Fifty-five strains of enterococci isolated from the piglet intestine were characterized in vitro for probiotic activity. Identification of the isolates revealed Enterococcus faecium as the predominant species (84 %). Forty strains (73 %) were found to produce bacteriocin-like substances (only into solid media) with activity almost only toward Gram-positive genera. Thirty-eight % of strains were resistant to tetracycline, 27 % to chloramphenicol, 18 % to erythromycin and 16 % to vancomycin. In addition to control of strain safety, 6 % of isolates were beta-hemolytic and 16 % produced gelatinase. Seven strains selected for further probiotic assays exhibited sufficient survival rate at pH 3.0 after 3 h, in the presence of 1 % ox-bile and lysozyme after 1 d (over 107 CFU/mL in all tests). The adhesion of tested strains to porcine and human intestinal mucus was found in a similar range (1.4-14.0 % and 1.4-17.6 %, respectively). In accordance with current research effort to use and/or to combine various health promoting substances, the sensitivity of all isolates toward plant extracts and toward bacteriocins produced by animal and environmental strains was determined. All enterococci were sensitive toward oregano and sage extracts and toward one (E. faecium EF55--chicken isolate, activity of 25 600 AU/mL) of ten bacteriocin substances. It means that a similar anti-enterococcal potential of some bacteriocin substances may be observed as for certain plant extracts.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Antibiosis MeSH
• Bacterial Adhesion MeSH
• Drug Resistance, Bacterial MeSH
• Bacteriocins biosynthesis   pharmacology   MeSH
• Origanum chemistry   MeSH
• Enterococcus classification   drug effects   isolation & purification   physiology   MeSH
• Gastrointestinal Tract microbiology   MeSH
• Acids toxicity   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Microbial Viability MeSH
• Mucins metabolism   MeSH
• Muramidase metabolism   MeSH
• Swine microbiology   MeSH
• Probiotics pharmacology   MeSH
• Plant Extracts pharmacology   MeSH
• Bile Acids and Salts toxicity   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacteriocins MeSH
• Acids MeSH
• Mucins MeSH
• Muramidase MeSH
• Plant Extracts MeSH
• Bile Acids and Salts MeSH

Three hundred and ten enterococcal isolates (178 Enterococcus faecium, 68 E. durans, 49 E. faecalis, 8 E. italicus, 3 E. gallinarum, 3 E. casseliflavus, and 1 E. hirae) from Slovak Bryndza cheese were evaluated for susceptibility to nine antimicrobial agents (vancomycin, teicoplanin, ampicillin, streptomycin, gentamicin, erythromycin, rifampicin, nitrofurantoin, and ciprofloxacin). All enterococcal isolates from Bryndza cheese were susceptible to ampicillin, streptomycin, gentamicin, vancomycin, and teicoplanin as determined by the disk diffusion method. Vancomycin resistance genes vanA and vanB were not detected. Resistance rates of enterococcal isolates to rifampicin, erythromycin, ciprofloxacin, and nitrofurantoin were 24, 26, 2, and 1 %, respectively. Thirty-six % of E. faecium isolates and 22 % of the E. faecalis isolates were resistant to erythromycin. Resistance to rifampicin was similar in E. faecium (31 %) and E. faecalis (29 %). Both E. faecium and E. faecalis strains showed the same resistance to ciprofloxacin (2 %). E. durans isolates showed low levels of resistance to rifampicin, erythromycin, ciprofloxacin, and nitrofurantoin (1-4 %). Forty-eight (30 %) of the E. faecium isolates, two (3 %) of the E. durans isolates, and six (12 %) of the E. faecalis isolates exhibited multidrug resistance. The highest frequency of resistant enterococci was observed in Bryndza produced in winter season.

• MeSH
• Anti-Infective Agents pharmacology   MeSH
• Enterococcus classification   drug effects   isolation & purification   MeSH
• Drug Resistance MeSH
• Microbial Sensitivity Tests MeSH
• Food Microbiology * MeSH
• Seasons MeSH
• Cheese microbiology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Geographicals
• Slovakia MeSH
• Names of Substances
• Anti-Infective Agents MeSH

