An adaptable microreactor to investigate the influence of interfaces on
biofilm development of Pseudomonas aeruginosa
Abstract
Biofilms are ubiquitous and notoriously difficult to eradicate and
control, complicating human infections, industrial and agricultural
biofouling. Current biofilm studies are commonly performed with the
biofilm cultured on mono-interface and generally have neglected to
consider more realistic biofilm, where diverse interfaces are involved.
In our study, a reusable dual-chamber microreactor with interchangeable
membranes was developed to establish multiple interfaces for biofilm
culture and test. Protocol for culturing Pseudomonas aeruginosa (PAO1)
on the air-liquid interface (ALI) and liquid-liquid interface (LLI)
under static environmental conditions for 48h was optimized using this
novel device. This study shows that LLI model biofilms are more
susceptible to physical disruption compared to ALI model biofilm. SEM
images revealed a unique ‘mushroom-shaped’ microcolonies morphological
feature, which is more distinct on ALI biofilms than LLI. Furthermore,
the study showed that ALI and LLI biofilms produced a similar amount of
extracellular polymeric substances (EPS). As differences in biofilm
structure and properties may lead to different outcomes when using the
same eradication approaches, the antimicrobial effect of an antibiotic,
Ciprofloxacin (CIP), was chosen to test the susceptibility of 48h-old
ALI and LLI biofilms. Our results show that the minimum eradication
concentration (MBCE) of CIP using our dual-chamber device reached
1600μg/ml, which is significantly higher than the conventional
microtiter plate method (64μg/ml). The results highlight the importance
of having a model that can closely mimic in-vivo conditions to develop
more effective biofilm management strategies.