Purpose: NO has an important role as part of the innate host response against bacterial infections. Flavohemoglobin, which is encoded by the hmp gene, protects Escherichia coli against nitrosative stress. We compared the NO tolerance of UPEC and nonpathogenic strains, and examined the involvement of flavohemoglobin.
Materials And Methods: The E. coli K12 derivates HB101 and DH5alpha represent nonpathogenic strains, while J96 and IA2 represent UPEC strains. HB101 was used as the host for a pBR322 plasmid carrying the hmp gene. Bacterial tolerance to NO was evaluated by determining cfu. Flavohemoglobin expression was examined using Northern and Western blot analysis.
Results: In the stationary growth phase, J96 was significantly more tolerant to DETA/NO (Alexis Biochemical, Lausen, Switzerland) (1 mM) compared to HB101 (47% +/- 11% vs 6.4% +/- 3.1% cfu). In the exponential growth phase DETA/NO exposure resulted in 98% +/- 4.6% cfu for J96 and 74% +/- 7.6% cfu for IA2 compared to 15% +/- 5.9% for HB101 and 21% +/- 12% for DH5alpha. HB101 over expressing hmp showed increased tolerance to DETA/NO (0.5 mM) compared to WT HB101 (106% +/- 5.6% vs 67 +/- 6.2%, p <0.01). Northern and Western blot analysis demonstrated increased flavohemoglobin expression after DETA/NO exposure and the strongest expression in HB101 carrying hmp on a multicopy plasmid.
Conclusions: UPEC strains were significantly more tolerant to DETA/NO than nonpathogenic strains, which suggests a correlation between virulence and NO tolerance. Flavohemoglobin expression increased after DETA/NO exposure in UPEC and in nonpathogenic strains.
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http://dx.doi.org/10.1016/S0022-5347(05)00144-8 | DOI Listing |
J Agric Food Chem
January 2025
Department of General Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China.
Background Severe acute pancreatitis (SAP) manifests as a critical state marked by acute abdominal symptoms, often associated with intestinal barrier dysfunction, exacerbating SAP retroactively. Ganoderic acid A (GAA) demonstrates anti-inflammatory properties in various inflammatory disorders. Nonetheless, its potential therapeutic impact on SAP and the underlying mechanisms remain unexplored.
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June 2025
Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Riboflavin, an important vitamin utilized in pharmaceutical products and as a feed additive, is mainly produced by metabolically engineered bacterial fermentation. However, the reliance on antibiotics in the production process leads to increased costs and safety risks. To address these challenges, an antibiotic-free riboflavin producer was constructed using metabolic engineering approaches coupled with a novel plasmid stabilization system.
View Article and Find Full Text PDFiScience
January 2025
Laboratoire de Biochimie, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL Research University, ESPCI Paris, 10 Rue Vauquelin, 75005 Paris, France.
Cellular fitness depends on multiple phenotypes that must be balanced during evolutionary adaptation. For instance, coordinating growth and motility is critical for microbial colonization and cancer invasiveness. In bacteria, these phenotypes are controlled by local regulators that target single operons, as well as by global regulators that impact hundreds of genes.
View Article and Find Full Text PDFMater Today Bio
February 2025
Department of Orthopedics, The Third Affiliated Hospital of Shandong First Medical University (Affiliated Hospital of Shandong Academy of Medical Sciences), NO.38, Wuyingshan Road, Tianqiao District, Jinan, 250031, China.
The bacterial infection and oxidative wound microenvironment delay skin repair and necessitate intelligent wound dressings to enable scarless wound healing. The immunoglobulin of yolk (IgY) exhibits immunotherapeutic potential for the potential treatment of antimicrobial-resistant pathogens, while cerium oxide nanoparticles (CeO NPs) could scavenge superoxide dismutase (SOD) and inflammation. The overarching objective of this study was to incorporate IgY and CeO NPs into poly(L-lactide-co-glycolide)/gelatin (PLGA/Gel)-based dressings (P/G@IYCe) for infected skin repair.
View Article and Find Full Text PDFInfect Drug Resist
January 2025
Department of Pathology and Clinical Laboratory, French Medical Institute for Mother and Children (FMIC), Kabul, Afghanistan.
Introduction: The widespread use of antibiotics is a serious and alarming situation in terms of the development of antimicrobial resistance. The current study was conducted to demonstrate the types of organism isolated from the urine of patients presenting with UTI symptoms as well as their antimicrobial sensitivity spectrum.
Methodology: A descriptive cross-sectional study was conducted, and 272 positive urine cultures from children under 5 years of age with signs and symptoms of a UTI were included in the study.
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