Tolerance to Vancomycin in Pneumococci: Detection with a Molecular Marker and Assessment of Clinical Impact

• Published in: The Journal of infectious diseases 2004-10, Vol.190 (8), p.1481-1487
• Main Authors: Rodriguez, Carina A., Atkinson, Robyn, Bitar, Wally, Whitney, Cynthia G., Edwards, Kathryn M., Mitchell, Lauren, Li, Juan, Sublett, Jack, Li, Chin-Shang, Liu, Tiebin, Chesney, P. Joan, Tuomanen, Elaine I.
• Format: Article
• Language: English
• Subjects: Alleles; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antibiotics; Archives; Bacteria; Bacteriology; Biological and medical sciences; Carrier State - microbiology; Child; Disease resistance; Drug Resistance - genetics; Female; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetic Markers; Haemophilus meningitis; Humans; Infectious diseases; Male; Medical sciences; Meningitis - drug therapy; Meningitis - microbiology; Meningitis - mortality; Microbiology; Miscellaneous; N-Acetylmuramoyl-L-alanine Amidase - genetics; Nasopharynx - microbiology; Penicillin; Pneumococcal meningitis; Polymorphism, Single Nucleotide; Protein Kinases - genetics; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - isolation & purification; Survival Analysis; Vancomycin - pharmacology; Vancomycin - therapeutic use
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/424467

Background. Vancomycin is often added to therapy for meningitis caused by Streptococcus pneumoniae. Tolerant bacteria without classic resistance that escape killing by multiple antibiotics have been reported sporadically. We determined the prevalence of tolerance to vancomycin in pneumococci and its effect on the outcome of meningitis. Methods. Archival samples of 215 nasopharyngeal (NP) and 113 meningitis isolates were tested for the killing efficacy of vancomycin. Specific DNA sequence changes in a transporter locus were identified for tolerant isolates. Similar tests were conducted prospectively on 517 NP isolates from healthy children. Results. In archival isolates, tolerance to vancomycin was detected in 3.7% of NP and 10.6% of invasive isolates. Patients with meningitis caused by tolerant isolates had a worse estimated 30-day survival than did patients with meningitis caused by nontolerant isolates (49% vs. 86%; P = .048); 62.5% of tolerant archival NP isolates harbored a specific sequence change for pep27 and vex2 (P = .021). Prospective analysis of 517 carriage isolates indicated that 8.1% were tolerant to vancomycin and that 82.1% of tolerant isolates harbored the specified marker gene sequences (P = .001). Conclusions. Tolerance to vancomycin exists in the population of pneumococci. Tolerant isolates are associated with meningitis of increased mortality, and these isolates can be tracked by specific marker sequences in 2 genes.