Staphylococcus rostri sp. nov., a haemolytic bacterium isolated from the noses of healthy pigs

Abstract

Twenty coagulase-negativeStaphylococcusstrains displayingα-haemolysis (δ-haemolysin) on sheep-blood agar were isolated from the noses of different pigs in Switzerland. The strains were Gram-stain-positive, non-motile cocci, catalase-positive and coagulase-negative. Sequence analysis of the 16S rRNA gene,sodA,rpoB,dnaJandhsp60and phylogenetic characteristics revealed that the strains showed the closest relatedness toStaphylococcus microtiCCM 4903TandStaphylococcus muscaeDSM 7068T. The strains can be differentiated fromS. microtiby the absence of mannose fermentation and arginine arylamidase and fromS. muscaeby the absence ofβ-glucuronidase activity and production of alkaline phosphatase. The chosen type strain ARI 262Tshared 20.1 and 31.9 % DNA relatedness withS. microtiDSM 22147TandS. muscaeCCM 4903T, respectively, by DNA–DNA hybridization. iso-C15 : 0, anteiso-C15 : 0and iso-C17 : 0were the most common fatty acids. Cell-wall structure analysis revealed the peptidoglycan type A3αl-Lys–Gly2–l-Ser–Gly (type A11.3). The presence of teichoic acid was determined by sequencing theN-acetyl-β-d-mannosaminyltransferase genetarA, which is involved in biosynthesis of ribitol teichoic acid. Menaquinone 7 (MK-7) was the predominant respiratory quinone. The G+C content of ARI 262Twas 38.8 mol%. The isolated strains represent a novel species of the genusStaphylococcus, for which we propose the nameStaphylococcus rostrisp. nov. The type strain is ARI 262T(=DSM 21968T=CCUG 57266T) and strain ARI 602 (=DSM 21969 =CCUG 57267) is a reference strain.