High clonal diversity in erythromycin-resistant Streptococcus pneumoniae invasive isolates in Madrid, Spain (2000-07).
J Antimicrob Chemother
; 64(6): 1165-9, 2009 Dec.
Article
em En
| MEDLINE
| ID: mdl-19837717
ABSTRACT
OBJECTIVES:
Erythromycin resistance in Streptococcus pneumoniae is still increasing worldwide. All 78 erythromycin-resistant S. pneumoniae isolates collected from blood cultures in our hospital (2000-07) were studied and the population structure was analysed by using different mathematical diversity indexes.METHODS:
Erythromycin resistance determinants were screened by PCR. The population structure, including multilocus sequence typing, was analysed by using quantitative clonal diversity (diversity ratio, Simpson, Selander-Levin and Shannon mathematical indexes).RESULTS:
The leading resistance gene was erm(B) (74.3% of the isolates), followed by the erm(B) plus mef(A) combination (17.9%) and mef(A) alone (7.7%). The most frequent serotypes were 14 (18%), 19A (15.4%) and 6B (11.5%). A polyclonal structure was detected in resistant strains, including the Spain(9V)-3, Spain(6B)-2 and Denmark(14)-32 international clones. Both genetic diversity and genetic distribution were high, particularly among clones containing erm(B) and erm(B) plus mef(A) determinants.CONCLUSIONS:
The resistance determinants erm(B) and the combination of erm(B) plus mef(A) were observed within multiple S. pneumoniae bacteraemic clones. The preservation of a polyclonal structure might provide a suitable background for further evolution of antibiotic resistance.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Infecções Pneumocócicas
/
Streptococcus pneumoniae
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Variação Genética
/
Eritromicina
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Farmacorresistência Bacteriana
/
Antibacterianos
Limite:
Adult
/
Humans
País como assunto:
Europa
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article