Table 2.

Lysostaphin susceptibility testing using the turbidity reduction assay of various MRSA isolates obtained from the cranial implant margins of 2 treatment and one control animals before and after lysostaphin (Tx) or buffer (control) treatment.

S. aureus isolate designation	TOD50 ratio of sample to reference (MSSA 8325)	TOD50 ratio of sample to reference (MRSA MW2)
Pre-Lysostaphin Treatment
Tx sample no.1 (Animal 1)	1.25 ± 0.22	1.00 ± 0.18
Tx sample no.2 (Animal 1)	1.54 ± 0.04	1.23 ± 0.03
Tx sample no.8 (Animal 2)	1.69 ± 0.09	1.36 ± 0.07
Tx sample no.9 (Animal 2)	1.13 ± 0.00	0.90 ± 0.00
Pre-Tx Mean	1.40 ± 0.09	1.12 ± 0.07
Control sample no.18 (Animal 3)	1.26 ± 0.02	1.01 ± 0.02
Control sample no.19 (Animal 3)	1.39 ± 0.02	1.11 ± 0.02
Pre-Control Mean	1.3 ± 0.02	1.06 ± 0.02
Post-Lysostaphin Treatment
Tx sample no.6 (Animal 1)	1.85 ± 0.06	1.48 ± 0.05
Tx sample no.7 (Animal 1)	2.19 ± 0.02	1.76 ± 0.02
Tx sample no.13 (Animal 2)	1.17 ± 0.00	0.93 ± 0.00
Tx sample no.14 (Animal 2)	1.32 ± 0.05	1.06 ± 0.04
Post-Tx Mean	1.63 ± 0.03	1.31 ± 0.03
Control sample no.23 (Animal 3)	0.76 ± 0.02	0.61 ± 0.02
Control sample no.24 (Animal 3)	2.50 ± 0.00	2.00 ± 0.00
Post-Control Mean	1.63 ± 0.01	1.31 ± 0.01
References
MSSA 8325	12 ± 3.1 min to TOD50	N/A
MRSA MW2	N/A	15 ± 2.2 min to TOD50

The concentration of lysostaphin used for this assay was 10 µg/mL. All isolates were tested 3 times and compared with the reference strains MSSA 8325 and MRSA MW2. N/A = not applicable.