Genotyping of methicillin-resistant Staphylococcus aureus isolates obtained in the Northeast region of Brazil.
Methicillin-resistant Staphylococcus aureus (MRSA) is a major agent of hospital infections worldwide. In Brazil, a multiresistant MRSA lineage (ST239-SCCmecIIIA), the so-called Brazilian epidemic clone (BEC), has predominated in all regions. However, an increase in nosocomial infections caused by non-multiresistant MRSA clones has recently been observed. In the present study, 45 clinical isolates of MRSA obtained from a university hospital located in Natal city, Brazil, were identified by standard laboratory methods and molecularly characterized using staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was carried out using CLSI methods. The MRSA isolates studied displayed a total of 8 different pulsed-field gel electrophoresis patterns (types A to H) with predominance (73%) of pattern A (BEC-related). However, MRSA harboring SCCmec type IV were also identified, 3 (7%) of which were genetically related to the pediatric clone--USA800 (ST5-SCCmecIV). In addition, we found a considerable genetic diversity within BEC isolates. MRSA displaying SCCmecIV are frequently susceptible to the majority of non-beta-lactam antibiotics. However, emergence of multiresistant variants of USA800 was detected.
Departamento de Microbiologia e Parasitologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brasil.
F C de
FC
Sousa-Junior
M C
MC
Silva-Carvalho
M J B C
MJ
Fernandes
M F P
MF
Vieira
F L P C
FL
Pellegrino
A M S
AM
Figueiredo
M C N
MC
de Melo
E P
EP
Milan
D000900:Anti-Bacterial Agents; D015373:Bacterial Typing Techniques; D001938:Brazil; D004269:DNA, Bacterial / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006785:Hospitals, University; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial