%0 Journal Article
%T Staphylococcus aureus requires cardiolipin for survival under conditions of high salinity
%A Melody Tsai
%A Ryosuke L Ohniwa
%A Yusuke Kato
%A Sayaka L Takeshita
%A Toshiko Ohta
%A Shinji Saito
%A Hideo Hayashi
%A Kazuya Morikawa
%J BMC Microbiology
%D 2011
%I BioMed Central
%R 10.1186/1471-2180-11-13
%X Using an improved extraction method, the analysis of phospholipid composition suggested that CL levels increased slightly toward stationary phase, but that this was not induced by high salinity. Deletion of the two CL synthase genes, SA1155 (cls1) and SA1891 (cls2), abolished CL synthesis. The cls2 gene encoded the dominant CL synthase. In a cls2 deletion mutant, Cls1 functioned under stress conditions, including high salinity. Using these mutants, CL was shown to be unnecessary for growth in either basal or high-salt conditions, but it was critical for prolonged survival in high-salt conditions and for generation of the L-form.CL is not essential for S. aureus growth under conditions of high salinity, but is necessary for survival under prolonged high-salt stress and for the generation of L-form variants.Staphylococcus aureus is an opportunistic pathogen that causes a wide range of diseases in both immunologically normal and compromised hosts. The natural habitat of S. aureus is the nasal cavity of warm-blooded animals. Over the past ~50 years, S. aureus has undergone genetic changes that have resulted in antibiotic-resistant strains [1,2]. Importantly, the methicillin-resistant strains (MRSA) are now the most common cause of nosocomial S. aureus infections and are spreading throughout communities [3].Staphylococcus aureus has a number of characteristics that allow it to survive host bactericidal factors and environmental stresses, including drastic changes in osmotic pressure [4-6]. Osmoprotectants such as choline, glycine betaine, and proline accumulate in cells in response to osmotic stress [7-11]. Multiple genes, including the branched-chain amino acid transporter gene brnQ [12] and the arsenic operon regulatory gene arsR [13], cooperatively participate in salt tolerance. In addition, a very large cell wall protein, Ebh, is involved in tolerance to transient hyperosmotic pressure [14].In general strategy, the phospholipid composition of bacteria changes in resp
%U http://www.biomedcentral.com/1471-2180/11/13