TABLE 2.

Additional tests for correct identification of strains identified with low discrimination by VITEK 2 NH card

Reference identification	VITEK 2 NH results	Additional test(s) for correct identification to species level
C. jejuni subsp. jejuni	C. coli-C. jejuni	Hippurate hydrolysis: C. jejuni subsp. jejuni (positive), C. coli (negative)
H. influenzae	H. influenzae-H. haemolyticus	Hemolysis on horse blood agar: H. haemolyticus (positive), H. influenzae (negative)
H. parainfluenzae	H. parainfluenzae-H. segnis-H. haemolyticus	Oxidase testing: H. parainfluenzae (positive), H. haemolyticus (positive), H. segnis (negative)
		Hemolysis on horse blood agar: H. haemolyticus (positive), H. parainfluenzae (negative), H. segnis (negative)
		X-factor requirement: H. haemolyticus (positive), the other species (negative)
N. meningitidis	N. meningitidis-N. sicca	Growth on Martin-Lewis agar: N. meningitidis (positive), N. sicca (negative)
	N. meningitidis-K. denitrificans	Catalase testing: N. meningitidis (positive), K. denitrificans (negative)
		Gram stain: N. meningitidis (cocci), K. denitrificans (rods)
N. elongata subsp. elongata	N. elongata-E. corrodens	Colony morphology: typical for E. corrodens colonies after 48 h of incubation (clear center often surrounded by spreading growth, may pit the agar)
K. denitrificans	K. denitrificans-N. cinerea	Gram stain: N. cinerea (cocci), Kingella (rods); catalase testing: N. cinerea (positive), K. denitrificans (negative)
H. aphrophilus or H. paraphrophilus	H. aphrophilus-H. paraphrophilus-H. segnis	V-factor requirement: positive for H. paraphrophilus, H. segnis; negative for H. aphrophilus
		X-factor requirement: weakly positive for H. aphrophilus
		Oxidase testing: positive for H. paraphrophilus, negative for H. segnis