Bacterial characterization in Staphylococcus epidermidis septicemia.
An analysis of the in vitro characteristics of Staphylococcus epidermidis strains isolated from patients with true S. epidermidis septicemia was undertaken. From a potential population of 921 cultures from adult patients with coagulase-negative bacteremia, highly defined selective criteria limited the population to 20 patients with S. epidermidis sepsis, from whose blood cultures the study organisms were isolated. Another population of 11 S. epidermidis blood isolates, clinically determined to be contaminants, were tested as a control group. In vitro assays performed on all isolates included slime quantification, hydrophobicity, surface hexoses, and capsule presence. Murine spleen phagocytosis of intravenously administered isolates was measured in vivo. The assayed quantity of cell-associated bacterial hexose sugars positively correlated with organism virulence to the host (p = 0.02). This bacterial population was also low in slime but varied as to the presence of capsule and ease of phagocytosis. Permanent catheter-bearing patients' bacteria were somewhat more hydrophobic (p = 0.07). We conclude that in vitro assays can differentiate bacteremic cultures from contaminants and that the characteristic that best relates to host toxicity in these S. epidermidis isolates was bacterial cell surface-associated carbohydrate.
Dall
L
L
Section of Infectious Diseases, UMKC School of Medicine.
Wang
J
J
Herndon
B
B
Suvarna
P
P
D000328:Adult; D000818:Animals; D016667:Bacterial Capsules; D006601:Hexoses / Q000378:metabolism; D006801:Humans; D051379:Mice; D010587:Phagocytosis; D018805:Sepsis / Q000382:microbiology*; D013154:Spleen / Q000166:cytology / Q000502:physiology; D013203:Staphylococcal Infections / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence
D006601:Hexoses