scholarly journals Study of Inhibitory agent produced by Streptococcus thermophilus on growth and Biofilm formation for some pathogenic bacteria

2013 ◽  
Vol 7 (2) ◽  
pp. 24-31
Author(s):  
Jehan A.S. Salman ◽  
Khawlah J. Khalaf ◽  
Mohammed F. Al-Marjani
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Streptococcus Thermophilus ◽  
Inhibitory Effect ◽  
E Coli ◽  
Chloroform Methanol ◽  
Klebsiella Spp ◽  
Lipophilic Fraction

Inhibitory activity of Streptococcus thermophilus unconcentrated and concentrated filtrate was studied against some pathogenic bacteria included: Pseudomonas aeruginosa, Klebsiella spp., Staphylococcus aureu, Escherichia coli. Inhibitory activity of protein that extracted from S. thermophilus concentrated filtrate was studied after precipitate by ammonium sulphate and inhibitory activity of lipophilic fraction that extracted from concentrated filtrate with chloroform-methanol (1:1 vol/ vol) was studied against pathogenic bacteria. Also inhibitory activity of biosurfactant produced by S. thermophilus was studied against growth and biofilm formation for pathogenic bacteria. The results showed that unconcentrated and concentrated filtrate had inhibitory activity against all pathogenic bacteria. Also protein and lipophilic fraction had inhibitory effect against pathogenic bacteria, while the biosurfactant show inhibitory activity against growth of all pathogenic bacteria but show inhibitory effect on biofilm formation only for pathogenic bacteria S. aureus and E. coli.

Enhanced Inhibition of Escherichia coli O157:H7 by Lysozyme and Chelators

2003 ◽  
Vol 66 (10) ◽  
pp. 1783-1789 ◽  
Author(s):  
J. S. BOLAND ◽  
P. M. DAVIDSON ◽  
J. WEISS
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Chelating Agents ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Inhibitory Effects ◽  
Antimicrobial Spectrum ◽  
E Coli ◽  
Dilution Assay ◽  
Microbroth Dilution

This study examined the effects of three chelating agents (EDTA, disodium pyrophosphate [DSPP], and pentasodium tripolyphosphate [PSTPP]) on the inhibition of the growth of Escherichia coli O157:H7 by lysozyme. The objective of this study was to identify replacement chelators that exhibit synergistic properties similar to those of EDTA. The inhibitory effects of EDTA at 300 to 1,500 μg/ml and of DSPP and PSTPP at 3,000 to 15,000 μg/ml in combination with lysozyme at 200 to 600 μg/ml for up to 48 h at pHs of 6.0, 7.0, and 8.0 on four strains of E. coli O157:H7 was studied with the use of a microbroth dilution assay. The addition of EDTA enhanced lysozyme's inhibitory effect on strains of E. coli O157:H7. EDTA at ≥300 μg/ml combined with lysozyme at 200 to 600 μg/ml was sufficient to inhibit the growth of the strains at pHs of 6.0 and 8.0. At pH 7.0, lysozyme at 200 to 600 μg/ml and EDTA concentrations of ≥1,000 μg/ml were effective in inhibiting three of the four strains. DSPP at pH 6.0 was inhibitory at ≥10,000 μg/ml when combined with lysozyme at 200 to 300 μg/ml. In contrast, PSTPP increased the inhibitory activity of lysozyme more effectively at pH 8.0. Lysozyme at 200 to 600 μg/ml was effective against two strains of E. coli O157:H7 when used in conjunction with PSTPP at ≥5,000 μg/ml. The remaining strains were inhibited by PSTPP at ≥10,000 μg/ml. Our results indicate that inhibition occurred with each lysozyme-chelator combination, but the concentrations of phosphates required to increase the antimicrobial spectrum of lysozyme against E. coli O157:H7 were higher than the EDTA concentrations required to achieve the same effect.

scholarly journals Apple Flavonoid Phloretin Inhibits Escherichia coli O157:H7 Biofilm Formation and Ameliorates Colon Inflammation in Rats

2011 ◽  
Vol 79 (12) ◽  
pp. 4819-4827 ◽  
Author(s):  
Jin-Hyung Lee ◽  
Sushil Chandra Regmi ◽  
Jung-Ae Kim ◽  
Moo Hwan Cho ◽  
Hyungdon Yun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Trinitrobenzene Sulfonic Acid ◽  
Content Type ◽  
E Coli ◽  
Colon Inflammation ◽  
K 12

