TABLE 4.

Statistical comparison of data collected from B. subtilis subsp. niger-contaminated flooring materials with no P. chrysogenum background contamination (n = 3), 10² CFU of P. chrysogenum per cm² (n = 2), and 10⁴ CFU of P. chrysogenum per cm² (n = 2)^a

Sampling method	Flooring material	P value
		PCR	Culture
Swab kit	Vinyl tile	0.663	0.769
	Commercial carpet	0.408	0.813
	Residential carpet	0.773	0.296
	Soiled residential carpet	0.652	0.543
Sponge swipe	Vinyl tile	0.241	0.482
	Commercial carpet	0.091	0.746
	Residential carpet	0.839	0.045b
	Soiled residential carpet	0.395	0.812

^aAnalysis of variance tests were performed with PCR and culture data for the swab kit and sponge swipe sampling methods. 

^bThe P value less than 0.05 indicates that there was a significant difference between data for different P. chrysogenum contamination levels.