Typhimurium virulence in the murine model, as an yqiC mutant strain was unable to kill mice within the period of time assayed and
had a significantly higher LD50. The basis for this attenuation in virulence may be related to the observed defect to grow at physiological temperature in vitro. Temperature represents a common environmental challenge that microorganisms should be able to sense and respond to in order to survive . selleck products Many other single gene mutations produce temperature-sensitive, virulence-attenuated Salmonella strains. Examples include smpA, which encodes for an outer membrane lipoprotein, uspA, which encodes for an universal stress response protein and the genes for DegP and DegQ proteases [29–31]. Interestingly, temperature sensitivity could not be the only factor responsible for the virulence attenuation observed for the yqiC mutant, as this strain was still able to invade and replicate inside macrophages and epithelial
cell lines incubated at 37°C. These phenotypes may be due to differences in the metabolic status and environmental conditions affecting bacteria replication in rich media under laboratory conditions and inside the eukaryotic cell. Conclusion We have demonstrated in this work LY2874455 that S. Typhimurium YqiC shares structural and biochemical characteristics with B. abortus BMFP, in spite
of their relatively low sequence identity. Thus, members of the COG 2960 may accomplish a conserved function among phylogenetically distant bacteria. This function may be necessary to display full virulence. This seems to be the case, as in a parallel work we observed virulence selleck chemical attenuation when analyzing a B. abortus BMFP-defective strain (Cravero et al, unpublished work). This work is the first demonstration of the in vivo importance of a member of the COG 2960. However, future research is necessary to clarify the physiological processes in which the membrane fusogenic activity and possibly other unknown functions of YqiC are required. Methods Ethics Statement All experiments involving animals have been approved by the ethics committee of the Instituto Nacional de Tecnologia Agropecuaria (INTA) where they were conducted. This ethics committee works according with the National Institutes of Health Guide for the Care and Use of Animals Laboratory . Bacterial Strains and selleck chemicals Growth Conditions For this study, we used the WT Salmonella enterica serovar Typhimurium strain ATCC 14028. Bacterial strains were grown in Luria-Bertani (LB) or M9 minimal medium containing casamino acids and glucose. Appropriate antibiotics were added to the following final concentrations: 100 μg ml-1 ampicillin, 25 μg ml-1 kanamycin, and 10 μg ml-1 chloramphenicol.