ABSTRACTPathogenic biofilms have been associated with persistent infections due to their high resistance to antimicrobial agents, while commensal biofilms often fortify the host's immune system. Hence, controlling biofilm formation of both pathogenic bacteria and commensal bacteria is important in bacterium-related diseases. We investigated the effect of plant flavonoids on biofilm formation of enterohemorrhagicEscherichia coliO157:H7. The antioxidant phloretin, which is abundant in apples, markedly reducedE. coliO157:H7 biofilm formation without affecting the growth of planktonic cells, while phloretin did not harm commensalE. coliK-12 biofilms. Also, phloretin reducedE. coliO157:H7 attachment to human colon epithelial cells. Global transcriptome analyses revealed that phloretin repressed toxin genes (hlyEandstx2), autoinducer-2 importer genes (lsrACDBF), curli genes (csgAandcsgB), and dozens of prophage genes inE. coliO157:H7 biofilm cells. Electron microscopy confirmed that phloretin reduced fimbria production inE. coliO157:H7. Also, phloretin suppressed the tumor necrosis factor alpha-induced inflammatory responsein vitrousing human colonic epithelial cells. Moreover, in the rat model of colitis induced by trinitrobenzene sulfonic acid (TNBS), phloretin significantly ameliorated colon inflammation and body weight loss. Taken together, our results suggest that the antioxidant phloretin also acts as an inhibitor ofE. coliO157:H7 biofilm formation as well as an anti-inflammatory agent in inflammatory bowel diseases without harming beneficial commensalE. colibiofilms.

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs

2017 ◽  
Vol 8 (5) ◽  
pp. 779-783 ◽  
Author(s):  
W. Vahjen ◽  
T. Cuisiniere ◽  
J. Zentek
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Coli Strain ◽  
Protective Effects ◽  
Macconkey Agar ◽  
Challenge Strain ◽  
E Coli ◽  
Pathogenic Factors

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic E. coli in pigs.

scholarly journals Biotic and Abiotic Factors Influencing In Vitro Growth of Escherichia coli O157:H7 in Ruminant Digestive Contents

2006 ◽  
Vol 72 (6) ◽  
pp. 4136-4142 ◽  
Author(s):  
Fr�d�rique Chaucheyras-Durand ◽  
Jordan Madic ◽  
Florent Doudin ◽  
Christine Martin
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Rumen Fluid ◽  
Abiotic Factors ◽  
Probiotic Strain ◽  
Inhibitory Effect ◽  
Main Site ◽  
E Coli ◽  
Biotic And Abiotic Factors

ABSTRACT The gastrointestinal tract (GIT) of ruminants is the main reservoir of enterohemorrhagic Escherichia coli, which is responsible for food-borne infections in humans that can lead to severe kidney disease. Characterization of biotic and abiotic factors that influence the carriage of these pathogens by the ruminant would help in the development of ecological strategies to reduce their survival in the GIT and to decrease the risk of contamination of animal products. We found that growth of E. coli O157:H7 in rumen fluid was inhibited by the autochthonous microflora. Growth was also reduced when rumen fluid came from sheep fed a mixed diet composed of 50% wheat and 50% hay, as opposed to a 100% hay diet. In fecal suspensions, E. coli O157:H7 growth was not suppressed by the autochthonous flora. However, a probiotic strain of Lactobacillus acidophilus inhibited E. coli O157:H7 growth in fecal suspensions. The inhibitory effect was dose dependent. These lactic acid bacteria could be a relevant tool for controlling O157:H7 development in the terminal part of the ruminant GIT, which has been shown to be the main site of colonization by these pathogenic bacteria.

scholarly journals Effect of Lactobacillus salivarius supernatant against growth and biofilm formation of some pathogenic microorganisms

2016 ◽  
Vol 13 (2) ◽  
pp. 247-252
Author(s):  
Baghdad Science Journal
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Inhibitory Effect ◽  
Pathogenic Microorganisms ◽  
Lactobacillus Salivarius ◽  
Inhibition Effect ◽  
Probiotic Lactobacillus ◽  
Diffusion Assay ◽  
Klebsiella Spp

