Project description:Biofilms are ubiquitous in natural, medical, and engineering environments. While most antibiotics that primarily aim to inhibit cell growth may result in bacterial drug resistance, biofilm inhibitors do not affect cell growth and there is less chance of developing resistance. This work sought to identify novel, non-toxic and potent biofilm inhibitors from Streptomyces bacteria for reducing the biofilm formation of Pseudomonas aeruginosa PAO1. Out of 4300 Streptomyces strains, one species produced and secreted peptide(s) to inhibit P. aeruginosa biofilm formation by 93% without affecting the growth of planktonic cells. Global transcriptome analyses (DNA microarray) revealed that the supernatant of the Streptomyces 230 strain induced phenazine, pyoverdine, and pyochelin synthesis genes. Electron microscopy showed that the supernatant of Streptomyces 230 strain reduced the production of polymeric matrix in P. aeruginosa biofilm cells, while the Streptomyces species enhanced swarming motility of P. aeruginosa. Therefore, current study suggests that Streptomyces bacteria are an important resource of biofilm inhibitors as well as antibiotics.
Project description:Prenatal exposure to synthetic corticosteroids can significantly alter postnatal development through changes in neurotransmitters and their receptors, and thus having long-lasting behavioral effects. Some of these changes have been observed in animal experiments, others also in humans prenatally exposed to synthetic corticosteroids. Here, we focused on transcriptomic changes within the prefrontal cortex of female rats prenatally exposed to either betamethasone or saline. The transcriptome has been assessed by novel computational tools to determine complex changes that may have life-long effects on phenotype, i.e., behavior. We analyzed how composition, topology and modulatory networks of the genomic fabric of the dopaminergic, GABAergic, and glutamatergic synapse (the transcriptome of the most interconnected and stably expressed gene network responsible for specific transmission) are afected by the prenatal exposure to corticosteroids and postnatal ketamine-induced seizures. One sex (F) x two prenatal exposures (B = betamethasone, S = saline) x two postnatal treatments (K = ketamine, S = saline). Biological replicates: 4 FSS, 4 FBS, 4 FBK.
Project description:Biofilms are ubiquitous in natural, medical, and engineering environments. While most antibiotics that primarily aim to inhibit cell growth may result in bacterial drug resistance, biofilm inhibitors do not affect cell growth and there is less chance of developing resistance. This work sought to identify novel, non-toxic and potent biofilm inhibitors from Streptomyces bacteria for reducing the biofilm formation of Pseudomonas aeruginosa PAO1. Out of 4300 Streptomyces strains, one species produced and secreted peptide(s) to inhibit P. aeruginosa biofilm formation by 93% without affecting the growth of planktonic cells. Global transcriptome analyses (DNA microarray) revealed that the supernatant of the Streptomyces 230 strain induced phenazine, pyoverdine, and pyochelin synthesis genes. Electron microscopy showed that the supernatant of Streptomyces 230 strain reduced the production of polymeric matrix in P. aeruginosa biofilm cells, while the Streptomyces species enhanced swarming motility of P. aeruginosa. Therefore, current study suggests that Streptomyces bacteria are an important resource of biofilm inhibitors as well as antibiotics. For the microarray experiments, P. aeruginosa were inoculated in 25 0ml of LB medium in 1000 ml shake flasks with overnight cultures that were diluted 1:100. Streptomyces 230 strain culture media was added in at 1% . Cells were cultured with 10g of glass wool in LB at 37M-BM-0C with 100 rpm shaking for 7 hrs. Cells were immediately chilled with dry ice and 95% ethanol (to prevent RNA degradation) for 30 sec before centrifugation in 50 ml centrifuge tubes at 13,000 g for 2 min; cell pellets were frozen immediately with dry ice and stored -80M-BM-0C. RNA was isolated using Qiagen RNeasy mini Kit (Valencia, CA, USA). RNA quality was assessed by Agilent 2100 bioanalyser using the RNA 6000 Nano Chip (Agilent Technologies, Amstelveen, The Netherlands), and quantity was determined by ND-1000 Spectrophotometer (NanoDrop Technologies, Inc., DE, USA).
Project description:Prenatal exposure to synthetic corticosteroids can significantly alter postnatal development through changes in neurotransmitters and their receptors, and thus having long-lasting behavioral effects. Some of these changes have been observed in animal experiments, others also in humans prenatally exposed to synthetic corticosteroids. Here, we focused on transcriptomic changes within the prefrontal cortex of female rats prenatally exposed to either betamethasone or saline. The transcriptome has been assessed by novel computational tools to determine complex changes that may have life-long effects on phenotype, i.e., behavior. We analyzed how composition, topology and modulatory networks of the genomic fabric of the dopaminergic, GABAergic, and glutamatergic synapse (the transcriptome of the most interconnected and stably expressed gene network responsible for specific transmission) are affected by prenatal exposure to corticosteroids and postnatal ketamine/saline treated NMDA-induced seizures.
Project description:Intercellular signal indole and its derivative hydroxyindoles inhibit Escherichia coli biofilm and diminish Pseudomonas aeruginosa virulence. However, indole and bacterial indole derivatives were unstable in microbial community due to the widespread of diverse oxygenases that could quickly degrade them. Hence, we sought to identify novel non-toxic, stable, and potent indole derivatives from plant sources for inhibiting biofilm formation of E. coli O157:H7 and P. aeruginosa PAO1. Here, plant auxin 3-indolylacetonitrile (IAN) was found to inhibit biofilm formation of both E. coli O157:H7 and P. aeruginosa without affecting its growth. IAN inhibited biofilms more effectively than indole for both E. coli and P. aeruginosa. Additionally, IAN decreased the production of virulence factor pyocyanin in P. aeruginosa. DNA microarray analysis indicated that IAN repressed genes involved in curli formation and glycerol metabolism, while IAN induced indole-related genes and prophage genes in E. coli. It appears that IAN inhibits biofilm formation of E. coli by reducing curli formation and inducing indole production. Furthermore, unlike bacterial indole derivatives, plant-originated IAN was stable in the presence of either E. coli or P. aeruginosa.
Project description:Chronic Pseudomas aeruginosa infection in the lung is a common in people with cystic fibrosis (CF). Current therapies for CF fail to eliminate persistent bacterial infections, chronic inflammation, or irreversible lung damage. Our group engineered mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) to carry the microRNA let-7b-5p as a dual anti-infective and anti-inflammatory treatment. In a preclinical CF mice model, we found that let-7b-5p-loaded MSC EVs reduced P. aeruginosa burden, immune cells and proinflammatory cytokines in the lungs. This research hypothesized two mechanisms of the observed effects in the mouse model: anti-inflammatory properties of the let-7b-5p-loaded MSC EVs and inhibition of antibiotic-resistant P. aeruginosa biofilm formation in CF airways. Primary human broncial epithelial cells (pHBECs) were exposed to P. aeruginosa and treated with differet MSC EV conditions. The results demonstrated that MSC EVs engineered to contain let-7b-5p effectively blocked the formation of P. aeruginosa biofilms on pHBECs while also reducing P. aeruginosa-induced inflammation by CF-pHBECs.