Table 4.

Correlation analysis of relationship between different potential opportunistic pathogens in BCV and PCF^a

Water distribution system and source	Spearman's rank correlation (P)
	Legionella spp. vs 16S rRNA gene	Mycobacterium spp. vs 16S rRNA gene	H. vermiformisvs 16S rRNA gene	Legionella spp. vs Mycobacterium spp.	Legionella spp. vs H. vermiformis	Mycobacterium spp. vs H. vermiformis
BCV
First draw	0.3243 (0.086)	0.7729 (<0.001)	0.2650 (0.165)	0.3619 (0.054)	0.5907 (<0.001)	0.4020 (0.031)
After flushing	0.0756 (0.699)	0.6216 (<0.001)	0.3089 (0.103)	0.2932 (0.123)	0.4356 (0.018)	0.3697 (0.048)
Water heater	0.4593 (0.008)	0.7401 (<0.001)	0.3863 (0.029)	0.3786 (0.033)	0.3550 (0.046)	0.2283 (0.209)
PCF
First draw	0.4372 (0.103)	0.5107 (0.054)	0.4633 (0.082)	0.0860 (0.760)	0.4124 (0.127)	0.5560 (0.031)
After flushing	0.2901 (0.294)	−0.0036 (0.995)	−0.2017 (0.471)	0.0090 (0.975)	0.3839 (0.158)	0.0733 (0.795)
Water heater	0.4231 (0.152)	0.5494 (0.055)	0.6911 (0.009)	0.5549 (0.052)	0.3195 (0.287)	0.4644 (0.110)
Biofilm	0.2516 (0.215)	0.7308 (<0.001)	0.5107 (<0.001)	0.1972 (0.334)	0.3541 (0.076)	0.4853 (0.012)

^aCorrelation results were presented in the form of Spearman's rank correlation (ρ). P values were indicated in parentheses. Bold values indicate significant difference with 95% confidence (P < 0.05).