Characteristics of Staphylococcus aureus, isolated from airways of cystic fibrosis patients, and their small colony variants.

摘要: The colonization of respiratory tract by Staphylococcus aureus is a frequent feature cystic fibrosis (CF), especially in pediatric patients. formation small colony variants (SCVs), which produce reduced amounts α-toxin, one the proposed ways staphylococcal accommodation an intracellular niche. aim present study was to compare some properties S. SCVs and their parent strains. A site-directed hemB mutant strain 8325-4 were included (control pair). Normal SCV pairs from CF patients as well control strains tested for susceptibility defensins, killing activity professional phagocytes adhesion A549 cell line. Because are exposed many cationic proteins host, we challenged clinical isolate with minimal subinhibitory concentration (subMIC) protamine found that hemin menadione auxotrophic emerged. more resistant than normal but not dermaseptin. bactericidal magainin same resistance strongly enhanced high salt concentration. cells higher parental However, number adherent bacteria (SCVs) diminished presence auxotrophs. uptake granulocytes lower ingestion strains, killed equal or greater potency. adapted survival persistence host under certain circumstances. ability form variant subpopulation affords additional options.