The recent data indicate that rtxC is not necessary for the MARTX toxin function in V. cholerae, but the MARTX toxin without rtxC activation showed reduced actin cross-linking activity (Cheong et al., 2010), while a deletion of rtxC had no effect on the virulence of V. vulnificus (Lee et al., 2007; Liu et al., 2007;).
We utilized this mutant LacI to investigate whether operator-binding property of LacI is responsible for its effect on the virulence of S. enterica.
The presence of GFP did not show any significant effect on the virulence of the WT strain (CI = 1.22±0.24; P>0.05).
As in S. aureus, which lowered the expression of leukotoxins in the presence of IL-1β [4], IL-1β might also regulate the expression of A. actinomycetemcomitans leukotoxin, thus having a broader effect on the virulence of the species.
Moreover, Salmonella grown in various media demonstrated that ion concentrations had a direct effect on the virulence of the spaceflight cultures.
Besides being an essential process, we also demonstrated that protein-O-glycosylation has a significant effect on the virulence of C. neoformans, even in instances in which it is not required for viability.
However, as shown in Fig. 3, even at 100 µg/ml, gentamicin only appeared to have a marginal effect on the virulence of PA14 in the Arabidopsis pathogenicity assay.
Several amino acid mutations of the polymerase (PB2, PB1, and PA) and NP protein may have an important effect on the virulence and adaptation of H5N1 virus in the hosts including mice [39] [42].
Although the flagella, siderophores, porin, and bacterial capsules have been previously reported to have correlations with A. hydrophila pathogenesis, the mutation of these factors in this study did not show any major effects on the virulence of A. hydrophila AH-3 in P. leniusculus or in T. molitor larvae.
Predictably, DsbA disruption affects multiple downstream effector molecules, resulting in pleiotropic effects on the virulence of important human pathogens.
