TABLE 3.

Impact of cell preparation protocols on the attachment to different substrata of test organisms exposed to different combinations of washing and resuspension media

Organism	Treatment	% of reference valuea
		NaCl/NaClb				NaCl/H2O				H2O/NaCl				H2O/H2O
		Stainless steel	Aluminum	Perspex	Polypropylene	Stainless steel	Aluminum	Perspex	Polypropylene	Stainless steel	Aluminum	Perspex	Polypropylene	Stainless steel	Aluminum	Perspex	Polypropylene
Carbon-limited strain SW8	15,000 × gc	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100
	Freeze-drying	—d	—d	—d	—d	—d	—d	—d	—d	40	13	33	17	5	4	25	4
	Air drying	54	17	35	13	100	100	100	100	28	22	100	100	20	9	25	0
Nitrogen-limited strain SW8	15,000 × gc	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	0
	Freeze-drying	—d	—d	—d	—d	—d	—d	—d	—d	48	100	18	100	97	15	9	40
	Air drying	100	100	29	0	100	100	100	100	352	656	100	100	26	10	0	0
E. coli	15,000 × gc	29	100	100	522	13	5	100	100	1,300	2,028	35	100	3,827	196	0	0
	Freeze-drying	—d	—d	—d	—d	—d	—d	—d	—d	100	100	13	100	18	age	100	100
	Air drying	100	100	20	256	42	12	36	100	1,466	557	60	100	291	9	0	100
S. epidermidis	15,000 × gc	100	100	100	100	100	100	100	100	100	100	413	100	100	209	100	100
	Freeze-drying	—d	—d	—d	—d	—d	—d	—d	—d	—f	—f	—f	—f	—f	—f	—f	—f
	Air drying	390	100	21	400	100	190	19	—g	196	143	488	100	51	39	0	—g

^aThe values are percentages of reference values determined after centrifugation at 5,000 × g. 

^bWashing medium/resuspension medium. 

^cCentrifugation at 15,000 × g. 

^dThe bacterial cells used for XPS analysis were not washed in the NaCl solution. 

^eag, cells aggregated on the surface. 

^fFreeze-dried S. epidermidis cells could not be resuspended. 

^gNo cells adhered to the reference substratum.