scholarly journals Identification of Synbiotics Conducive to Probiotics Adherence to Intestinal Mucosa Using an In Vitro Caco-2 and HT29-MTX Cell Model

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 569
Author(s):  
Gabriela Krausova ◽  
Iveta Hynstova ◽  
Roman Svejstil ◽  
Iva Mrvikova ◽  
Robert Kadlec

The ability of bacteria to adhere to the intestinal mucosa is a critical property necessary for the long-term colonization of the intestinal tract. This ability can be highly sensitive to the presence of prebiotics. However, limited data are available in this respect for beneficial bacteria such as probiotics or resident gut microbiota. We previously demonstrated that the presence of prebiotics may decrease adherence in several pre- and probiotic combinations. Thus, characterizing the interactions between numerous combinations involving different classes of pre- and probiotics can be crucial in identifying new synbiotics. Accordingly, here, we extend our prior analyses to evaluate the adhesion of five lactobacilli, six bifidobacteria, and one probiotic Escherichia coli strains, as commercial probiotics or promising probiotic candidates, together with the cariogenic Bifidobacterium dentium strain. As an in vitro intestinal mucosa model, Caco-2 and mucin-secreting HT29-MTX cells were co-cultured at 9:1 in the presence or absence of prebiotics. Commercial inulin-type fructooligosaccharide prebiotics Orafti® GR, Orafti® P95, and galactooligosaccharide-based prebiotic formula Vivinal®, including purified human milk oligosaccharides (HMOs) were added into the cultivation media as the sole sugar source (2.5% each). Adherence was tested using microtiter plates and was evaluated as the percentage of fluorescently labeled bacteria present in the wells after three washes. Consistent prebiotics-mediated enhanced adherence was observed only for the commercial probiotic strain E. coli O83. For the remaining strains, the presence of HMO or prebiotics Orafti® P95 or Orafti® GR decreased adherence, reaching statistical significance (p < 0.05) for three of out of eight (HMO) or five of out of 11 strains tested, respectively. Conversely, Vivinal® enhanced adhesion in six out of the 12 strains tested, and notably, it significantly attenuated the adherence of the cariogenic Bifidobacterium dentium Culture Collection of Dairy Microorganisms (CCDM) 318. To our knowledge, this represents the first report on the influence of commercial prebiotics and HMOs on the adhesion of the cariogenic Bifidobacterium sp. Vivinal® seems to be a promising prebiotic to be used in the formulation of synbiotics, supporting the adhesion of a wide range of probiotics, especially the strains B. bifidum BBV and BBM and the probiotic Escherichia coli O83.

2007 ◽  
Vol 51 (4) ◽  
pp. 1481-1486 ◽  
Author(s):  
C. Andrew DeRyke ◽  
Mary Anne Banevicius ◽  
Hong Wei Fan ◽  
David P. Nicolau

ABSTRACT The purpose of this study was to examine the in vivo efficacies of meropenem and ertapenem against extended-spectrum-β-lactamase (ESBL)-producing isolates with a wide range of MICs. Human-simulated dosing regimens in mice were designed to approximate the free drug percent time above the MIC (fT>MIC) observed for humans following meropenem at 1 g every 8 h and ertapenem at 1 g every 24 h. An in vivo neutropenic mouse thigh infection model was used to examine the bactericidal effects against 31 clinical ESBL Escherichia coli and Klebsiella pneumoniae isolates and 2 non-ESBL isolates included for comparison at a standard 105 inoculum. Three isolates were examined at a high 107 inoculum as well. Meropenem displayed greater in vitro potency, with a median MIC (range) (μg/ml) of 0.125 (0.03 to 32), than did ertapenem, with 0.5 (0.012 to 128). Seven of the 31 ESBL isolates were removed from the efficacy analysis due to their inability to establish infection in the mouse model. When MICs were ≤1.5 μg/ml for ertapenem (≤0.5 μg/ml for meropenem), similar reductions in CFU (≈ 2-log kill) were observed for both ertapenem (fT>MIC ≥ 23%) and meropenem (fT>MIC ≥ 75%). Ertapenem showed bacterial regrowth for seven of eight isolates, with MICs of ≥2 μg/ml (fT>MIC ≤ 20%), while meropenem displayed antibacterial potency that varied from a static effect to a 1-log bacterial reduction in these isolates (fT>MIC = 30 to 65%). At a 107 inoculum, both agents eradicated bacteria due to adequate exposures (fT>MIC = 20 to 45%). Due to low MICs, no difference in bacterial kill was noted for the majority of ESBL isolates tested. However, for isolates with raised ertapenem MICs of ≥2 μg/ml, meropenem displayed sustained efficacy due to its greater in vitro potency and higher resultant fT>MIC.


