Characterization of <i>Staphylococcus intermedius</i> Group Isolates Associated with Animals from Antarctica and Emended Description of <i>Staphylococcus delphini</i>

• Main Authors: Veronika Vrbovská, Ivo Sedláček, Michal Zeman, Pavel Švec, Vojtěch Kovařovic, Ondrej Šedo, Monika Laichmanová, Jiří Doškař, Roman Pantůček
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Microorganisms
• Subjects: <i>staphylococcus delphini</i>; <i>staphylococcus pseudintermedius</i>; antarctica; mobile genetic elements; surface proteins; exfoliative toxin; adélie penguin; weddell seal
• Online Access: https://www.mdpi.com/2076-2607/8/2/204

Members of the genus <i>Staphylococcus</i> are widespread in nature and occupy a variety of niches, however, staphylococcal colonization of animals in the Antarctic environment has not been adequately studied. Here, we describe the first isolation and characterization of two <i>Staphylococcus intermedius</i> group (SIG) members, <i>Staphylococcus delphini</i> and <i>Staphylococcus pseudintermedius,</i> in Antarctic wildlife. <i>Staphylococcus delphini</i> were found exclusively in Ad&#233;lie penguins. The report of <i>S. pseudintermedius</i> from Weddell seals confirmed its occurrence in all families of the suborder Caniformia. Partial RNA polymerase beta-subunit (<i>rpoB)</i> gene sequencing, repetitive PCR fingerprinting with the (GTG)₅ primer, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry gave consistent identification results and proved to be suitable for identifying SIG members. Comparative genomics of <i>S. delphini</i> isolates revealed variable genomic elements, including new prophages, a novel phage-inducible chromosomal island, and numerous putative virulence factors. Surface and extracellular protein distribution were compared between genomes and showed strain-specific profiles. The pathogenic potential of <i>S. delphini</i> was enhanced by a novel type of exfoliative toxin, trypsin-like serine protease cluster, and enterotoxin C. Detailed analysis of phenotypic characteristics performed on six Antarctic isolates of <i>S. delphini</i> and eight reference strains from different animal sources enabled us to emend the species description of <i>S. delphini</i>.