Table 1.

Correlation of infection type and biofilm formation in collection of S. aureus clinical isolates. Biofilm formation was measured as A₅₇₀. Mann-Whitney U test was used for statistical comparisons. p>0.05 was considered non-significant (n.s.).

infection type	n	Biofilm formation [mean ± SEM]	p compared to other invasive isolates
all invasive	159	1.9 ± 0.1	-
bacteraemia without focus	31	1.7±0.2	n.s.
invasive skin and soft tissue	37	1.9 ± 0.2	n.s.
biofilm – related:	27	2.5 ± 0.2	0.002
- line-associated	22	2.6 ± 0.2	0.004
- prosthetic joint	2	2.4 ± 0.5	n.s.
native joint arthritis	17	2.0±0.3	n.s.
endovascular	11	1.7±0.4	n.s.
osteomyelitis (all):	13	1.9±0.3	n.s.
- vertebral osteomyelitis	6	2.3 ± 0.6	n.s.
respiratory tract infection	7	1.2 ±0.4	n.s.
urinary tract infection	8	1.7±0.5	n.s.
intraabdominal	7	1.1±0.2	n.s.
other type	1	2.1	n.s.
non-invasive skin infections	49	2.3 ± 0.2	0.031