Table 1.

Number and infection rates of the mediastinal tissues and all infected rats

Groups		Samples						All infected ratsa
		Tissue		Blood		Steel
		n	%	n	%	n	%	n	%
Group A	Grown	1	16.7	1	16.7	-	-	1	16.7*
n = 6	Not grown	5	83.3	5	83.3	-	-	5	88.3
Group B	Grown	1	16.7	1	16.7	1	16.7*	1	16.7*
n = 6	Not grown	5	83.3	5	83.3	5	83.3	5	83.3
Group C	Grown	3	50	0	0	2	33.3*	5	83.3*
n = 6	Not grown	3	50	6	100	4	66.7	1	16.7
Group D	Grown	4	66.7	3	50	6	100*	6	100*
n = 6	Not grown	2	33.3	3	50	0	0	0	0

^a Bacterial growth from at least one of the maediastinal organs, blood or steel wire has been taken as presence of infection.

* Differences between groups: rate of growth from the steel wire pieces between B and D; P = 0.005, rate of growth from steel wire pieces between C and D; P = 0.019, rate of total growth between A and C; P = 0.027, rate of total growth between A and D; P = 0.005, rate of total growth between B and C; P = 0.027, rate of total growth between B and D; P = 0.005.