Volume 6, Spring 2008 - Saddleback College

Fall 2007 Biology 3A Abstracts
cm, 0.0 cm, 0.0 cm, 0.1 cm, and 0.6 cm. Tobramycin
is more effective in killing S. aureus in the 2 nd
generation with mean radius of the zone, 0.69 cm
±0.04 compared to the radius of 0.20 cm ±0.09 by
Polymyxin (Table 2.). There is higher resistance with
Polymyxin.
The radii of zone of inhibition (cm) of
Tobramycin, for all eight zones after the 3rd generation
were 1.1 cm, 0.9 cm, 1.5 cm, 1.6 cm, 0.5 cm, 1.5 cm,
1.5 cm, and 1.0 cm. The radiuses of zone of inhibition
(cm) of Polymyxin, for all eight zones after the 3rd
generation were 0.1 cm, 0.35 cm, 0.15 cm, 0.0 cm, 0.5
cm, 0.2 cm, 0.1 cm, and 0.0 cm. The 3 rd generation
Tobramycin is more effective in killing S. aureus with
mean radius of the zone, 1.2 cm ±0.1 compared to the
radius of 0.18 cm ±0.06 by Polymyxin (Table 3.).
There is higher resistance with Polymyxin.
There is a significant difference between the
radiuses of the zone of inhibitions produced by
Tobramycin and Polymyxin at each generation; P value
is less than 0.05 (Table 4.), and it can be concluded
from Figure 3 that as next generation was entered, S.
aureus became more resistance to Polymyxin and
much less to Tobramycin.
Polymyxin
2nd Gen
Polymyxin
2nd Gen
0.5 0.4 0 0 0
0 0.1 0.6
Table 3. Radius of the zone of inhibitions observed for
Tobramycin and Polymyxin 50% diluted solution of
the 3 rd generation. Mean radius for Tobramycin is 1.2
cm ±0.1 and for Polymyxin is 0.18 cm ±0.06.
Tobramycin
3rd Gen
Tobramycin
3rd Gen
Radius of Zone of Inhibition
(cm)
1.1 0.9 1.5 1.6 0.5
1.5 1.5 1.0
Table 1. Radius of the zone of inhibitions observed for
Tobramycin and Polymyxin 20% diluted solution of
the 1 st generation. Mean radius for Tobramycin is 0.26
cm ±0.07 and for Polymyxin is 0.38 cm ±0.07.
Radius of Zone of Inhibition (cm)
Polymyxin
3rd Gen
Polymyxin
3rd Gen
0.1 0.35 0.15 0 0.5
0.2 0.1 0
Tobramycin
1 st Gen
Polymyxin
1 st Gen
0.4 0.4 0.1 0.1 0.3
0.6 0.5 0.3 0.3 0.2
Table 4. Statistical significance calculated based on the
ANOVA results and the table produced by the
software. T represents the Tobramycin and P represents
the Polymyxin followed by the generation number. In
all generations, there is a significant difference.
Table 2. Radius of the zone of inhibitions observed for
Tobramycin and Polymyxin 40% diluted solution of
the 2 nd generation. Mean radius for Tobramycin is 0.69
cm ±0.04 and for Polymyxin is 0.20 cm ±0.09.
Radius of Zone of Inhibition (cm)
Comparison Significant? (P