Cell surface‐associated aggregation‐promoting factor from Lactobacillus gasseri SBT2055 facilitates host colonization and competitive exclusion of Campylobacter jejuni

Abstract

SummaryCampylobacter jejuni, one of the most common causes of gastroenteritis worldwide, is transmitted to humans through poultry. We previously reported that Lactobacillus gasseri SBT2055 (LG2055) reduced C. jejuni infection in human epithelial cells in vitro and inhibited pathogen colonization of chickens in vivo. This suggested that the LG2055 adhesion and/or co-aggregation phenotype mediated by cell-surface aggregation-promoting factors (APFs) may be important for the competitive exclusion of C. jejuni. Here, we show that cell surface-associated APF1 promoted LG2055 self-aggregation and adhesion to human epithelial cells and exhibited high affinity for the extracellular matrix component fibronectin. These effects were absent in the apf1 knockout mutant, indicating the role of APF1 in LG2055-mediated inhibition of C. jejuni in epithelial cells and chicken colonization. Similar to APF1, APF2 promoted the co-aggregation of LG2055 and C. jejuni but did not inhibit C. jejuni infection. Our data suggest a pivotal role for APF1 in mediating the interaction of LG2055 with human intestinal cells and in inhibiting C. jejuni colonization of the gastrointestinal tract. We thus provide new insight into the health-promoting effects of probiotics and mechanisms of competitive exclusion in poultry. Further research is needed to determine whether the probiotic strains reach the epithelial surface.

Coadministration of the Campylobacter jejuni N-Glycan-Based Vaccine with Probiotics Improves Vaccine Performance in Broiler Chickens

“…For another Lactobacillus species, L. gasseri SBT2055, it was suggested that this strain reduces C. jejuni colonization in chickens by competitive exclusion (44,45). In the current study, coadministration of the robust colonizing isolate L. reuteri CSF8 with the E. coli vaccine also improved vaccine efficacy.…”

“…Previous reports also described an antagonistic relationship between C. jejuni and Lactobacillus species (44,45), including L. reuteri (46). Thus, L. reuteri probiotic strain CSF8 was also selected by using an experimental design validated for comparison of the ecological competitiveness of L. reuteri strains in chickens in vivo (39).…”

Lactobacillus johnsonii ameliorates intestinal, extra-intestinal and systemic pro-inflammatory immune responses following murine Campylobacter jejuni infection

“…In case of campylobacteriosis, probiotics (in particular lactobacilli) have been shown to co-aggregate with C . jejuni thus reducing the adhesion to and invasion of the intestinal epithelial cell layers and to suppress motility which is essential for pathogenicity 24, 35 . The modes of actions of the corresponding probiotic formulations have been examined for decades.…”

“…jeuni it has been conclusively demonstrated that L . gasseri SBT2055 inhibits invasion of epithelial cells by co-aggregation in vitro and counteracts pathogenic colonization in chicken 23, 24 . Furthermore, production of organic acids (mainly lactic acid) by probiotic lactobacilli exerts killing of C .…”

Is it feasible to control pathogen infection by competitive binding of probiotics to the host?

“…44 Calabi et al 45 reported Clostridium diffcile adhered to collagen I via its surface layer proteins, and hence collagen I is potential to be a good target for competitive exclusion of pathogens that adhere to ECM and/or submucosa in the GIT. To ensure the results shown by Lehri et al, 43 in vivo experiments should be performed in the future as was reported by Nishiyama et al, 46 in which Lactobacillus gasseri SBT2055 reduced C. jejuni infection in chicken by competitive binding to the host cells and/or co-aggregation with the pathogen in mediation of cell-surface aggregation-promoting factors.…”