TABLE 3.

Phenotypic properties of biofilm-negative S. epidermidis transposon mutants

Strain	Classa	Expression on TSBBBLb		Expression on TSBOxoidb		Hemagglutinationc (reciprocal titer)
		Biofilm (OD570)	PIA (reciprocal titer)	Biofilm (OD570)	PIA (reciprocal titer)
1457	wt	2.489	1,024	1.246	256	512
1457c	wt	1.582	1,024	1.326	128	512
M13	I	0.053	0	0.016	0	Neg
M21	I	0.155	8	0.031	0	4
M22	I	0.044	0	0.027	0	Neg
M23	I	0.047	0	0.021	0	Neg
M24	I	0.060	0	0.045	0	Neg
M12	II	0.020	0	0.013	0	Neg
M15	III	0.217	32	0.030	0	16
M19	III	0.228	32	0.033	0	16
M17	IV	1.596	256	0.039	16	16

^awt, wild type. 

^bFor the biofilm data, strains were grown in the respective medium in 96-well tissue culture plates, the plates were washed with phosphate-buffered saline, cells were fixed with Bouin's fixative, and adherent bacterial biofilms were stained with Gentian violet. Biofilm-producing strains were arbitrarily defined to have a mean OD₅₇₀ of >0.1. The PIA expression was determined by coagglutination of extracts of strains grown in the respective medium. A coagglutination reagent specific for PIA was prepared by sensitizing S. aureus Cowan I with PIA-specific absorbed antiserum as described in Materials and Methods. 

^cHemagglutination was assessed as described in Materials and Methods. Neg, negative.