Recent progress in experimental and human disease-associated multi-species biofilms

Abstract

Human bodies are colonized by trillions of microorganisms, which are often referred to as human microbiota and play important roles in human health. Next generation sequencing studies have established links between the genetic content of human microbiota and various human diseases. However, it remains largely unknown about the spatial organizations and interspecies interactions of individual species within the human microbiota. Bacterial cells tend to form surface-attached biofilms in many natural environments, which enable intercellular communications and interactions in a microbial ecosystem. In this review, we summarize the recent progresses on the experimental and human disease-associated multi-species biofilm studies. We hypothesize that engineering biofilm structures and interspecies interactions might provide a tool for manipulating the composition and function of human microbiota.

Keywords: Chronic infections; Microbiota; Multi-species biofilm.

Graphical abstract

Fig. 1

P. aeruginosa matrix polysaccharides Pel and Psl and SiaD diguanylate cyclase contribute to its predominance in dual-species biofilms with S. aureus. Psl enhances P. aeruginosa competitiveness in early stages, possibly via SiaD activation, whereas Pel enables biofim expansion to increase P. aeruginosa predominance in the later stages. Figure was adapted from with permission.

Fig. 2

P. aeruginosa population dynamics in the multi-species biofilm community is affected by H1-T6SS (clpV1) and biofilm formation determinants such as Psl exopolysaccharide (pslBCD), type IV pili (pilA) and quorum sensing (lasR and mvfR). Grey bars: biofilm microbial community; Black bars: planktonic microbial community. Figure was adapted from with permission.

Fig. 3

Biofilms were detected using FISH and DAPI staining on colon tumor of patient with colorectal tumor (upper panel), paired normal colon in same patient (middle panel) and normal colon without colorectal cancer (lower panel). Biofilms detected on right colon (left panel). Biofilms detected from left colon (right panel). Closeup image showing at the lower left corners of top and middle images on left panel indicated the bacteria cells located in close proximity to epithelial cells in patient with colorectal cancer. Bacteria were stained red while nucleus was stained blue. Figure was adapted from with permission. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Host-pathogen interactions model during the catheter-associated urinary tract infection. The left circles describe bacterial strategies to evade host immune response while the right circles depict interspecies interactions and adaptation strategies by P. aeruginosa and M. morganii. Figure was adapted from with permission.