Antimicrobial synergism against different lineages of methicillin-resistant Staphylococcus aureus carrying SCCmec IV
Article first published online: 11 MAR 2014
© 2014 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 116, Issue 6, pages 1418–1426, June 2014
How to Cite
de Matos, P.D.M., Sedaca, S., Ferreira, D.C., Iorio, N.L., Toledo, V.C.S., Freitas, A.I.C., Coelho, F.L., Sousa, C., dos Santos, K.R.N. and Pereira, M.O. (2014), Antimicrobial synergism against different lineages of methicillin-resistant Staphylococcus aureus carrying SCCmec IV. Journal of Applied Microbiology, 116: 1418–1426. doi: 10.1111/jam.12472
- Issue published online: 19 MAY 2014
- Article first published online: 11 MAR 2014
- Accepted manuscript online: 13 FEB 2014 01:39PM EST
- Manuscript Accepted: 7 FEB 2014
- Manuscript Revised: 4 FEB 2014
- Manuscript Received: 3 DEC 2013
- Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
- Coordenação de Aperfeiçoamento Pessoal de Nível Superior (CAPES)
- Fundação Universitária José Bonifácio (FUJB)
- Programa de Núcleos de Excelência (PRONEX)
- . Grant Numbers: PTDC/SAUSAP/113196/2009/ FCOMP-01-0124-FEDER-016012, PEst-OE/EQB/LA0023/2013;
- ‘BioHealth-Biotechnology and Bioengineering approaches to improve health quality’. Grant Number: NORTE-07-0124-FEDER-000027
- Programa Operacional Regional do Norte, QREN. Grant Number: RECI/BBB-EBI/0179/2012/FCOMP-01-0124-FEDER-027462
- drug synergism;
- MRSA ;
- SCC mec IV
To evaluate the synergistic activity of antimicrobial drugs against lineages of methicillin-resistant Staphylococcus aureus (MRSA) carrying SCCmec IV. The biofilm production and related genes were also detected.
Methods and Results
Forty two MRSA isolates were tested for biofilm production and related genes. Biofilm/biomass susceptibility to gentamicin (G), linezolid (L), rifampicin (R) and vancomycin (V) was determined for six isolates from three lineages prevalent in Rio de Janeiro hospitals in concentrations ranging from 0·25 to 64 μg ml−1. Biomass was evaluated by microtitre plate test and number of viable cells (CFU cm−2) and inspected by epifluorescence microscopy. All isolates presented the icaA and sasG genes, but only 38% were biofilm producers. There were 50 and 45% biomass reductions when concentrations ≥4 μg ml−1 of R or L and ≥16 μg ml−1 of G or V, respectively, were used. Synergism tests produced a 55% biomass reduction with + , + , + , and + . Number of viable cells was reduced from 2 to 3 logs with + and + .
Synergisms involving R plus L and R plus V caused important reductions in biofilm/biomass and the number of viable cells. Drug combinations should be considered in the chemotherapies of MRSA-SCCmec IV infections.
Significance and Impact of the Study
Biofilms in MRSA infections restrict the clinical choice of antimicrobials. Thus, knowledge of the best options for monotherapy and drug synergisms could improve clinical results.