To study the effect of RNA interference (RNAi) on the activity of gene lon in Escherichia coli, genetic constructs were used that could express RNA molecules complementary to the 5' region of lon mRNA in the same direction. These RNAs were termed parallel RNAs (pRNAs). Two approaches were used to control expression. In one approach, lon gene activity was estimated genetically, based on the effect of the Lon protease on bioluminescence determined by the Vibrio fischeri lux regulon. The other approach was direct testing of ATP-dependent proteolysis in vitro. It was found that pRNA considerably suppressed lon expression. The antiparallel RNA (apRNA) was a less effective suppressor of this gene. The specific RNAi was found to decay gradually by the 40th generation. The data obtained indicate that Eubacterium cells have mechanisms for specific regulation of gene activity that are sensitive to the formation of both parallel and antiparallel RNA duplexes involving mRNA of the given gene.
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J Ultrasound
January 2025
Argentinian Critical Care Ultrasonography Association (ASARUC), Buenos Aires, Argentina.
Hepatic gas gangrene (HGG) is a rare but life-threatening condition typically caused by anaerobic bacteria such as Clostridium perfringens, though Gram-negative bacteria like Escherichia coli and Klebsiella species have also been implicated. Traditionally diagnosed via computed tomography (CT), point-of-care ultrasound (POCUS) has emerged as a valuable tool in critical care settings for its non-invasive, bedside utility. We report the case of a 51-year-old female with choledochal syndrome secondary to cholangiocarcinoma who developed HGG following left extended hepatectomy and biliary reconstruction.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Biology, New York University, New York, New York, 10003, USA. Electronic address:
The outer membrane is the defining structure of Gram-negative bacteria. We previously demonstrated that it is a major load-bearing component of the cell envelope and is therefore critical to the mechanical robustness of the bacterial cell. Here, to determine the key molecules and moieties within the outer membrane that underlie its contribution to cell envelope mechanics, we measured cell-envelope stiffness across several sets of mutants with altered outer-membrane sugar content, protein content, and electric charge.
View Article and Find Full Text PDFNPJ Antimicrob Resist
January 2025
College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, ON, Canada.
Since its discovery nearly 60 years ago, TolC has been associated with various cellular functions in Escherichia coli, including the efflux of environmental stressors and virulence factors. It also acts as a receptor for specific bacteriophages and the colicin E1 toxin. This review highlights key discoveries over the past six decades and emphasizes the remaining gaps in understanding how TolC contributes to physiological functions in E.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address:
Conventional light-driven antimicrobial strategies of zinc oxide (ZnO) are limited by inadequate illumination in dark environments. In this study, carboxylated cellulose nanocrystals (MCNC) mediated flower-like ZnO (C@Z) with self-promoted reactive oxygen species release under dark is fabricated. The adsorption of Zn ions on MCNC prompts the growth of ZnO along the (002) crystal plane, forming a flower-like hybrid with superior dispersibility and oxygen vacancies compared to MCNC-free ZnO, which exposes the (100) plane.
View Article and Find Full Text PDFBMJ Case Rep
January 2025
Obstetrics and Gynecology, All India Institute of Medical Sciences Bhopal, Bhopal, Madhya Pradesh, India.
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