scholarly journals Nanoliposome-Encapsulated Phenolic Rich Fraction From Alcea Rosea as a Dietary Phytobiotic in Mice Challenged by Escherichia Coli

Author(s):  
Niloofar Hassirian ◽  
Ehsan Karimi ◽  
Ehsan Oskoueian

Abstract Purpose This research was performed to evaluate the antibacterial and health-promoting potentials of the nanoliposome-encapsulated phenolic rich fraction (PRF) from Alcea rosea leaves as a dietary phytobiotic in mice challenged by enteropathogenic Escherichia coli (E. coil; O157: H7). Method: The PEF was encapsulated in nanoliposomes (PEF-NLs) and the phenolic profiling of PEF-NLs was confirmed by HPLC. Then 40 white male balb/c mice at four treatment groups were provided and antibacterial potential of PEF-NLs were assessed by measuring the mice blood parameters and liver lipid peroxidation in mice infected by E. coli. Finally, the expression of cyclooxygenase 2 (COX2), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were determined in miceʼs ileum tissues. Meanwhile, relative fold changes in the ileum population of E. coli was analyzed using Real time PCR. Results The overall results demonstrated that the nanoliposome-loaded PRF contained gallic acid, salicylic acid, pyrogallol, cinnamic acid, catechin, naringin, ferulic acid. The E. coil challenge in mice impaired the weight gain, food intake, liver enzymes, lipid peroxidation, morphometric characteristics of the ileum, up-regulated the inflammatory genes (COX2, iNOS), down-regulated the antioxidant-related genes (SOD and GPx) and increased the population of E. coil in the ileum. The dietary inclusion of nonencapsulated PRF and nanoliposome-encapsulated PRF at the concentration of 10 mg TPC/kg BW/day improved these parameters however the nanoliposome-encapsulated PRF appeared to be more effective as compared to nonencapsulated PRF in improving the health parameters in mice. Conclusion Consequently, the nanoliposome-encapsulated PRF could play a critical role as a promising phytobiotic against E. coil infection in mice.

2021 ◽  
Author(s):  
Niloofar Hassirian ◽  
Ehsan Karimi ◽  
Ehsan Oskoueian

Abstract Background: This research was performed to evaluate the antibacterial and health-promoting potentials of the nanoliposome-encapsulated phenolic rich fraction (PRF) from Alcea rosea leaves as a dietary phytobiotic in mice challenged by enteropathogenic Escherichia coli (E. coil; O157: H7). Results: The overall results demonstrated that the nanoliposome-loaded PRF contained gallic acid, salicylic acid, pyrogallol, cinnamic acid, catechin, naringin, ferulic acid. The E. coil challenge in mice impaired the weight gain, food intake, liver enzymes, lipid peroxidation, morphometric characteristics of the ileum, up-regulated the inflammatory genes (COX2, iNOS), down-regulated the antioxidant-related genes (SOD and GPx) and increased the population of E. coil in the ileum. The dietary inclusion of nonencapsulated PRF and nanoliposome-encapsulated PRF at the concentration of 10 mg TPC/kg BW/day improved these parameters however the nanoliposome-encapsulated PRF appeared to be more effective as compared to nonencapsulated PRF in improving the health parameters in mice. Conclusion: Consequently, the nanoliposome-encapsulated PRF could play a critical role as a promising phytobiotic against E. coil infection in mice.


2013 ◽  
Vol 454 (3) ◽  
pp. 585-595 ◽  
Author(s):  
Joana Sá-Pessoa ◽  
Sandra Paiva ◽  
David Ribas ◽  
Inês Jesus Silva ◽  
Sandra Cristina Viegas ◽  
...  