The Inhbititory effect of cocentrated and non-cocentrated supernatant of the probiotic Lactobacillus salivarius against growth of some potential pathogenic microorganisms which included Pseudomonas eruginosa, Klebsiella spp, Escherichia coli and Candida albicans. The results were diffusion assay revealed that concentrated and non-concentrated supernatant had inhitory effect against pathogenic bacteria with inhibition zone renged between 13-17mm while inhibition effect of concentrated supernatant against C.albicans was inhibition zone 8mm. On the other hand, the effect of these suprnatant against biofilm formation of the tested microorganisms was studied. The result showed that the concentrated supernatant had inhibitory effect on biofilm formation for all tested microorganisms with percentage (28-29)% against tested bacteria and (23)% against C.albicans.

Inhibitory Activity of Bifidobacterium longum HY8001 against Vero Cytotoxin of Escherichia coli O157:H7

2001 ◽  
Vol 64 (11) ◽  
pp. 1667-1673 ◽  
Author(s):  
SO HYUN KIM ◽  
SOO JIN YANG ◽  
HYE CHEONG KOO ◽  
WON KI BAE ◽  
JI YEON KIM ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Culture Supernatant ◽  
Bifidobacterium Longum ◽  
Inhibitory Effect ◽  
Resistant Bacteria ◽  
Korean Isolate ◽  
E Coli ◽  
B Subunit ◽  
Tnf Α

Vero cytotoxin (VT)-producing Escherichia coli (VTEC), such as E. coli O157:H7, are emerging foodborne pathogens worldwide. VTs are associated with hemorrhagic colitis and hemolytic uremic syndrome in humans. Attachment of the B subunit of VTs to its receptor, globotriaosylceramide (Gb3), at gut epithelium is the primary step and, consequently, the A subunit of VTs inhibits protein synthesis in the target cell. Proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, up-regulate Gb3 expression, increase sensitivity to VTs, and enhance VT action in developing disease. Currently, there is a growing interest in probiotics, given the increasing occurrence of antibiotic-resistant bacteria. In particular, much work on bifidobacteria among probiotics, regarded as microorganisms targeted for technological and therapeutic applications, has been performed. In Korea, the neutralizing effect of the culture supernatant of Bifidobacterium longum HY8001, Korean isolate, against the VTs from E. coli O157:H7 was found. Therefore, this study focused on the raveling of the inhibitory effect of B. longum HY8001 against VTs, through the interference B subunit of VTs and Gb3 interaction. Mice were inoculated intragastrically with B. longum HY8001 culture supernatant before and after challenge with E. coli O157:H7. Control mice were inoculated intragastrically only with E. coli O157:H7. Cytokine, TNF-α, and IL-1β levels in sera and expression of their mRNA were decreased, and expression of Gb3 in renal tubular epithelial cells was reduced in mice treated with B. longum HY8001 culture supernatant. In competitive enzyme-linked immunosorbent assays (ELISAs), the culture supernatant of B. longum HY8001 primarily binds VTs to interfere the VTs with Gb3 interaction. These results suggest that soluble substance(s) in B. longum HY8001 culture supernatant may have inhibitory activity on the expression of Gb3, VT-Gb3 interaction, or both. Further study should be done to elucidate the property of soluble substances in B. longum HY8001 culture supernatant.

scholarly journals Inhibitory Effect of Sodium Citrate, Sodium Nitrite and Cinnamaldehyde on Biofilm-forming Escherichia coli O157:H7

2021 ◽  
Vol 4 (2) ◽  
pp. 11-16
Author(s):  
A.H. Jauro ◽  
I. Shu’aibu ◽  
G. Lawan ◽  
M.T. Adamu ◽  
M.Y. Iliyasu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sodium Nitrite ◽  
Food Processing ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Sodium Citrate ◽  
Food Additives ◽  
Inhibitory Effect ◽  
Latex Agglutination ◽  
Escherichia Coli O157

The development of biofilms by the foodborne pathogens attached to surfaces in the food processing environments results in the deterioration of products, persistence of pathogenic bacteria and transmission of food-associated diseases. In addition, biofilms are more resistant to antimicrobials than their planktonic counterparts which make their elimination from food and the food processing facilities a great challenge. This study aim was to determine the inhibitory effect of food additives on biofilm forming Escherichia coli O157:H7. The isolate obtained was subjected to Gram’s staining and various biochemical identifications and later confirmed by latex agglutination test. Biofilm formation potential was done on Congo red media and the confirmed biofilm former was subjected to biofilm formation at 10℃ and 37℃ for 168hrs. Antimicrobial susceptibility testing, MIC, MBC, and antibiofilm effect was determined following CLSI 2017 guideline. The highest zone of growth inhibition of 31 mm was exhibited by cinnamaldehyde, sodium nitrite with 26 mm and sodium citrate with 13 mm. The MIC 2.5 mg/mL was recorded for sodium citrate, 0.25 mg/mL for sodium nitrite and 0.125 μl/mL for cinnamaldehyde. Strong biofilm was formed at 37 ℃ with 7.82 x 109 CFU/mL viable cells at 168hrs while 6.79 x 109 CFU/mL were obtained at 10 ℃. All the three additives showed antibiofilm effect (at 10℃ and 37℃), cinnamaldehyde exhibited 70%-90.1%, sodium nitrite; 70%-88.2% inhibition and sodium nitrite; 75%-88% inhibition respectively. This study showed that sodium citrate, sodium nitrite and cinnamaldehyde exerted strong antimicrobial and antibiofilm properties indicating their potential as good preservatives.

scholarly journals Inhibition of Glucosyltransferase Activity and Glucan Production as an Antibiofilm Mechanism of Lemongrass Essential Oil against Escherichia coli O157:H7

Antibiotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 102 ◽  
Author(s):  
Luis A. Ortega-Ramirez ◽  
M. Melissa Gutiérrez-Pacheco ◽  
Irasema Vargas-Arispuro ◽  
Gustavo A. González-Aguilar ◽  
Miguel A. Martínez-Téllez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Cymbopogon Citratus ◽  
Docking Analysis ◽  
E Coli ◽  
Lemongrass Essential Oil

The resistance of Escherichia coli O157:H7 to disinfection is associated with its ability to form biofilms, mainly constituted by glucans produced by glucosyltransferases. Citral and geraniol, terpenes found in the essential oil of Cymbopogon citratus (EO), have proven antibacterial activity against planktonic E. coli; however, no information was found about their efficacy and mode of action against E. coli biofilms. Therefore, the inhibitory effect of C. citratus EO, citral, and geraniol on glucans production and glucosyltransferase activity as anti-biofilm mechanism against E. coli was evaluated. EO, citral, and geraniol inhibited the planktonic growth of E. coli (minimal inhibitory concentration or MIC= 2.2, 1.0, and 3.0 mg/mL, respectively) and the bacterial adhesion (2.0, 2.0, and 4.0 mg/mL, respectively) on stainless steel. All compounds decreased the glucans production; citral and geraniol acted as uncompetitive inhibitors of glucosyltransferase activity (The half maximal inhibitory concentrations or IC50 were 8.5 and 6.5 µM, respectively). The evidence collected by docking analysis indicated that both terpenes could interact with the helix finger of the glucosyltransferase responsible for the polymer production. In conclusion, C. citratus EO, citral, and geraniol inhibited glucosyltransferase activity, glucans production, and the consequent biofilm formation of E. coli O157:H7.

scholarly journals Antibacterial Activities of Soft Coral Extract Lobophytum sp. towards Pathogenic Bacteria (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa)

2020 ◽  
Vol 25 (2) ◽  
pp. 151
Author(s):  
May Juna putri Tanjung ◽  
Dessy Yoswaty ◽  
Irwan Effendi
Keyword(s):  
Escherichia Coli ◽  
Research Method ◽  
Pathogenic Bacteria ◽  
Soft Coral ◽  
Antibacterial Activities ◽  
Inhibitory Effect ◽  
E Coli ◽  
Activity Test ◽  
Diffusion Technique ◽  
West Sumatra

