Monitoring persistence of coagulase-negative staphylococci in a hematology department using phenotypic and genotypic strategies.
OBJECTIVE
To determine persistence of coagulase-negative staphylococci (CNS) on a hematology-oncology ward and to determine the value of phenotypic and genotypic procedures for establishing clonality among CNS isolates.


METHODS
Strains of CNS isolated from bacteremic patients (n = 139) were typed by biochemical reactivity, antibiotic susceptibility, DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE), and arbitrary primed polymerase chain reaction (AP PCR). Coagulase-negative staphylococci were subgrouped in a random collection (n = 20) used for the evaluation of the typing procedures and a collection of 119 CNS isolates from hematologic patients displaying multiple bacteremic episodes.


RESULTS
Analysis of the reference collection demonstrated the usefulness of the DNA typing procedures, indicating that AP PCR and PFGE can be used for epidemiologic typing of CNS in a concordant fashion. Certain strains appeared to be permanent colonizers of the hematology ward or ward-related personnel. In individual patients, persistent colonization by a single type was demonstrated. However, a number of patients also experienced bacteremic episodes caused by CNS belonging to different types.


CONCLUSIONS
We conclude that monitoring of CNS infections on a hematology ward by various genotypic techniques provides insight into nosocomial epidemiology and elucidates the complexity of the infections taking place. DNA typing is preferred over phenotypic procedures and can identify persistent CNS strains in a given location.
Department of Bacteriology, University Hospital Dijkzigt, Rotterdam, The Netherlands.
A
A
van Belkum
J
J
Kluijtmans
W
W
van Leeuwen
W
W
Goessens
E
E
ter Averst
J
J
Wielenga
H
H
Verbrugh
D016470:Bacteremia / Q000453:epidemiology; D015373:Bacterial Typing Techniques / Q000592:standards; D003030:Coagulase / Q000032:analysis*; D003428:Cross Infection / Q000453:epidemiology*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000592:standards; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D008826:Microbial Sensitivity Tests; D009369:Neoplasms; D009426:Netherlands / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000592:standards; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000145:classification* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*
D003030:Coagulase