Genome analysis identifies a spontaneous nonsense mutation in ppsD leading to attenuation of virulence in laboratory-manipulated Mycobacterium tuberculosis

Table 1 Virulence characteristics of strains used in the study^a

Strain	Background	DevR expression	Body weight score	Organ weight ratio		Organ visual score		Bacterial load		Virulence index
Strain	Background	DevR expression	Body weight score	Spleen	Lung	Spleen	Lung	Spleen	Lung	Virulence index
H37Rv (wild type)	–	+	1.000	1.000	1.000	1.000	1.000	1.000	1.000	1.000
Mut 1	H37Rv disrupted in devR by Kan^R-cassette insertion	–	1.004	0.827	1.048	0.903	0.938	0.269***	2.687	1.096
Comp1	Mut1	+	1.251*	0.357***	0.610***	0.069***	0.219*	0.00002***	0.0003*	0.358
Comp9	Mut1	+	1.019	0.785	1.155	0.787	0.521	0.222***	1.165	0.808
Comp11	Mut1	+	0.980	0.851	0.975	0.972	0.938	0.227***	2.341	1.041

^aThe data is compiled from our earlier publication [16]. A score of 1 is assigned to all parameters (body weight score etc.) and to the overall virulence index at 13 weeks that were measured during guinea pig infection with H37Rv. The relative scores for other strains are calculated with reference to that of H37Rv. [*** pvalue < 0.001; * pvalue < 0.05]

ISSN: 1471-2164