Anti-biofilm activity of dalbavancin against methicillin-resistant Staphylococcus aureus (MRSA) isolated from human bone infection

Abstract

The presence of methicillin-resistant Staphylococcus aureus (MRSA) in bone infections difficults its treatment and is a sign of concern. The aim of this study was to evaluate in vitro activity of dalbavancin on pre-established adhered cells and 24 h old biofilms of MRSA strains isolated from a human bone infection. Thirty-three MRSA were isolated from osteomyelitis episodes. The antimicrobial susceptibility of these strains was assessed by the Kirby-Bauer disc diffusion method and the presence of resistance genes was screened by PCR. MRSA planktonic minimum inhibitory concentration and minimum bactericidal concentration were assessed. Minimum biofilm eradication concentration (MBEC) was performed by the microtiter biofilm formation assay. All 33 MRSA strains were classified as multidrug-resistant strains and susceptible to dalbavancin. Dalbavancin inhibited the growth of 54.6% and 52% of strains at the concentrations of 0.05 µg/mL and 1 µg/mL, respectively. The MBEC values up to 0.4 µg/mL demonstrated that dalbavancin was active against most strains in pre-established adhered cells and 24 h old biofilms. The current results show that dalbavancin is active against adhered cells and biofilms in vitro, suggesting that this antimicrobial agent may be an option for the treatment of bone infections caused by MRSA.

Keywords:

• Dalbavancin
• biofilms
• MRSA
• MIC
• MBEC
• osteomyelitis

Additional information

Funding

This work was supported by the Associate Laboratory for Green Chemistry - LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). The work was also funded by the R&D Project CAREBIO2 - Comparative assessment of antimicrobial resistance in environmental biofilms through proteomics - toward innovative theranostic biomarkers, with reference NORTE-01-0145FEDER-030101 and PTDC/SAU-INF/30101/2017, financed by the European Regional Development Fund (ERDF) through the Northern Regional Operational Program (NORTE 2020) and the Foundation for Science and Technology (FCT). Vanessa Silva is grateful to FCT for financial support through the PhD grant SFRH/BD/137947/2018.

Notes on contributors

Vanessa Silva

Vanessa Silva holds a master’s degree in Biochemistry from the University of Trás-os-Montes and Alto Douro and currently develops her doctoral thesis in Veterinary Sciences funded by FCT. She is a guest assistant in curricular unit Genomics and Proteomics at the same institution. Her research interests include antimicrobial resistance, epidemiology of genetic lineages, bacterial biofilms and multi-omics.

Carla Miranda has a PhD in Veterinary Sciences. She is currently a researcher at the University of Trás-os-Montes and Alto Douro. Her main areas of research include infectious diseases, zoonoses, microbiology, virology and molecular biology in a One Health approach.

Mário Bezerra is a master’s student in Comparative and Technological Molecular Genetics at the University of Trás-os-Montes and Alto Douro. His main areas of interest are microbiology, proteomics and allergens.

H. Sofia Antão is a Medical Doctor and works at Kmed Europa. Her research interests are pharmacy and medicine.

João Guimarães is the Medical Director and Director of Regulatory Affairs of Angelini. His research interests are pharmacovigilance, medicine, clinical trials and clinical research.

Justina Prada holds a PhD in Veterinary Sciences from the University of Trás-os-Montes and Alto Douro and is an Assistant Professor at the same university. Her research interests are dermatopathology, pathologic anatomy and immunohistochemistry.

Isabel Pires holds a PhD in Veterinary Sciences from the University of Trás-os-Montes and Alto Douro and is an Assistant Professor with Habilitation at the same university. Her research interests are cytological and histological diagnosis, pathologic anatomy and necropsy.

Luís Maltez completed his PhD in Veterinary Sciences at the University of Trás-os-Montes and Alto Douro in 2013. He is an Assistant Professor at the same institution. His research interests are pet surgery, orthopedic surgery and antibiotic therapy.

José E. Pereira is an Assistant Professor at the University of Trás-os-Montes and Alto Douro and holds a PhD in Veterinary Sciences. His research interests are antibiotic therapy and orthopedic surgery.

José L. Capelo is an Associate Professor with Habilitation at NOVA School of Science and Technology. He has a PhD in Chemistry by the University of Vigo. His research interests are proteomics, ultrasonics, biomarkers, nanoproteomics and mass spectrometry.

Gilberto Igrejas has a PhD in Genetics and Biotechnology. He is an Associate Professor with Habilitation at the University of Trás-os-Montes and Alto Douro. His research interests include genomics, proteomics, molecular genetics and biotechnology.

Patricia Poeta holds a PhD in Veterinary Medicine by the University of Trás-os-Montes and Alto Douro and specialist in Medical Microbiology. She is a Full Professor at the same institution. Her man research interest is the characterization of antibiotic resistance mechanisms in bacteria of different origins.