The antimicrobial activity of C2-C18 fatty acids was determined in vitro in cultures of two strains of Escherichia coli grown on glucose. Antimicrobial activity was expressed as IC50 (a concentration at which only 50% of the initial glucose in the cultures was utilized). Utilization of glucose was inhibited by caprylic acid (IC50 0.30-0.85 g/L) and capric acid (IC50 1.25-2.03 g/L). Neither short-chain fatty acids (C2-C6) nor fatty acids with longer chain (C12-C18) influenced substrate utilization. Caproic acid, however, decreased cell yield in cultures of E. coli in a dose-dependent manner. No inhibition of glucose utilization was produced with unsaturated fatty acids, oleic and linoleic. Calcium ions added in excess reversed the antimicrobial effect of capric acid, but not that of caprylic acid. Antimicrobial activity of caprylic and capric acid decreased when the bacteria were grown in the presence of straw particles, or repeatedly subcultured in a medium containing these compounds at low concentrations. Counts of viable bacteria determined by plating decreased after incubation with caprylic and capric acid (30 min; 1 g/L) at pH 5.2 from > 10(9) to approximately 10(2)/mL. A reduction of a mere 0.94-1.96 log10 CFU was observed at pH 6.5-6.6. It can be concluded that caprylic acid, and to a lesser extent also capric acid, has a significant antimicrobial activity toward E. coli. Effects of other fatty acids were not significant or absent.

• MeSH
• Antifungal Agents pharmacology   MeSH
• Drug Resistance, Bacterial MeSH
• Escherichia coli drug effects   growth & development   MeSH
• Caprylates pharmacology   MeSH
• Hydrogen-Ion Concentration MeSH
• Culture Media pharmacology   MeSH
• Decanoic Acids pharmacology   MeSH
• Fatty Acids pharmacology   MeSH
• In Vitro Techniques MeSH
• Calcium pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antifungal Agents MeSH
• decanoic acid MeSH Browser
• Caprylates MeSH
• Culture Media MeSH
• Decanoic Acids MeSH
• Fatty Acids MeSH
• octanoic acid MeSH Browser
• Calcium MeSH

In an attempt to obtain biological control agents for controlling bacterial spot of cucumber, over 250 bacterial strains were isolated from agricultural soil samples, collected from different localities in Giza Governorate (Egypt) and screened for in vitro antibiosis towards Xanthomonas campestris. Only 2 strains showed antagonistic activity. They and their culture filtrates restricted the growth of a number of G- and G(+)-indicator bacteria. On Chrome Azurol S agar, both strains exhibited a marked siderophore production. Biolog plates identified these strains as Rahnella aquatilis. Their characteristics were studied and compared with literature data on R. aquatilis. This antagonistic bacterium has not been previously isolated in Egypt.

• MeSH
• Bacteriocins metabolism   MeSH
• Cucumis sativus microbiology   MeSH
• Microscopy, Electron MeSH
• Soil Microbiology * MeSH
• Rahnella classification   metabolism   ultrastructure   MeSH
• Siderophores metabolism   MeSH
• Xanthomonas campestris growth & development   MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Egypt MeSH
• Names of Substances
• Bacteriocins MeSH
• Siderophores MeSH

Nondenaturing polyacrylamide gel electrophoresis revealed the presence of diversity among bacteriocins produced by strains of Bacillus sphaericus. Bacteriocin bands of six strains (pathogenic and non pathogenic) were found to be located just below the stacking gel. However, in two other strains (1 pathogenic and 1 collection strain) more than one protein band with bacteriocin activity were seen in the middle of resolving gel. In bacteriocin-treated cultures, electron-microscopy studies revealed the growth of lysedswollen ghost cells, and loss of viability among sensitive strains.

• MeSH
• Bacillus drug effects   metabolism   pathogenicity   MeSH
• Bacteriocins chemistry   metabolism   pharmacology   MeSH
• Culicidae microbiology   MeSH
• Electrophoresis, Polyacrylamide Gel MeSH
• Microscopy, Electron MeSH
• Larva microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Bacteriocins MeSH

The activity in vitro of four types of colicins (A, E1, E3, U) against one human standard fibroblast line and against 11 human tumor-cell lines carrying defined mutations of the p53 gene was quantified by MTT (tetrazolium bromide) assay. Flow cytometry showed that the pore-forming colicins A, E1 and U affected the cell cycle of 5 of these cell lines. Colicins E3 and U did not show any distinct inhibitory effects on the cell lines, while colicins E1 and especially A inhibited the growth of all of them (with one exception concerning colicin E1). Colicin E1 inhibited the growth of the tumor lines by 17-40% and standard fibroblasts MRC5 by 11%. Colicin A exhibited a differentiated 16-56% inhibition, the growth of standard fibroblasts being inhibited by 36%. In three of the lines, colicins A and E1 increased the number of cells in the G1 phase (by 12-58%) and in apoptosis (by 7-58%). These results correlated with the data from sensitivity assays. Hence, the inhibitory effect of colicins on eukaryotic cells in cell-selective, colicin-specific and can be considered to be cytotoxic.

