Description:
<jats:title>ABSTRACT</jats:title>
<jats:p>
In a nationwide study in Germany covering 13 clinical microbiology laboratories, a total of 307
<jats:italic>Streptococcus pyogenes</jats:italic>
(mainly pharyngitis) and 333
<jats:italic>Streptococcus pneumoniae</jats:italic>
(respiratory tract infections) strains were collected from outpatients less than 16 years of age. The MICs of penicillin G, amoxicillin, cefotaxime, erythromycin A, clindamycin, levofloxacin, and telithromycin were determined by the microdilution method. In
<jats:italic>S. pyogenes</jats:italic>
isolates, resistance rates were as follows: penicillin, 0%; erythromycin A, 13.7%; and levofloxacin, 0%. Telithromycin showed good activity against
<jats:italic>S. pyogenes</jats:italic>
isolates (MIC
<jats:sub>90</jats:sub>
= 0.25 μg/ml; MIC range, 0.016 to 16 μg/ml). Three strains were found to be telithromycin-resistant (MIC ≥ 4 μg/ml). Erythromycin-resistant strains were characterized for the underlying resistance genotype, with 40.5% having the efflux type
<jats:italic>mef</jats:italic>
(A), 38.1% having the
<jats:italic>erm</jats:italic>
(A), and 9.5% having the
<jats:italic>erm</jats:italic>
(B) genotypes.
<jats:italic>emm</jats:italic>
typing of macrolide-resistant
<jats:italic>S. pyogenes</jats:italic>
isolates showed
<jats:italic>emm</jats:italic>
types 4 (45.2%), 77 (26.2%), and 12 (11.9%) to be predominant. In
<jats:italic>S. pneumoniae</jats:italic>
, resistance rates were as follows: penicillin intermediate, 7.5%; penicillin resistant, 0%; erythromycin A, 17.4%; and levofloxacin, 0%. Telithromycin was highly active against pneumococcal isolates (MIC
<jats:sub>90</jats:sub>
≤ 0.016 μg/ml; range, 0.016 to 0.5 μg/ml). The overall resistance profile of streptococcal respiratory tract isolates is still favorable, but macrolide resistance is of growing concern in Germany.
</jats:p>