C. Voneiff et al., ISOLATION OF SMALL COLONY VARIANTS OF STAPHYLOCOCCUS-AUREUS FOLLOWINGGENTAMICIN BEAD PLACEMENT FOR OSTEOMYELITIS AS A POSSIBLE CAUSE FOR RECURRENCE, Zeitschrift fur Orthopadie und Ihre Grenzgebiete, 136(3), 1998, pp. 268-271
Aim: Recently, S. aureus small colony variants (SCVs) were reported to
persist within cultured endothelial cells and to cause persistent and
antibiotic resistant infections in humans. Because gentamicin call ve
ry reproducably select for electron transport deficient SCVs as shown
in earlier in vitro experiments, we searched for SCVs in a patient wit
h chronic osteomyelitis, who received gentamicin beads. Method: Specia
l culture and identification procedures for determination of SCVs were
used, including testing of the S. aureus specific nuc gene, pulsed fi
eld gel electrophoresis (PFGE) as a typing method and characterization
of the auxotrophism of the SCVs. Results:In a case of a 34-year-old p
atient with chronic osteomyelitis who had previously been treated with
gentamicin beads, menadione auxotrophic S. aureus SCVs as well as wil
d type S. aureus were recovered in multiple bone specimen. All differe
nt colony types isolated from simultaneous or from sequential specimen
were shown to be clonal by PFGE. Conclusion: Recovery of S. aureus SC
Vs from a patient treated with gentamicin beads suggests that the slow
release of gentamicin into the local environment may be an efficient
way to select for and/or induce SCVs. These data should alert physicia
ns to also consider SCVs when a treatment failure occurs in a patient
that has received gentamicin beads.