LicT Modulates Biofilm Formation of Streptococcus pyogenes

Masaaki Minami^1*, Hiroshi Takase², Ryoko Sakakibara³, Taichi Imura³, Hideo Morita⁴, Michio Ohta⁵

¹Department of Bacteriology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan.
²Core Laboratory, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan.
³Department of Clinical Investigation, Daido Hospital, Nagoya, Japan.
⁴Department of Gastroenterology, Daido Hospital, Nagoya, Japan.
⁵School of Nursing, Sugiyama Jyogakuen University, Nagoya, Japan.

DOI: 10.4236/jbm.2014.29001                

Abstract

Streptococcus pyogenes frequently causes purulent infections in humans. Biofilm formation is an important virulence property of S. pyogenes because of decreased susceptibility of bacteria to antibiotic treatment. Biofilm is composed of various types of matrix including glycocalyx which is an important exocellular matrix material related to bacterial sugar metabolism. A putative antiterminator protein, LicT (Spy0571), is one of the components of the glucose-independent β-gluco-side-specific phosphotransferase system (PTS). Although the PTS, a carbohydrate metabolic system, may play a role in biofilm formation, the relationship between LicT and biofilm formation has not yet been elucidated. Here, we evaluated whether LicT affected biofilm formation in modified chemically defined medium (CDMM) supplemented with glucose or β-glucoside:salicin. We created licT- and licT-complemented mutant strains from S. pyogenes 1529. Although the licT mutant strain tended to have higher growth rate than wild-typestrain in CDMM with glucose, it had a significant lower growth rate than the wild-type strain in CDMM with salicin. In addition, the licT mutant exhibited lower biofilm formation in CDMM containing salicin than the wild-type strain by 96 well plate analysis and confocal laser scanning microscopic analysis. Our results suggest that LicT plays an important role in biofilm formation of S. pyogenes.

Keywords

Streptococcus pyogenes, LicT, Biofilm

Conflicts of Interest

The authors declare no conflicts of interest.

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