Continuous culture models to study pathogens in biofilms

Abstract

A multi-stage continuous culture apparatus has been constructed to model mono-species biofilms and high species diversity biofilm consortia found in clinical practice, the natural environment and the built environment. New artificial saliva and urine media were developed, and natural and treated potable waters obtained, for the defined, reproducible generation of the biofilms containing bacterial and protozoal pathogens on various hydroxyapatite, plastic, metal and paint-covered substrata over many months. Following several modifications to the design, each chemostat vessel, linked in series or parallel, consists of a titanium top plate containing a variety of insertion ports for the monitoring electrodes, and addition/removal of gases, media, effluent, pH and redox titrants, antibacterial agents and coupon substrata for biofilm generation. Each top plate is clamped to a 1 liter glass vessel, containing the culture medium, and mounted on a stirrer with a heater pad to facilitate external heating and stirring, controlling the shear rate across the immersed coupons. There are few internal parts to go wrong. The growth rate is controlled by continuous addition of medium to the planktonic and sessile phases of the cultures. These model systems are ideal for generating biofilms either aerobically or anaerobically, and containing microaerophilic or anaerobic species, even in highly aerated media.

More information

Identifiers

ORCID for C. William Keevil: orcid.org/0000-0003-1917-7706

Catalogue record

Export record

Altmetrics