cerevisiae cells. This work originated from TRANSLUCENT, a SysMo ERA-NET-funded project, and COST activity CM 0902. It was supported by a GACR grant (P503/10/0307) and MSMT COST LD13037. The stay of Y-27632 molecular weight D.B. in the H.S. laboratory was supported by a FEMS Research Fellowship. “
“Horizontal gene transfer by conjugation has been reported to increase overall biofilm formation. Biofilm is considered a hot spot for plasmid transfer, and it has been found that social interactions during biofilm formation can increase the biomass. In this study, we demonstrate a contrast to previous studies by showing that the conjugative IncP-1 plasmid pKJK5 influences biofilm formation negatively. The results showed

that a co-culture (Pseudomonas putida, Kluyvera sp., and Escherichia coli) formed significantly more

biofilm than the strains did individually. Ibrutinib cell line When pKJK5 was inserted into P. putida, biofilm formation was significantly reduced compared with the co-culture without plasmid. A nonconjugative version of pKJK5 was also used, and the biofilm formation was restored. Visualization with the BioFlux 1000 facility showed that the presence of pKJK5-containing P. putida in the co-culture led to a changed biofilm structure, where the cells showed a higher tendency to attach to other cells rather than surfaces. This study thus indicates that the presence of conjugative plasmids in some species may decrease the surface-associated biofilm formation of a mixed co-culture by facilitating cell–cell attachment with reduced surface attachment as the consequence. “
“After uptake by susceptible host cells, Legionella pneumophila displays Glutamate dehydrogenase the ability to arrest phagolysosome fusion. To elucidate the role of lipopolysaccharide (LPS) in this mechanism, we investigated its influence on Acanthamoeba castellanii, A/J mouse macrophages and human monocytes. For this, legionellae were cultured in broth to the replicative, noninfectious phase or

to the infectious phase expressing virulence traits. Shed LPS-enriched outer membrane vesicles (OMV) and LPS species <300 kDa were obtained from L. pneumophila Corby strains possessing the virulence-associated LPS epitope recognized by monoclonal antibody (MAb) 3/1 and its mutant TF 3/1, which has lost this epitope due to a mutation in the lag-1 gene. The shed LPS components were attached by specific antibodies to latex beads and added to the host cells for phagocytosis. We demonstrated for the first time that evasion of lysosomal degradation of phagosomes for up to 5 h can also be set off by LPS that is not tied up in OMV. Moreover, our cell culture models showed that the influence of MAb 3/1-positive and -negative LPS was identical. Our data clearly substantiate that LPS is an independent factor for evading lysosomal degradation, which is independent of the bacterial expression of known virulence traits.