(446f) Patterned Biofilm Formation Reveals the Maximum Distance for Interaction Between Bacterial Clusters | AIChE

(446f) Patterned Biofilm Formation Reveals the Maximum Distance for Interaction Between Bacterial Clusters

Authors 

Hou, S. - Presenter, Syracuse University

Bacterial adhesion to a surface and subsequent formation
of microcolonies play important roles in biofilm formation, which is a major
cause of nosocomial infections and persistent biofouling. Despite the
significance, these processes are still poorly understood due to the lack of
well-defined surfaces and the heterogeneity in biofilm structure and gene
expression. We recently reported that bacterial adhesion and biofilm formation
can be confined in specific patterns by bio-inert surface chemistry afforded by
micro-contact printed self-assembled monolayers (SAMs) presenting functional
groups (Applied and Environmental Microbiology, 2007, 73: 4300-4307; Chemical
Communications, 2009: 1207-1209). In this study, we applied such patterned
surfaces to identify the maximum distance that allows communication and
physical interactions between bacterial colonies.

The
non-inhibitory alkanethiol [HS(CH2)14CH3] was
used to create square patterns with various dimensions including 2x2, 5x5,
10x10, 15x15,
20x20, 30x30,
40x40, and 50x50 μm2. The background was filled with the
inhibitory alkanethiol [HS(CH2)11(OCH2CH2)3OH]
and the distance between patterns (D) was varied to be 2, 5, 10, 15, 20, 30,
40, and 50 μm, respectively. Escherichia coli RP437 was labeled with the plasmid pRSH103 to
constitutively express DsRed-express. Its biofilms formed on patterned surfaces
were analyzed with confocal laser scanning microscopy. The biofilm images were
then analyzed with the COMSTAT software to quantify surface coverage. Clear
biofilm patterns were observed only on surfaces with patterns separated by 10
μm or more of inhibitory SAM, which suggests that biofilms expended from
non-resistant patterns to resistant background when D<10 μm.
Consistently, a significant decrease in surface coverage was observed when the
patterns were separated by 10 μm or more. These data indicate that 10 mm is
the maximum distance that allows communication and physical interaction between
cell clusters under our experimental condition. This platform opens access to
the study of fundamental questions such as how the physiology and gene
expression of microbes respond to a restrained and well-defined
microenvironment. It is useful for studying microbe-surface and microbe-host
interactions and for developing antifouling and anticorrosion strategies.