In the present paper we describe a new carboxylic acid transporter in Escherichia coli encoded by the gene yaaH. In contrast to what had been described for other YaaH family members, the E. coli transporter is highly specific for acetic acid (a monocarboxylate) and for succinic acid (a dicarboxylate), with affinity constants at pH 6.0 of 1.24±0.13 mM for acetic acid and 1.18±0.10 mM for succinic acid. In glucose-grown cells the ΔyaaH mutant is compromised for the uptake of both labelled acetic and succinic acids. YaaH, together with ActP, described previously as an acetate transporter, affect the use of acetic acid as sole carbon and energy source. Both genes have to be deleted simultaneously to abolish acetate transport. The uptake of acetate and succinate was restored when yaaH was expressed in trans in ΔyaaH ΔactP cells. We also demonstrate the critical role of YaaH amino acid residues Leu131 and Ala164 on the enhanced ability to transport lactate. Owing to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate–Acetate Transporter Protein.


2015 ◽  
Vol 78 (8) ◽  
pp. 1554-1559 ◽  
Author(s):  
RONG WANG ◽  
NORASAK KALCHAYANAND ◽  
JAMES L. BONO

Bacterial biofilms are one of the potential sources of cross-contamination in food processing environments. Shiga toxin–producing Escherichia coli (STEC) O157:H7 and O111:H8 are important foodborne pathogens capable of forming biofilms, and the coexistence of these two STEC serotypes has been detected in various food samples and in multiple commercial meat plants throughout the United States. Here, we investigated how the coexistence of these two STEC serotypes and their sequence of colonization could affect bacterial growth competition and mixed biofilm development. Our data showed that E. coli O157:H7 strains were able to maintain a higher cell percentage in mixed biofilms with the co-inoculated O111:H8 companion strains, even though the results of planktonic growth competition were strain dependent. On solid surfaces with preexisting biofilms, the sequence of colonization played a critical role in determining the composition of the mixed biofilms because early stage precolonization significantly affected the competition results between the E. coli O157:H7 and O111:H8 strains. The precolonizer of either serotype was able to outgrow the other serotype in both planktonic and biofilm phases. The competitive interactions among the various STEC serotypes would determine the composition and structure of the mixed biofilms as well as their potential risks to food safety and public health, which is largely influenced by the dominant strains in the mixtures. Thus, the analysis of mixed biofilms under various conditions would be of importance to determine the nature of mixed biofilms composed of multiple microorganisms and to help implement the most effective disinfection operations accordingly.


2017 ◽  
Vol 18 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Shinji Yamasaki ◽  
Tuyen Danh Le ◽  
Mai Quang Vien ◽  
Chinh Van Dang ◽  
Yoshimasa Yamamoto

AbstractEmergence and spread of antimicrobial-resistant bacteria, including extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, have become serious problems worldwide. Recent studies conducted in Vietnam revealed that ESBL-producing E. coli are widely distributed in food animals and people. CTX-M-9 and CTX-M-1 are the most prevalent β-lactamases among the identified ESBLs. Furthermore, most of the ESBL-producing E. coli isolates were multi-drug resistant. Residual antimicrobials such as sulfamethoxazole, trimethoprim, sulfadimidine, cephalexin, and sulfadiazine were also detected at a high level in both animal meats and environmental water collected from several cities, including Ho Chi Minh city and Can Tho city. These recent studies indicated that improper use of antimicrobials in animal-originated food production might contribute to the emergence and high prevalence of ESBL-producing E. coli in Vietnam. Although clonal ESBL-producing E. coli was not identified, CTX-M-55 gene-carrying plasmids with similar sizes (105–139 kb) have been commonly detected in the ESBL-producing E. coli strains isolated from various food animals and human beings. This finding strongly suggests that horizontal transfer of the CTX-M plasmid among various E. coli strains played a critical role in the emergence and high prevalence of ESBL-producing E. coli in Vietnam.


2007 ◽  
Vol 70 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. L. REICKS ◽  
M. M. BRASHEARS ◽  
K. D. ADAMS ◽  
J. C. BROOKS ◽  
J. R. BLANTON ◽  
...  

