Molecular characterization of methicillin-resistantStaphylococcus aureusresistant to tigecycline and daptomycin isolated in a hospital in Brazil

Abstract

SUMMARYWe report the molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) with resistance to tigecycline and to daptomycin isolated from intensive-care-unit patients in Brazil over a 6-month period. Thirty-six isolates (25 from infection sites, 11 from nasal sites) recovered from 23 patients who presented with MRSA infection during this period were characterized by pulsed-field gel electrophoresis, multilocus sequence typing, staphylococcal cassette chromosome mec (SCCmec) typing, and antimicrobial susceptibility profiling. Ten isolates from six patients and two isolates from different patients were resistant to tigecycline and daptomycin, respectively. Eight pulsotypes were identified and one, type A, accounted for 21 isolates from 12 patients; type A isolates were SCCmecII as were a further nine isolates of other pulsotypes. All but four of the total isolates were sequence type (ST) 5 or ST105 and classified as clonal complex (CC) 5; the historically prevalent lineage in Brazil, ST239-SCCmecIII, was identified in only three patients. Tigecycline-resistant strains were all ST105-SCCmecII and two patients were nasally colonized by strains of the same pulsotype found in infection sites. Two ST5-SCCmecII were daptomycin resistant after 48 h incubation. The origin and mechanism of these resistant strains remains unknown and further studies are warranted to determine whether such clones are becoming endemic in Brazilian hospitals and to assess their impact on infection control practice.

In Vitro Activity of Ceftaroline against Staphylococcus aureus Isolates Collected in 2012 from Latin American Countries as Part of the AWARE Surveillance Program

“…All isolates, except for one with a ceftaroline MIC of 2 g/ml, showed the sequence type ST-5. This sequence type, ST-5, was similar to that in a study among S. aureus isolates from Brazil that were resistant to tigecycline and daptomycin (36). A possible relationship with this sequence type and increased resistance to these drug classes would require more extensive typing and analysis.…”

Daptomycin and methicillin-resistant Staphylococcus aureus isolated from a catheter-related bloodstream infection: a case report

“…Only one was recovered in Latin American. However, Dabul & Camargo [4] recently reported two daptomycin-resistant S. aureus isolates in Brazil, collected from a catheter tip and a leg abscess in different patients. Both the isolates were methicillin-resistant and belonged to the SCC mec II/USA100/ST5 lineage, the same profile found in this study.…”

“…In Brazil, there is only one report describing two isolates of daptomycin-resistant S. aureus ; however no information was given concerning the clinical conditions of the patients [4]. This study reports the case of a daptomycin-resistant MRSA isolate recovered from the blood of a Brazilian patient undergoing hemodialysis, also the susceptibility profile and molecular characteristics of the isolate are described.…”

Multidrug-ResistantStaphylococcus aureus, India, 2013–2015

“…Most linezolid-resistant S. aureus has been isolated from patients in North America and Europe ( 8 ). The tigecycline-resistant S. aureus isolate (MIC >0.5 mg/L) reported from Brazil was also susceptible to linezolid, teicoplanin, and vancomycin ( 9 ). …”