Related Experiment Videos
A multi-centre study of nosocomial methicillin-resistant Staphylococcus aureus in Greece. Greek MRSA Study Group
M Kantzanou1, P T Tassios, A Tseleni-Kotsovili
1Department of Microbiology, Medical School, University of Athens, Greece.
Abstract:
All 105 non-replicate consecutive Staphylococcus aureus strains isolated in 1997 from seven Greek hospitals, were found to be susceptible to vancomycin, teicoplanin and chloramphenicol, but only five (8%) were susceptible to all 16 antibiotics tested. Forty-three (41%) isolates were methicillin-resistant, 58% homogeneously (homMRSA) and 42% heterogeneously (hetMRSA). Resistance of homMRSA strains to other antibiotics was generally high (88-100%), although only one strain was resistant to netilmicin. Resistance in hetMRSA (6-39%) or in MSSA (5-11%) was significantly lower. Consequently, the majority (76%) of homMRSA were multi-drug resistant, while the dominant phenotype of hetMRSA and MSSA was resistance to penicillin (50% and 76%, respectively). Comparison of these strains with isolates from 1994 showed higher resistance rates to erythromycin among MSSA, to erythromycin and amikacin among hetMRSA and to rifampicin among homMRSA strains.
Insights
In 1997, Greek Staphylococcus aureus strains showed high vancomycin susceptibility but low overall antibiotic susceptibility. Methicillin-resistant Staphylococcus aureus (MRSA) strains, particularly homogeneous MRSA, exhibited significant multi-drug resistance.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Staphylococcus aureus is a significant human pathogen.
- Antimicrobial resistance in S. aureus is a growing global health concern.
- Understanding resistance patterns is crucial for effective treatment strategies.
Purpose of the Study:
- To assess the antibiotic susceptibility patterns of Staphylococcus aureus strains isolated in Greece in 1997.
- To characterize methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) isolates.
- To compare current resistance trends with historical data from 1994.
Main Methods:
- Analysis of 105 non-replicate consecutive Staphylococcus aureus isolates from seven Greek hospitals in 1997.
- Phenotypic testing of susceptibility to 16 different antibiotics.
- Classification of MRSA into homogeneous (homMRSA) and heterogeneous (hetMRSA) types.
Main Results:
- All strains were susceptible to vancomycin, teicoplanin, and chloramphenicol.
- Only 8% of isolates were susceptible to all 16 tested antibiotics.
- 41% of isolates were MRSA (58% homMRSA, 42% hetMRSA).
- HomMRSA showed high resistance to most antibiotics (88-100%), with 76% being multi-drug resistant.
- Resistance rates in hetMRSA (6-39%) and MSSA (5-11%) were significantly lower.
- Increased resistance rates observed compared to 1994 for erythromycin (MSSA, hetMRSA), amikacin (hetMRSA), and rifampicin (homMRSA).
Conclusions:
- Vancomycin remains a reliable treatment option for S. aureus infections in this Greek cohort.
- High rates of multi-drug resistance, particularly in homMRSA, pose a significant challenge.
- Emergence of increased resistance to certain antibiotics highlights the dynamic nature of antimicrobial resistance patterns.