Adherence of Staphylococcus aureus isolated in peritoneal dialysis-related exit-site infections to HEp-2 cells and silicone peritoneal catheter materials.
BACKGROUND
Peritoneal catheter exit-site infections cause a relevant morbidity in peritoneal dialysis patients and are frequently caused by Staphylococcus aureus. We tested the hypothesis that adherence of exit-site-derived S. aureus to epithelial cells and peritoneal catheter silicone tubes discriminates virulent and less virulent strains.


METHODS
The binding of isolated S. aureus to an epithelial cell line (HEp-2) and to silicone tubes was analyzed using light-microscopy or radioactive labeling of bacteria.


RESULTS
Of 378 exit-site swabs, 99 (26%) were positive for microbial growth. S. aureus was cultured in 25 of 99 positive swabs; three of 13 swabs taken in exit-site infections grade 3 and 4 that had tested positive for S. aureus. Adherence of S. aureus from exit-site infections grade 2, 3 and 4 to Hep-2 cells did not differ from adherence of bacteria isolated from asymptomatic or moderately inflamed catheter exit sites (grade 0-2). However, binding of S. aureus to silicone tubes was enhanced in grade 0/1 compared with grade 2-4 exit-site isolates.


CONCLUSIONS
Staphylococcus aureus is an important pathogen in CAPD-related exit-site infection being isolated in about 6.6% of all exit-site swabs (and in 25% of all positive swabs). Silicone-adhesive strains may be of more clinical significance in peritoneal dialysis patients since adhesion to silicone was increased in S. aureus strains isolated in more severe exit-site infections.
Kreft
B
B
Medizinische Klinik I, Medizinische Universität Lübeck, Germany.
Ilic
S
S
Ziebuhr
W
W
Kahl
A
A
Frei
U
U
Sack
K
K
Trautmann
M
M
D001422:Bacterial Adhesion / Q000502:physiology*; D002404:Catheterization; D002460:Cell Line; D004269:DNA, Bacterial / Q000032:analysis; D004847:Epithelial Cells / Q000382:microbiology*; D006801:Humans; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects* / Q000295:instrumentation; D012828:Silicones; D013203:Staphylococcal Infections / Q000209:etiology* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*
D004269:DNA, Bacterial; D012828:Silicones