deoxycholic-acid and Escherichia-coli-Infections

Resistance to antimicrobials is normally caused by mutations in the drug targets or genes involved in antimicrobial activation or expulsion. Here we show that an

Topics: Anti-Bacterial Agents; Chromosome Inversion; Deoxycholic Acid; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests

Escherichia coli is the species that is most frequently isolated from bile of patients with biliary tract diseases. This study was aimed to investigate any association between resistance and virulence properties of these isolates with occurrence of the diseases. A total of 102 bile samples were obtained from patients subjected to endoscopic retrograde cholangiopancreatography for different biliary diseases. Clinical data were collected and culture of the bile samples was done on selective media. Resistance of characterized Escherichia coli isolates to deoxycholate sodium (0-7%) and nineteen antibiotics was determined and PCR using 16 pairs of primers targeting stx1, stx2, exhA, eae, bfp, agg, pcvd432, lt, st, ipaH, pic, pet, ast, set, sen, and cdtB genes was done. Our results showed a statistically significant association between E. coli colonization and existence of common bile duct and gallbladder stones (p value 0.028). Out of the 22 E. coli strains (22/102) multidrug resistance phenotype was present in 95.45%. None of the strains belonged to common E. coli pathotypes. However, bfp + EhxA-hly, bfp + astA, bfp + EhxA-hly + pic, and EhxA-hly + pic + astA, bfp, and astA genotypes were detected in these strains. bfp (7/22, 31.8%) and astA (5/22, 22.7%) were among most frequent virulence factors in these strains. Results of this study showed significant association between colonization of E. coli and choledocholithiasis. Unusual existence of virulence gene combinations in these strains and their resistance to DOC and multiple classes of antibiotics could be considered as possible causes of their persistence in this harsh microenvironment.

Topics: Bile; Bile Ducts; Biliary Tract Diseases; Choledocholithiasis; Deoxycholic Acid; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Enterotoxigenic Escherichia coli; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gallbladder; Genes, Bacterial; Genotype; Humans; Iran; Microbial Sensitivity Tests; Phenotype; Virulence; Virulence Factors

Chitosan (CH) coated ciprofloxacin-sodium deoxycholate surfplex (CFn-SDC) loaded nanoemulsion (LE-CH-CFn-SDC) developed in order to improve tissue penetration of the CFn as well as to mop up the endotoxin (Lipopolysaccharides or LPS) released from bacteria during antibiotic treatment.. Size and zeta potential was evaluated for nanoemulsions prepared by high-speed homogenization and sonication. Drug analysis in samples was done by HPLC equipped with fluorescence detector. All formulations were evaluated for any change in LPS induced NO and TNF-α release and ROS generation in J774 macrophages. The formulations were also evaluated for in-vitro killing efficiency on E-Coli. The efficacy of formulations in terms of survival and pharmacokinetics and inhibition of induction of cytokines was carried out in E-coli induced peritonitis model in rats. LE-CH-CFn-SDC interacted with LPS both by electrostatic and hydrophobic interactions.. LE-CH-CFn-SDC resulted in reduction of endotoxin release and MIC values for E. coli. LE-CH-CFn-SDC also reduced NO and TNF-α as well as ROS generation by reducing the uptake of LPS in J774 macrophages. LE-CH-CFn-SDC improved CFn pharmacokinetics and tissue distribution, by reducing the bacterial burden, LPS and cytokines (TNF-α and IL-6) thereby improving survival in a rat model of E. coli induced peritonitis.. In conclusion, this work highlights the effectiveness of the chitosan-coated nanoemulsion as intracorporeal approach for therapeutic intervention of E. coli induced peritonitis as well as in sepsis.

Topics: Animals; Anti-Bacterial Agents; Cations; Chitosan; Ciprofloxacin; Deoxycholic Acid; Drug Carriers; Emulsions; Escherichia coli; Escherichia coli Infections; Lipopolysaccharides; Microbial Sensitivity Tests; Nanostructures; Particle Size; Peritonitis; Rats, Wistar; Sepsis; Technology, Pharmaceutical

Shiga toxin-producing Escherichia coli (STEC) can cause conditions ranging from diarrhea to potentially fatal hemolytic uremic syndrome. Enteropathogen adaptation to the intestinal environment is necessary for the development of infection, and response to bile is an essential characteristic. We evaluated the response of STEC strain M03 to the bile salt sodium deoxycholate through proteomic analysis. Cell extracts of strain M03 grown with and without sodium deoxycholate were analyzed by two-dimensional electrophoresis; the differentially expressed proteins were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Three proteins were found to be differentially expressed due to sodium deoxycholate. Glycerol dehydrogenase and phosphate acetyltransferase, which are involved in carbon metabolism and have been associated with virulence in some bacteria, were downregulated. The elongation factor Tu (TufA) was upregulated. This protein participates in the translation process and also has chaperone activities. These findings help us understand strategies for bacterial survival under these conditions.

