UNASSIGNED: We have previously demonstrated conjugation of @entity526 into vacuoles of the protozoal ciliate ( @entity14825 ). This indicated a possible role of ciliates in evoking bacterial quorum sensing, directly connecting bacterial survival via accumulation in the ciliate vacuoles. We therefore assessed if ciliates promoted bacterial autoinducer (AI)-2 accumulation with vacuole formation, which controls quorum sensing. @entity526 @entity409 was significantly enhanced in the supernatants of a mixed culture of ciliates and bacteria, likely depending on ciliate density rather than bacterial concentration. As expected, @entity1605 production was significantly correlated with vacuole formation. The experiment with @entity526 luxS mutants showed that ciliates failed to enhance @entity2348 , denying a nonspecific phenomenon. Fluorescence microscopy revealed accumulation of fragmented bacteria in ciliate vacuoles, and, more importantly, expulsion of the vacuoles containing disrupted bacteria into the culture supernatant. There was no increase in the expression of luxS (encoding @entity1605 ) or ydgG (a transporter for controlling bacterial export of @entity1605 ). We conclude that ciliates promote @entity2348 in a mixed culture, via accumulation of disrupted bacteria in ciliate vacuoles followed by expulsion of the vacuoles, independently of luxS or ydgG gene induction. This is believed to be the first demonstration of a relationship between @entity526 @entity1605 dynamics and ciliates. In the natural environment, ciliate biotopes may provide a survival advantage to bacteria inhabiting such biotopes, via evoking quorum sensing.

Protozoal ciliate promotes XXXX in mixed culture with @entity526 .

@entity1605 :: ('OMIM:217000', 'Disease') :: ['AI-2'] @entity409 :: ('MESH:D008107', 'Disease') :: ['AI-2 accumulation'] @entity2348 :: ('MESH:D001424', 'Disease') :: ['bacterial AI-2 accumulation'] @entity14825 :: ('5911', 'Species') :: ['Tetrahymena thermophila'] @entity526 :: ('562', 'Species') :: ['Escherichia coli', 'E. coli']
@entity2348 :: (MESH:D001424,Disease) :: ['bacterial autoinducer-2 accumulation']
