We assessed the in vitro susceptibility of Streptococcus pneumoniae isolates from patients with confirmed community-acquired
pneumonia (CAP) to β-
lactams,
macrolides and
fluoroquinolones and the association of non-susceptibility and resistance with serotypes/serogroups (STs/SGs), patient's risk factors and vaccination status. Samples (blood or lower respiratory tract) were obtained in 2007-2009 from 249 patients (from seven hospitals in Belgium) with a clinical and radiological diagnosis of CAP [median age 61 years (11.6% aged <5 years); 85% without previous
antibiotic therapy; 86% adults with level II Niederman's severity score]. MIC determination (EUCAST breakpoints) showed for: (i)
amoxicillin, 6% non-susceptible;
cefuroxime (oral), 6.8% resistant; (ii)
macrolides: 24.9%
erythromycin-resistant [93.5% erm(B)-positive] but 98.4%
telithromycin-susceptible; and (iii)
levofloxacin and
moxifloxacin, all susceptible. Amongst SGs: ST14, all resistant to
macrolides and most intermediate to β-
lactams; SG19 (>94% ST19A), 73.5% resistant to
macrolides and 18-21% intermediate to β-
lactams; and SG6, 33% resistant to
clarithromycin. Apparent
vaccine failures: 3/17 for 7-valent
vaccine (children; ST6B, 23F); 16/29 for
23-valent vaccine (adults ST3, 7F, 12F, 14, 19A, 22F, 23F, 33F). Isolates from
nursing home residents, hospitalised patients and patients with non-respiratory co-morbidities showed increased MICs for
amoxicillin, all β-
lactams, and β-
lactams and
macrolides, respectively. Regarding
antibiotic susceptibilities: (i)
amoxicillin is still useful for empirical
therapy but with a high daily dose; (ii)
cefuroxime axetil and
macrolides (but not
telithromycin) are inappropriate for empirical
therapy; and (iii)
moxifloxacin and
levofloxacin are the next 'best empirical choice' (no resistant isolates) but
levofloxacin will require 500 mg twice-daily dosing for effective coverage.