Genomic analysis of penicillin-resistant Streptococcus pneumoniae in Southeastern Michigan - 24/08/11
Abstract |
Objective. The emergence of multidrug resistance within Streptococcus pneumoniae population was analysed, correlating penicillin resistance Pen(R) with secondary antibiotic resistance, capsular serotype, and genetic diversity among isolates.
Methods. DNA fingerprinting, following macro-restriction enzyme digestion and pulse field gel electrophoresis (PFGE), and restriction fragment analysis of the PBP 2b gene, following PCR amplification, were performed on the Pen(R) S. pneumoniae, among 377 clinical isolates obtained from the clinical microbiology laboratory (University of Michigan Medical Center).
Results. Overall 35% of the isolates were Pen(R) of which 45% demonstrated high-level penicillin (Pen(R)-R, MIC>1). Respiratory isolates were more likely to be Pen(R) (p<0.001) than non-respiratory isolates and the rate of Pen(R)-R was significantly increased in children <10 years of age (59.6%, p<0.02). Secondary antibiotic resistance was more frequently associated with Pen(R)-R. Genomic DNA fingerprinting analysis and restriction fragment analysis of the PBP 2b gene demonstrated genomic divergence with discrete conserved pattern in the PBP 2b gene among the resistant isolates.
Conclusion. The emergence of multidrug resistance in the S. pneumoniae population in SE Michigan is not due to expansion of a single or limited number of resistant clones, is occurring most frequently in the paediatric population and is associated with a decreased susceptibility to penicillin.
Le texte complet de cet article est disponible en PDF.Keywords : Penicillin-resistant Streptococcus pneumoniae, Penicillin resistance Pen(R), TRIS–HCl
Abbreviations : CEFU, cefuroxime, CEFO, cefotaxime, CEFT, ceftriaxone, DTT, dithiothreitol, DOX, doxycycline, EES, erythromycin, MIC, minimal inhibitory concentration, PBP, penicillin binding protein, Pen(S), penicillin sensitive Streptococcus pneumoniae, Pen(R), penicillin resistant Streptococcus pneumoniae, Pen(R)-R, penicillin resistant Streptococcus pneumoniae with MIC greater than 2.0 μg/ml, high level penicillin resistance, Pen(R)-I, penicillin resistant Streptococcus pneumoniae with MIC greater than 0.12–1.0 μg/ml, intermediate level penicillin resistance, PETT, IV, 10 mM TRIS–HCl, pH 7.6 containing 1 M NaCl, PFGE, pulse field gel electrophoresis, RIF, rifampin, S. pneumoniae, Streptococcus pneumoniae, TMP/SMX, trimethaprim/sulfamethoxazole, VAN, vancomycin
Plan
Vol 49 - N° 2
P. 126-135 - août 2004 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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