Prevalence of Multidrug-Resistant Listeria monocytogenes in Dairy Products with Reduction Trials Using Rosmarinic Acid, Ascorbic Acid, Clove, and Thyme Essential Oils

Table 1

Biochemical tests used to differentiate between Listeria spp.

Species	Hemolysis	Catalase test	Oxidase test	D-mannitol fermentation	Rhamnose fermentation	D-xylose fermentation	CAMP (S. aureus)	Listeria latex agglutination	Permissible counts	Reference
L. monocytogenes	+ (β)	+	−	−	+	−	+	+++	ND	MacFaddin [19]
L. innocua	−	+	−	−	V	−	−	+	ND
L. ivanovii	+	+	−	−	−	+	−	+	ND
L. seeligeri	(+)	+	−	−	−	+	(+)	+	ND
L. welshimeri	−	+	−	−	V	+	−	+	ND
L. grayi	−	+	−	+	−	−	−	+	ND

+: Positive test; -: negative test; (+): weak reaction; V: variable results; and +++: strong positive result. The permissible count for L. monocytogenes in milk and dairy products is zero (ND: not detected) [20,21].