Zone of inhibition (ZOI) diameter of ZnO samples against (a) E. coli and (b) A. baumannii, (c) S. aureus, and (d) S. epidermidis was measured from n = 3 and one of the representative data was shown. N.D. indicates that the zone of inhibition was not detecteda.
| Bacteria cells | Zone of inhibition (mm) | ||||
|---|---|---|---|---|---|
| (i) ZO | (ii) 2NZO | (iii) 5NZO | (iv) Antibiotics | (v) DMSO | |
| (a) E. coli ATCC25922 | N.D. | 18 | 24 | 14a | N.D. |
| (b) A. baumannii ATCC19606 | N.D. | N.D. | 12 | 13a | N.D. |
| (c) S. aureus ATCC25923 | 13 | 14 | 14 | 38b | N.D. |
| (d) S. epidermidis ATCC12228 | N.D. | 11 | 14 | 14b | N.D. |
a
Antibiotics, aPolymyxin B or bAmpicillin was used as a control for Gram-negative or -positive bacteria, respectively.