• MeSH
• Cell Cycle drug effects   MeSH
• Eukaryotic Cells drug effects   MeSH
• Fibroblasts drug effects   MeSH
• G1 Phase drug effects   MeSH
• Colicins pharmacology   MeSH
• Humans MeSH
• Mutation MeSH
• Tumor Cells, Cultured drug effects   MeSH
• Tumor Suppressor Protein p53 genetics   MeSH
• Tetrazolium Salts metabolism   MeSH
• Thiazoles metabolism   MeSH
• Cell Survival drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Colicins MeSH
• Tumor Suppressor Protein p53 MeSH
• Tetrazolium Salts MeSH
• Thiazoles MeSH
• thiazolyl blue MeSH Browser

The majority of antibiotics and substances with diverse biological activity used in medicine are produced by actinomycetes, nonfilamentous bacteria and fungi. Other microorganisms, such as myxobacteria, pseudomonads, nocardias, basidiomycetes, marine microorganisms, enterobacteria, halobacteria, hyperthermophiles etc. are investigated for new biologically active metabolites.

• MeSH
• Anti-Bacterial Agents chemistry   MeSH
• Bacteria chemistry   MeSH
• Biological Products chemistry   MeSH
• Fungi chemistry   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Biological Products MeSH

A strain of Enterococcus faecium isolated from Bulgarian yellow cheese "kashkaval" produced a bacteriocin-like substance named enterococcin A 2000. The antibacterial substance had a low molar mass (< 2 kDa), was relatively stable toward heat but was sensitive to selected proteolytic enzymes. It was active against Gram-positive bacteria including enterococci, such as Listeria, Bacillus and Streptococcus, and also against Gram-negative E. coli. Production of enterococcin A 2000 has a maximum near the end of the exponential phase of producer growth. The peptide was purified by ammonium sulfate precipitation, butanol extraction, followed by cation-exchange chromatography and reversed-phase chromatography. A partial sequence of purified enterococcin A 2000 indicated that this substance does not belong to the class IIa of bacteriocins presenting the consensus anti-Listeria motif YGNGV.

• MeSH
• Amino Acids analysis   MeSH
• Anti-Bacterial Agents chemistry   isolation & purification   pharmacology   MeSH
• RNA, Bacterial genetics   MeSH
• Bacteriocins chemistry   genetics   isolation & purification   pharmacology   MeSH
• DNA, Bacterial genetics   MeSH
• Enterococcus faecium chemistry   genetics   MeSH
• Escherichia coli drug effects   MeSH
• Listeria drug effects   MeSH
• Molecular Weight MeSH
• Polymerase Chain Reaction MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• RNA, Ribosomal, 23S genetics   MeSH
• Amino Acid Sequence MeSH
• Base Sequence MeSH
• Cheese microbiology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Amino Acids MeSH
• Anti-Bacterial Agents MeSH
• RNA, Bacterial MeSH
• Bacteriocins MeSH
• DNA, Bacterial MeSH
• RNA, Ribosomal, 16S MeSH
• RNA, Ribosomal, 23S MeSH

The production of a novel broad-spectrum antimicrobial peptide enterococcin A 2000, active against Gram-positive and Gram-negative microorganisms including Listeria subsp. and Escherichia coli, by Enterococcus faecium strain A 2000 isolated from the surface of traditional Bulgarian yellow cheese "kash-kaval" is considerably influenced by complex nitrogen sources in the production medium. Medium components, especially peptone and yeast extract, and their concentration contributed to the increase in bacteriocin production during the stationary phase (16-46 h) of cultivation even in the absence of one of the components present in the basal cultivation MRS medium.

• MeSH
• Bacteriocins biosynthesis   metabolism   pharmacology   MeSH
• Nitrogen metabolism   MeSH
• Enterococcus faecium metabolism   MeSH
• Escherichia coli metabolism   MeSH
• Yeasts metabolism   MeSH
• Listeria metabolism   MeSH
• Peptones metabolism   MeSH
• Cheese MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bacteriocins MeSH
• Nitrogen MeSH
• Peptones MeSH

Two DNA-based techniques were used for species identification of enterococci. PvuII digestion of the genus-specific PCR product yielded four different restriction profiles among 20 enterococcal species; one of them was species-specific for E. faecium. In the second case, 32 reference strains belonging to 20 enterococcal species were divided to 12 groups by amplification of internal transcribed spacer of rRNA operon. Interspecies and some intraspecies profile variability was determined. Both methods gave similar results.

• MeSH
• Species Specificity MeSH
• Enterococcus classification   genetics   metabolism   MeSH
• DNA, Intergenic chemistry   genetics   MeSH
• Polymerase Chain Reaction methods   MeSH
• DNA, Protozoan chemistry   genetics   MeSH
• Deoxyribonucleases, Type II Site-Specific metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• CAGCTG-specific type II deoxyribonucleases MeSH Browser
• DNA, Intergenic MeSH
• DNA, Protozoan MeSH
• Deoxyribonucleases, Type II Site-Specific MeSH