TABLE 1.

Virulence of (p)ppGpp-defective mutants.

Bacterial Pathogen	Strain	Basal (p)ppGpp	Stringent response	Animal Model/Virulence	References
Acinetobacter baumanii	ΔrelA	Yes	No	G. mellonella: attenuated	Perez-Varela et al. (2020)
Bacillus anthracis	Δrel	Yes	No	Mouse subcutaneous: ND1	van Schaik et al. (2007)
Borrelia burgdorferi	Δrel	No	No	Mouse intradermal: avirulent	Bugrysheva et al. (2005)
Brucella melitensis	Δrel	No	No	Mouse systemic: attenuated	Dozot et al. (2006)
Burkholderia pseudomallei	ΔrelAΔspoT	No	No	G. mellonella and mouse: attenuated	Muller et al. (2012)
Enterococcus faecalis	Δrel	Yes	No	G. mellonella or C. elegans: ND; Mouse CAUTI: ND; Rabbit abscess: ND; Rabbit endocarditis: attenuated	Abranches et al. (2009); Yan et al. (2009), Gaca et al. (2012); Frank et al. (2014), Colomer-Winter et al. (2018, 2019)
	ΔrelQ	Yes	Yes	G. mellonella or C. elegans: ND; Mouse CAUTI: ND; Rabbit abscess: ND; Rabbit endocarditis: ND	Abranches et al. (2009); Gaca et al. (2012), Frank et al. (2014); Colomer-Winter et al. (2018),Colomer-Winter et al. (2019)
	ΔrelΔrelQ	No	No	G. mellonella or C. elegans: attenuated; Mouse CAUTI: attenuated; Rabbit abscess: attenuated; Rabbit endocarditis: ND	Abranches et al. (2009); Gaca et al. (2012), Frank et al. (2014); Colomer-Winter et al. (2018),Colomer-Winter et al. (2019)
Francisella novocida	ΔrelA	Yes	No	Mouse (intranasal): attenuated	Dean et al. (2009)
Francisella tularensis	ΔrelAΔspoT	No	No	Mouse (intranasal): avirulent	Charity et al. (2009); Ma et al. (2019)
Haemophilus ducreyi	ΔrelAΔspoT	No	No	Human pustule: attenuated	Holley et al. (2014)
Listeria monocytogenes	Δrel	Yes	No	Mouse systemic: avirulent	Taylor et al. (2002), Bennett et al. (2007)
	rel:Tn	?	?	Mouse systemic: attenuated	Taylor et al. (2002)
	ΔrelΔrelPΔrelQ	No	No	Mouse systemic: attenuated	Whiteley et al. (2015)
Mycobacterium tuberculosis	relH344Y	Yes	No	Mouse lung: attenuated	Weiss and Stallings (2013)
	relH80A	Yes	Yes	Mouse lung: attenuated	Weiss and Stallings (2013)
	ΔrelΔSAS	No	No	Mouse lung: attenuated	Weiss and Stallings (2013)
	Δrel	Yes	No	Mouse lung and guinea pig lung: attenuated	Dahl et al. (2003); Klinkenberg et al. (2010)
Pseudomonas aeruginosa	ΔrelA	Yes	No	D. melanogaster: attenuated; Mouse abscess: ND	Vogt et al. (2011); Pletzer et al. (2017)
	ΔrelAΔspoT	No	No	D. melanogaster, Mouse pneumonia: avirulent/attenuated; Mouse abscess/skin: attenuated	Vogt et al. (2011); Xu et al. (2016), Pletzer et al. (2017)
Salmonella Gallinarum	ΔrelAΔspoT	No	No	Chicken (oral): attenuated	Park et al. (2010)
Salmonella Typhi	ΔrelAΔspoT	No	No	Mouse (oral): avirulent	Dasgupta et al. (2019)
Salmonella Typhimurium	ΔrelA	Yes	No	Mouse (intragastric): attenuated	Pizarro-Cerda and Tedin (2004)
	spoT-Δctd	Yes	Yes	Mouse (oral): attenuated	Fitzsimmons et al. (2020)
	ΔrelAΔspoT	No	No	Mouse (intragastric): avirulent	Pizarro-Cerda and Tedin (2004)
Staphylococcus aureus	relSaF128Y	High	Yes	G. mellonella: attenuated	Gao et al. (2010)
	relSasyn	Yes	No	Mouse kidney: attenuated; Mouse skin: attenuated	Geiger et al. (2010); Mansour et al. (2016)
	ΔrelP	Yes	Yes	Rabbit endocarditis: ND	Li et al. (2020)
Streptococcus pneumoniae	ΔrelSpn	Yes	No	Mouse pneumonia: attenuated	Kazmierczak et al. (2009)
Streptococcus suis	ΔrelΔrelQ	No	No	Mouse systemic: avirulent	Zhu et al. (2016)
Vibrio cholerae	ΔrelA	Yes	No	Suckling mouse: attenuated/ND 2; Rabbit ileal loop: attenuated	Haralalka et al. (2003)
	ΔrelAΔspoT	Yes	No	Infant mouse: ND	Oh et al. (2014)
	ΔrelAΔspoTΔrelV	No	No	Infant mouse: attenuated	Oh et al. (2014)
Yersinia pestis	ΔrelA	Yes	No	Mouse: ND	Sun et al. (2009)
	ΔrelAΔspoT	No	Yes	Mouse: attenuated	Sun et al. (2009)

ND, no differences when compared to parent strain. Conflicting data from different laboratories.