Emergence of vancomycin resistance during therapy against methicillin-resistant Staphylococcus aureus in a burn patient—importance of low-level resistance to vancomycin
| Autor: | Shigeru Fukamachi, Keiichi Hiramatsu, Isao Haraga, Hideaki Hanaki, Ariaki Nagayama, Shuichi Nomura, Hiroyuki Ohjimi |
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| Rok vydání: | 2002 |
| Předmět: |
Male
Microbiology (medical) Staphylococcus aureus Micrococcaceae Genotype medicine.drug_class Antibiotics Population Microbial Sensitivity Tests medicine.disease_cause Microbiology Vancomycin medicine Humans education Antibacterial agent education.field_of_study biology business.industry Vancomycin Resistance General Medicine Staphylococcal Infections biochemical phenomena metabolism and nutrition biology.organism_classification Methicillin-resistant Staphylococcus aureus Glycopeptide Anti-Bacterial Agents Culture Media Phenotype Treatment Outcome Infectious Diseases Child Preschool Wound Infection Methicillin Resistance business medicine.drug |
| Zdroj: | International Journal of Infectious Diseases. 6(4):302-308 |
| ISSN: | 1201-9712 |
| DOI: | 10.1016/s1201-9712(02)90165-7 |
| Popis: | Objectives: Staphylococcus aureus with low-level resistance to vancomycin (VLSA) which could develop into vancomycin-resistant S. aureus (VRSA) is most important. However, VLSA is difficult to detect by standard laboratory methods. We describe here improved methods to detect VLSA. Methods: Three methicillin-resistant S. aureus (MRSA) strains, designated Fu6, Fu10, and Fu18, were sequentially isolated from the burn wound site of a patient, during vancomycin therapy. The properties of these strains were compared with those of reference strains Mu3 and Mu50 (previous resistant isolates from other patients). Results: The isolated strains, Fu10 and Fu18, had identical phenotypes and genotypes. The vancomycin resistance of Fu10 was equivalent to that of strain Mu3, whereas Fu18 had much higher vancomycin resistance than Fu10 and Mu3, although reaching the level of Mu50. Fu18 showed similar growth to Mu50 on gradient gels and on Mu3 medium. Conclusions: Our data indicate that the VLSA developed vancomycin resistance during exposure to vancomycin in vivo. The population analysis of tested VLSA and vancomycin intermediately resistant S. aureus (VISA) indicates that a penem at relatively low concentrations induced a significant increase in the number of vancomycin-resistant subpopulations. Furthermore, we confirmed that gradient gel analysis and Mu3 medium are simple and useful methods for the detection of VLSA judged as VSSA by its conventional MIC alone. |
| Databáze: | OpenAIRE |
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