The Molecular Epidemiology of Streptococcus pneumoniae with Quinolone Resistance Mutations

• Published in: Clinical infectious diseases Vol. 40; no. 2; pp. 225 - 235
• Main Authors: Richter, S. S., Heilmann, K. P., Beekmann, S. E., Miller, N. J., Rice, C. L., Doern, G. V.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 15.01.2005; University of Chicago Press; Oxford University Press
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobials; Bacterial diseases; Biological and medical sciences; Ciprofloxacin - pharmacology; DNA Gyrase - genetics; DNA Topoisomerase IV - genetics; Drug resistance; Drug Resistance, Bacterial; Epidemiology; Fluoroquinolones; Genetic mutation; Genetic relationships; Human bacterial diseases; Humans; Infectious diseases; Levofloxacin; Major Articles; Medical sciences; Microbial Sensitivity Tests; Molecular epidemiology; Mutation; Ofloxacin - pharmacology; Penicillin; Pharmacology. Drug treatments; Pneumococcal Infections - drug therapy; Pneumococcal Infections - epidemiology; Pneumococcal Infections - microbiology; Population Surveillance; Quinolones; Serotyping; Staphylococcal infections, streptococcal infections, pneumococcal infections; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Surveillance; Time Factors; United States; United States; North America; America; United States > US; Levofloxacin; Prevalence; Drug susceptibility test; Method; Streptococcus pneumoniae; Infection; Resistance; Streptococcaceae; Fluoroquinolone derivatives; Gene; Surveillance; Streptococcal infection; Minimum inhibitory concentration; Bacteriosis; Molecular epidemiology; Bacteria; Micrococcales; Mutation; Antibacterial agent; Ciprofloxacin; Pneumococcal infection; Quinolone derivatives
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1086/426817

Background. The purpose of this study was to determine the prevalence of fluoroquinolone resistance and quinolone resistance—determining region (QRDR) mutations among Streptococcus pneumoniae isolates in the United States during the period of 2001–2002. A second objective was to examine the genetic relatedness of pneumococcal isolates with parC and/or gyrA mutations during the period of 1994–2002. Methods. Susceptibility testing was performed for 1902 S. pneumoniae isolates collected in the United States during the period of 2001–2002. On the basis of the minimum inhibitory concentration (MIC) of ciprofloxacin, 146 isolates were selected from the 2001–2002 study for QRDR analysis of parC, parE, gyrA, and gyrB genes. The genetic relatedness of isolates with parC and/or gyrA mutations from 2001–2002 (n = 55) and from 3 US surveillance studies conducted during 1994–2000 (n = 56) was determined by pulsed-field gel electrophoresis (PFGE). Results. Between 1999–2000 and 2001–2002, there was a 2-fold increase in the rate of ciprofloxacin resistance (MIC, ⩾4 µg/mL), from 1.2% to 2.7%, and in the rate of levofloxacin nonsusceptibility (MIC, ⩾4 µg/mL), from 0.6% to 1.3%. The 111 isolates with parC and/or gyrA mutations were assigned to 48 different PFGE types. Forty-four isolates (40%) belonged to 8 PFGE types that were closely related to widespread clones. Fifteen of the 43 levofloxacin-nonsusceptible pneumococci (LNSP) belonged to 4 PFGE types that were closely related to major clones (Spain23F-1 [n = 6]; Spain6B-2 [n = 5], Taiwan19F-14 [n = 2], and Tennessee23F-4 [n = 2]). Conclusion. The population of fluoroquinolone-resistant S. pneumoniae in the United States has increased but remains genetically diverse. However, 35% of LNSP were related to widespread pneumococcal clones, increasing the potential for the rapid spread of quinolone resistance in this species.