Clonal expansion of Staphylococcus epidermidis strains causing Hickman catheter-related infections in a hemato-oncologic department.
The detailed analysis of 411 strains of coagulase-negative staphylococci (CoNS) obtained from 40 neutropenic hemato-oncologic patients (61 Hickman catheter episodes) on intensive chemotherapy is described. By random amplification of polymorphic DNA (RAPD) analysis, a total of 88 different genotypes were detected: 51 in air samples and 30 in skin cultures prior to insertion, 12 in blood cultures after insertion, and only 5 involved in catheter-related infections (CRI). Two RAPD genotypes of Staphylococcus epidermidis predominated, and their prevalence increased during patient hospitalization. At insertion, these clones constituted 11 of 86 (13%) CoNS isolated from air samples and 33 of 75 (44%) CoNS isolated from skin cultures. After insertion, their combined prevalence increased to 33 of 62 (53%) in catheters not associated with CRI and 139 of 188 (74%) in catheters associated with CRI (P = 0.0041). These two predominant S. epidermidis clones gave rise to a very high incidence of CRI (6.0 per 1,000 catheter days) and a very high catheter removal rate for CRI, 70%, despite prompt treatment with vancomycin. A likely source of S. epidermidis strains involved in CRI appeared to be the skin flora in 75% of cases. The validity of these observations was confirmed by pulsed-field gel electrophoresis (PFGE) of SmaI DNA macrorestriction fragments of blood culture CoNS isolates. Again, two predominant CoNS genotypes were found (combined prevalence, 60%). RAPD and PFGE yielded concordant results in 75% of cases. Retrospectively, the same two predominant CoNS clones were also found among blood culture CoNS isolates from the same hematology department in the period 1991 to 1993 (combined prevalence, 42%) but not in the period 1978 to 1982. These observations underscore the pathogenic potential of clonal CoNS types that have successfully and persistently colonized patients in this hemato-oncology department.
Department of Medical Microbiology & Infectious Diseases, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands. nouwen@bacl.azr.nl
J L
JL
Nouwen
A
A
van Belkum
S
S
de Marie
J
J
Sluijs
J J
JJ
Wielenga
J A
JA
Kluytmans
H A
HA
Verbrugh
D000391:Air Microbiology; D019072:Antibiotic Prophylaxis; D001431:Bacteriological Techniques; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D002408:Catheters, Indwelling / Q000009:adverse effects*; D002939:Ciprofloxacin / Q000627:therapeutic use; D015725:Fluconazole / Q000627:therapeutic use; D005838:Genotype; D019337:Hematologic Neoplasms / Q000150:complications / Q000188:drug therapy; D006801:Humans; D009181:Mycoses / Q000517:prevention & control; D009503:Neutropenia; D019105:Random Amplified Polymorphic DNA Technique; D015183:Restriction Mapping; D012867:Skin / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000209:etiology* / Q000382:microbiology / Q000517:prevention & control; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification
D002939:Ciprofloxacin; D015725:Fluconazole