scholarly journals Lactobacillus rhamnosus GG and Saccharomyces cerevisiae boulardii exert synergistic antipathogenic activity in vitro against enterotoxigenic Escherichia coli

2019 ◽  
Vol 10 (8) ◽  
pp. 923-935 ◽  
Author(s):  
F. Moens ◽  
C. Duysburgh ◽  
P. van den Abbeele ◽  
M. Morera ◽  
M. Marzorati
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Synergistic Effects ◽  
Lactobacillus Rhamnosus ◽  
Proximal Colon ◽  
Enterotoxigenic Escherichia Coli ◽  
Short Term ◽  
Lactobacillus Rhamnosus Gg ◽  
Mucosal Layer

Short-term colonic in vitro batch incubations were performed to elucidate the possible synergistic effects of Lactobacillus rhamnosus GG (CNCM-I-4798) and Saccharomyces cerevisiae boulardii (CNCM-I-1079) (associated in Smebiocta/Smectaflora Protect®) on the colonic microbial fermentation process, as well as their antipathogenic activity against enterotoxigenic Escherichia coli (LMG2092) (ETEC). These incubations adequately simulate the native microbiota and environmental conditions of the proximal colon of both adult and toddler donors, including the colonic mucosal layer. Results indicated that both strains were capable of growing together without showing antagonistic effects. Co-cultivation of both strains resulted in increased butyrate (stimulated by L. rhamnosus GG), propionate (stimulated by S. boulardii), and ethanol (produced by S. boulardii) production compared to the control incubations, revealing the additive effect of both strains. After inoculation of ETEC under simulated dysbiotic conditions, a 40 and 46% reduction in the concentration of ETEC was observed upon addition of both strains during the experiments with the adult and toddler donor, respectively. Furthermore, ETEC toxin levels decreased upon S. boulardii inoculation, probably due to proteolytic activity of this strain, with a synergistic effect being observed upon co-cultivation of L. rhamnosus GG and S. boulardii resulting in a reduction of 57 and 46% for the adult and toddler donor, respectively. Altogether, the results suggest that both probiotics together may help microbiota functionality, in both adults and toddlers and under healthy or impaired conditions, which could be of great interest when the colonic microbiota is dysbiotic and therefore sensitive to pathogenic invasion such as during antibiotic treatment.

In Vivo, In Vitro and Transplacental Immune Effects of a Probiotic Bacterium Lactobacillus rhamnosus GG in Humans

2009 ◽  
Vol 123 (2) ◽  
pp. S200-S200
Author(s):  
R.J. Boyle ◽  
L. Mah ◽  
S. Kivivuori ◽  
A. Chen ◽  
S.J. Lahtinen ◽  
...  
Keyword(s):  
Lactobacillus Rhamnosus ◽  
Probiotic Bacterium ◽  
Lactobacillus Rhamnosus Gg

scholarly journals In Vitro and In Vivo Assessment of the Potential of Escherichia coli Phages to Treat Infections and Survive Gastric Conditions

2021 ◽  
Vol 9 (9) ◽  
pp. 1869
Author(s):  
Joanna Kaczorowska ◽  
Eoghan Casey ◽  
Gabriele A. Lugli ◽  
Marco Ventura ◽  
David J. Clarke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Galleria Mellonella ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Composite Mixture ◽  
Ph Conditions ◽  
The Stability ◽  
Higher Sensitivity

Enterotoxigenic Escherichia coli (ETEC) and Shigella ssp. infections are associated with high rates of mortality, especially in infants in developing countries. Due to increasing levels of global antibiotic resistance exhibited by many pathogenic organisms, alternative strategies to combat such infections are urgently required. In this study, we evaluated the stability of five coliphages (four Myoviridae and one Siphoviridae phage) over a range of pH conditions and in simulated gastric conditions. The Myoviridae phages were stable across the range of pH 2 to 7, while the Siphoviridae phage, JK16, exhibited higher sensitivity to low pH. A composite mixture of these five phages was tested in vivo in a Galleria mellonella model. The obtained data clearly shows potential in treating E. coli infections prophylactically.

scholarly journals CfaD-Dependent Expression of a Novel Extracytoplasmic Protein from Enterotoxigenic Escherichia coli

2007 ◽  
Vol 189 (14) ◽  
pp. 5060-5067 ◽  
Author(s):  
M. Carolina Pilonieta ◽  
Maria D. Bodero ◽  
George P. Munson
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Secretory Pathway ◽  
Dnase I ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Dnase I Footprinting ◽  
Virulence Regulator

ABSTRACT H10407 is a strain of enterotoxigenic Escherichia coli (ETEC) that utilizes CFA/I pili to adhere to surfaces of the small intestine, where it elaborates toxins that cause profuse watery diarrhea in humans. Expression of the CFA/I pilus is positively regulated at the level of transcription by CfaD, a member of the AraC/XylS family. DNase I footprinting revealed that the activator has two binding sites upstream of the pilus promoter cfaAp. One site extends from positions −23 to −56, and the other extends from positions −73 to −103 (numbering relative to the transcription start site of cfaAp). Additional CfaD binding sites were predicted within the genome of H10407 by computational analysis. Two of these sites lie upstream of a previously uncharacterized gene, cexE. In vitro DNase I footprinting confirmed that both sites are genuine binding sites, and cexEp::lacZ reporters demonstrated that CfaD is required for the expression of cexE in vivo. The amino terminus of CexE contains a secretory signal peptide that is removed during translocation across the cytoplasmic membrane through the general secretory pathway. These studies suggest that CexE may be a novel ETEC virulence factor because its expression is controlled by the virulence regulator CfaD, and its distribution is restricted to ETEC.

