Most bacterial and archaeal genomes contain many genes with little or no similarity to other genes, a property that impedes identification of gene origins. By comparing the codon usage of genes shared among strains (primarily vertically inherited genes) and genes unique to one strain (primarily recently horizontally acquired genes), we found that the plurality of unique genes in Escherichia col...

Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli. Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid resistance (AR) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of AR in E. coli. The rol...

Bacterial strains which possess genes to produce ESBL most often are multiresistant and also carry genes responsible for the resistance to most other antibiotics, including aminoglycosides, sulfamethoxazole+trimethoprim and fluoroquinolones. Therefore, practically the biggest contemporary clinical problem are infections of humans and animals caused by ESBL-producing strains of E. coli, Kleibsie...

Adaptation in bacterial chemotaxis involves reversible methylation of specific glutamate residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins. The specific sites of methylation in Salmonella enterica and Escherichia coli chemoreceptors, identified 2 decades ago, established a consensus sequence for methylation by methyltransferase CheR. Here we report the in vitro met...

Objective(s) Extensive use of quinolones has been associated with raising level of resistance. In the current, we focused on assessing the prevalence of Escherichia coli resistance to quinolones and frequency of qnrA, qnrB and qnrS in non ESBLs (extended spectrum beta-lactamases) and ESBLs producing E. coli with blaSHV and blaTEM. Materials and Methods One hundred and fifty E. coli isolates ...

Translation elongation factor P (EF-P), a ubiquitous protein over the entire range of bacterial species, rescues ribosomal stalling at consecutive prolines in proteins. In Escherichia coli and Salmonella enterica, the post-translational β-lysyl modification of Lys34 of EF-P is important for the EF-P activity. The β-lysyl EF-P modification pathway is conserved among only 26-28% of bacteria. Rece...

From 1948 to 1988, there were 6 confirmed foodborne disease outbreaks in the U.S. transmitted with domestically produced hard cheeses as the food vehicle. Various research reports have raised concerns about the public health protection provided by the current 60-day aging period in the manufacture of hard cheeses made with unpasteurized milk. The objective of this study was to investigate the a...

Intestinal inflammation induces alterations of the gut microbiota and promotes overgrowth of the enteric pathogen Salmonella enterica by largely unknown mechanisms. Here, we identified a host factor involved in this process. Specifically, the C-type lectin RegIIIβ is strongly upregulated during mucosal infection and released into the gut lumen. In vitro, RegIIIβ kills diverse commensal gut bact...

Growing interest to use natural preservatives and spices with antimicrobial effects and large amounts of floral bio-residues (92.6 g per 100 g) generated and wasted in the production of saffron spice guided this study  to evaluate  the opportunity to expand the uses of C. sativus flowers (petals and stamens), beyond the spice (dried stigmas). The antibacterial potential of total extrac...

Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowled...