Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

Table 2

Effect of fluoroquinolone resistance selection on the growth of C. perfringens strains (shown by OD₇₅₀) with different concentrations of sodium chloride, urea, sodium lactate, and sodium nitrite^a.

C. perfringens strain	Compound	Wild type	Norfloxacin-resistant	Ciprofloxacin-resistant	Gatifloxacin-resistant
VPI	Sodium chloride	1%	1%	4%^*b	2%
NCTR		2%	2%	2%	1%
3626		2%	2%	2%	2%
13124		6.5%	4%^*	6%	2%^*
VPI	Urea	6%	6%	4%	4%^*
NCTR		6%	4%	3%	2%^*
3626		3%	4%	4%	2%
13124		7%	6%	7%^**c	6%^*
VPI	Sodium lactate	1%	1%	2%^*	2%
NCTR		2%	1%	2%^**	2%
3626		1%	2%	2%	2%
13124		6%	4%^*	5%^*	3%^**
VPI	Sodium nitrite	60 mM	40 mM^*	40 mM^*	60 mM
NCTR		60 mM	40 mM	60 mM^**	20 mM^*
3626		20 mM	40 mM	40 mM	20 mM
13124		60 mM	60 mM	60 mM	40 mM^*

The percent (%) or mM value indicates the concentration in which the strain would grow. ^b*Statistically significant differences are marked by asterisks ( < 0.05). ^c**Better growth was observed for the mutant than for the wild type ( < 0.05) at the concentrations marked by double asterisks.