English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

It has long been observed that smooth  Brucella  can dissociate into rough mutants that are cytotoxic to macrophages. However, the  in vivo  biological significance and/or mechanistic details of  Brucella  dissociation and cytotoxicity remain incomplete. In the current report, a plaque assay was developed using  Brucella  strains exhibiting varying degrees of cytotoxicity. Infected monolayers were observed daily using phase contrast microscopy for plaque formation while  Brucella  uptake and replication were monitored using an immunofluorescence assay (IFA). Visible plaques were detected at 4–5 days post infection (p.i.) with cytotoxic  Brucella  16MΔ manBA  at an MOI of 0.1. IFA staining demonstrated that the plaques consisted of macrophages with replicating  Brucella . Visible plaques were not detected in monolayers infected with non-cytotoxic 16MΔ manBA Δ virB2  at an MOI of 0.1. However, IFA staining did reveal small groups of macrophages (foci) with replicating  Brucella  in the monolayers infected with 16MΔ manBA Δ virB2 . The size of the foci observed in macrophage monolayers infected with rough  Brucella  correlated directly with cytotoxicity measured in liquid culture, suggesting that cytotoxicity was essential for  Brucella  egress and dissemination. In monolayers infected with 16M, small and large foci were observed. Double antibody staining revealed spontaneous rough mutants within the large, but not the small foci in 16M infected monolayers. Furthermore, plaque formation was observed in the large foci derived from 16M infections. Finally, the addition of gentamicin to the culture medium inhibited plaque formation, suggesting that cell-to-cell spread occurred only following release of the organisms from the cells. Taken together, these results demonstrate that  Brucella -induced cytotoxicity is critical for  Brucella  egress and dissemination.

Brucella dissociation is essential for macrophage egress and bacterial dissemination