1992 ◽  
Vol 60 (5) ◽  
pp. 2083-2091 ◽  
Author(s):  
S Knutton ◽  
R K Shaw ◽  
M K Bhan ◽  
H R Smith ◽  
M M McConnell ◽  
...  

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Erin M. Nawrocki ◽  
Hillary M. Mosso ◽  
Edward G. Dudley

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo. Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.


1989 ◽  
Vol 96 (4) ◽  
pp. 1079-1086 ◽  
Author(s):  
H. Embaye ◽  
R.M. Batt ◽  
J.R. Saunders ◽  
B. Getty ◽  
C.A. Hart

2010 ◽  
Vol 78 (11) ◽  
pp. 4958-4964 ◽  
Author(s):  
Maura C. Strauman ◽  
Jill M. Harper ◽  
Susan M. Harrington ◽  
Erik Juncker Boll ◽  
James P. Nataro

ABSTRACT Enteroaggregative Escherichia coli (EAEC) is responsible for inflammatory diarrhea in diverse populations, but its mechanisms of pathogenesis have not been fully elucidated. We have used a previously characterized polarized intestinal T84 cell model to investigate the effects of infection with EAEC strain 042 on tight junction integrity. We find that infection with strain 042 induces a decrease in transepithelial electrical resistance (TER) compared to uninfected controls and to cells infected with commensal E. coli strain HS. When the infection was limited after 3 h by washing and application of gentamicin, we observed that the TER of EAEC-infected monolayers continued to decline, and they remained low even as long as 48 h after the infection. Cells infected with the afimbrial mutant strain 042aafA exhibited TER measurements similar to those seen in uninfected monolayers, implicating the aggregative adherence fimbriae II (AAF/II) as necessary for barrier dysfunction. Infection with wild-type strain 042 induced aberrant localization of the tight junction proteins claudin-1 and, to a lesser degree, occludin. EAEC-infected T84 cells exhibited irregular shapes, and some cells became elongated and/or enlarged; these effects were not observed after infection with commensal E. coli strain HS or 042aafA. The effects on tight junctions were also observed with AAF/I-producing strain JM221, and an afimbrial mutant was similarly deficient in inducing barrier dysfunction. Our results show that EAEC induces epithelial barrier dysfunction in vitro and implicates the AAF adhesins in this phenotype.


Chemotherapy ◽  
2021 ◽  
Author(s):  
Lluvia Itzel López-López ◽  
Ernesto Rivera-Ávalos ◽  
Cecilia Villarreal-Reyes ◽  
Fidel Martínez-Gutiérrez ◽  
Denisse de Loera

Background: The synthesis and biological evaluation of 1,4-naphthoquinone derivatives are of great interest since these compounds exhibit strong antibacterial, antifungal, antimalarial, and anticancer activities. The electronic properties of naphthoquinones are usually modulated by attaching functional groups containing nitrogen, oxygen and sulfur atoms, which tune their biological potency and selectivity. Methods: A series of 13 amino acid 1,4-naphthoquinone derivatives were synthesized under assisted microwave and ultrasound conditions. The antibacterial activity compounds was tested against American type Culture Collection (ATCC): Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis, as well two multidrug resistant pathogens: Escherichia coli and Staphylococcus aureus from clinical isolated. Minimal inhibitory concentration (MIC) was determined using the broth microdilution method. Results: MIC of derivatives 4–11, 14 and 16 showed antimicrobial activity against gram-positive and gram-negative bacteria. Antimicrobial activities of the compounds 4–8 and 14 were ≤MIC 24.7 μg∙mL-1 against all the reference strain, even more the compound 6 showed the most potent activity with a MIC of 3.9 μg∙mL-1 on S. aureus. On the clinical isolated the compounds 7, 8 and 14 showed a MIC of 49.7 and 24.7 μg∙mL-1 against S. aureus y E. coli respectively. About ADME properties and Osiris analysis, the compounds 4-16 presented high gastrointestinal absorption and good characteristics for oral bioavailability and the compound 14 was the less toxic. Conclusion: amino acid 1,4-naphthoquinone derivatives showed good in vitro antibacterial activity against clinical strains, and modifications on C-3 with cloride atom enhanced the efficiency against same pathogens.