In vitro activity of antimicrobial agents with and without sulbactam, EDTA and sulbactam-EDTA on ESBLs-producing Escherichia coli isolated from healthy Tibetan yaks

2020 ◽  
Author(s):  
Baoguang Liu ◽  
Xiaoling Yuan ◽  
Yiheng Chen ◽  
Xiaoshen Li ◽  
Ming Bai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nasal Swab ◽  
Antimicrobial Agents ◽  
Synergistic Effects ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Third Generation Cephalosporins ◽  
Enhance Activity

Abstract Background The spread of ESBLs-producing bacteria has been strikingly rapid in many regions of the world and it causes therapeutic difficulties in everyday practice. The aims of this study were to investigate the prevalence and susceptibilities of ESBLs-producing Escherichia coli isolates from healthy Tibetan yaks in China, to evaluate the activity of drug combinations on ESBLs-producing E. coli isolates. Methods From July 2018 to August 2019, a total of 750 nasal swab samples were tested for the presence of E. coli and ESBLs-producing strains. The MICs of 11 antimicrobial agents alone and combinations with sulbactam, EDTA or sulbactam-EDTA against 240 ESBLs-producing E.coli strains were determined by the broth microdilution method. Results Overall, 59.87% (n = 449) of the samples were positive for E. coli, 240 (53.45%) of 449 E. coli isolates were confirmed to be ESBLs-producing. The addition of sulbactam to the third generation cephalosporins, amikacin and fosfomycin for all isolates resulted in low MICs, increasing the level of susceptibility from 0, 0 and 0% to 50 ~ 87.5, 4.2 and 100% respectively. The addition of EDTA to fluoroquinolones, doxycycline, florfenicol, amikacin and fosfomycin, showed improved activities and resulted in low MICs, increasing the level of susceptibility from 0, 0, 8.3, 0 and 0% to 4.2 ~ 29.2, 33.3, 33.3, 66.7 and 45.8%, respectively. All other antibacterials (except fluoroquinolones, doxycycline and florfenicol), when combined with sulbactam-EDTA, were found to be more active than combinations only with sulbactam or with EDTA against most of isolates, with lower MIC50s and MIC90s. Conclusion In conclusion, ESBLs-producing E. coli isolates were widespread in healthy Tibetan yaks in China. ESBLs-producing E. coli isolates exhibited varying degrees of multidrug resistance. This study these findings suggested that sulbactam can enhance activity of β-lactams and some non-β-lactams of antimicrobial agents and had a synergistic effects with EDTA in improving activities of some families of antimicrobials.

scholarly journals Nitrofurantoin Combined With Amikacin: A Promising Alternative Strategy for Combating MDR Uropathogenic Escherichia coli

2020 ◽  
Vol 10 ◽  
Author(s):  
Zi-Xing Zhong ◽  
Ze-Hua Cui ◽  
Xiao-Jie Li ◽  
Tian Tang ◽  
Zi-Jian Zheng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Galleria Mellonella ◽  
Synergistic Effects ◽  
Promising Alternative ◽  
Poor Patient Compliance ◽  
Life Threatening ◽  
Tract Infections ◽  
Time Kill

Urinary tract infections (UTI) are common infections that can be mild to life threatening. However, increased bacterial resistance and poor patient compliance rates have limited the effectiveness of conventional antibiotic therapies. Here, we investigated the relationship between nitrofurantoin and amikacin against 12 clinical MDR uropathogenic Escherichia coli (UPEC) strains both in vitro and in an experimental Galleria mellonella model. In vitro synergistic effects were observed in all 12 test strains by standard checkerboard and time-kill assays. Importantly, amikacin or nitrofurantoin at half of the clinical doses were not effective in the treatment of UPEC infections in the G. mellonella model but the combination therapy significantly increased G. mellonella survival from infections caused by all 12 study UPEC strains. Taken together, these results demonstrated synergy effects between nitrofurantoin and amikacin against MDR UPEC.

scholarly journals Minimal and RNA-free RNase P in Aquifex aeolicus

2017 ◽  
Vol 114 (42) ◽  
pp. 11121-11126 ◽  
Author(s):  
Astrid I. Nickel ◽  
Nadine B. Wäber ◽  
Markus Gößringer ◽  
Marcus Lechner ◽  
Uwe Linne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Rnase P ◽  
Aquifex Aeolicus ◽  
Trna Processing ◽  
Hyperthermophilic Bacterium ◽  
Domains Of Life

RNase P is an essential tRNA-processing enzyme in all domains of life. We identified an unknown type of protein-only RNase P in the hyperthermophilic bacterium Aquifex aeolicus: Without an RNA subunit and the smallest of its kind, the 23-kDa polypeptide comprises a metallonuclease domain only. The protein has RNase P activity in vitro and rescued the growth of Escherichia coli and Saccharomyces cerevisiae strains with inactivations of their more complex and larger endogenous ribonucleoprotein RNase P. Homologs of Aquifex RNase P (HARP) were identified in many Archaea and some Bacteria, of which all Archaea and most Bacteria also encode an RNA-based RNase P; activity of both RNase P forms from the same bacterium or archaeon could be verified in two selected cases. Bioinformatic analyses suggest that A. aeolicus and related Aquificaceae likely acquired HARP by horizontal gene transfer from an archaeon.

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