Fusidic Acid Resistance Determinants in Staphylococcus aureus Clinical Isolates

• DOI: 10.1128/aac.00523-10
• Publication Date: 2010-09-21T04:51:28Z
• Authors: Hsiao-Jan Chen; Wei-Chun Hung; Sung-Pin Tseng; Jui-Chang Tsai; Po-Ren Hsueh; Lee-Jene Teng
• Keywords: Fusidic acid; SCCmec

A total of 71 fusidic acid-resistant Staphylococcus aureus (45 methicillin-resistant and 26 methicillin-susceptible) isolates were examined for the presence resistance determinants. Among 45 S. (MRSA), isolates, 38 (84%) had fusA mutations conferring high-level to acid (the MIC was ≥128 μg/ml 22/38), none fusB, 7 (16%) fusC. For methicillin-susceptible (MSSA), only 3 possessed mutations, but 15 (58%) fusB 8 (31%) Low-level (MICs ≤ 32 μg/ml) found in most fusB- or fusC-positive isolates. 41 (38 MRSA MSSA), with a 21 amino substitutions EF-G (fusA gene) detected, which R76C, E444K, E444V, C473S, P478S, M651I identified first time. The nucleotide sequencing flanking regions an MSSA isolate revealed structure partial IS257-aj1-LP-fusB-aj2-aj3-IS257-partial blaZ, is identical corresponding region pUB101, rest fusB-carrying also show similar structures. On basis spa staphylococcal cassette chromosome mec element (SCCmec) typing, two major genotypes, type t037-SCCmec III (t037-III; 28/45; 62%) t002-II (13/45; 29%), predominant among By pulsed-field gel electrophoresis analysis, divided into 12 clusters, while clusters. Taken together, distribution determinants fusC) quite different between groups.