1980 ◽  
Vol 28 (3) ◽  
pp. 1019-1027 ◽  
Author(s):  
Christopher P. Cheney ◽  
Peter A. Schad ◽  
Samuel B. Formal ◽  
Edgar C. Boedeker

We have previously described an in vitro assay for examining the mucosal adherence of a rabbit diarrheagenic Escherichia coli , RDEC-1. That assay defined the in vitro characteristics of RDEC-1 adherence to brush borders isolated from rabbit ileal epithelial cells. The present study was conducted to examine the species specificity of both in vitro RDEC-1 adherence and in vivo infectivity of RDEC-1 and to compare these specificities. Species specificity in vitro adherence was examined by using brush borders prepared from intestinal epithelial cells of rats, guinea pigs, and rabbits, as well as from a surgically resected specimen of human ileum. Strain RDEC-1 adherence to rabbit brush borders in vitro was significantly greater ( P < 0.001) than its adherence to brush borders from any of the other species. Regional specificity of in vitro adherence of RDEC-1 to ileal segments of rabbit intestinal mucosa was also demonstrated. There was significantly greater adherence of RDEC-1 to rabbit ileal brush borders as compared to rabbit jejunal brush borders ( P < 0.05). In vivo infectivity was assessed by inoculating RDEC-1 into rats, guinea pigs, and rabbits. RDEC-1 elicited diarrhea in all inoculated rabbits with the mean onset of illness occurring 5 days after inoculation. In contrast, none of the RDEC-1-inoculated rats or guinea pigs developed diarrhea. Furthermore, colonization studies in these animals revealed that RDEC-1 heavily colonized the ileum and cecum (10 9 RDEC-1 colony-forming units/g of tissue) of rabbits; however, only minimal colonization was observed in guinea pigs and rats. In conclusion, the correlation between in vitro adherence and in vivo infectivity that we have observed suggests that the presence of receptors, specific for bacteria, on the surface of the host intestinal mucosa determines species susceptibility to enteric colonization and infectivity by certain strains of enteropathogenic E. coli .


2014 ◽  
Vol 81 (2) ◽  
pp. 578-586 ◽  
Author(s):  
Maria Alessandra Damiano ◽  
Daniela Bastianelli ◽  
Sascha Al Dahouk ◽  
Stephan Köhler ◽  
Axel Cloeckaert ◽  
...  

ABSTRACTBrucellais an expanding genus of major zoonotic pathogens, including at least 10 genetically very close species occupying a wide range of niches from soil to wildlife, livestock, and humans. Recently, we have shown that in the new speciesBrucella microti, the glutamate decarboxylase (Gad)-dependent system (GAD system) contributes to survival at a pH of 2.5 and also to infection in mice by the oral route. In order to study the functionality of the GAD system in the genusBrucella, 47 isolates, representative of all known species and strains of this genus, and 16 strains of the closest neighbor genus,Ochrobactrum, were studied using microbiological, biochemical, and genetic approaches. In agreement with the genome sequences, the GAD system of classical species was not functional, unlike that of most strains ofBrucella ceti,Brucella pinnipedialis, and newly described species (B. microti,Brucella inopinataBO1,B. inopinata-like BO2, andBrucellasp. isolated from bullfrogs). In the presence of glutamate, these species were more acid resistantin vitrothan classical terrestrial brucellae. Expression intransof thegadlocus from representativeBrucellaspecies in theEscherichia coliMG1655 mutant strain lacking the GAD system restored the acid-resistant phenotype. The highly conserved GAD system of the newly described or atypicalBrucellaspecies may play an important role in their adaptation to acidic external and host environments. Furthermore, the GAD phenotype was shown to be a useful diagnostic tool to distinguish these latterBrucellastrains fromOchrobactrumand from classical terrestrial pathogenicBrucellaspecies, which are GAD negative.


