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Updated: Dec 21, 2025
Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
Published on: September 5, 2013
First Report on the Characteristics of Methicillin-Resistant Staphylococcus Capitis Isolates and an NRCS-A-clone
Parisa Asadollahi1, Behrooz Farzan2, Faranak Rezaei3
1Department of Microbiology, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
Background:
Methicillin-resistant staphylococcus capitis (MRSC) NRCS-A clone (Multi- resistant and vancomycin-non susceptible) has been recently described as an emerging cause of nosocomial bacteremia, especially in neonatal intensive-care units (NICUs).
Objective:
The objective of this study was to evaluate the antibiotic and antiseptic resistance patterns, biofilm-producing ability and the prevalence of SCCmec and ACME types among MRSC isolates as well as to check the possible presence of NRCS-A clone at Tehran's Children's Medical Center, Iran.
Methods:
A total of 256 coagulase-negative Staphylococcal isolates were collected, of which 10 S. capitis isolates were obtained and tested for susceptibility against 13 antimicrobial and 3 antiseptic agents, as well as biofilm production. The presence of 15 distinct resistance genes, staphylococcal cassette chromosome mec (SCCmec), and arginine catabolic mobile elements (ACMEs) were tracked.
Results:
Seven out of 10 S. capitis isolates were MRSC (MIC90 van=8μg/mL) and resistant to trimethoprim/sulfamethoxazole, produced biofilm, (3 as strong biofilm producers) and carried ACME types I and II. Despite the identification of mec and ccr complexes in some isolates, all the SCCmec cassettes were untypeable (UT).
Conclusion:
According to the studied features, only one isolate belonged to the NRSC-A clone. The results indicate that MRSC with high antibiotic resistance and unknown SCCmec might become a serious problem in the future for the treatment of patients, particularly children.
Insights
Methicillin-resistant Staphylococcus capitis (MRSC) is an emerging threat in NICUs. This study found MRSC isolates with high antibiotic resistance and unknown SCCmec, indicating a potential future challenge for pediatric patient treatment.
Area of Science:
- Clinical Microbiology
- Infectious Diseases
- Bacterial Genetics
Background:
- Methicillin-resistant Staphylococcus capitis (MRSC) NRCS-A clone is an emerging cause of nosocomial bacteremia, particularly in neonatal intensive-care units (NICUs).
- Understanding the resistance mechanisms and genetic elements of MRSC is crucial for effective treatment strategies.
Purpose of the Study:
- To evaluate antibiotic and antiseptic resistance patterns of MRSC isolates.
- To assess biofilm production and the prevalence of staphylococcal cassette chromosome mec (SCCmec) and arginine catabolic mobile elements (ACME) types.
- To identify the NRCS-A clone in MRSC isolates at Tehran's Children's Medical Center, Iran.
Main Methods:
- Analysis of 10 Staphylococcus capitis isolates for susceptibility to 13 antimicrobial and 3 antiseptic agents.
- Assessment of biofilm production capabilities.
- Detection of 15 resistance genes, SCCmec, and ACME types using molecular methods.
Main Results:
- Seven of 10 S. capitis isolates were identified as MRSC, exhibiting resistance to trimethoprim/sulfamethoxazole and producing biofilm.
- ACME types I and II were identified in MRSC isolates; however, all SCCmec cassettes were untypeable (UT).
- Only one isolate was confirmed to belong to the NRCS-A clone.
Conclusions:
- The study identified MRSC isolates with significant antibiotic resistance and uncharacterized SCCmec elements.
- The prevalence of MRSC with high resistance and unknown SCCmec poses a potential future challenge for treating pediatric infections.
- Further research is needed to understand the implications of untypeable SCCmec in MRSC infections.
