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Updated: Jan 1, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
[Inducible resistance to clindamycin in methicillin-resistant Staphylococcus aureus isolated from Paraguayan
Marlene Silvagni1, Rosa Guillén2, Fátima Rodríguez2
1Laboratorio de Microbiología y Servicio de Pediatría, Hospital Central-Instituto de Previsión Social, Paraguay.
Background:
The double disc diffusion method is an alternative diagnostic that allows the identification of Staphylococcus aureus isolates apparently susceptible to clindamycin but that may develop resistance due to an induction phenomena, mainly asociated to the increase in resistance to methicillin, thus increasing the possibility of failure in the treatment.
Aim:
To determine the frequency of induced clindamycin resistance in methicillin-resistant S. aureus (MRSA) isolated from Paraguayan children.
Materials And Methods:
In this cross sectional study, we collected 145 S. aureus isolates that caused skin and soft tissue and osteoarticular infections in pediatric patients of the Central Hospital I.P.S. in the period from December-2012 to November-2013. Resistance to clindamycin was determined by automated methods and double disc diffusion. PCR was performed for ermA, ermB, ermC and msrA genes from representative isolates.
Results:
The global resistance to methicillin and clindamycin was 67 and 13%, respectively (11% attributable to the inducible mechanism). The ermC and msrA genes were detected individually in 25 and 17% of the isolates respectively while an isolate presented both genes simultaneously.
Discussion:
The frequency of inducible resistance to clindamycin indicates the importance of double disc diffusion methods in microbiological practice, as well as being within the cut off points considered acceptable for the use of this antibiotic for skin infections. and osteoarticular caused by MRSA.
Insights
Induced clindamycin resistance in methicillin-resistant Staphylococcus aureus (MRSA) was investigated in Paraguayan children. The double disc diffusion method is crucial for identifying this resistance, which can lead to treatment failure.
Area of Science:
- Microbiology
- Infectious Diseases
- Clinical Diagnostics
Background:
- Clindamycin susceptibility in Staphylococcus aureus can mask inducible resistance.
- This inducible resistance, often linked to methicillin resistance, can cause treatment failure.
- The double disc diffusion method aids in detecting this inducible resistance.
Purpose of the Study:
- To determine the frequency of induced clindamycin resistance in methicillin-resistant S. aureus (MRSA) from Paraguayan children.
- To assess the clinical implications of inducible clindamycin resistance in pediatric MRSA infections.
Main Methods:
- A cross-sectional study of 145 S. aureus isolates from pediatric skin, soft tissue, and osteoarticular infections.
- Clindamycin resistance was evaluated using automated methods and double disc diffusion.
- PCR analysis identified ermA, ermB, ermC, and msrA genes in representative isolates.
Main Results:
- Global resistance to methicillin was 67%, and to clindamycin was 13%.
- Approximately 11% of clindamycin resistance was attributed to inducible mechanisms.
- The ermC and msrA genes were detected in 25% and 17% of isolates, respectively.
Conclusions:
- The prevalence of inducible clindamycin resistance underscores the importance of the double disc diffusion method in routine diagnostics.
- Inducible clindamycin resistance in MRSA isolates was found within acceptable limits for antibiotic use in pediatric skin and osteoarticular infections.
- Continued surveillance of antibiotic resistance mechanisms in S. aureus is essential for effective treatment strategies.
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