Rudolf Lütticken

Macrolide-Resistant Streptococcus pneumoniae and Streptococcus pyogenes in the Pediatric Population in Germany during 2000-2001

ABSTRACT In a nationwide study in Germany covering 13 clinical microbiology laboratories, a total of 307 Streptococcus pyogenes (mainly pharyngitis) and 333 Streptococcus pneumoniae (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 S. pyogenes isolates, resistance rates were as follows: penicillin, 0%; erythromycin A, 13.7%; and levofloxacin, 0%. Telithromycin showed good activity against S. pyogenes isolates (MIC90 = 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 mef(A), 38.1% having the erm(A), and 9.5% having the erm(B) genotypes. emm typing of macrolide-resistant S. pyogenes isolates showed emm types 4 (45.2%), 77 (26.2%), and 12 (11.9%) to be predominant. In S. pneumoniae, 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 (MIC90 ≤ 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.

Ribosomal Mutations Conferring Resistance to Macrolides in Streptococcus pneumoniae Clinical Strains Isolated in Germany

ABSTRACT Among a collection of 4,281 pneumococcal isolates, 7 strains isolated in Germany had an unusual macrolide resistance phenotype. The isolates were found to have multiple mutations in the 23S rRNA and alterations in the L4 ribosomal protein. One strain had an amino acid alteration in the L22 ribosomal protein.

Antimicrobial resistance of Streptococcus pneumoniae recovered from outpatients with respiratory tract infections in Germany from 1998 to 1999: results of a national surveillance study.

ABSTRACT Clinically significant pneumococcal isolates were prospectively collected from outpatients with respiratory tract infections by 19 different clinical microbiology laboratories in Germany. Resistance rates in a total of 961 isolates were as follows: penicillin, 6.6%; clarithromycin, 10.6%; tetracycline, 13.9%; and levofloxacin, 0.1%. Among 324 isolates from children, pneumococcal serotypes 19F (17.0%), 23F (13.0%), and 6B (11.7%) were the predominant types.

Clonal relatedness of erythromycin-resistant Streptococcus pyogenes isolates in Germany.

ABSTRACT In a nationwide study in Germany, a total of 381 Streptococcus pyogenes were collected. Erythromycin A-resistant strains were characterized for the underlying resistance genotype, showing 55.6% had the efflux type mef(A), 31.5% had erm(A), and 13.0% had erm(B). A total of 23 different multilocus sequence types were observed.

Comparison of Two Chromogenic Media for Selective Isolation of Vancomycin-Resistant Enterococci from Stool Specimens

ABSTRACT Two chromogenic media (Chromagar VRE and chromID VRE [C-ID]) performed equally well in the direct detection of vancomycin-resistant enterococci (VRE) in stool specimens after an overnight enrichment step and a 48-h incubation period, with a sensitivity of 98.2% (56/57) for both and specificities of 96.5% (195/202) and 97.5% (197/202), respectively. However, assigning discriminatory colony color was sometimes difficult, especially on C-ID. In order to facilitate simple species identification, biochemical key reactions were implemented.

Antimicrobial Resistance of Streptococcus pneumoniae Isolates of Outpatients in Germany, 1999–2000

Background: The aim of the study was to determine the prevalence of antimicrobial resistance among clinical isolates of Streptococcus pneumoniae during the winter of 1999–2000 in Germany. Methods: Pneumococcal isolates were prospectively collected by 14 different clinical microbiology laboratories. Minimal inhibitory concentrations of penicillin G, erythromycin A, clarithromycin, roxithromycin, azithromycin, clindamycin, levofloxacin and telithromycin were determined by the broth microdilution method. Results: Among 328 strains 4.6% were nonsusceptible to penicillin G (intermediate and resistant strains) and 9.5% were resistant to erythromycin A. Analysis of erythromycin-resistant strains for the underlying resistance determinants revealed that 12 (38.7%) belonged to the erm(B) and 19 (61.3%) to the mef(E) type of resistance. Among the macrolide-resistant strains, serotypes 19F (n = 9) and 14 (n = 8) were the predominant types. Conclusions: Macrolide resistance in Germany is of growing concern and mainly due to the high prevalence of pneumococci expressing the mef(E) type of resistance.

Nationwide German Multicenter Study on the Prevalence of Antibiotic Resistance in Streptococcal Blood Isolates from Neutropenic Patients and Comparative In Vitro Activities of Quinupristin-Dalfopristin and Eight Other Antimicrobials

ABSTRACT In a prospective multicenter study (1996 to 1999), 156 episodes of bacteremic streptococcal infections of neutropenic patients were evaluated. Streptococcus oralis (26.3%),S. pneumoniae (26.3%), S. agalactiae (11.5%),S. mitis (9%), and S. pyogenes(5.8%) were the predominant species. Four strains (2.6%) were found to be intermediately resistant to penicillin. One strain (0.6%) was found to be highly resistant to penicillin (MIC, 8 mg/liter). Reduced susceptibility to penicillin was detected among S. oralis(14.6%), S. mitis (7.1%), and S. pneumoniae(4.9%) isolates but was not recorded among S. agalactiaeand S. pyogenes. Resistance rates and intermediate resistance rates for other antimicrobials were as follows (all species): amoxicillin, 1.3 and 3.2%; erythromycin, 16 and 2.6%; clindamycin, 5.8 and 0%; ciprofloxacin, 1.9 and 7.7%. Quinupristin-dalfopristin showed good in vitro activity against most streptococcal isolates (MIC at which 50% of the isolates were inhibited [MIC50], 0.5 mg/liter; MIC90, 1 mg/liter, MIC range, 0.25 to 4 mg/liter).

drs (Distantly Related sic) Gene Polymorphisms among emm12-Type Streptococcus pyogenes Isolates

ABSTRACT Twenty-eight emm12-type Streptococcus pyogenes isolates from patients with invasive and noninvasive infections or from asymptomatic carriers were genetically typed. Sequencing of drs (distantly related sic [streptococcal inhibitor of complement]) genes identified two novel alleles and revealed a polymorphism for drs similar to that of sic. No association was observed between the five different drs alleles and the five restriction patterns of the vir regulon for the isolates studied. These data suggest that drs sequencing may be useful for further differentiation of S. pyogenes isolates with emm12 and identical vir regulon restriction patterns.