TABLE 2.

Primary attachment to plastic^a

Time of assessment and growth condition	Microscopic count (mean ± SD)	P
Primary attachment
−NTZ	314 ± 10
+NTZ	300 ± 16	0.157
After 3 h growth (shaken)
−NTZ	423 ± 36
+NTZ	342 ± 40	0.263
After 3 h growth (static)
−NTZ	324 ± 95	0.062
+NTZ	243 ± 76
+NTZ + 10 μM Zn2+	310 ± 7	0.49

^aS. epidermidis strain 9142 was grown overnight in TSB with shaking, diluted to an OD₆₀₀ of 0.01 in fresh medium, and grown for 3 h (with or without shaking). The bacteria were suspended in PBS to an OD₆₀₀ of 0.1, and 1 ml was added to six-well plates, as described in the text. NTZ was added to the wells at 15 μg/ml, and ZnSO₄ was added at 10 μM. −NTZ, no NTZ added; +NTZ, NTZ added. The adherent bacteria were enumerated microscopically, and mean and SD values were computed from multiple fields of triplicates. Data were analyzed by a one-tail t test. None of the listed P values was considered significant.