The relationship between biofilm formations and capsule in Haemophilus influenzae.

Abstract

To evaluate the biofilm formation of non-typeable Haemophilus influenzae (NTHi) and H. influenzae type b (Hib) clinical isolates, we conducted the following study. Serotyping and polymerase chain reaction were performed to identify β-lactamase-negative ampicillin (ABPC)-susceptible (BLNAS), β-lactamase-negative ABPC-resistant (BLNAR), TEM-1 type β-lactamase-producing ABPC-resistant (BLPAR)-NTHi, and Hib. Biofilm formation was investigated by microtiter biofilm assay, as well as visually observation with a scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) in a continuous-flow chamber. As a result, totally 99 strains were investigated, and were classified into 4 groups which were 26 gBLNAS, 22 gBLNAR, 28 gBLPAR-NTHi and 23 Hib strains. The mean OD600 in the microtiter biofilm assay of gBLNAS, gBLNAR, gBLPAR-NTHi, and Hib strains were 0.57, 0.50, 0.34, and 0.08, respectively. NTHi strains were similar in terms of biofilm formations, which were observed by SEM and CLSM. Five Hib strains with the alternated type b cap loci showed significantly increased biofilm production than the other Hib strains. In conclusion, gBLNAS, gBLNAR, and gBLPAR-NTHi strains were more capable to produce biofilms compared to Hib strains. Our data suggested that resistant status may not be a key factor but capsule seemed to play an important role in H. influenzae biofilm formation.

DOI: 10.1016/j.jiac.2013.06.001

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Cite this paper

@article{Qin2014TheRB, title={The relationship between biofilm formations and capsule in Haemophilus influenzae.}, author={Liang Qin and Yutaka Kida and Naruhiko Ishiwada and Kiyofumi Ohkusu and Chiharu Kaji and Yoshiro Sakai and Kiwao Watanabe and Akitsugu Furumoto and Akitoyo Ichinose and Hiroshi Watanabe}, journal={Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy}, year={2014}, volume={20 3}, pages={151-6} }