Next Article in Journal
The Effect of Blue Light on the Production of Citrinin in Monascus purpureus M9 by Regulating the mraox Gene through lncRNA AOANCR
Next Article in Special Issue
Molecular Epidemiology of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus in Wild, Captive and Laboratory Rats: Effect of Habitat on the Nasal S. aureus Population
Previous Article in Journal
Rationally Designed Synthetic Haptens to Generate Anti-Ciguatoxin Monoclonal Antibodies, and Development of a Practical Sandwich ELISA to Detect Ciguatoxins
Previous Article in Special Issue
Distribution of Toxinogenic Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus from Different Ecological Niches in Algeria
Article

Molecular Characterization of Equine Staphylococcus aureus Isolates Exhibiting Reduced Oxacillin Susceptibility

1
Institute of Microbiology and Epizootics, Centre for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, 14163 Berlin, Germany
2
Advanced Light and Electron Microscopy (ZBS-4), Robert Koch Institute, 13353 Berlin, Germany
3
Equine Clinic: Surgery and Radiology, Freie Universität Berlin, 14163 Berlin, Germany
*
Author to whom correspondence should be addressed.
Received: 26 August 2019 / Revised: 8 September 2019 / Accepted: 9 September 2019 / Published: 13 September 2019
The detection of borderline oxacillin-resistant Staphylococcus aureus (BORSA) represents a challenge to both, veterinary and human laboratories. Between 2015 and 2017, 19 equine S. aureus with elevated minimal inhibitory concentrations for oxacillin were detected in routine diagnostics. The aim of this study was to characterize these isolates to identify factors possibly associated with the BORSA phenotype. All S. aureus were subjected to antimicrobial susceptibility testing and whole genome sequencing (WGS). A quantifiable β-lactamase activity assay was performed for a representative subset of 13 isolates. The WGS data analysis of the 19 BORSA isolates identified two different genomic lineages, sequence type (ST) 1 and ST1660. The core genome multilocus sequence typing (cgMLST) revealed a close relatedness of all isolates belonging to either ST1 or ST1660. The WGS analysis identified the resistance genes aadD, dfrG, tet(L), and/or blaZ and aacA-aphD. Phenotypic resistance to penicillins, aminoglycosides, tetracyclines, fluoroquinolones and sulfamethoxazole/trimethoprim was observed in the respective isolates. For the penicillin-binding proteins 1–4, amino acid substitutions were predicted using WGS data. Since neither transglycosylase nor transpeptidase domains were affected, these alterations might not explain the BORSA phenotype. Moreover, β-lactamase activity was found to be associated with an inducible blaZ gene. Lineage-specific differences regarding the expression profiles were noted. View Full-Text
Keywords: borderline oxacillin resistance; BORSA; susceptibility testing; MSSA; whole genome sequencing; blaZ borderline oxacillin resistance; BORSA; susceptibility testing; MSSA; whole genome sequencing; blaZ
Show Figures

Figure 1

MDPI and ACS Style

Scholtzek, A.D.; Hanke, D.; Walther, B.; Eichhorn, I.; Stöckle, S.D.; Klein, K.-S.; Gehlen, H.; Lübke-Becker, A.; Schwarz, S.; Feßler, A.T. Molecular Characterization of Equine Staphylococcus aureus Isolates Exhibiting Reduced Oxacillin Susceptibility. Toxins 2019, 11, 535. https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11090535

AMA Style

Scholtzek AD, Hanke D, Walther B, Eichhorn I, Stöckle SD, Klein K-S, Gehlen H, Lübke-Becker A, Schwarz S, Feßler AT. Molecular Characterization of Equine Staphylococcus aureus Isolates Exhibiting Reduced Oxacillin Susceptibility. Toxins. 2019; 11(9):535. https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11090535

Chicago/Turabian Style

Scholtzek, Anissa D., Dennis Hanke, Birgit Walther, Inga Eichhorn, Sabita D. Stöckle, Katja-Sophia Klein, Heidrun Gehlen, Antina Lübke-Becker, Stefan Schwarz, and Andrea T. Feßler 2019. "Molecular Characterization of Equine Staphylococcus aureus Isolates Exhibiting Reduced Oxacillin Susceptibility" Toxins 11, no. 9: 535. https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11090535

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop