Detection of a lactobacillus substance that inhibits Escherichia coli

1988 ◽  
Vol 34 (8) ◽  
pp. 974-978 ◽  
Author(s):  
Jacqueline A. McGroarty ◽  
Gregor Reid
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Lactobacillus Acidophilus ◽  
Lactobacillus Casei ◽  
Clinical Importance ◽  
Inhibitory Effect ◽  
Prevention Of Infection ◽  
E Coli ◽  
Bioactive Substance ◽  
Uropathogenic Bacteria

Recent studies have shown that certain lactobacilli strains have the ability to interfere with the adherence and growth of uropathogenic bacteria. This interaction is believed to be important in the maintenance of a normal urogenital flora and in the prevention of infection in females. In the present study, Lactobacillus casei ssp. rhamnosus GR-1 and Lactobacillus acidophilus 76 were found to exert an inhibitory effect on pyelonephritogenic mutant Escherichia coli Hu 734 and E. coli ATCC 25922. The bioactivity of the inhibitor produced by strain GR-1 was retained under pH buffered conditions and was bactericidal. The bioactive substance was heat labile, not precipitated by up to 80% ammonium sulphate, and extractable in chloroform. The data indicated that the inhibitor is not lactic acid or hydrogen peroxide and has a molecular weight greater than 12 000 – 14 000. Human urine supported production of the inhibitor and reduced and delayed outgrowth of the E. coli. The ability of L. casei GR-1 and possibly other lactobacilli strains to produce inhibitors of uropathogenic bacteria may have clinical importance and significance in the microbial ecology of the urogenital tract.

Antagonistic Action of Lactobacillus acidophilus Toward Intestinal and Foodborne Pathogens in Associative Cultures1

1977 ◽  
Vol 40 (12) ◽  
pp. 820-823 ◽  
Author(s):  
S. E. GILLILAND ◽  
M. L. SPECK
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Foodborne Pathogens ◽  
Lactobacillus Acidophilus ◽  
Inhibitory Effect ◽  
Enteropathogenic Escherichia Coli ◽  
Anaerobic Conditions ◽  
Antagonistic Action ◽  
E Coli

Lactobacillus acidophilus exerted antagonistic actions on growth of Staphylococcus aureus, Salmonella typhimurium, enteropathogenic Escherichia coli, and Clostridium perfringens when grown with each in associative cultures. S. aureus and C. perfringens were more sensitive to the inhibition than were S. typhimurium and E. coli. The amount of the antagonism produced varied among strains of L. acidophilus and could not be directly related to amounts of acid produced; hydrogen peroxide produced by the lactobacilli appeared to be partially responsible for the antagonistic interaction. The inhibitory effect was produced also under anaerobic conditions in a pre-reduced medium.

Prevention of Infections Produced by Escherichia coli and Listeria monocytogenes by Feeding Milk Fermented With Lactobacilli

1993 ◽  
Vol 56 (5) ◽  
pp. 401-405 ◽  
Author(s):  
MARIA ELENA NADER DE MACÍAS ◽  
NORA C. ROMERO ◽  
MARÍA CRISTINA APELLA ◽  
SILVIA N. GONZÁLEZ ◽  
GUILLERMO OLIVER
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Survival Rate ◽  
Lactobacillus Acidophilus ◽  
Lactobacillus Casei ◽  
Fermented Milk ◽  
Pathogenic Microorganisms ◽  
E Coli ◽  
Prevention Of Infections ◽  
Set Up

Challenge studies were set up feeding Lactobacillus casei and Lactobacillus acidophilus fermented milk and two different pathogenic microorganisms: Listeria monocytogenes and enteroinvasive Escherichia coli. Mice were fed for 8 consecutive days with fermented milk and then challenged with the pathogens. The survival rate in control mice was 62% for Listeria and 83% for E. coli, while 100% protection was observed for the 20 d per vial in treated mice. Colonization of the liver and spleen by E. coli was markedly inhibited by pretreatment with fermented milk; the pathogen was not detected on the 5th day postchallenge. In the Listeria challenged mice, the pathogen was present in 1 to 2 log units lower than control up the 10th day. The levels of antipathogen sera and intestinal antibodies were 2 to 4 times higher in the treated mice, with lower values in the Listeria treated mice. The mechanism of protection in both types of infections was discussed. The results obtained suggested that milk fermented with L. casei and L. acidophilus could be used as a prophylactic against selected infections.

Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

2017 ◽  
Vol 17 (1) ◽  
pp. 69-77
Author(s):  
Tu Lijun ◽  
Sun Hanju ◽  
He Shudong ◽  
Zhu Yongsheng ◽  
Yu Ming ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Green Tea ◽  
Lactobacillus Acidophilus ◽  
Pathogenic Bacteria ◽  
Epigallocatechin Gallate ◽  
Microbial Populations ◽  
Medium Ph ◽  
Bioactive Substance ◽  
Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

Cloning and expression of Xylella fastidiosa antigens in Escherichia coli and Erwinia stewartii

1989 ◽  
Vol 35 (4) ◽  
pp. 487-491 ◽  
Author(s):  
Paul H. Goodwin
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Genomic Dna ◽  
Xylella Fastidiosa ◽  
Gene Bank ◽  
Cloning And Expression ◽  
Western Blots ◽  
E Coli ◽  
Cosmid Vector ◽  
Erwinia Stewartii

Xylella fastidiosa DNA, partially digested with Sau3A, was ligated into the cosmid vector, pUCD615. Approximately 4500 ampicillin-resistant Escherichia coli colonies were obtained. The frequency of complementation of leucine auxotrophy in transfected E. coli indicated that the cosmid gene bank was representative of X. fastidiosa genomic DNA. Colonies were lysed directly onto nitrocellulose membranes using a thermo-inducible λ lysogen and screened for expression of X. fastidiosa antigens. Approximately 16.5% of a random sample of clones were found to express X. fastidiosa antigens as determined by Western blots. These proteins comigrated with proteins of X. fastidiosa and ranged in molecular weight from 10 000 to 160 000. Conjugation of several of the plasmids into Erwinia stewartii resulted in expression of the similar molecular weight cloned proteins with similar levels of expression as in E. coli.Key words: Xylella fastidiosa, Pierce's disease, immunological clone screening, thermo-inducible lysogeny.

scholarly journals Antimicrobial activity of lactic acid bacteria isolated from garri on Escherichia coli strains isolated from clinical and environmental samples

2020 ◽  
Vol 12 (4) ◽  
pp. 357-365
Author(s):  
H.I. Atta ◽  
A. Gimba ◽  
T. Bamgbose
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Lactobacillus Acidophilus ◽  
Plant Pathogens ◽  
Resistant Bacteria ◽  
Fermented Foods ◽  
Environmental Isolates ◽  
E Coli

Abstract. The production of bacteriocins by lactic acid bacteria affords them the ability to inhibit the growth of bacteria; they are particularly important in the biocontrol of human and plant pathogens. Lactic acid bacteria have been frequently isolated from fermented foods due to the high acidity these foods contain. In this study, lactic acid bacteria were isolated from garri, a popular Nigerian staple food, which is fermented from cassava, and their antagonistic activity against clinical and environmental isolates of Escherichia coli was determined. The species of Lactobacillus isolated include: Lactobacillus plantarum (50%), Lactobacillus fermentum (20%), Lactobacillus acidophilus (20%), and Lactobacillus salivarius (10%). Growth inhibition of the strains of E.coli was observed in Lactobacillus plantarum that inhibited the growth of both. The clinical and environmental isolates of E. coli were inhibited by Lactobacillus plantarum, while Lactobacillus acidophilus showed activity against only the clinical isolate. The greatest zone of inhibition against the strains of E. coli was recorded by Lactobacillus acidophilus (22.7±1.53 mm). The bacteriocins produced by Lactobacillus species have a good potential in the biocontrol of pathogens, and should be the focus of further studies on antibiotic resistant bacteria.

scholarly journals MazF-Mediated Cell Death in Escherichia coli: a Point of No Return

2004 ◽  
Vol 186 (24) ◽  
pp. 8295-8300 ◽  
Author(s):  
Shahar Amitai ◽  
Yussuf Yassin ◽  
Hanna Engelberg-Kulka
Keyword(s):  
Escherichia Coli ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Inhibitory Effect ◽  
Luria Bertani ◽  
E Coli ◽  
Ectopic Overexpression ◽  
Point Of No Return ◽  
The Rich ◽  
Overexpression System

