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Published on: February 23, 2014
Evolution of macrolide resistance in Streptococcus pneumoniae clinical isolates in the prevaccine era
George L Daikos1, Anastasia Koutsolioutsou, Sotirios Tsiodras
1First Department of Propaedeutic Medicine, University of Athens, 11527 Athens, Greece.
Abstract:
Six hundred twelve invasive and noninvasive Streptococcus pneumoniae isolates were examined. Serogrouping was performed by the latex agglutination test and serotyping by the quellung reaction. Susceptibilities to macrolides were determined by Etest. The presence of mef(A), mef(E), and erm(B) genes were detected by polymerase chain reaction. Outpatient macrolide and lincosamide consumption was expressed in defined daily doses per 1000 inhabitants daily (DID). A significant increase in macrolide resistance rate was noted from 7.4% (14/190) in the period 1985 to 1996 to 53.7% (144/268) in 2001 to 2004 (P = 0.003). An increase in macrolide and lincosamide consumption was also observed from 4.31 +/- 0.72 in 1990 to 1996 to 6.97 +/- 1.02 DID in 2001 to 2004 (P = 0.002). Macrolide resistance was mediated by mef(E) gene in 44.5% of isolates, mef(A) in 25.6%, erm(B) in 19.8%, both erm(B) and mef(E) genes in 4.8%, and none of the examined genes in 5.3%. In the setting of increasing macrolide use, there has been a parallel increase in macrolide resistance among pneumococci in our region. The predominant resistance determinants were the mef(A) and mef(E) genes.
Insights
Macrolide resistance in Streptococcus pneumoniae has significantly increased due to rising antibiotic use. The mef(A) and mef(E) genes are the primary drivers of this growing macrolide resistance in pneumococci.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Streptococcus pneumoniae is a leading cause of bacterial infections.
- Macrolide antibiotics are commonly used to treat pneumococcal infections.
- Increasing antimicrobial resistance poses a significant public health threat.
Purpose of the Study:
- To investigate the trend of macrolide resistance in Streptococcus pneumoniae.
- To correlate macrolide resistance rates with antibiotic consumption.
- To identify the genetic mechanisms underlying macrolide resistance.
Main Methods:
- Analysis of 612 invasive and noninvasive Streptococcus pneumoniae isolates.
- Serogrouping using latex agglutination and serotyping by quellung reaction.
- Macrolide susceptibility testing via Etest.
- Detection of resistance genes (mef(A), mef(E), erm(B)) using polymerase chain reaction.
- Quantification of macrolide and lincosamide consumption (DID).
Main Results:
- Macrolide resistance rate increased from 7.4% (1985-1996) to 53.7% (2001-2004).
- Antibiotic consumption (DID) also rose significantly during the study period.
- mef(E) (44.5%) and mef(A) (25.6%) were the predominant resistance genes identified.
Conclusions:
- Increasing macrolide use is paralleled by a significant rise in macrolide resistance in pneumococci.
- The mef(A) and mef(E) genes are the main determinants of macrolide resistance in this region.
- Monitoring antibiotic consumption and resistance patterns is crucial for effective treatment strategies.
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