Microbiota-derived lantibiotic restores resistance against vancomycin-resistant Enterococcus (original) (raw)

Comparative Study of Bacterial Groups within the Human Cecal and Fecal Microbiota

Applied and Environmental Microbiology, 2001

The composition of the human cecal microbiota is poorly known because of sampling difficulties. Samples of cecal fluid from eight subjects were collected via an intestinal tube. Feces were also collected. Total anaerobes, facultative anaerobes, bifidobacteria, and Bacteroides were enumerated by culture methods, and the predominant phylogenetic groups were quantified by molecular hybridization using a set of six rRNA-targeted probes. The numbers of strict anaerobes, bifidobacteria, Bacteroides, and members of the Clostridium coccoides group and Clostridium leptum subgroup were lower in the cecum. Facultative anaerobes represented 25% of total bacteria in the cecum versus 1% in the feces.

Comprehensive analysis of Enterococcus strains isolated from human microbiome and evaluation of their benefits for digestive system

Meta Gene, 2020

Background: Some studies have highlighted a mutualistic relationship between human and Enterococcus spp.; however, other surveys have showed only a commensal connection. This study aimed to clearly answer this question that whether or not Enterococci strains have a beneficial potential for the human GI tract? Methods: The fecal samples were collected from 1000 healthy volunteers. Inhibitory potency of these bacteria was evaluated on three intestinal pathogens using phenotypic agar spot assay and genotypic PCR method. After typing bacteria by PFGE, the probiotic supplemented tests were used for evaluating Enterococci beneficial potential. Results: Out of 1000 fecal isolated Enterococci strains, 91 isolates were identified as E. faecium; entA (88.6%) and entB (26.8%) were present almost in all of the isolates. Also, 100% of the E. faecium isolates were active against EAEC and Shigella dysenteriae (zone ≥10 mm); however, these E. faecium isolates weren't effective against EPEC. Moreover, it was found that 9 out of 91 E. faecium isolates had > 50% viability in bile salts and acid stress assays, and only 4 of these 9 acid-bile resistant isolates were able to adhere to HT-29 cell line. Conclusions: To sum up, almost 4% of human isolated Enterococcus spp. were shown to have a mutualistic behavior with an impressive probiotic potential. It is believed that in the future, these mutualistic Enterococci could be replaced by commensal ones in all people by taking probiotic supplements containing Enterococci.

Probiotic assessment of Enterococcus faecalis CP58 isolated from human gut

International Journal of Food Microbiology, 2011

A total of seventy lactic acid bacteria (LAB) were isolated from the faeces of healthy humans and their identities were confirmed by sequencing of their 16S rDNA genes. Of these only 5 isolates were found to resist bile salts and indicated survival in the simulated in vitro digestion assay which reproduces the stomach and intestinal digestion indicating their tolerance to gastric enzymes and the low pH conditions. Species that showed the best resistance to these conditions were: Lactobacillus casei, Lactobacillus sp., uncultured bifidobacteria, Enterococcus faecalis and Streptococcus anginosus. These strains were investigated further to study their capacity to adhere to human intestinal Caco-2 cells. E. faecalis was the most adherent strain. Examination of the virulence determinants for this strain indicated that it was positive for efaAfs, gelE, agg, cpd, cob, ccf and cad, a profile that is similar to that of many E. faecalis isolates from food sources. The cytolysin biosynthetic genes cylA, cylB and cylM that are more associated with the clinical isolates of E. faecium were not detected in this strain. The antibiotic susceptibility tests indicated that the strain was sensitive to vancomycin, tetracycline, rifampicin and erythromycin but resistant only to kanamycin and chloramphenicol. These data suggest that the strain E. faecalis CP58 may be tested further for beneficial properties and developed as a new probiotic.