Soft coral extract of Lobophytum sp. can inhibit the growth of pathogenic bacteria with a weak to very strong category. The purpose of this study was to determine the activity of Lobophytum sp. against pathogenic bacteria E. coli, S. aureus, and P. aeruginosa and analyze the concentration of Lobophytum sp. effective against pathogenic bacteria E. coli, S. aureus, and P. aeruginosa. Sampling was carried out in the waters of Pigago Island, West Pasaman Regency, West Sumatra. This research method is an experimental method and antibacterial activity test is carried out with agar diffusion diffusion technique. This soft coral extract has the potential to inhibit pathogenic bacteria. The highest inhibitory effect on E. coli bacteria was the highest yield at a concentration of 100% with a yield of 13.95 mm, in the S. aureus bacteria the highest yield at a concentration of 100% with a yield of 12.53 mm and in P.aureginosa bacteria at a concentration of 100% was 23.87 mm.

scholarly journals Influence of cell-free extracts of Bifidobacterium bifidum and Lactobacillus reuteri on proliferation and biofilm formation by Escherichia coli and Pseudomonas aeruginosa

2019 ◽  
Vol 10 (2) ◽  
pp. 251-256 ◽  
Author(s):  
O. V. Knysh ◽  
O. Y. Isayenko ◽  
Y. V. Voyda ◽  
O. O. Kizimenko ◽  
Y. M. Babych
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Proliferative Activity ◽  
Lactobacillus Reuteri ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Bifidobacterium Bifidum ◽  
Plate Method ◽  
E Coli ◽  
Test Cultures

The development of new effective preparations for the correction of microecological disorders based on probiotic derivatives requires a comprehensive study of the biological activity of the latter. We studied the proliferative activity and biofilm formation by clinical isolates: Escherichia coli and Pseudomonas aeruginosa under the influence of cell-free extracts containing structural components and metabolites of the Bifidobacterium bifidum and Lactobacillus reuteri probiotic strains. Cell-free extracts were obtained from disintegrates and cultures of probiotics. Disintegrates were prepared by cyclic freezing-thawing of probiotic cell suspensions. The cultures were obtained by cultivating probiotic microorganisms in their own disintegrates. The obtained disintegrates and cultures were filtered. The proliferative activity of the test cultures was studied using the spectrophotometric microtiter plate method after an hour-long exposure in undiluted cell-free extracts and subsequent cultivation in a nutrient medium containing 30%vol of the studied extracts at 37 °C for 24 hours. The biofilm formation of the test cultures was studied with 30% vol content of cell-free extracts in the cultivation medium using the spectrophotometric microtiter plate method. All the studied extracts exerted a similar effect on the proliferative activity and biofilm formation by E. coli and P. aeruginosa. Exposure of the test cultures in all undiluted extracts during an hour led to a significant decrease in the optical density of the test samples: optical density of the test wells ranged from 36.5% to 49.8% of the control wells. The test cultures that were exposed to the extracts: filtrate of L. reuteri disintegrate (L), filtrate of В. bifidum disintegrate (B) and filtrate of В. bifidum culture, grown in В. bifidum disintegrate (MB) after dilution and subsequent cultivation over the next 24 hours completely restored the ability to proliferate. The proliferative activity of the test cultures that were exposed to the extracts: filtrate of L. reuteri culture, grown in L. reuteri disintegrate (ML) and filtrate of L. reuteri culture, grown in L. reuteri disintegrate supplemented with 0.8 M glycerol and 0.4 M glucose (MLG), was significantly inhibited after dilution and subsequent cultivation. The inhibition indices calculated for the ML extract were: 25.9% (E. coli) and 53.0% (P. aeruginosa). Inhibition indices calculated for the MLG extract were: 62.0% (E. coli) and 96.9% (P. aeruginosa). MLG extract had more pronounced inhibitory effect on the proliferation of the test cultures than ML extract. All the studied extracts exerted significant inhibitory effect on the biofilm formation of the test cultures. Analysis of the results of the study shows that cell-free extracts of L. reuteri culture grown in its disintegrate without supplementation or supplemented with glycerol and glucose have the highest antimicrobial activity and can be used as metabiotics to prevent overgrowth of potentially pathogenic bacteria, as well as inoculation and proliferation of pathogenic gram-negative bacteria in the gastrointestinal tract. They can be used alone or in combination with cellular probiotics to enhance their probiotic action. This study encourages further careful investigation of the biochemical composition of cell-free extracts and clarifying the mechanism of their action.

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