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Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Fluoroquinolone-resistant Streptococcus agalactiae isolates from Argentina.
D Faccone1, L Guerriero, E Méndez
1Senrvicio Antimicrobianos, INEI-ANLIS Dr. Carlos G. Malbran, Ciudad Autónoma de Buenos Aires, Argentina.
Revista Argentina De Microbiologia
|December 25, 2010
Summary
Fluoroquinolone resistance in Streptococcus agalactiae is emerging. This study identified the first fluoroquinolone-resistant S. agalactiae in Latin America, with specific genetic mutations and clonal types found.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Fluoroquinolone resistance is a growing global health concern.
- Emergence of resistance in Streptococcus agalactiae (Group B Streptococcus) is a recent phenomenon.
- Surveillance of antimicrobial susceptibility is crucial for public health.
Purpose of the Study:
- To investigate the prevalence and characteristics of fluoroquinolone resistance in clinical isolates of S. agalactiae in Argentina.
- To identify the genetic basis and molecular epidemiology of fluoroquinolone-resistant S. agalactiae.
Main Methods:
- Levofloxacin susceptibility testing was performed on 1128 clinical S. agalactiae isolates collected between 2005-2007.
- Resistant isolates were further analyzed for specific mutations in ParC and GyrA proteins.
- Genetic relatedness was assessed using ApaI-PFGE.
Main Results:
- Ten (0.9%) S. agalactiae isolates exhibited resistance to levofloxacin.
- Nine resistant isolates were identified from hospitals in Buenos Aires and four Argentinean provinces, primarily from urine and vaginal samples.
- All nine fluoroquinolone-resistant isolates shared identical mutations (Ser79Phe in ParC, Ser81Leu in GyrA) and belonged to two distinct clones (A and B).
- Three strains also displayed co-resistance to macrolides, lincosamides, and streptogramins B, mediated by the ermA gene.
Conclusions:
- This study reports the first detection of fluoroquinolone-resistant S. agalactiae in Latin America.
- The identified mutations and clonal types provide insight into the emergence and spread of resistance.
- Continued surveillance is necessary to monitor fluoroquinolone resistance trends in S. agalactiae.
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