Characterization of Enterococcus faecalis isolates originating from different sources for their virulence factors and genes, antibiotic resistance patterns, genotypes and biofilm production

PubMed, 2015

In this study, 72 Enterococcus faecalis isolates originating from humans (n=39), dogs (n=26) and cats (n=7) were investigated for some virulence factors, some virulence genes, antibiotic resistance phenotypes, randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) patterns and biofilm production. Of the isolates, 31 (43.1%) were positive for gelatinase, 11 (15.3%) for aggregation substance and cytolysine, 38 (52.8%) for gelE and 34 (47.2%) for asa1 genes. All isolates were found to be negative for hyl, esp and cylA genes. All isolates were found to be resistant to nalidixic acid and kanamycin. On the other hand, all isolates were cited for susceptible to amoxicillin. Vancomycin resistance genes (vanA, vanB, vanC1/C2 or vanD) have not been detected in any of the phenotypically vancomycin resistant isolates. Isolates from humans, dogs and cats were grouped into 8, 2 and 4 antibiotypes depending upon susceptibilities to 12 different antibiotics. In all human, dog and cat isolates, 9, 12 and 2 genotypes were determined by RAPD-PCR, respectively. Nine (34.6%) of the dog isolates were found to be positive for biofilm production. This study showed that multiple antibiotic resistance among human isolates is more frequent than in dog and cat isolates.

Isolation of Anti-Inflammatory and Epithelium Reinforcing Bacteroides and Parabacteroides Spp. from A Healthy Fecal Donor

Nutrients

Altered intestinal microbiota is associated with systemic and intestinal diseases, such as inflammatory bowel disease (IBD). Dysbiotic microbiota with enhanced proinflammatory capacity is characterized by depletion of anaerobic commensals, increased proportion of facultatively anaerobic bacteria, as well as reduced diversity and stability. In this study, we developed a high-throughput in vitro screening assay to isolate intestinal commensal bacteria with anti-inflammatory capacity from a healthy fecal microbiota transplantation donor. Freshly isolated gut bacteria were screened for their capacity to attenuate Escherichia coli lipopolysaccharide (LPS)-induced interleukin 8 (IL-8) release from HT-29 cells. The screen yielded a number of Bacteroides and Parabacteroides isolates, which were identified as P. distasonis, B. caccae, B. intestinalis, B. uniformis, B. fragilis, B. vulgatus and B. ovatus using whole genome sequencing. We observed that a cell-cell contact with the epithelium w...

Isolation and characterisation of new putative probiotic bacteria from human colonic flora

British Journal of Nutrition, 2007

The present study describes a novel bacterial isolate exhibiting high ability to synthesise and secrete butyrate. The novel isolated bacterium was obtained from human faeces and grown in selective liquid intestinal microflora medium containing rumen fluid under microaerobic conditions. Its probiotic properties were demonstrated by the ability of the isolate to survive high acidity and medium containing bile acids and the ability to adhere to colon cancer cells (Caco-2) in vitro. Phylogenetic identity to Enterococcus durans was established using specific primers for 16S rRNA (99 % probability). PCR analyses with primers to the bacterial gene encoding butyrate kinase, present in the butyrogenic bacteria Clostridium, showed that this gene is present in E. durans. The in vivo immunoprotective and anti-inflammatory effects of E. durans were assessed in dextran sodium sulfate (DSS)-induced colitis in Balb/c mice. Administration of E. durans ameliorated histological, clinical and biochemical scores directly related to intestinal inflammation whereas the lactic acid bacterium Lactobacillus delbrueckii was ineffective in this regard. Colonic cDNA concentrations of IL-1b and TNF-a were significantly down regulated in DSS-treated E. durans-fed mice but not in control or DSS-treated L. delbrueckii-fed mice. Fluorescent in situ hybridisation analyses of colonic tissue from mice fed E. durans, using a butyrate kinase probe, demonstrated that E. durans significantly adheres to the colonic tissue. The novel isolated bacterium described in the present paper, upon further characterisation, can be developed into a useful probiotic aimed at the treatment of patients suffering from ulcerative colitis.

