Project description:The aim of this experiment was to determine if the development of resistance to antibiotics can be driven by the concentration and speciation of Cu. Experimental setup was designed to investigate two hypotheses for which two strains of Gram- bacteria have been selected: - Do TE enhance AR in resistant bacteria? Resistant strain: Bioluminescent Pseudomonas aeruginosa PAO1 (Xen41, Tetracycline resistant) - Do TE induce AR in sensitive bacteria? Sensitive strain: Pseudomonas aeruginosa PAO1 (Wild Type)
Project description:Background:
- Some bacteria found in the large and small intestines help keep people healthy and aid digestion. They may also affect a person s risk of developing cancer. Researchers want to study the relationship between intestinal bacteria and breast cancer risk factors. They can do this by looking at stool and urine samples from postmenopausal women.
Objectives:
- To study intestinal bacteria and its relationship to urine-based markers of breast cancer risk in women.
Eligibility:
- Women between 55 and 69 years of age with a recent mammogram that showed no signs of cancer.
Design:
* Participants will be screened with a medical history and basic health questionnaire.
* At home, participants will complete questionnaires about cancer risk factors and food consumption.
* Participants will also collect urine and stool samples. They will send the samples to the designated labs for study.
* No treatment will be provided as part of this protocol.
Project description:Indole is an intercellular and interkingdom signaling molecule, which is widespread in diverse ecological niches. Caenorhabditis elegans is a bacterivorous nematode living in soil and compost environments and a useful model host for the study of host-microbe interactions. While various bacteria and some plants produce a large quantity of extracellular indole, little is known about the effects of indole, its derivatives, and indole-producing bacteria on behaviors in C. elegans and animals. Here, we show that C. elegans senses and moves toward indole and indole-producing bacteria, such as Escherichia coli, Shigella boydii, Providencia stuartii, and Klebsiella oxytoca, while avoids non-indole producing pathogenic bacteria. It was also found that indole-producing bacteria and non-indole-producing bacteria exert divergent effects on egg-laying behavior of C. elegans via indole. In addition, various indole derivatives also modulate chemotaxis, egg-laying behavior, and survival of C. elegans. In contrast, indole at a high concentration to kill C. elegans that has the ability to detoxify indole via oxidation and glucosylation, indicating predator-prey interactions via a double-edged molecule indole. Transcriptional analysis showed that indole markedly up-regulated gene expression of cytochrome P450 family, UDP-glucuronosyltransferase, glutathione S-transferase, which explained well the modification of indole in C. elegans, while down-regulated expression of collagen genes and F-box genes. Our findings suggest that indole and its derivatives are important interkingdom signaling molecules in bacteria-nematode interactions.
Project description:Background: Probiotic-like bacteria treatment has been described to be associated with gut microbiota modifications. Goal: To decipher if the effects of the tested probiotic-like bacteria are due to the bacteria itself or due to the effects of the bacteria on the gut microbiota. Methodology: In this study, gut microbiota has been analyzed from feces samples of subjects with metabolic syndrome and treated with one of the 2 tested probiotic-like bacteria or with the placebo during 3months.
Project description:Bacteria-based cancer immunotherapy, dated back to Coley’s toxins (inactivated bacteria) in 1893, has recently regained substantial attentions, usually by using attenuated bacteria to transform immune-silent “cold” tumors into immune-inflamed “hot” ones. However, while inactivated bacteria showed limited antitumor efficacy, attenuated live bacteria often possessed significant safety risks. Herein, by biomineralizing growth of manganese dioxide on the surface of paraformaldehyde-fixed gram-negative Salmonella typhimurium (S. typhimurium), we obtained MnO2-coated fixed S. typhimurium (M@F.S), which showed potent immune-stimulating effects via activating multiple pathways including Toll-like receptors (TLRs), cyclic GMP-AMP Synthase (cGAS)-stimulator of interferon genes (STING) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs). Single intratumoral administration of M@F.S at safe doses resulted in surprisingly strong efficacies in suppressing various types of mouse tumor models and a rabbit cancer model, and the cured mice and rabbits gained immune memory to reject re-challenged tumors. An abscopal antitumor effect was also observed, suggesting systemic antitumor immunity triggered by local injection of M@F.S. The antitumor mechanisms of M@F.S were preliminarily demonstrated to be innate immune activation initiated by multiple signaling pathways, followed by subsequent activation of tumor-specific immune responses, together with the modulation of immunosuppressive tumor microenvironment. We further demonstrated the efficacy of biomineralized bacteria in inhibiting an orthotopic breast tumor model established on tree shrews, an alternative animal model to primates with better clinical relevance. Such oncolytic biomineralized bacteria could be a potent yet safe immunotherapeutic agent for treatment of various solid tumors.
Project description:The aim of this experiment was to determine if the development of resistance to antibiotics can be driven by the concentration and speciation of Cu. Experimental setup was designed to investigate two hypotheses for which two strains of Gram- bacteria have been selected: - Do TE enhance AR in resistant bacteria? Resistant strain: Bioluminescent Pseudomonas aeruginosa PAO1 (Xen41, Tetracycline resistant) - Do TE induce AR in sensitive bacteria? Sensitive strain: Pseudomonas aeruginosa PAO1 (Wild Type)