ABSTRACT mazEF is a stress-induced toxin-antitoxin module, located on the chromosome of Escherichia coli, that we have previously described to be responsible for programmed cell death in E. coli. mazF specifies a stable toxin, and mazE specifies a labile antitoxin. Recently, it was reported that inhibition of translation and cell growth by ectopic overexpression of the toxin MazF can be reversed by the action of the antitoxin MazE ectopically overexpressed at a later time. Based on these results, it was suggested that rather than inducing cell death, mazF induces a state of reversible bacteriostasis (K. Pederson, S. K. Christensen, and K. Gerdes, Mol. Microbiol. 45:501-510, 2002). Using a similar ectopic overexpression system, we show here that overexpression of MazE could reverse MazF lethality only over a short window of time. The size of that window depended on the nature of the medium in which MazF was overexpressed. Thus, we found “a point of no return,” which occurred sooner in minimal M9 medium than it did in the rich Luria-Bertani medium. We also describe a state in which the effect of MazF on translation could be separated from its effect on cell death: MazE overproduction could completely reverse the inhibitory effect of MazF on translation, while not affecting the bacteriocidic effect of MazF at all. Our results reported here support our view that the mazEF module mediates cell death and is part of a programmed cell death network.

scholarly journals DIFFERENTIAL INHIBITORY EFFECTS OF CHOLERA TOXOIDS AND GANGLIOSIDE ON THE ENTEROTOXINS OF VIBRIO CHOLERAE AND ESCHERICHIA COLI

1973 ◽  
Vol 137 (4) ◽  
pp. 1009-1023 ◽  
Author(s):  
Nathaniel F. Pierce
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
E Coli ◽  
Stable Component ◽  
Heat Stable ◽  
Cholera Enterotoxin ◽  
Gut Mucosa

Natural cholera toxoid appears to act as a competitive inhibitor of cholera enterotoxin and is thus a useful tool for studying the interaction of cholera enterotoxin with cell membranes. Cholera enterotoxin binds to gut mucosa more rapidly than does its natural toxoid. Once binding occurs, however, it appears to be prolonged for both materials. Formalinized cholera toxoid has no inhibitory effect upon cholera enterotoxin. Enterotoxic activity, ability to bind to gut mucosa, and antitoxigenicity appear to be independent properties of cholera enterotoxin. Natural cholera toxoid does not inhibit Escherichia coli enterotoxin, indicating that although the two enterotoxins activate the same mucosal secretory mechanism they occupy different binding sites in the mucosa. Ganglioside, which may be the mucosal receptor of cholera enterotoxin, is highly efficient in deactivating cholera enterotoxin. By contrast, ganglioside is relatively inefficient in deactivating heat-labile E. coli enterotoxin and is without effect upon the heat-stable component of E. coli enterotoxin. These findings suggest that ganglioside is not likely to be the mucosal receptor for E. coli enterotoxin. Differences in cellular binding of E. coli and cholera enterotoxins may explain, at least in part, the marked differences in the time of onset and duration of their effects upon gut secretion.

scholarly journals Purification and parcial characterization of a hemagglutinating factor (HAF): a possible adhesive factor of the diffuse adherent of Escherichia coli (DAEC)

1996 ◽  
Vol 38 (6) ◽  
pp. 401-406 ◽  
Author(s):  
Yano Tomomasa ◽  
Cleide Ferreira Catani ◽  
Michiko Arita ◽  
Takeshi Honda ◽  
Toshio Miwatani
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Hela Cells ◽  
Immunofluorescence Test ◽  
Native Form ◽  
Bacterial Surface ◽  
E Coli ◽  
Sds Page ◽  
Adhesive Factor

