Title Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation
Author Hae-In Jung1, Yun-Jung Kim1, Yun-Jung Lee1, Hee-Soo Lee2, Jung-Kee Lee3, and Soo-Ki Kim1*
Address 1Department of Animal Science and Technology, Konkuk University, Seoul 05029, Republic of Korea, 2National Veterinary Research and Quarantine Service, Anyang, 14033, Republic of Korea, 3Department of Life Science and Genetic Engineering, Paichai University, Daejeon 35345, Republic of Korea
Bibliography Journal of Microbiology, 55(10),800-808, 2017,
DOI 10.1007/s12275-017-7374-7
Key Words quorum sensing, Burkholderia lata, transposon, Caenorhabditis elegans, c-di-GMP phosphodiesterase, BDSF
Abstract Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.