Table 1.

The numbers (%) of patients with different types of bacteria in the nose and the groin before (n = 133) and after (n = 120) a primary hip or knee arthroplasty. Pairwise comparison of pre- and postoperative findings with McNemar’s exact test

	Nose			Groin			Nose and groin (either or both)
	Preop.	Postop.	p-value	Preop.	Postop.	p-value	Preop.	Postop.	p-value
Staphylococcus aureus Coagulase-negative	37 (28)	27 (23)	0.3	9 (7)	8 (7)	1.0	42 (32)	28 (23)	0.06
staphylococci	103 (77)	95 (79)	0.6	126 (95)	101 (84)	0.01	130 (98)	114 (95)	0.4
Staphylococcus lugdunensis	5 (4)	12 (10)	0.1	17 (13)	18 (15)	0.7	21 (16)	27 (23)	0.2
Streptococci	1 (1)	2 (2)	1.0	2 (2)	0 (0)	1.0	3 (2)	2 (2)	1.0
Enterococcus faecalis	0 (0)	1 (1)	1.0	1 (1)	3 (3)	0.3	1 (1)	4 (3)	0.1
Gram-negative bacteria a	11 (8)	8 (7)	0.8	7 (5)	21 (18)	0.002	16 (12)	26 (22)	0.02
Other bacteria b	3 (2)	1 (1)	1.0	4 (3)	3 (3)	1.0	5 (4)	3 (3)	1.0
No bacteria	10 (8)	11 (9)	1.0	3 (2)	4 (3)	1.0	0 (0)	1 (1)	1.0

^a E. coli, Citrobacter diversus, Pseudomonas aeruginosa, Klebsiella oxytoca, Proteus mirabilis, Morganella morganii, Enterobacteriaceae sp.

^b Bacillus cereus, Corynebacterium sp., Acinetobacter, mixed Gram-negative and Gram-positive culture.