Evaluation of Intestinal Microbiotas of Healthy Japanese Adults and Effect of Antibiotics Using the 16S Ribosomal RNA Gene Based Clone Library Method

Biological and Pharmaceutical Bulletin, 2011

Intestinal microbiotas of human subjects and effect of antibiotic treatment on them have been reported with cultivation independent methods. However, Japanese fecal microbiotas have not been studied enough. We have constructed a clone library method to obtain results within 3 d. In this study, intestinal microbiotas of 29 healthy Japanese adults, whose fecal samples were collected twice at 5 month intervals from each subject, were analyzed with our clone library method, and using those data as a benchmark effect of antibiotic treatment on intestinal microbiotas was evaluated. The fifty-eight fecal microbiotas were assessed based on percentages at genus level, and the variability was analyzed with a principal component analysis (PCA). PCA showed that the microbiotas divided into three groups depending on the large eigenvectors (genera Ruminococcus, Bacteroides, and Prevotella), and the dual samples from the twenty-two individuals have belonged to the same PCA group. It suggests that almost Japanese adults have own stable intestinal microbiota. The genera Ruminococcus and Bacteroides were present in almost subjects, while the genus Prevotella was found only in nine subjects (approximately 30%) which was preserved with 5 months intervals. Next, the microbiotas before and after antibiotic treatment were evaluated comparing with the 58 healthy adult microbiotas. The results showed that beta-lactams influenced profoundly on intestinal microbiotas and the effect of macrolides depended on the cases. It suggests that our clone library method could show overview of intestinal microbiota and would give us useful information about the effect of antibiotic treatment for daily clinical diagnosis.

The Many Faces of Enterococcus spp.—Commensal, Probiotic and Opportunistic Pathogen

Microorganisms

Enterococcus spp. are Gram-positive, facultative, anaerobic cocci, which are found in the intestinal flora and, less frequently, in the vagina or mouth. Enterococcus faecalis and Enterococcus faecium are the most common species found in humans. As commensals, enterococci colonize the digestive system and participate in the modulation of the immune system in humans and animals. For many years reference enterococcal strains have been used as probiotic food additives or have been recommended as supplements for the treatment of intestinal dysbiosis and other conditions. The use of Enterococcus strains as probiotics has recently become controversial due to the ease of acquiring different virulence factors and resistance to various classes of antibiotics. Enterococci are also seen as opportunistic pathogens. This problem is especially relevant in hospital environments, where enterococcal outbreaks often occur. Their ability to translocate from the gastro-intestinal tract to various tissue...

Clinical Utility and Alterations in Bacterial Flora in Fecal Microbiome Transplantation

International Journal of Medical Students

Dysbiotic states of gut ecology can be altered directly by transplantation of fecal preparation from healthy donors to patients with therapeutic intent. This paper assesses this fecal microbiota transplantation (FMT) in two respects: (1) the bacterial shifts in patient microbiomes with FMT and (2) clinical outcomes and variables of FMT. The PubMed database was searched using the MeSH terms “Feces/microbiology,” “Microbiota,” and “Transplantation.” Thirteen papers found examined clinical outcomes and variables of FMT, and eight assessed metagenomic data and bacterial composition in the peri-FMT period. FMT was reported to have high cure rates in Clostridium difficile infection (CDI), generally increased levels of members of the phyla Bacteriodetes and Firmicutes, and decreased levels of members of Proteobacteria. Therapeutic FMT alters bacterial composition from a dysbiotic state pre-FMT to a healthy commensal state post-FMT in CDI patients, but further studies are necessary to under...

In Vitro Assessment of Physiological Properties of Enterococcus Strains of Human Origin for Possible Probiotic Use

Asian Journal of Pharmaceutical and Clinical Research

Objective: The human vagina and gut are known to harbor a wide range of bacteria. Some useful bacteria maintain the vaginal pH around 3–4.5. This acidity of the vagina helps to inhibit pathogenic organisms that cause urogenital infections. The present study involved screening of previously identified Enterococcus strains of human origin for their probiotic physiological properties. Materials and Methods: The strains were screened for their biofilm, antibiofilm, antagonistic, antibiotic resistance, adherence, aggregating, and hydrogen peroxide production abilities. Results: Enterococcus canintestini S26B, Entamoeba dispar S27A, E. dispar S26A, E. dispar S20B, E. canintestini AB2, Enterococcus villorum SB2, and Enterococcus rivorum S22C displayed in vitro probiotic properties. Conclusions: These strains can be used as probiotic candidates and may prove their potential in human or animal feed only after further clinical studies.