Routine use of mupirocin at the peritoneal catheter exit site and mupirocin resistance: still low after 7 years.
OBJECTIVE
The purpose of this study (the third in a series of similar studies) is to evaluate the prevalence of Staphylococcus aureus (SA), methicillin-resistant SA (MRSA) and mupirocin-resistant SA (MuRSA) carriers in a peritoneal dialysis centre where patients have been instructed to use prophylactic mupirocin ointment at the catheter exit site over the last 7 years.


METHODS
Swabs were taken from catheter exit site, nares, axillae and groin in 147 chronic peritoneal dialysis out-patients between November 2003 and January 2004. Axillae/groin and nasal samples were pooled and cultured in the same medium, whereas exit site swabs were cultured separately. All SA isolated were tested for methicillin and mupirocin resistance using oxacillin screening plates and E-test strips.


RESULTS
Sixteen of 147 patients (10.9%) were found to be SA carriers: of these 13 (8.8%) had a positive nasal/axillae/groin culture; two (1.4%) had both nasal/axillae/groin- and exit site-positive culture; and one (0.7%) had only exit site-positive culture. In these 16 SA carriers, we found mupirocin-resistant strains (MuRSA) in four patients (25%) and MRSA in two patients (12.5%). Among the four MuRSA carriers, one had both nasal/axillae/groin- and exit site-positive culture and three had only nasal/axillae/groin-positive culture. Three high-level resistance and one low-level resistance MuRSA carriers were isolated. One MuRSA strain was also methicillin resistant. All MRSA strains were sensitive to vancomycin and rifampicin.


CONCLUSIONS
After 7 years' routine use of prophylactic mupirocin ointment at the catheter exit site in non-selected chronic peritoneal dialysis patients, MuRSA was found in 25% of SA strains isolated or in 2.7% of the patients. Compared with our previous study, 3 years earlier, there is no significant increase in the MuRSA prevalence in peritoneal dialysis patients who routinely apply mupirocin ointment at the catheter exit site.
Division of Nephrology, University Health Network, Toronto, Canada.
Thierry
T
Lobbedez
Michael
M
Gardam
Helen
H
Dedier
Dorothy
D
Burdzy
Maggie
M
Chu
Sharon
S
Izatt
Joanne M
JM
Bargman
Sarbjit V
SV
Jassal
Stephen
S
Vas
James
J
Brunton
Dimitrios G
DG
Oreopoulos
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002408:Catheters, Indwelling / Q000009:adverse effects; D024881:Drug Resistance, Bacterial; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D016712:Mupirocin / Q000494:pharmacology / Q000627:therapeutic use*; D010530:Peritoneal Dialysis; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects; D013997:Time Factors
D000900:Anti-Bacterial Agents; D016712:Mupirocin