; 0%), 1999 (2; 2%), 2000 (0; 0%), 2001 (2; 1%), 2005 (32; 6%)None
None
2002 (21; 17%)6 (5.0)66660.25–0.50.064–0.125
None
2003 (27; 21%)5 (3.8)5None550.25–0.50.125
3 (2.3)None3330.064–0.0940.064–0.125
2004 (17; 11%)None
3 (2.0)12330.032–0.0640.064–0.125
2006 (49; 11%)2 (0.5)2None220.047–0.0940.064–0.125
3 (0.7)3None230.032–0.0470.064
2007 (43; 9%)10 (2.1)10None10100.032–0.250.032–0.125
9 (1.8)56990.016–0.0470.032–0.064
2008 (81; 15%)20 (3.8)20None19190.023–0.250.023–0.25
12 (2.3)11None12100.023–0.190.023–0.125
2009 (57; 13%)35 (8.1)33None34340.032–0.380.008–0.125
7 (1.6)6None770.023–0.0640.023–0.094
  • * 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.