Enterococcus faecalis Isolated From Infant Feces Inhibits Toxigenic Clostridioides (Clostridium) difficile

Abstract

Clostridioides (Clostridium) difficile infection is implicated as a major cause of antibiotic-associated diarrhea in hospitals worldwide. Probiotics, especially lactic acid bacteria, are the most frequently used alternative treatment. This study aims to identify potential probiotic enterococci strains that act against C. difficile strains and exert a protective effect on colon adenocarcinoma cells (HT-29 cells). To this end, nine Enterococcus strains isolated from the feces of breast-fed infants were investigated. They were identified as E. faecalis by 16s rRNA sequencing and MALDI-TOF. The probiotic properties including their viabilities in simulated gastrointestinal condition, cell adhesion ability, and their safety were evaluated. All strains exhibited more tolerance toward both pepsin and bile salts and adhered more tightly to HT-29 cells compared with the reference probiotic strain Lactobacillus plantarum ATCC 14917. Polymerase chain reaction (PCR) results exhibited that six of nine strains carried at least one virulence determinant gene; however, none exhibited virulence phenotypes or carried transferable antibiotic resistance genes. These strains did not infect Galleria mellonella when compared to pathogenic E. faecalis strain (p < 0.05). Moreover, their antibacterial activities against C. difficile were examined using agar well-diffusion, spore production, and germination tests. The six safe strains inhibited spore germination (100-98.20% ± 2.17%) and sporulation, particularly in C. difficile ATCC 630 treated with E. faecalis PK 1302. Furthermore, immunofluorescence assay showed that the cytopathic effects of C. difficile of HT-29 cells were reduced by the treatment with the cell-free supernatant of E. faecalis strains. These strains prevented rounding of HT-29 cells and preserved the F-actin microstructure and tight junctions between adjacent cells, which indicated their ability to reduce the clostridial cytopathic effects. Thus, the study identified six E. faecalis isolates that have anti-C. difficile activity. These could be promising probiotics with potential applications in the prevention of C. difficile colonization and treatment of C. difficile infection.

The Role of Microbiota in Infant Health: From Early Life to Adulthood

“…Interestingly, Rada et al found that both the Clostridia and Bifidobacteria in the feces of infant (3-253Radadays old) grow vigorously on the prebiotic oligosaccharides, which may pose a challenge for supplementing prebiotics to infant lacking Bifidobacteria (144). In contrast, Enterococcus faecalis isolated from infant feces can inhibit the growth of Clostridium difficile, which may have potential applications for preventing Clostridium difficile colonization and infection (145). In short, in early life, we need to beware of Clostridium to prevent them from becoming the dominant species in infant gut microbiota.…”

Effects of Postbiotic from Bacteriocin-Like Inhibitory Substance Producing Enterococcus faecalis on Toxigenic Clostridioides difficile

“…Thus, the anti-spore germination activity might be facilitated by the action of BSH enzymes. Romyasamit et al, 2020, also found that E. faecalis PK 1201 probiotics can produce BSH enzymes, which break down bile salt and are further implicated in the decline of C. difficile spore development 10 . In this study, the BSH enzymes might secrete out into the CFS used to prepare LCFS that shows anti-spore germination activity.…”

Gut Microbiota Composition Associated with Clostridioides difficile Colonization and Infection

“…Additionally, a resistance to vancomycin has emerged in this genus [ 102 , 105 ]. Romyasamit et al (2020) exhibited that six E. faecalis strains have a probiotic effect and anti- C. difficile activity [ 106 ]. Klebsiella pneumonae is present in the mucus layer with C. difficile [ 107 ].…”