|278-1||IDENTIFICATION OF HEALTHCARE ASSOCIATED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS “CORDOBES/CHILEAN CLONE” IN SOUTHERN CHILE.|
|Autores:||Gustavo Medina (UACH - Instituto Microbiologia Clinica Universidad Austral de Chile) ; Carola Otth (UACH - Instituto Microbiologia Clinica Universidad Austral de Chile) ; Laura Otth (UACH - Instituto Microbiologia Clinica Universidad Austral de Chile) ; Heriberto Fernandez (UACH - Instituto Microbiologia Clinica Universidad Austral de Chile) ; Myra Wilson (UACH - Instituto Microbiologia Clinica Universidad Austral de Chile) |
Methicillin-resistant Staphylococcus aureus (MRSA) clones have emerged as a cause of global public health concern. Several major pandemic MRSA clones have been identified around the world, but molecular epidemiology of MRSA in Latin America is largely unknown.
In order to evaluate the molecular epidemiology of nosocomial infections caused by MRSA at the County Hospital of Osorno (Southern Chile), representative sample of 32 clinical isolates of healthcare-associated MRSA were analyzed by SCCmec type detection, spa typing and PFGE.
The presence of SCCmec I was detected in 50% of the isolates and SCCmec IV in the remaining 50%. The spa sequencing analysis allowed to classify all the isolates like spa type t149 (repeated succession r26r30r17r13r17r20r17r12r17r12r17r16). PFGE allowed to classify the isolates into 4 pulsotypes defined as pulsotypes A (7/32), B (8/32), C (9/32) and D (8/32). The percentages of similarity for isolates clustered in pulsotypes A, B, C and D were 70.5%, 71.2%, 72.5% and 78.6% respectively. Since the isolates were not collected during an outbreak, these percentages of similarity could be explained because the isolates were collected over a period of 6 months, thus considered a "prolonged endemic situation", during which it would be expected to find a relative genetic variability. Importantly, we detected a 92.3% similarity between one isolate from pulsotype A with the Cordobes/Chilean Clone, previously detected in northern Chile, Argentina, Colombia and Paraguay.
According to PFGE, spa typing and SCCmec type detection, we can infer that MRSA circulating strains at the County Hospital of Osorno belong to the Cordobes/Chilean clone (MRSA t149 – SCCmec I). In addition, SCCmec IV isolates could belong to a variant of the Cordobes/Chilean clone, situation that must be confirmed by MLST.
Funding: DID S-2010-02-UACh
Palavras-chave: MRSA, PFGE, spa type