Project description:The expression levels of uropathogenic E. coli (UPEC) UTI89 cells in YESCA broth with and without 4% dimehtyl sulfoxide (DMSO) and 2% ethanol (EtOH) were studied.
Project description:Intercalated cells are known to be involved in acid-base homeostasis via vacuolar ATPase (H+-ATPase or V-ATPase) expression. Increasing evidence supports an innate immune role for ICs along with their traditional function of pH regulation. In this study, human kidney tissue was enriched for viable intercalated cells then exposed to uropathogenic E. coli versus saline control. Single cell transcriptomics was performed. Six intercalated cell subtypes were identified including hybrid principal-intercalated cells. Cell specific cluster marker gene list generated from this sequencing data was put through ingenuity pathway analysis pipeline which predicted “phagosome maturation” as a key biological pathway that increased in rank following exposure to uropathogenic E. coli in two of the intercalated cell subtypes. Uptake of E. coli and pHrodo coated E. coli BioParticlesTM during live animal intravital microscopy demonstrated that intercalated cell phagocytosis of bacteria was an active process that involved acidification. Taken together, our finding indicate that intercalated cells represent an epithelial cell with characteristics of professional phagocytes like macrophages or neutrophils, which includes the ability to phagocytose E. coli and acidify phagolysosomes.
Project description:Antibiotic resistance is a growing global health threat. Most research has focused on understanding how mobile genetic elements are acquired by pathogenic bacteria. However, bacteria have intrinsic chromosomally encoded systems to protect themselves against antimicrobial assault. Our lab has uncovered such a system in uropathogenic E. coli. PmrAB and QseBC are connected two component systems that confer resistance to polymyxins, a last resort antibiotic. The histidine kinase PmrB responds to ferric iron and activates its cognate response regulator PmrA, as well as the non-cognate response regulator QseB. QseC, the other histidine kinase plays an important role in resetting the system. To better understand how PmrAB and QseBC mediate polymyxin resistance, this project aimed to elucidate the regulon of the two response regulators QseB and PmrA in the uropathogenic E. coli strain UTI89. In this strain, isogenic mutants were made lacking qseB and pmrA singly and together. These strains and wild-type UTI89 were stimulated with ferric iron and samples for RNA sequencing were taken prior to stimulation and at 15 and 60 minutes post stimulation. Samples were then sent for sequencing on the Illumina platform and analyzed using Rockhopper software.
Project description:While in transit within and between hosts, uropathogenic E. coli (UPEC) encounter multiple stresses, including substantial levels of nitric oxide and reactive nitrogen intermediates. Strains of UPEC become conditioned to high concentrations of acidified sodium nitrite (ASN), a model system used to generate nitrosative stress. We used microarrays to define the expression profile of UPEC that have been conditioned for growth in ASN.