The human bile salt sodium deoxycholate induces metabolic and cell envelope changes in Typhi leading to bile resistance.

serovar Typhi (. Typhi) is the etiological agent of typhoid fever. To establish an infection in the human host, this pathogen must survive the presence of bile salts in the gut and gallbladder.

The CRISPR-Cas System Is Involved in OmpR Genetic Regulation for Outer Membrane Protein Synthesis in Typhi.

The CRISPR-Cas cluster is found in many prokaryotic genomes including those of the Enterobacteriaceae family. serovar Typhi (. Typhi) harbors a Type I-E CRISPR-Cas locus composed of , , , , , , , , and a CRISPR1 array.

The Salmonella enterica Serovar Typhi Gene Encodes Two Proteins Whose Transcriptional Expression Is Upregulated by Alkaline pH and Repressed at Their Promoters and Coding Regions by H-NS and Lrp.

LtrR is a LysR-type regulator involved in the positive expression of to promote and expression. This regulatory network is fundamental for the control of bacterial transformation and resistance to the bile salt sodium deoxycholate in serovar Typhi. In this work, the transcriptional regulation of was characterized, revealing that the use of alternative promoters results in two transcripts.

The CRISPR-Cas system in Enterobacteriaceae.

In nature, microorganisms are constantly exposed to multiple viral infections and thus have developed many strategies to survive phage attack and invasion by foreign DNA. One of such strategies is the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) bacterial immunological system. This defense mechanism is widespread in prokaryotes including several families such as Enterobacteriaceae.

CRISPR-Cas system presents multiple transcriptional units including antisense RNAs that are expressed in minimal medium and upregulated by pH in Salmonella enterica serovar Typhi.

The CRISPR-Cas system is involved in bacterial immunity, virulence, gene regulation, biofilm formation and sporulation. In Salmonella enterica serovar Typhi, this system consists of five transcriptional units including antisense RNAs. It was determined that these genetic elements are expressed in minimal medium and are up-regulated by pH.