INTRODUCTION: Although the production of biofilm is thought to be crucial in the pathogenesis of abscess formations caused by oral resident microorganisms, the particular mechanisms are still unknown. The aim of this study was to identify gene(s) responsible for maintaining the cell surface-associated meshwork-like structures, which are found in some biofilm-producing bacteria, in a clinical isolate of Actinomyces oris K20. METHODS: Random insertional mutagenesis by using transposon EZ-Tn5 was performed against the strain K20. Transposon insertion mutants were screened by scanning electron microscopy for the absence of cell surface-associated meshwork-like structures. The disrupted genes by the transposon insertion were determined by direct genome sequencing with the transposon-end primers. RESULTS: Five mutants without the meshwork-like structures were identified from 175 mutants. Sequencing of flanking regions of transposon insertion revealed that 3 mutants had a gene encoded polysaccharide deacetylase, Spo0J containing ParB-like nuclease domain, and hypothetical protein, respectively. The other 2 mutants had an insertion in a noncoding region and an unidentified region, respectively. CONCLUSIONS: Our findings indicated that these genes might be involved in the formation of meshwork-like structures on Actinomyces oris K20.
INTRODUCTION: Although the production of biofilm is thought to be crucial in the pathogenesis of abscess formations caused by oral resident microorganisms, the particular mechanisms are still unknown. The aim of this study was to identify gene(s) responsible for maintaining the cell surface-associated meshwork-like structures, which are found in some biofilm-producing bacteria, in a clinical isolate of Actinomyces oris K20. METHODS: Random insertional mutagenesis by using transposon EZ-Tn5 was performed against the strain K20. Transposon insertion mutants were screened by scanning electron microscopy for the absence of cell surface-associated meshwork-like structures. The disrupted genes by the transposon insertion were determined by direct genome sequencing with the transposon-end primers. RESULTS: Five mutants without the meshwork-like structures were identified from 175 mutants. Sequencing of flanking regions of transposon insertion revealed that 3 mutants had a gene encoded polysaccharide deacetylase, Spo0J containing ParB-like nuclease domain, and hypothetical protein, respectively. The other 2 mutants had an insertion in a noncoding region and an unidentified region, respectively. CONCLUSIONS: Our findings indicated that these genes might be involved in the formation of meshwork-like structures on Actinomyces oris K20.
Authors: Skander Hathroubi; Stephanie L Servetas; Ian Windham; D Scott Merrell; Karen M Ottemann Journal: Microbiol Mol Biol Rev Date: 2018-05-09 Impact factor: 11.056
Authors: Eric Hong Jian Wong; Chow Goon Ng; Eng Guan Chua; Alfred Chin Yen Tay; Fanny Peters; Barry J Marshall; Bow Ho; Khean Lee Goh; Jamuna Vadivelu; Mun Fai Loke Journal: PLoS One Date: 2016-11-21 Impact factor: 3.240