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Genetic Relatedness of Levofloxacin-Nonsusceptible Streptococcus pneumoniae Isolates from North America
- Source :
- Journal of Clinical Microbiology. 41:2458-2464
- Publication Year :
- 2003
- Publisher :
- American Society for Microbiology, 2003.
-
Abstract
- We characterized 32 levofloxacin-nonsusceptible Streptococcus pneumoniae (LNSP) isolates obtained from a broad geographic region of North America over a 5-year period by using capsular serotypes, antimicrobial susceptibility profiles, BOX-PCR, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Sixteen international clones identified by the Pneumococcal Molecular Epidemiology Network also were included for comparison. Fifteen serotypes were represented, with serogroups 6, 9, 14, 19, and 23 accounting for 63% of isolates. Among isolates whose quinolone resistance-determining regions were sequenced, all contained gyrA and parC point mutations. Sixty-three percent were penicillin susceptible, and 84% were erythromycin susceptible. BOX-PCR analysis identified 39 different band patterns among 32 LNSP and 16 international clones and grouped 16 isolates, including 2 international clones, into seven unrelated groups of 2 to 4 isolates each. PFGE analysis identified 35 different band patterns among 32 LNSP and 16 international clones and grouped 21 isolates, including 3 international clones, into eight unrelated groups of 2 to 6 isolates each. MLST performed on 10 isolates identified five allelic profiles and separated 9 isolates into four groups of 2 to 3 isolates each. Overall, each typing method indicated that the LNSP were heterogeneous and that resistance to fluoroquinolones was not closely associated with a particular serotype or with coresistance to other antimicrobial classes and suggests that LNSP have likely arisen through independent mutational events as a result of selective pressure. However, seven LNSP were found to be related to three international clones by PFGE.
- Subjects :
- Microbiology (medical)
Serotype
Ofloxacin
Levofloxacin
Microbial Sensitivity Tests
Biology
medicine.disease_cause
Pneumococcal Infections
Microbiology
Anti-Infective Agents
Drug Resistance, Bacterial
Genotype
Streptococcus pneumoniae
Pulsed-field gel electrophoresis
medicine
Humans
Typing
Serotyping
Bacterial Capsules
Antibacterial agent
Genetics
Molecular epidemiology
Bacteriology
Sequence Analysis, DNA
Anti-Bacterial Agents
Bacterial Typing Techniques
Electrophoresis, Gel, Pulsed-Field
North America
Multilocus sequence typing
Subjects
Details
- ISSN :
- 1098660X and 00951137
- Volume :
- 41
- Database :
- OpenAIRE
- Journal :
- Journal of Clinical Microbiology
- Accession number :
- edsair.doi.dedup.....e3a01bda9bb9f3b347536b511c202e92