In natural habitats, bacterial cells often form biofilms to structurally organize and protect their communities. A biofilm is an aggregate of microbial cells that adhere to a live/nonliving surface, and the adherent cells in biofilms are enclosed in a self-produced matrix of extracellular polymeric substances (EPS), including nucleic acids, proteins, polysaccharides, and lipids. Bacterial biofilm formation is a complex developmental process involving several stages, including migration and initial attachment, EPS production and irreversible attachment, maturation, destruction, and cell dispersion. Pathogenic bacteria build biofilms on various medical implants and human tissues, and they have a strong resistance to antimicrobial agents, as well as persistently colonizing patients with chronic diseases. In most environments, microorganisms can switch from a free-living state to a sessile mode of life to form biofilms displaying specific properties.
Infection and pathogenesis is a continuous interplay between the host and microbes and between microbes themselves. These interactions can influence and determine the fate of infection and they are complex and dynamic, which makes it difficult to study them in a relevant manner in in vitro models. The success of in vitro models but also their limitations, notably their failure to reproduce the host environment, led to a rapid development of multiple in vivo models.
In the past ten years, in order to overcome the practical difficulty associated with the use of mammalian models, non-mammalian models traditionally used to study development like the fruit fly, Drosophila melanogaster or the zebrafish, Danio rerio, have been adapted to study host-microbe interactions and immune system responses, notably related to colonization of the gut by biofilms.
Figure 1. Non-mammalian in vivo models.
(David Lebeaux et al. Pathogens 2013)
Creative Diagnostics has established several different bio-film models ranging from simple plant models such as Arabidopsis thaliana and Lemna minor, which were successfully used to correlate virulence and biofilm formation in pathogenic S. aureus and P. aeruginosa to more complex invertebrates like Caenorhabditis elegans, D. melanogaster or the vertebrate zebrafish.
Organisms involved in an abdominal abscess include the following:
Take Drosophila melanogaster for example. Ten male fruit flies are selected and introduced in standard fly vials. A dilution of a Vibrio cholerae overnight culture to 5 * 108 CFU/mL is used to impregnate a 0.5-inch cellulose acetate plug placed at the bottom of each vial. Then, the vials are kept at 24 °C with appropriate light-dark cycles. Fruit fly survival is monitored twice a day for 5 to 7 days.
Creative Diagnostics is a full-service contract research organization specializing in microbiology and preclinical infectious disease research. The correct animal model provides unlimited possibilities for drug discovery and human health advancement. At Creative Diagnostics, we believe that providing clients with the best animal model solutions is the most effective way to promote key research from creativity to reality. We guarantee that the animal models required in research are strictly regulated to ensure responsible, ethical, and humane treatment.