DNA supercoiling and regulation of intrinsic β-lactamase in pathogenic Escherichia coli.

This review addresses the involvement of DNA supercoiling in the development of virulence and antibiotic profiles for uropathogenic Escherichia coli and the emergence of new pathotypes such as strain ST131 (serotype O25:H4). The mechanism suggests a role for topoisomerase enzymes and associated mutations in altering the chromosomal supercoiling state and introducing the required DNA twists for expression of intrinsic β-lactamase by ampC and certain virulence factors. In Escherichia coli, constitutive hyperexpression of intrinsic ampC is associated with specific mutations in the promoter and attenuator regions.

Patterns of antimicrobial resistance observed in the Middle East: Environmental and health care retrospectives.

Antimicrobial resistance is one of the biggest worldwide challenging problems that associates with high morbidity and mortality rates. The resistance of bacteria to various antibiotic classes results in difficulties in the treatment of infectious diseases caused by those bacteria. This paper highlights and provides a critical overview of observational and experimental studies investigating the presence of antibiotic resistant bacteria in different environments in Middle East countries and the mechanisms by which bacteria acquire and spread resistance.

Identification of novel DNA sequence associated with pathogenicity island III locus in Uropathogenic Escherichia coli isolate and distribution of virulence determinants in β-lactam resistant isolates.

Background: There is an increase in the number of Enterobacteriaceae with Extended-spectrum beta-lactamase (ESBL) type of antibiotic resistance in the Kingdom of Bahrain. However, the virulence determinants of the clinical isolates have not been previously assessed. The current study investigates the distribution of different virulence factors and the phylogenetic groups of antibiotic resistant Escherichia coli isolates in extraintestinal infections.

MobilomeFINDER: web-based tools for in silico and experimental discovery of bacterial genomic islands.

MobilomeFINDER (http://mml.sjtu.edu.

A novel strategy for the identification of genomic islands by comparative analysis of the contents and contexts of tRNA sites in closely related bacteria.

We devised software tools to systematically investigate the contents and contexts of bacterial tRNA and tmRNA genes, which are known insertion hotspots for genomic islands (GIs). The strategy, based on MAUVE-facilitated multigenome comparisons, was used to examine 87 Escherichia coli MG1655 tRNA and tmRNA genes and their orthologues in E.coli EDL933, E.