2021 ◽  
Author(s):  
Amrutha Bindu ◽  
Lakshmidevi N

Abstract The present aim was to determine the characteristic feature and stability of antimicrobial compound (AMC) produced by probiotic strains of Enterococcus durans MCC4243, Lactiplantibacillus plantarum (Basanym: Lactobacillus plantarum MCC4246) and Limosilactobacillus fermentum (Basonym: Lactobacillus fermentum MCC4233) against Staphylococcus aureus MTCC96 and Escherichia coli MTCC118. Growth kinetic assay revealed 24h of incubation to be optimum for bacteriocin production. Ammonium sulphate precipitation-dialysis was found to be favorable method for extraction of AMC compared to other methods employed. The partially purified compound after ion-exchange chromatography was found to be thermo-resistant upto 90°C and stable under wide range of pH. The compound was sensitive to proteinase-K, but resistant to trypsin, α-amylase and lipase. The apparent molecular weight of AMC from MCC4243 and MCC4246 was found to be 3.5KDa. PCR confirmed the presence of plantaricinA gene in MCC4246. Translated partial amino acid sequence of plnA gene of MCC4246 displayed 48 amino acid sequence which had 100% similarity with plantaricinA of Lactobacillus plantarum (WP 0036419). The sequence revealed 7 β sheets, 6 α sheets, 6 predicted coils and 9 predicted turns and functions on cytoplasm with 10.82 isoelectric point and 48.6% hydrophobicity. From the study, the amino acid sequence “KSSAYSLQMGATAIKQVKKLFKKWGW” of peptide was predicted to be responsible for antimicrobial activity.


2016 ◽  
Vol 15 (2) ◽  
pp. 172-177
Author(s):  
Quazi Rubyath Banna ◽  
Badar Uddin Umar ◽  
S M Niazur Rahman ◽  
Tanbira Alam ◽  
Kazi Selim Anwar ◽  
...  

Objective: Medicinal plants remain in vogue to treat some diseases in lower socio-economic communities, despite the availability of antimicrobials, often. Majority of rural Bangladeshi and tribal people being grossly illiterate and ignorant, use various herbs to treat a wide range of diseases. Of several medicinal-plants, neem is reported to have enormous impact in treating inflammation and infections. We, therefore, compared the antimicrobial effect of ethanolic neem leave extract (ENLE) on Escherichia coli (E. coli), with that of Ciprofloxacin. Materials & Methods: This experimental study compared the in vitro antimicrobial activity between ENLE and Ciprofloxacin on E. coli carried out in Department of Pharmacology and Therapeutics of SS-Medical College, Dhaka, Bangladesh. Antimicrobial efficacy of ENLE and ciprofloxacin (5µg; Oxoid, UK) was determined against E. coli following minimum inhibitory concentration. By filtration and evaporation of Neem leaves ENLE was prepared. Antibiotic Sensitivity Test was performed on Muller-Hinton agar using a twofold serial dilution. Results: ENLE showed an inhibitory effect on the growth of E. coli at the concentration of 3.125 mg/ml. Antibacterial susceptibility of E. coli was performed on MHA and diameters of zone of inhibition by both ENLE and Ciprofloxacin were measured after overnight aerobic incubation at 37°C. Diameter of zone of inhibition against E. coli was 28 ± 0.16 mm with ENLE, 36 ± 0.07 mm with Ciprofloxacin (5µg/disk) (p<0.000). Conclusion: Findings of this preliminary in-vitro experiment though suggests that, ENLE against E. coli showed limited efficacy, better efficacy of Ciprofloxacin cannot be ruled out unless further in depth studies elucidates stronger evidences to support it.Bangladesh Journal of Medical Science Vol.15(2) 2016 p.172-177


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