Additional file 1 of Can the use of azithromycin during labour reduce the incidence of infection among puerperae and newborns? A systematic review and meta-analysis of randomized controlled trials

Supplementary Material

Image1_The Small Regulatory Antisense RNA PilR Affects Pilus Formation and Cell Motility by Negatively Regulating pilA11 in Synechocystis sp. PCC 6803.PDF

<p>Pili are found on the surface of many bacteria and play important roles in cell motility, pathogenesis, biofilm formation, and sensing and reacting to environmental changes. Cell motility in the model cyanobacterium Synechocystis sp. PCC 6803 relies on expression of the putative pilA9-pilA10-pilA11-slr2018 operon. In this study, we identified the antisense RNA PilR encoded in the noncoding strand of the prepilin-encoding gene pilA11. Analysis of overexpressor [PilR(+)] and suppressor [PilR(−)] mutant strains revealed that PilR is a direct negative regulator of PilA11 protein. Although overexpression of PilR did not affect cell growth, it greatly reduced levels of pilA11 mRNA and protein and decreased both the thickness and number of pili, resulting in limited cell motility and small, distinct colonies. Suppression of PilR had the opposite effect. A hypothetical model on the regulation of pilA9-pilA10-pilA11-slr2018 operon expression by PilR was proposed. These results add a layer of complexity to the mechanisms controlling pilA11 gene expression and cell motility, and provide novel insights into how sRNA and the intergenic region secondary structures can work together to discoordinatly regulate target gene in an operon in cyanobacterium.</p

2‑Hydroxychalcone as a Novel Natural Photosynthesis Inhibitor against Bloom-Forming Cyanobacteria

The control of harmful cyanobacterial blooms has been becoming a global challenge. The development of eco-friendly algicides with strong specificity is urgently needed. The photosynthetic apparatus is a promising target site for algicides to minimize the possible harmful effects on animals and humans. In this study, biologically derived 2-hydroxychalcone efficiently inhibited the growth of bloom-forming M. aeruginosa by selectively interfering with photosynthesis. 2-Hydroxychalcone targeting Photosystem II (PSII) inhibited electron transfer between the primary and secondary electron acceptors (QA and QB) and the binding of plastoquinone (PQ) molecules to the QB binding pocket at the acceptor side of PSII, as revealed by polyphasic chlorophyll (Chl) a fluorescence induction and QA– reoxidation kinetics. Molecular docking for 2-hydroxychalcone to D1 protein and the proteomic responses of M. aeruginosa suggested that 2-hydroxychalcone formed a stable monodentate ligand with the nonheme iron in D1 protein, provoking significant modulation of PSII proteins. The unique binding mode of 2-hydroxychalcone with PSII differentiated it from classical PSII inhibitors. Furthermore, 2-hydroxychalcone down-regulated the expression of microcystin (MC) synthesis-related genes to restrain MC synthesis and release. These results indicated the potential application of 2-hydroxychalcone as an algicide or a template scaffold for designing novel derivatives with superior algicidal activity