Prevalences of Escherichia coli O157:H7, Salmonella, and total aerobic microorganisms were determined on the hides of beef feedlot cattle before and after transport from the feedyard to the harvest facility in clean and dirty trailers. Swab samples were taken from the midline and withers of 40 animals on each of 8 days before and after shipping. After samples were collected, animals were loaded in groups of 10 on upper and lower levels of clean and dirty trailers. Animals were unloaded at the harvest facility and kept in treatment groups for sample collection after exsanguination. Salmonella was found more often on hide swabs collected from the midline than on than samples collected from the withers from animals transported in both clean and dirty trailers. Salmonella was found on significantly more hide swabs collected at harvest from both sampling locations than on those collected at the feedyard, with no differences attributed to the type of trailer. At the feedyard, clean trucks had a lower percentage of Salmonella-positive samples than did dirty trucks before animals were loaded. However, after transport, both clean and dirty trucks had a similar prevalence of Salmonella. There were no differences in Salmonella prevalence on hides collected from animals transported on the top and bottom levels of clean and dirty trucks. E. coli O157:H7 was detected on less than 2% of the samples; therefore, no practical conclusions about prevalence could be drawn. Hides sampled at harvest had higher concentrations of aerobic microorganisms than did hides sampled at the feedyard, and concentrations were higher on the midline than on the withers. Although the prevalences of Salmonella and total aerobic microorganisms increased on hides after transport from the feedyard to the plant, this increase was not related to the cleanliness of the trailers or the location of the cattle in the trailers.


2015 ◽  
Vol 113 (6) ◽  
pp. 923-934 ◽  
Author(s):  
Sugiharto Sugiharto ◽  
Ann-Sofie Riis Poulsen ◽  
Nuria Canibe ◽  
Charlotte Lauridsen

The present study investigated the effect of feeding bovine colostrum (BC) to piglets in comparison with feeding a milk replacer (MR) and conventional rearing by the sow on the intestinal immune system and number of enterotoxigenic Escherichia coli (ETEC) colonising the intestinal tissue. Piglets (23-d-old) were allocated to one of the following four groups: (1) killed at the beginning of the experiment (Base); (2) separated from the sow and fed BC (BC-fed); (3) separated from the sow and fed a MR (MR-fed); (4) kept with the sow (Sow-Milk). Blood was sampled on days 1 and 8, and faecal samples were collected on days 1, 3, 5 and 8. On day 8, piglets were killed and gastrointestinal digesta and intestinal segments were collected. The frequency of diarrhoea was found to be higher (P≤ 0·019) in MR-fed piglets than in BC-fed and Sow-Milk piglets. Piglets from the MR-fed group had the lowest lactic acid bacteria:haemolytic E. coli ratio (Ptreat= 0·064) in the faeces. The number of E. coli colonising the intestinal tissue was higher (P< 0·001) in piglets from the MR-fed group than in those from the BC-fed and Sow-Milk groups. Piglets from the Sow-Milk group had a higher (P= 0·020) mucosal IgG concentration than those from the MR-fed group, but did not exhibit any difference when compared with piglets from the Base and BC-fed groups. Piglets from the BC-fed group exhibited a reduced (P≤ 0·037) expression level of Toll-like receptor-4 in the intestinal mucosa when compared with those from the MR-fed and Sow-Milk groups. The expression level of IL-2 was higher (P≤ 0·051) in piglets from the MR-fed group than in those from the other treatment groups. In conclusion, feeding BC rather than MR to the piglets reduced the colonisation of intestine by ETEC and modulated the intestinal immune system, whereas no differences were observed in piglets fed BC and conventionally reared by the sows.


2019 ◽  
Author(s):  
Theodoulakis Christofi ◽  
Stavria Panayidou ◽  
Irini Dieronitou ◽  
Christina Michael ◽  
Yiorgos Apidianakis

