The strain Escherichia coli Nissle 1917 (EcN) is widely used as an efficient probiotic in therapy and prevention of human infectious diseases, especially of the intestinal system. Concurrently, small adult pigs are being used as experimental omnivore models to study human gastrointestinal functions. EcN bacteria were applied to 6 adult healthy female pigs in a 2-week trial. 6 Control animals remained untreated. Altogether, 164 and 149 bacterial strains were isolated from smear samples taken from gastrointestinal mucosa in the experimental and control group, respectively. Each individual E. coli strain was then tested for the presence of 29 bacteriocin-encoding determinants as well as for DNA markers of A, B1, B2 and D phylogenetic groups. A profound reduction of E. coli genetic variance (from 32 variants to 13 ones, P = 0.0006) was found in the experimental group, accompanied by a lower incidence of bacteriocin producers in the experimental group when compared to control (21.3 and 34.9%, respectively; P = 0.007) and by changes in the incidence of individual bacteriocin types. The experimental administration of EcN strain was not sufficient for stable colonization of porcine gut, but induced significant changes in the enterobacterial microbiota.

• MeSH
• Genes, Bacterial MeSH
• Bacteriocins genetics   MeSH
• Escherichia coli classification   isolation & purification   MeSH
• Phylogeny MeSH
• Genetic Variation MeSH
• Molecular Typing MeSH
• Swine MeSH
• Probiotics administration & dosage   MeSH
• Biota * MeSH
• Intestinal Mucosa microbiology   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Bacteriocins MeSH

The current incidence of Escherichia coli strains in healthy humans capable of producing the inhibitory exoproducts, such as temperate bacteriophages, corpuscular or HMW (high-molar mass) and proteinaceous or LMW (low-molar mass) colicins and siderophores was determined. Fifty-three E. coli strains were collected from the colons of 53 healthy human volunteers in Brno (Czechia) and tested for spontaneous and induced production of inhibitory exoproducts in a cross-test against each other. Of the strains tested, 37.7% produced bacteriophages, 41.5% produced from one to several LMW colicins, 11.3% formed HMW colicins and 15.1% (eight strains) produced exocellular siderophores different from enterochelin. Of these, seven strains formed aerobactin and one strain formed an untyped siderophore. E. coli strains differ greatly in the incidence of colicinogeny and lysogeny from its closest systemic relatives in the genus Escherichia and therefore should not be regarded as a model bacterium in this respect.

• MeSH
• Antibiosis physiology   MeSH
• Bacteriophages metabolism   MeSH
• Escherichia coli metabolism   MeSH
• Feces microbiology   MeSH
• Colicins metabolism   pharmacology   MeSH
• Colon microbiology   MeSH
• Humans MeSH
• Lysogeny physiology   MeSH
• Siderophores metabolism   pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Colicins MeSH
• Siderophores MeSH

Colicins are toxic exoproteins produced by bacteria of colicinogenic strains of Escherichia coli and some related species of Enterobacteriaceae, during the growth of their cultures. They inhibit sensitive bacteria of the same family. About 35% E. coli strains appearing in human intestinal tract are colicinogenic. Synthesis of colicins is coded by genes located on Col plasmids. Until now more than 34 types of colicins have been described, 21 of them in greater detail, viz. colicins A, B, D, E1-E9, Ia, Ib, JS, K, M, N, U, 5, 10. In general, their interaction with sensitive bacteria includes three steps: (1) binding of the colicin molecule to a specific receptor in the bacterial outer membrane; (2) its translocation through the cell envelope; and (3) its lethal interaction with the specific molecular target in the cell. The classification of colicins is based on differences in the molecular events of these three steps.

• MeSH
• Escherichia coli chemistry   metabolism   MeSH
• Escherichia coli Infections microbiology   MeSH
• Colicins classification   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Colicins MeSH

• MeSH
• Adsorption MeSH
• Escherichia coli * MeSH
• Colicins * MeSH
• In Vitro Techniques MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Colicins * MeSH

• Keywords
• ANTIBIOTICS *, BACTERIOPHAGE *,
• MeSH
• Anti-Bacterial Agents * MeSH
• Bacteriophages * MeSH
• Humans MeSH
• Lysogeny * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents * MeSH

• Keywords
• ANTIBIOTICS/pharmacology *, ESCHERICHIA COLI/pharmacology *, PENICILLIN/pharmacology *,
• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Diploidy * MeSH
• Escherichia coli pharmacology   MeSH
• Colicins * MeSH
• Penicillins pharmacology   MeSH
• Spheroplasts * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Colicins * MeSH
• Penicillins MeSH