Intravital Multiphoton Examination of Implant-Associated Staphylococcus aureus Biofilm Infection

Abstract

Bacterial infections associated with implanted medical devices represents a healthcare crisis due to their persistence, antibiotic tolerance, and immune avoidance. Indwelling devices are rapidly coated with host plasma and extracellular matrix proteins which can then be exploited by bacterial pathogens for adherence and subsequent biofilm development. Our understanding of the host-pathogen interface that determines the fate of biofilm-mediated infections is limited to the experimental models employed by laboratories studying these organisms. Current in vivo models of biofilm-mediated infection, while certainly useful, are typically limited to end-point analyses of bacterial burden enumeration, immune cell profiling, and cytokine/chemokine analysis. Thus, with these models, the complex, real-time assessment of biofilm development and innate immune cell activity remains imperceptible. Here, we describe a novel murine biofilm infection model employing time-lapse intravital multiphoton microscopy which permits concurrent and real-time visualization of Staphylococcus aureus biofilm formation and immune cell activity. Using cell tracking, we found that S. aureus biofilms impede neutrophil chemotaxis, redirecting their migration patterns to prevent biofilm invasion. This approach is the first to directly examine device-associated biofilm development and host-pathogen interactions and will serve to both further our understanding of infection development and help reveal the effects of future antibiofilm treatment strategies.

Differential Early in vivo Dynamics and Functionality of Recruited Polymorphonuclear Neutrophils After Infection by Planktonic or Biofilm Staphylococcus aureus

“…This means that the protective barrier role that biofilms exert are common between these two S. aureus strains, and probably among all biofilm-producing strains. The two strains used in our previous works were both MSSAs, but a “biofilm” phenotype has also been described for the MRSA strain USA300 ( Thurlow et al, 2011 ; Gries et al, 2020b ). The use of biofilms grown over longer periods (3 or 4 days) in the latter experiments compared to those used in this report further suggest a common immune evasion mechanism conserved throughout biofilm maturation.…”

“…In these works, either S. aureus planktonic or biofilm bacteria were intradermally inoculated into the mouse ear pinna, which allowed the study of their effects on immune cell dynamics using intravital confocal microscopy ( Forestier et al, 2017 ; Abdul Hamid et al, 2020 ; Sauvat et al, 2020 ). The use of this type of imaging in the context of biofilm infections has rarely been done but has allowed new insights into the study of immune responses from a cellular dynamic perspective ( Gries et al, 2020b ). Here, classic immunology techniques were coupled with intravital confocal imaging to rigorously compare inflammatory responses and phagocyte behavior in response to either the planktonic or biofilm form of S. aureus .…”

Speciality Grand Challenge for “Biofilms”

“…Additionally, numerous other detection methods are under development and efforts should be made to allow these technologies to translate into the clinic ( Achinas et al., 2020 ; Parlak and Richter-Dahlfors, 2020 ). Among them, recently there has been the successful use of imaging technologies using bioluminescence ( Chauhan et al., 2016 ; Hoffmann et al., 2019 ; Maiden et al., 2019 ; Gordon et al., 2020 ; Kreth et al., 2020 ; Redman et al., 2020 ; Van Dyck et al., 2020 ) or intravital imaging ( Thanabalasuriar et al., 2019 ; Abdul Hamid et al., 2020 ; Gries et al., 2020 ; Tian et al., 2020 ) to study the effect of antimicrobial agents on biofilms or the behavior of immune cells in contact with biofilms in various in vivo models of biofilm-related infections.…”

Bacterial Biofilms and Implant Infections: A Perspective

“…Such studies demand advancement in technologies for assaying biomolecular composition of the biofilms and cell biochemistry and metabolic dynamics of biofilm-forming microorganisms. In addition, to animal models simulating chronic infections [26,27], in vivo, innovative methods for disrupting biofilms without the use of antibiotics are solicited [28]. The on-going advancements in interdisciplinary research to cognizant…”