AbstractGut microbiota acts as a barrier against intestinal pathogens, but species-specific protection of the host from infection remains relatively unexplored. Taking a Koch’s postulates approach in reverse to define health-promoting microbes we find thatEscherichia colinaturally colonizes the gut of healthy mice, but it is depleted from the gut of antibiotic-treated mice, which become susceptible to intestinal colonization byPseudomonas aeruginosaand concomitant mortality. Reintroduction of fecal bacteria andE. coliestablishes a high titer ofE. coliin the host intestine and increases defence againstP. aeruginosacolonization and mortality. Moreover, diet is relevant in this process because high sugars or dietary fat favoursE. colifermentation to lactic acid andP. aeruginosagrowth inhibition. To the contrary, low sugars allowP. aeruginosato produce the oxidative agent pyocyanin that inhibitsE. coligrowth. Our results provide an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.Author SummaryHere we interrogate the conundrum as to whyPseudomonas aeruginosais not a clinical problem in the intestine as opposed to other tissues.P. aeruginosainteracts with Neisseria, Streptococcus, Staphylococcus and Actinomyces species found in the human lung. These are predominantly gram-positive bacteria that induceP. aeruginosavirulence. Moreover, peptidoglycan, which is abundant in gram-positive bacteria, can directly trigger the virulence ofP. aeriginosa. We reasoned thatP. aeruginosamight be benign in the human gut due to the inhibitory action of benign gram-negative intestinal bacteria, such asEscherichia coli. Therefore, we dissected the antagonism betweenE. coliandP. aeruginosaand the effect of a conventional, a fat-, a carbohydrate-and a protein-based diet in intestinal dysbiosis. Our findings support the notion that an unbalanced diet or antibiotics induces gut dysbiosis by the elimination of commensalE. coli, in addition to lactic acid bacteria, imposing a gut environment conducive toP. aeruginosainfection. Moreover, commensalE. coliprovides an explanation as to whyP. aeruginosadoesn’t commonly infect the human gut, despite being a formidable microbe in lung and wound infections.


2022 ◽  
Author(s):  
Michael Schmidt ◽  
Theresa Proctor ◽  
Rucheng Diao ◽  
Peter L. Freddolino

Thioesterases play a critical role in metabolism, membrane biosynthesis, and overall homeostasis for all domains of life. In this present study, we characterize a putative thioesterase from Escherichia coli MG1655 and define its role as a cytosolic enzyme. Building on structure-guided functional predictions, we show that YigI is a medium- to -long chain acyl-CoA thioesterase that is involved in the degradation of conjugated linoleic acid (CLA) in vivo, showing overlapping specificity with two previously defined E. coli thioesterases TesB and FadM. We then bioinformatically identify the regulatory relationships that induce YigI expression, which include: an acidic environment, high oxygen availability, and exposure to aminoglycosides. Our findings define a role for YigI and shed light on why the E. coli genome harbors numerous thioesterases with closely related functions.


