TABLE 1

Antimicrobial MICs, characteristics of the 13 patients, and molecular characterization of the persistent pneumococcal strainsa

Patient no. (age, gender)MLST genotypeEpisode no. (day/mo/yr)β-lactam MIC (μg/ml)PBP1A/2B/2X allelebFluoroquinolone MIC (μg/ml)Aa substitutions in ParC/GyrAMIC (μg/ml)d
PENA/CCTX-CROCIPLEVMOXERYTET
1 (58, male)ST1569V1st (19/10/1995)22/11A/A.1/A.182<0.25S79F/none<0.25≤2
2nd (29/11/1995)22/11A/A.1/A.182<0.25S79F/none<0.25≤2
3rd (28/04/1996)22/11A/A.1/A.182<0.25S79F/none<0.25≤2
2 (46, male)ST1569V1st (24/07/1995)21/0.51A/A.1/A.121<0.25None<0.25≤2
2nd (07/11/1995)21/0.51A/A.1/A.121<0.25None<0.25≤2
3rd (17/03/1996)21/0.51A/A.1/A.121<0.25None<0.25≤2
3 (76, male)ST8389V1st (06/11/2002)28/41A/B.1/A.221<0.25None<0.25≤2
2nd (08/05/2003)28/41A/B.1/A.221<0.25None<0.25≤2
3rd (24/09/2003)28/41A/B.1/A.2c21<0.25None<0.25≤2
4th (17/04/2004)28/41A/B.1/A.221<0.25None<0.25≤2
4 (77, female)ST8389V1st (11/08/2007)28/41A/B.1/A.2>32324S79F/S81F<0.25≤2
2nd (24/01/2008)28/41A/B.1/A.2>32324S79F/S81F<0.25≤2
3rd (16/06/2008)28/41A/B.1/A.2>32324S79F/S81F<0.25≤2
5 (62, male)ST8389V1st (29/10/1997)28/41A/B.1/A.2>32324S79Y/S81F<0.25≤2
2nd (20/10/1998)28/41A/B.1/A.282<0.25S79F/none<0.25≤2
3rd (03/04/2000)28/41A/B.1/A.2>32324S79F/S81F<0.25≤2
6 (60, male)ST652111A1st (21/05/2009)28/41A/B.2/A.221<0.25None<0.25≤2
2nd (25/10/2009)28/41A/B.2/A.2c21<0.25None<0.25≤2
3rd (14/03/2010)28/41A/B.2/A.2c21<0.25None<0.25≤2
7 (75, male)ST6315A1st (09/11/2008)0.25<0.5/0.250.12B/C/B22<0.25None>32>4
2nd (28/12/2008)0.25<0.5/0.250.12B/C/B21<0.25None>32>4
3rd (29/01/2009)0.25<0.5/0.250.12B/C/B>32324S79Y/S81F>32>4
4th (15/04/2009)0.25<0.5/0.250.12B/C/B>32324S79Y/S81F>32>4
6th (16/06/2009)0.25<0.5/0.250.12B/C/B>32324S79Y/S81F>32>4
ST55835B5th (10/05/2009)12/11C/D/C11<0.25None<0.25≤2
7th (16/03/2010)12/11C/D/C11<0.25None<0.25≤2
8th (05/06/2010)12/11C/D/C11<0.25None<0.25≤2
8 (59, female)ST6315A1st (25/10/2005)0.25<0.5/0.250.12B/C/B21<0.25None>32>4
2nd (02/05/2006)0.25<0.5/0.250.12B/C/B42<0.25D78N/none>32>4
3rd (07/12/2006)0.25<0.5/0.250.12B/C/B42<0.25D78N/none>32>4
4th (06/11/2007)0.25<0.5/0.250.12B/C/B42<0.25D78N/none>32>4
5th (02/06/2008)0.25<0.5/0.250.12B/C/B42<0.25D78N/none>32>4
9 (78, male)ST8819F1st (24/12/1999)0.25<0.5/0.250.5D/E/D.111<0.25None>32>4
2nd (24/12/2000)0.25<0.5/0.250.5D/E/D.1>32324S79F/S81Y>32>4
3rd (28/04/2002)0.25<0.5/0.250.5D/E/D.1>32324S79F/S81Y>32>4
10 (64, male)ST8719F1st (26/10/2007)12/10.5E/F/D.111<0.25None>32>4
2nd (23/01/2008)12/10.5E/F/D.111<0.25None>32>4
3rd (19/09/2008)12/10.5E/F/D.111<0.25None>32>4
4th (09/12/2008)12/10.5E/F/D.111<0.25None>32>4
5th (25/12/2010)12/10.5E/F/D.111<0.25None>32>4
11 (73, male)ST210019F1st (08/01/2008)22/11E/A.2/D.2>32324S79Y/S81Y>32≤2
2nd (28/04/2009)22/11E/A.2/D.2c>32324S79Y/S81Y>32≤2
3rd (19/10/2009)22/11E/A.2/D.2c>32324S79Y/S81Y>32≤2
12 (38, male)ST27619A1st (12/12/2007)22/11F/G/A.121<0.25None>32>4
2nd (22/12/2008)22/11F/G/A.121<0.25None>32>4
3rd (18/03/2009)22/11F/G/A.121<0.25None>32>4
13 (65, male)ST16246B1st (19/06/2006)48/41G/B/E10.5<0.25None>32>4
2nd (20/03/2007)48/41G/B/E10.5<0.25None>32>4
3rd (22/08/2008)48/41G/B/E10.5<0.25None>32>4
4th (06/10/2009)48/41G/B/E10.5<0.25None>32>4
  • a PEN, penicillin (susceptible: MIC < 0.12 μg/ml); CTX-CRO, cefotaxime-ceftriaxone (susceptible: MIC ≤ 1 μg/ml); A/C, amoxicillin-clavulanic acid (susceptible: MIC < 4/2 μg/ml); CIP, ciprofloxacin (susceptible: MIC < 4 μg/ml); LEV, levofloxacin (susceptible: ≤ 2 μg/ml); MOX, moxifloxacin (susceptible: ≤ 1 μg/ml); ERY, erythromycin (susceptible:≤ 0.25 μg/ml); and TET, tetracycline (susceptible: ≤ 2 μg/ml). Boldface font indicates resistant isolates.

  • b Capital letters were used to define different alleles of each PBP, and numbers were used to differentiate small differences among sequences with identical capital letter (for details of the amino acid substitutions, see Fig. 3).

  • c Acquisition of an SNP in the PBP2X with respect to the first episode of the same patient.

  • d Gene erm(B) was detected only in ERY-resistant strains; gene tet(M) was detected only in TET-resistant strains.