Molecular characterization of methicillin-resistant Staphylococcus aureus isolates collected in Asunción, Paraguay

Abstract

We characterized 34 methicillin-resistant Staphylococcus aureus strains isolated in Paraguay in 2005. The strains belonged to two clones. The major clone (sequence type 5 [ST5] or ST221, spa type t149, staphylococcal cassette chromosome mec [SCCmec] type I) was similar to the Cordobes/Chilean clone spreading through South America, and the minor clone (ST239 or ST889, spa type t037, SCCmec type IIIA) was related to the Brazilian clone.

FIG. 1.

Dendrogram constructed from the schematic representation of the PFGE types of MRSA isolates included in this study together with their characteristics, such as drug resistance, CC, ST, spa type, SCCmec type, PFGE pattern, PFGE type, agr allele group, and toxin gene content. Drug resistance is indicated as follows: KTG, resistance to kanamycin, tobramycin, and gentamicin; OFX, ofloxacin; RIF, rifampin; TEL, tetracycline; ERY, erythromycin; LIN, lincomycin; FF, fosfomycin; and SXT, cotrimoxazole. The presence (+) or absence (−) of toxin genes egc (enterotoxin gene cluster), hlgv (gamma-hemolysin variant genes), lukED (leukocidin lukE and lukD genes), and hlb (beta-hemolysin gene) is shown. The other toxin genes were negative for all the strains (sea to see and seh, staphylococcal enterotoxin genes type A to E and H; hlg, gamma-hemolysin gene; lukSF-PV, Panton-Valentine leukocidin genes; eta and etb, exfoliatin toxin genes type A and B; and tst, toxin shock syndrome toxin 1 gene). CCs were assigned according to the MLST database (http://www.mlst.net). For the PFGE types, AS stands for Asunción, Paraguay. nd, not determined.