The mannose-resistant hemagglutinating factor (HAF) was extracted and purified from a diffuse adherent Escherichia coli (DAEC) strain belonging to the classic enteropathogenic E. coli (EPEC) serotype (0128). The molecular weight of HAF was estimated to be 18 KDa by SDS-PAGE and 66 KDa by Sephadex G100, suggesting that the native form of HAF consists of 3-4 monomeric HAF. Gold immunolabeling with specific HAF antiserum revealed that the HAF is not a rigid structure like fimbriae on the bacterial surface. The immunofluorescence test using purified HAF on HeLa cells, in addition to the fact that the HAF is distributed among serotypes of EPEC, suggests that HAF is a possible adhesive factor of DAEC strains

The genetic and physical basis of variability in Escherichia coli strains carrying a reference Inc N group plasmid

1981 ◽  
Vol 27 (6) ◽  
pp. 616-626 ◽  
Author(s):  
M. Konarska-Kozlowska ◽  
V. N. Iyer
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Sequence Homology ◽  
Dna Hybridization ◽  
Tetracycline Resistance ◽  
Resistance Marker ◽  
E Coli ◽  
Reference Plasmid ◽  
Dna Fragment ◽  
K 12

The nature and basis of variability in the conjugational behaviour of RM98+ (RM98-carrying) strains of Escherichia coli K-12 that are otherwise similar in phenotype was studied. An explanation for such variability is provided.Some RM98+ strains of E. coli have a plasmid aggregate, which upon conjugation yields two different conjugative plasmids. The first (pCU1) is an N conjugative group plasmid by all available criteria. The second (pCU2) could not be placed in any conjugative group known among the Enterobacteriaceae. Reciprocal DNA hybridization experiments and the gel patterns displayed by the two plasmid DNAs upon digestion with different restriction endonucleases indicate no extensive sequence homology between pCU1 and pCU2. pCU2 DNA is much longer than pCU1 DNA.Despite the absence of extensive homology, the DNA of pCU1 and pCU2 can interact. Derivatives can be selected that have all the antibiotic markers of the aggregate plasmid but that neither contain nor segregate pCU2. It is shown that in such strains a DNA fragment of molecular weight 7.9 × 106 has been added to pCU1 concurrently with a tetracycline resistance marker originally present in pCU2 and absent in pCU1. These observations suggest that tetracycline resistance in pCU2 may be part of a large translocatable element.RM98 has been used to designate a reference Inc N group plasmid. The results presented indicate that this can lead to ambiguity. pCU1 would now be the appropriate reference plasmid.

Lactobacillus inhibitor production against Escherichia coli and coaggregation ability with uropathogens

1988 ◽  
Vol 34 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Gregor Reid ◽  
Jacqueline A. McGroarty ◽  
Rosanne Angotti ◽  
Roger L. Cook
Keyword(s):  
Escherichia Coli ◽  
Defense Mechanism ◽  
Inhibitory Effect ◽  
Second Phase ◽  
Vitro Assay ◽  
E Coli ◽  
Host Defense Mechanism ◽  
Important Host ◽  
Two Phases

Previous investigations have shown that certain strains of lactobacilli can competitively exclude uropathogens from attaching to uroepithelial cells and from causing urinary tract infection in animals. The finding of an inhibitory effect produced by Lactobacillus casei ssp. rhamnosus GR-1 against the growth of uropathogens was investigated further using two Escherichia coli indicator strains Hu 734 and ATCC 25922. There were two phases to the inhibitor studies. The first one using an agar sandwich technique showed that the inhibitor activity was heat stable and inhibitory to the E. coli. The second phase showed that MRS broth provided optimum lactobacilli growth and inhibitor production. In addition, the inhibition was present under conditions buffering for acid and pH. The data indicated that the inhibitory effect was not due to bacteriophages or hydrogen peroxide. Strain GR-1 was found to coaggregate with E. coli ATCC 25922 in urine, a phenomenon that has not previously been reported for urogenital bacteria. An in vitro assay system was developed to study the coaggregation of various lactobacilli and uropathogens. The results demonstrated that highest coaggregation scores occurred after 4 h incubation at 37 °C with lactobacilli and two type-1 fimbriated E. coli strains. Of the nine lactobacilli strains tested, each was found to coaggregate with 2 or more of the 13 uropathogens. The dominance of inhibitor-producing lactobacilli on the urogenital epithelium and the ability of these organisms to interact closely with uropathogens would constitute an important host defense mechanism against infection.

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