In Vitro Effect of the Cell-Free Supernatant of the Lactobacillus casei Strain IMAU60214 against the Different Pathogenic Properties of Diarrheagenic Escherichia coli

Abstract

Enteroaggregative Escherichia coli (EAEC) and enterohemorrhagic E. coli (EHEC) are E. coli pathotypes associated with unmanageable diarrhea in children and adults. An alternative to the treatment of infections caused by these microorganisms is the use of the bacteria of the Lactobacillus genus; however, the beneficial effects on the intestinal mucosa are specific to the strain and species. The interest of this study consisted of analyzing the coaggregation properties of Lactobacillus casei IMAU60214, as well as the effect of cell-free supernatant (CSF) on growth and anti-cytotoxic activity in a cell model of the human intestinal epithelium for an agar diffusion assay (HT-29) and the inhibition of biofilm formation on plates of DEC strains of the EAEC and EHEC pathotypes. The results showed that L. casei IMAU60214 exhibits time-dependent coaggregation (35–40%) against EAEC and EHEC that is similar to the control E. coli ATCC 25922. The CSF showed antimicrobial activity (20–80%) against EAEC and EHEC depending on the concentration. In addition, the formation and dispersion of biofilms of the same strains decrease, and the proteolytic pre-treatment with catalase and/or proteinase K (1 mg/mL) of CSF reduces the antimicrobial effect. When evaluating the effect in HT-29 cells pre-treated with CFS on the toxic activity induced by the EAEC and EHEC strains, a reduction of between 30 and 40% was observed. The results show that L. casei IMAU60214 and its CSF have properties that interfere with some properties associated with the virulence of the EAEC and EHEC strains that cause intestinal infection, which supports their use for the control and prevention of infections caused by these bacteria.

Inhibitory effect of some probiotic strains and essential oils on the growth of some foodborne pathogens

“…These studies disagreed with Yusra and Likaa (2013) who reported that in the case of B. cereus , L. plantarum MIC was 0.07 ml. Approaches of probiotics might successfully inhibit pathogens such as L. monocytogenes ( Wu et al , 2022 ), other studies stated that L. casei IMAU60214 was effective against Escherichia coli ( Rocha-Ramírez et al , 2023 ). Similarly, L. fermentum LBF433 and L. casei LBC 237 have sufficient action against Salmonella ( Lando et al , 2023 ).…”

A host-microbial metabolite interaction gut-on-a-chip model of the adult human intestine demonstrates beneficial effects upon inulin treatment of gut microbiome

“…Using cell-free culture supernatant, also called bacteria-free supernatant, fecal supernatant, or simply supernatant, has proven to be an effective way to study host-microbe, or in fact host-microbial metabolite, interactions. For example, a few studies report on the protective effect of probiotic culture supernatants against invasion of pathogenic Escherichia coli (E. coli) strains or against 5-fluorouracil (5-FU)-induced intestinal epithelial cell damage [68][69][70] . The latter study used an intestinal epithelial cell line derived from rat intestine [68] , wherefore results might be less relevant for humans, while the models that applied an E. coli challenge used either the human intestine-derived HT-29 cell line [70] or Caco-2 and T84 cell lines [69] .…”

“…For example, a few studies report on the protective effect of probiotic culture supernatants against invasion of pathogenic Escherichia coli (E. coli) strains or against 5-fluorouracil (5-FU)-induced intestinal epithelial cell damage [68][69][70] . The latter study used an intestinal epithelial cell line derived from rat intestine [68] , wherefore results might be less relevant for humans, while the models that applied an E. coli challenge used either the human intestine-derived HT-29 cell line [70] or Caco-2 and T84 cell lines [69] . One step further towards the physiological resemblance of the human intestinal tissue structure goes a Caco-2/dendritic cell co-culture model that studies the innate immune response towards a pathogenic challenge with Salmonella typhi [71] .…”

The Function of Probiotics and Prebiotics on Canine Intestinal Health and Their Evaluation Criteria

“…In addition, using probiotics instead of antibiotics to regulate the intestinal microbiota of dogs is also one of the current research hotspots. A variety of Lactobacillus have killing effects on some common therapeutic bacteria, such as Escherichia coli , Staphylococcus aureus , and Salmonella enteritidis [ 39 , 40 , 41 ]. However, there are still few reports on animal experiments.…”