Whole-genome sequence analysis of multidrug-resistant uropathogenic strains of Escherichia coli from Mexico.

Background : Escherichia coli is the main bacterium associated with urinary tract infections (UTIs), including cystitis and pyelonephritis. Uropathogenic E. coli (UPEC) harbors numerous genes that encode diverse virulence factors contributing to its pathogenicity. The treatment of UTIs has become complicated due to the natural selection of E. coli strains that are multiresistant to several groups of antibiotics regularly used in clinical settings such as hospitals. Genomic reports of the global composition and distribution of the antibiotic resistance and virulence genes of these pathogenic strains are lacking in the Mexican population. Purpose and methods : The aim of this study was to globally characterize the genomes of a group of UPEC strains by massive parallel sequencing to determine the prevalence and distribution of virulence and antibiotic resistance genes associated with different serotypes and phylogenetic groups. Results: The strains exhibited 138-197 virulence genes and 29 antibiotic resistance genes related to antibiotics that are commonly used in clinical practice.  Conclusions: These findings are relevant to the definition of new strategies for treating urinary tract infections in public hospitals and private practice. To further define the epidemiological distribution and composition of these virulence and antibiotic resistance genes, larger studies are needed.

Taenia solium: antioxidant metabolism enzymes as targets for cestocidal drugs and vaccines.

This review focuses in the role that antioxidant enzymes play in protection and other important physiological functions such as signal transduction, cell differentiation, growth and apoptosis. Parasites use these enzymes to evade ROS produced by the host immune response and for development inside the host. In the cestoda Taenia solium, three antioxidant enzymes have been studied: a cystosolic Cu,Zn superoxide dismutase that is a target of cestocidal drugs (bencimidazoles); a 2-Cys peroxiredoxin that is a regulatory enzyme of H(2)O(2), molecule essential for several physiological functions; and two isoforms of glutathione transferases that are immunological targets, since they protect immunized mice against cysticercosis. Moreover, all these enzymes are present in all stages of the parasite. These findings suggest that antioxidant enzymes have an important role in T. solium physiology and infection, therefore they might represent the Achilles' heel of the parasite.