Impact of probiotics on pathogen survival in an innovative human plasma biofilm model (hpBIOM)

Abstract

Background Despite of medical advances, the number of patients suffering on non-healing chronic wounds is still increasing. This fact is attended by physical and emotional distress and an economic load. The majority of chronic wounds are infected of harmful microbials in a protecting extracellular matrix. These biofilms inhibit wound healing. Biofilm-growing bacteria developed unique survival properties, which still challenge the appropriate wound therapy. The present in-vitro biofilm models are not suitable for translational research. By means of a novel in-vivo like human plasma biofilm model (hpBIOM), this study systematically analysed the influence of 3 probiotics on the survival of five clinically relevant pathogenic microorganisms. Methods Human plasma was used to produce the innovate biofilm. Pathogenic microorganisms were administered to the plasma. By stimulating the production of a fibrin scaffold, stable coagula-like discs with integrated pathogens were produced. The five clinically relevant pathogens P. aeruginosa , S. aureus , S. epidermidis , E. faecium and C. albicans were challenged to the probiotics L. plantarum , B. lactis and S. cerevisiae . The probiotics were administered on top of the biofilm and the survival was quantified after 4 h and 24 h of incubation. For statistics, two-way ANOVA with post-hoc Tukey’s HSD test was applied. P-value > 0.05 was considered to be significant. Results SEM micrographs depicted the pathogens on the surface of the fibrin scaffold, arranged in close proximity and produced the glycocalyx. The application of probiotics induced different growth-reducing capacities towards the pathogens. B. lactis and S. cerevisiae showed slight bacteria-reducing properties. The survival of C. albicans was not affected at all. The most antimicrobial activity was detected after the treatment with L. plantarum . Conclusions This study successfully reproduced a novel human biofilm model, which provides a human wound milieu and individual immune competence. The success of bacteriotherapy is dependent on the strain combination, the number of probiotics and the activity of the immune cells. The eradicating effect of L. plantarum on P. aeruginosa should be emphasized.

Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM)

“…During biofilm development, bacteria attach to the wound, proliferate and reorganize their surrounding environment to produce the EPS. To closely mimic such wound-biofilm conditions for translational research purposes, our research group developed a biofilm model based on human plasma including the individual buffy coat (containing the cellular immune competence) and integrating selected biofilm-forming pathogens 30 . By means of calcium-induced coagulation, thrombocyte-agglutination and fibrin polymerization, round coagula-like discs with the integrated pathogens are formed (Fig.…”

“…For this study we used a newly described human plasma biofilm model (hpBIOM), which was recently developed and published by our working group to specifically mimic a human, biofilm-challenged wound environment avoiding the deficiencies described above 30 . The aim was to primarily observe two established antiseptics in the newly developed challenging human biofilm environment with regard to their antiseptic performance against two commonly encountered biofilm-forming pathogens (MRSA, P. aeruginosa) after 12 and 24 hours of biofilm maturation in the hpBIOM.…”

Anti-biofilm activity of antimicrobial hypochlorous wound irrigation solutions compared to common wound antiseptics and bacterial resilience in an innovative in-vitro human plasma biofilm model (hpBIOM)

“…The development of our human plasma biofilm model (hpBIOM; Fig. 4a-c) (10,11), aims to narrow the gap between in-vitro and in-vivo biofilm research and provide a translational approach. The use of a complex biofilm model based on human material, including plasma and active immune cells, addresses the interactions of microbial biofilms with the human wound environment (3,14) as well as the relevant efficacy loss of antimicrobials under challenge (23,24), providing a 'close-to-reality' test scenario.…”

“…The development and use of the hpBIOM has been described in detail elsewhere (10,11) and was adapted to fit the specific agents and purpose pursued here. In brief, human plasma preserves (citrate buffered) and buffy coat from anonymous donors were obtained from the DRK-Blutspendedienst West (Hagen, Germany).…”

“…with high-protein, organic challenge as well as the human immune system need to be considered. Therefore, our research group developed an innovative human plasma biofilm model (hpBIOM) for quantifiable testing of anti-biofilm activity of antimicrobial and antiseptic agents in a challenging wound biofilm environment, closely resembling the in-vivo situation (10,11).…”