title: Persistent infection with small colony variant strains of Staphylococcus aureus in patients with cystic fibrosis.
abstract: In a 34-month prospective study to determine the prevalence of Staphylococcus aureus small colony variants (SCVs) in cystic fibrosis (CF) patients, S. aureus SCVs or SCVs plus normal S. aureus were recovered from 26 of 78 patients; 27 patients harbored only normal S. aureus. By pulsed-field gel electrophoresis, clonal identity was demonstrated of SCV and normal strains isolated at the same time and of multiple S. aureus SCV and normal strains in consecutive specimens from individual patients. All S. aureus SCVs were resistant to antifolate antibiotics, while the corresponding parent strains were susceptible, and in 11 of 12 SCV/normal pairs, gentamicin was less active against S. aureus with the SCV phenotype than against the normal isolate. Analysis of the underlying auxotrophism of SCVs revealed hemin, thymidine, and/or menadione dependencies. Thus, S. aureus SCVs are highly prevalent in respiratory secretions of CF patients, persist over extended periods, and may contribute to S. aureus persistence in CF patients.
authors.affiliation: Institute of Medical Microbiology and Department of Pediatrics, University of Muenster Hospital and Clinics, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Kahl
authors.forename: M
authors.initials: M
authors.lastname: Herrmann
authors.forename: A S
authors.initials: AS
authors.lastname: Everding
authors.forename: H G
authors.initials: HG
authors.lastname: Koch
authors.forename: K
authors.initials: K
authors.lastname: Becker
authors.forename: E
authors.initials: E
authors.lastname: Harms
authors.forename: R A
authors.initials: RA
authors.lastname: Proctor
authors.forename: G
authors.initials: G
authors.lastname: Peters
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D003550:Cystic Fibrosis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial