Modelling invasive group A streptococcal disease using bioluminescence

BMC Microbiology

Table 1 Fitness burden conferred by bioluminescence in M89::Lux during soft tissue infection

	Thigh muscle	Lymph node	Spleen	Liver	Blood
Number of mice with bacteria (WT or BLI strain) present^a	6/6	3/6	4/6	3/6	3/6
Median Competitive index^b (range)	0.70 (0.66–1.16)	1.9 (0.8–3)	0.25 ^c	^d	^d

^aMice infected i.m. with equal inocula of M89 and M89::Lux. Samples taken 24 h after infection. Number of mice where any GAS bacteria could be cultured is indicated (wildtype or bioluminescent strain)
^bCompetitive index calculated as M89::Lux cfu/M89 cfu and could only be calculated for mice with detectable bacteria. A value of 1 indicates no fitness burden. M89::Lux was distinguished from the parent strain by replica plating onto selective media
^c No range because only one CI could be calculated
^dCompetitive index could not be calculated because only WT disseminated to blood or liver (i.e. CI = 0)

ISSN: 1471-2180