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Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina
Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina
- Source :
- Annals of Clinical Microbiology and Antimicrobials, Repisalud, Instituto de Salud Carlos III (ISCIII), Annals of Clinical Microbiology and Antimicrobials, Vol 10, Iss 1, p 15 (2011)
- Publication Year :
- 2011
- Publisher :
- BioMed Central (BMC), 2011.
-
Abstract
- BACKGROUND: Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA) has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE) due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA) has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. CASE PRESENTATION: We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2) was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1) was fully vancomycin susceptible (VSSA). Although MRSA SaB2 was vancomycin susceptible (≤ 2 μg/ml) by MIC (agar and broth dilution, E-test and VITEK 2), a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET) and by GRD E-test] and confirmed by population analysis profile-(PAP). In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL) genes and had indistinguishable PFGE patterns (subtype I2), thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I) detected in our country. CONCLUSIONS: This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to produce severe and rapidly fatal infections such as IE, in addition to its ability to acquire low-level vancomycin resistance; for these reasons, it constitutes a new challenge for the Healthcare System of this country. This study was supported by the National Council for Scientific Research and Technology of Argentina (CONICET), Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT - PICT 01630 to JLB), Secretaría de Ciencia y Técnica-Universidad Nacional de Córdoba (SECyT-UNC) and Agencia Córdoba Ciencia. Sí
- Subjects :
- Microbiology (medical)
Methicillin-Resistant Staphylococcus aureus
Population
lcsh:QR1-502
Argentina
Case Report
Biology
medicine.disease_cause
Staphylococcal infections
lcsh:Microbiology
lcsh:Infectious and parasitic diseases
Microbiology
Bacterial Proteins
Vancomycin
medicine
Humans
lcsh:RC109-216
education
Epidemics
Aged
education.field_of_study
Teicoplanin
SCCmec
lcsh:RM1-950
Vancomycin Resistance
General Medicine
Endocarditis, Bacterial
biochemical phenomena, metabolism, and nutrition
Staphylococcal Infections
medicine.disease
bacterial infections and mycoses
Virology
Methicillin-resistant Staphylococcus aureus
Anti-Bacterial Agents
lcsh:Therapeutics. Pharmacology
Infectious Diseases
Infective endocarditis
Female
Daptomycin
medicine.drug
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Annals of Clinical Microbiology and Antimicrobials, Repisalud, Instituto de Salud Carlos III (ISCIII), Annals of Clinical Microbiology and Antimicrobials, Vol 10, Iss 1, p 15 (2011)
- Accession number :
- edsair.doi.dedup.....496f7cf3acf36eb201bad7560814a09d