Isolation and characterization of transposon mutants of Staphylococcus epidermidis deficient in capsular polysaccharide/adhesin and slime.
We used transposon (Tn) mutagenesis to study the role of capsular polysaccharide/adhesin (PS/A) and slime in adherence of Staphylococcus epidermidis to catheters. pLTV1, containing Tn917-LTV1, was transformed into S. epidermidis M187 by protoplast fusion with S. aureus RN4220(pLTV1), creating M187(pLTV1). Tn mutants were isolated following growth at 42 degrees C; mutants deficient in PS/A and slime production were selected. PS/A- and slime-deficient Tn mutants had a 10-fold decrease in vitro in the initial phase of adherence to catheters, comparable to levels of strains that do not produce PS/A. Introduction of Tn917-LTV1-interrupted DNA from PS/A-deficient mutant M187sn3 into the parental strain via transformation of protoplasts yielded recipients with inserts identical to those of the Tn mutant that were PS/A and slime deficient. Chromosomal DNA flanking the Tn in mutant M187sn3 was cloned into Escherichia coli. The cloned DNA was found to hybridize to approximately 5-kb EcoRI fragments from the parental strain and from control Tn mutants that express parental levels of PS/A and to either approximately 9- or approximately 14-kb EcoRI fragments from other highly adherent, PS/A-producing strains. Mapping studies demonstrated that in the eight PS/A-deficient mutants that have been isolated, the Tn insertions all occur within a region of approximately 11.6 kb that is defined by three EcoRI sites. These results support previous findings indicating that in S. epidermidis PS/A is involved with in vitro adherence to plastic biomaterials and elaboration of PS/A is closely associated with slime production.
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
E
E
Muller
J
J
Hübner
N
N
Gutierrez
S
S
Takeda
D A
DA
Goldmann
G B
GB
Pier
D001422:Bacterial Adhesion; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D009154:Mutation; D010957:Plasmids; D011135:Polysaccharides, Bacterial / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014169:Transformation, Bacterial
D004251:DNA Transposable Elements; D011135:Polysaccharides, Bacterial