Topics: Deoxycholic Acid; Drug Resistance, Bacterial; Escherichia coli Infections; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Hemolytic-Uremic Syndrome; Proteome; Proteomics; Shiga-Toxigenic Escherichia coli

Plasmid-mediated Qnr and AAC(6')-Ib-cr have been recognized as new molecular mechanisms affecting fluoroquinolone (FQ) resistance. C316, an Escherichia coli strain demonstrating resistance to various FQs, was isolated in Japan. Resistance to FQs was augmented in an E. coli CSH2 transconjugant, but PCR failed to detect qnr genes, suggesting the presence of novel plasmid-mediated FQ resistance mechanisms. Susceptibility tests, DNA manipulation, and analyses of the gene and its product were performed to characterize the genetic determinant. A novel FQ-resistant gene, qepA, was identified in a plasmid, pHPA, of E. coli C316, and both qepA and rmtB genes were mediated by a probable transposable element flanked by two copies of IS26. Levels of resistance to norfloxacin, ciprofloxacin, and enrofloxacin were significantly elevated in E. coli transformants harboring qepA under AcrB-TolC-deficient conditions. QepA showed considerable similarities to transporters belonging to the 14-transmembrane-segment family of environmental actinomycetes. The effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP) on accumulation of norfloxacin was assayed in a qepA-harboring E. coli transformant. The intracellular accumulation of norfloxacin was decreased in a qepA-expressing E. coli transformant, but this phenomenon was canceled by CCCP. The augmented FQ resistance level acquired by the probable intergeneric transfer of a gene encoding a major facilitator superfamily-type efflux pump from some environmental microbes to E. coli was first identified. Surveillance of the qepA-harboring clinical isolates should be encouraged to minimize further dissemination of the kind of plasmid-dependent FQ resistance determinants among pathogenic microbes.

Topics: Amino Acid Sequence; Anti-Bacterial Agents; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Chitosan; Conjugation, Genetic; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Humans; Malates; Microbial Sensitivity Tests; Molecular Sequence Data; Plasmids; Reverse Transcriptase Polymerase Chain Reaction; Transformation, Bacterial; Uncoupling Agents

Polymyxin B (PMB), an antibiotic, and sodium deoxycholate (NaD), a bile salt, are surface-active agents. Each protected mice against an otherwise lethal challenge with purified endotoxin (P less than .001). To determine if either of these agents was effective in treating established, overwhelming gram-negative septicemia, we infected rabbits by intraperitoneal injection of Escherichia coli K1. Animals were treated with moxalactam 1 hr after infection, then randomly assigned to groups receiving either saline, PMB, or NaD. Serial samples of blood were assayed for bacterial concentration, levels of plasma endotoxin, arterial blood gases, and complete blood cell counts. Physiologic functions were monitored continuously. Although levels of bacteremia and endotoxemia were similar in all three groups, rabbits receiving PMB had significantly higher mean arterial blood pressure, blood pH, and bicarbonate concentrations than did control rabbits (P less than .05). Rabbits receiving NaD fared no better than controls. In this model, PMB moderates some of the deleterious effects of established, overwhelming gram-negative bacterial sepsis.

Topics: Acidosis; Animals; Carbon Dioxide; Deoxycholic Acid; Endotoxins; Escherichia coli; Escherichia coli Infections; Hydrogen-Ion Concentration; Hypotension; Leukocyte Count; Mice; Oxygen; Platelet Count; Polymyxin B; Polymyxins; Rabbits; Sepsis

Freeze-thaw lysates prepared from strains of Escherichia coli belonging to serogroups O138, O139, and O141 contained a principle (edema disease principle) which induced edema disease in swine. All freeze-thaw lysates contained endotoxic activity that tended to obscure the edema disease syndrome and methods were developed to reduce such activity. Freeze-thaw lysates prepared from E. coli O139 induced the most characteristic edema disease syndrome. Partially purified edema disease principle prepared from O139 freeze-thaw lysates by sequential precipitation with ammonium sulphate and streptomycin sulphate had increased specific activity with markedly reduced endotoxic activity. This material was insoluble at acidic pH but readily soluble at alkaline pH. The effective molecular weight of edema disease principle, based on retention and filtration properties of diaflo membranes, appeared to be greater than 50,000 and less than 100,000. The biological activity of edema disease principle was thermolabile. Sodium deoxycholate treatment of edema disease principle further reduced endotoxic activity. A thermolabile, ammonium sulphate precipitable material was prepared from E. coli O139 that induced a predictable syndrome which resembled edema disease clinically and pathologically following intravenous inoculation in pigs.

Topics: Ammonium Sulfate; Animals; Chemical Precipitation; Culture Media; Deoxycholic Acid; Edema Disease of Swine; Endotoxins; Escherichia coli; Escherichia coli Infections; Female; Injections, Intravenous; Male; Molecular Weight; Shock, Septic; Streptomycin; Swine; Swine Diseases; Ultrafiltration

Topics: Administration, Oral; Bacterial Vaccines; Deoxycholic Acid; Enteritis; Escherichia coli; Escherichia coli Infections; Germany, East; Humans; Immunization, Secondary; Infant, Newborn; Infant, Newborn, Diseases; Vaccination; Vaccines, Attenuated