Table 5.

Characteristics of C. difficile strains with reduced susceptibility to metronidazole from 16 studies published between 2012 and 2015.

Antibiotic	Origin	Year of isolation	Country	Number of strains	PCR- ribotypes	MIC value (mg/l)	MICs after strains manipulation (mg/l)	References
Metronidazole
	Human
		2002–2007	Taiwan	2		>2		Chia et al. [2013]
		2009	Canada	1	027	>32	8	Lynch et al. [2013]
		2007–2010	Texas	36		32		Norman et al. [2014]
		2010–2011	Iran	4		32–64		Goudarzi et al. [2013]
		2011–2012	Europe	1	106	8		Freeman et al. [2015]
		2014	Israel	38	027	>2		Adler et al. [2015]
	Animal
	swine	-	Spain	4	078	≥256		Peláez et al. [2013]
	dog	-	Sweden	1		64	2–8	Wetterwik et al. [2013]
	swine	2007–2010	Texas	21		32		Norman et al. [2014]
	zebra	-	Spain	1		≥256	< 2	Álvarez-Pérez et al. [2014]
	dog	2007–2013	Italy	14	010 078	3–≥256	0.25–32	Spigaglia et al. [2015]
Vancomycin
	Human
		2002–2007	Taiwan	5		>2		Chia et al. [2013]
		2010–2011	Iran	2		4		Goudarzi et al. [2013]
		2010–2012	China	2		8		Dong et al. [2013]
		2005–2010	Taiwan	2		4		Liao et al. [2012]
		2014	Israel	98	027	>2		Adler et al. [2015]

MIC, minimum inhibitory concentration; PCR, polymerase chain reaction.