Staphylococcus schleiferi: one species or two separate subspecies? Faculty of Veterinary Medicine Els M. Broens, Jolisa de Laat, Aldert L. Zomer, Jaap A. Wagenaar, Birgitta Duim Department of Infectious Diseases and Immunology Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University

Background Phenotypic characterization The species S. schleiferi (Ss) includes two Phenotypic characterization was done in duplo subspecies: S. schleiferi subsp. schleiferi (Sss) Coagulase Genotyping by slide and tube coagulase test, urease test, which is coagulase negative and S. schleiferi Maldi-TOF analysis and API ID 32 STAPH. subsp. coagulans (Ssc) which is coagulase Isolate ID Origin tube slide Clade ClfB var Coag var KatA var Phenotypic tests performed on the 11 selected positive. Coagulase negative staphylococci are isolates failed to distinguish Ssc strains from VMDC-1 pos neg A 1 1B 1 often considered clinically less relevant, and are Sss strains. Coagulase production was variable often not identified in routine diagnostics. AP014944.1 JPN n.d n.d A 1 1B 1 and less evident than in S. aureus isolates. Traditional tests to indicate coagulase activity Remarkably, LMG13347 (= type strain for Sss) have shown to be variable in Ss. The objectives LMG22205 JPN pos pos A 2 1A 1 tested repeatedly positive in slide and tube of this study were to examine clinical relevance coagulase tests. of, and phenotypic and genotypic differentiation LMG13347 FR pos pos A 2 1A 1 The variability in coagulase activity stresses the of Ss isolates. need for further identification of coagulase VMDC-2 NL pos neg A 3 1B 1 negative Ss isolates in routine diagnostics. Selection of strains VMDC-3 NL pos neg A 3 2B 1 Eight Ss strains isolated at the Veterinary Genotypic characterization Microbiological Diagnostic Centre (VMDC) from LMG19137 BE pos neg A 2 1A 1 Genotypic characterization was done by whole canine skin and ear samples (VMDC 1-8) and genome sequencing. Several genes putatively three Ss reference strains (LMG) were selected VMDC-4 NL dub neg B 3 2B 2 associated with coagulase production were for further characterization. Five Ss genomes investigated. All strains contained a variant of available in GenBank were included for VMDC-5 NL pos neg B 3 1A 2 clumping factor B and coagulase, but the phylogenetic analysis. CP009470.1 US n.d n.d B 3 1A 2 assignment of different variants did not correlate with the observed phenotypic Clinical relevance VMDC-6 NL pos neg C 3 2A 3 coagulase activity. From Jan 2014 to Sept 2015, 156 Ss (identified Three phylogenetically different clades were with Maldi-TOF) were isolated from clinical VMDC-7 NL dub neg C 3 2A 3 identified based on core genome SNPs; the samples submitted to the VMDC; one third division in these clades did not correlate with VMDC-8 NL pos pos C 3 2A 3 tested negative in a tube coagulase test. coagulase activity nor with different subspecies Clinical conditions associated with Ss isolation CP009762.1 US n.d n.d C 3 2A 3 of S. schleiferi. were canine pyoderma and otitis externa; No correlation between genotype and proportions were not associated with coagulase CP009676 US n.d n.d C 3 2A 3 geographic region was observed. Interestingly, activity. Clinical features did not support the clade 3 appears to be a successful clone, as division into clinically relevant and clinically less CP010309.1 US n.d n.d C 3 2A 3 the genomes of the US and NL strains in this relevant subspecies based on coagulase clade are nearly identical. activity.

Clinical features and phenotypic and genotypic characteristics question the reliability of phenotypic Contact details: [email protected]; www.uu.nl/vmdc coagulase tests for distinction of separate Staphylococcus schleiferi subspecies . Copyright © 2016