Project description:Municipal wastewater effluent can impact its receiving environment. In the St. Lawrence River, male fish living downstream from Montreal exhibit increased hepatic vitellogenin, intersex, delayed spermatogenesis and altered immune function. Few studies have examined genome-wide effects associated with municipal effluent exposure in fish to decipher the mechanisms of toxicity. The present objective was to identify hepatic cellular signaling pathways in fathead minnows following exposure to municipal wastewater effluent. Immature minnows were exposed for 21 days to either 0% (Control) or 20% municipal effluent, the highest concentration in the St. Lawrence River. Hepatic RNA was extracted and used to hybridize a fathead minnow oligonucleotide microarray containing approximately 15K gene sequences.
Project description:Multi-drug resistant Staphylococcus aureus (S. aureus) infections continously threaten public health. The rapid escalation in morbidity and mortality rates associated with methicillin-resistant S. aureus (MRSA) infections necessitates the urgent development of novel antimicrobial agents. Our study reveals that the FDA-approved drug cinacalcet (CNA) effectively functions as an antibacterial and anti-biofilm agent against S. aureus without detectable resistance. It evidently improved survival rate of mice infected with clinical multi-resistant S. aureus in a pneumonia model. Subsequent proteomic and biochemical experiments suggest that the primary antibacterial mechanism involves membrane structure disruption, ATP content reduction, and reactive oxygen species (ROS) production. Concurrently, LiP-SMap combined with biochemical validation indicates that CNA inhibits biofilm formation by targeting IcaR, a negative regulator of icaADBC, thereby enhancing its binding capacity to the ica operator DNA and subsequently suppressing extracellular polysaccharide formation. Importantly, compared to vancomycin, CNA demonstrates stronger biofilm bacterial clearance in a mouse thigh infection model. Collectively, our findings propose that CNA can be repurposed as a potential therapeutic agent for treating multidrug-resistant S. aureus infections and their associated biofilms.
Project description:In this study, we exposed Caenorhabditis elegans wild types N2 to water collected from six sources in the Dutch village Sneek. The sources were: wastewater from a hospital, a community (80 households), a nursing home, influent into the local municipal wastewater treatment plant, effluent of the wastewater treatment plant, and surface water samples. The goal of the experiment was to determine if C. elegans can be used to identify pollutants in the water by transcriptional profiling. Age synchronized worms at developmental L4 larval stage were exposed to treatment for 24 hours. After flash freezing the samples, RNA was isolated, labeled and hybridized on oligo microarray (Agilent) slides.