title: Linezolid-resistant Staphylococcus haemolyticus and Staphylococcus hominis: single and double mutations at the domain V of 23S rRNA among isolates from a Rio de Janeiro hospital.
abstract: In this work, the molecular and phenotypic antimicrobial resistance and clonal diversity of 10 linezolid-resistant Staphylococcus spp. isolates were investigated. The 7 Staphylococcus haemolyticus isolates presented Staphylococcal cassete chromosome mec (SCCmec) V and belonged to the same pulsed-field gel electrophoresis pulsotype. Their MICs for oxacillin, vancomycin, and linezolid were ≥ 256 μg/mL, 1-4 μg/mL, and 8-16 μg/mL, respectively. The 3 S. hominis presented MIC values 32 to >256 μg/mL, 2-4 μg/mL, and 12-24 μg/mL, and all carried the nontypeable SCCmec (ccr1 + mecA class) and belonged to 2 different genotypes. The cfr gene was not found, but the mutation G2603T was detected in S. haemolyticus and C2190T and G2603T in Staphylococcus hominis in 23S rRNA. This study demonstrates the spread of a linezolid-resistant S. haemolyticus genotype and, for the first time, describes the mutation C2190T among S. hominis isolates with a double mutation in Brazil.
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Raiane Cardoso
authors.initials: RC
authors.lastname: Chamon
authors.affiliation: Universidade Federal Fluminense, Rio de Janeiro, Brazil.
authors.forename: Natalia Lopes Pontes
authors.initials: NL
authors.lastname: Iorio
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Fernanda Sampaio
authors.initials: FS
authors.lastname: Cavalcante
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Cristiane R S
authors.initials: CR
authors.lastname: Teodoro
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Ana Paula Chaves
authors.initials: AP
authors.lastname: de Oliveira
authors.affiliation: Hospital Naval Marcilio Dias, Rio de Janeiro, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Maia
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: santoskrn@micro.ufrj.br.
authors.forename: Kátia Regina Netto
authors.initials: KR
authors.lastname: dos Santos
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D006761:Hospitals; D006801:Humans; D000069349:Linezolid; D008826:Microbial Sensitivity Tests; D009154:Mutation; D023303:Oxazolidinones / Q000494:pharmacology*; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D013203:Staphylococcal Infections / Q000382:microbiology; D041162:Staphylococcus haemolyticus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D041181:Staphylococcus hominis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D012338:RNA, Ribosomal, 23S; D000069349:Linezolid
keywords: 23S rRNA gene mutation; Linezolid resistance; S. haemolyticus; S. hominis