2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Steviany Towoliu

Abstract: E. coli is part of the normal flora of the human and animal intestine and is commonly non pathogenic. However, one of the serotypes of this bacteria, which is enteropathogenic E. coli (EPEC), can cause primary infection on the intestine such diarrhea.  The growth of pathogenic bacteria in diarrheal patients can be inhibited by Lactobacillus.  Lactobacillus can function as probiotic which can affect the immune system of the digestive canals.  In addition, Lactobacillus also produce mucus  which can act as barrier to the pathogens.  The objective of this study was to reveal the effects of the administration of Lactobacillus on the microscopic features of the mucosa of the intestine of wistar rats infected by Escherichia coli.  This study was a laboratory experimental research employing 16 wistar rats divided into the control group (4 rats) and three treatment groups (12 rats) consisting of 4 rats each.  Results showed that; in group I the histological features were normal, in group II part of the epithelium of the mucosa showed erosion, dilatation of the capillary vessels, and many lymphosites were observed, in group III the epithelium of the mucosa was intact and the number of lymphosites was liitle, and in group IV the surface of the epithelium was intact, the presence of cell regeneration indicated by the increase number of goblet cells and a small number of  lymphocyes. Conclusions: The administration of after infection by E. coli has benefial effects indicated by the improvement of epithelial cells and the absence of denudation of the epithelium of the intestine. Keywords: E.coli, Lactobacillus, intestinal mucosa.   Abstrak: E.coli merupakan flora normal usus halus manusia dan hewan umumnya tidak menyebabkan penyakit.  Namun salah satu serotipe E.coli yaitu E.coli Enteropatogenik (EPEK) bersifat patogen dan dapat menyebabkan infeksi primer pada usus misalnya diare.  Pertumbuhan bakteri patogen pada pasien diare dapat dihambat oleh Lactobacillus. Lactobacillus merupakan probiotik yang akan mempengaruhi sistem imun saluran cerna serta memproduksi mukus yang berfungsi sebagai penghalang saluran cerna terhadap bakteri patogen.  Penelitian ini bertujuan untuk melihat efek pemberian Lactobacillus terhadap gambaran mikroskopis mukosa usus halus tikus wistar yang diinfeksi dengan Escherichia coli.  Penelitian ini merupakan penelitian eksperimental laboratorik.  Subjek penelitian terdiri dari 16 ekor tikur wistar yang dibagi dalam kelompok kontrol (4 ekor) dan kelompok  perlakuan (12 ekor) dibagi dalam 3 kelompok masing-masing 4 ekor.  Hasil penelitian kelompok I dengan gambaran histologik jaringan usus normal, kelompok II sebagian epitel mukosa usus halus terlihat erosi,  ada pelebaran pembuluh darah kapiler, dan banyak limfosit, kelompok III dengan permukaan epitel mukosa yang utuh dan jumlah limfosit sedikit, dan kelompok IV dengan permukaan epitel yang utuh, adanya regenerasi sel ditandai dengan bertambahnya sel goblet, dan sedikit limfosit.  Simpulan: Pemberian Lactobacillus setelah diberikan E.coli memberi efek yang baik berupa perbaikan sel epitel permukaan dan tidak terlihat denudasi epitel permukaan usus halus. Kata Kunci: E.coli, Lactobacillus, mukosa usus halus.


2021 ◽  
Author(s):  
Cynthia A. Hale ◽  
Logan Persons ◽  
Piet A. J. de Boer

The Tol-Pal system of Gram-negative bacteria helps maintain integrity of the cell envelope and ensures that invagination of the envelope layers during cell fission occurs in a well-coordinated manner. In E. coli , the five Tol-Pal proteins (TolQ, R, A, B and Pal) accumulate at cell constriction sites in a manner that normally requires the activity of the cell constriction initiation protein FtsN. While septal recruitment of TolR, TolB and Pal also requires the presence of TolQ and/or TolA, each of the the latter two can recognize constriction sites independently of the other system proteins. What attracts TolQ or TolA to these sites is unclear. We show that FtsN attracts both proteins in an indirect fashion, and that PBP1A, PBP1B and CpoB are dispensable for their septal recruitment. However, the β-lactam aztreonam readily interferes with septal accumulation of both TolQ and TolA, indicating that FtsN-stimulated production of septal peptidoglycan by the FtsWI synthase is critical to their recruitment. We also discovered that each of TolA's three domains can recognize division sites in a separate fashion. Notably, the middle domain (TolAII) is responsible for directing TolA to constriction sites in the absence of other Tol-Pal proteins and CpoB, while recruitment of TolAI and TolAIII requires TolQ and a combination of TolB, Pal, and CpoB, respectively. Additionally, we describe the construction and use of functional fluorescent sandwich fusions of the ZipA division protein, which should be more broadly valuable in future studies of the E. coli cell division machinery. IMPORTANCE Cell division (cytokinesis) is a fundamental biological process that is incompletely understood for any organism. Division of bacterial cells relies on a ring-like machinery called the septal ring or divisome that assembles along the circumference of the mother cell at the site where constriction will eventually occur. In the well-studied bacterium Escherichia coli , this machinery contains over thirty distinct proteins. We studied how two such proteins, TolA and TolQ, which also play a role in maintaining integrity of the outer-membrane, are recruited to the machinery. We find that TolA can be recruited by three separate mechanisms, and that both proteins rely on the activity of a well-studied cell division enzyme for their recruitment.


Sign in / Sign up

Export Citation Format

Share Document