Background: Nitrofurantoin has been re-introduced as a first-choice antibiotic to treat uncomplicated acute urinary tract infections in England and Wales. Highly effective against common uropathogens such as Escherichia coli, its use is accompanied by a low incidence (<10%) of antimicrobial resistance. Resistance to nitrofurantoin is predominantly via the acquisition of loss-of-function, step-wise mutations in the nitroreductase genes nfsA and nfsB.
Objective: To explore the in situ evolution of NitR in E. coli isolates from 17 patients participating in AnTIC, a 12-month open label randomized controlled trial assessing the efficacy of antibiotic prophylaxis in reducing urinary tract infections (UTIs) incidence in clean intermittent self-catheterizing patients.
Methods: The investigation of NitR evolution in E. coli used general microbiology techniques and genetics to model known NitR mutations in NitSE. coli strains.
Results: Growth rate analysis identified a 2%-10% slower doubling time for nitrofurantoin resistant strains: NitS: 20.8 ± 0.7 min compared to NitR: 23 ± 0.8 min. Statistically, these data indicated no fitness advantage of evolved strains compared to the sensitive predecessor (P-value = 0.13). Genetic manipulation of E. coli to mimic NitR evolution, supported no fitness advantage (P-value = 0.22). In contrast, data argued that a first-step mutant gained a selective advantage, at sub-MIC (4-8 mg/L) nitrofurantoin concentrations.
Conclusion: Correlation of these findings to nitrofurantoin pharmacokinetic data suggests that the low incidence of E. coli NitR, within the community, is driven by urine-based nitrofurantoin concentrations that selectively inhibit the growth of E. coli strains carrying the key first-step loss-of-function mutation.
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http://dx.doi.org/10.1093/jac/dkac398 | DOI Listing |
Microb Genom
January 2025
Center for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands.
Genes encoding OXA-48-like carbapenem-hydrolyzing enzymes are often located on plasmids and are abundant among carbapenemase-producing (CPE) worldwide. After a large plasmid-mediated outbreak in 2011, routine screening of patients at risk of CPE carriage on admission and every 7 days during hospitalization was implemented in a large hospital in the Netherlands. The objective of this study was to investigate the dynamics of the hospitals' 2011 outbreak-associated plasmid among CPE collected from 2011 to 2021.
View Article and Find Full Text PDFJ Med Microbiol
January 2025
Field Service - South East and London, UK Health Security Agency, London, UK.
Shiga toxin-producing (STEC) infections are of public health concern as STEC can cause large national foodborne outbreaks of severe gastrointestinal disease, particularly in the young and elderly. In recent years, the implementation of PCR by diagnostic microbiology laboratories has improved the detection of STEC, and there has been an increase in notifications of cases of non-O157 STEC. However, the extent this increase in caseload can be attributed to the improved detection by PCR, or a true increase in non-O157 STEC infections, is unknown.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Department of Biological Sciences, Minnesota State University Mankato, Mankato, Minnesota, USA.
Unlabelled: causes bacterial cold-water disease (BCWD) in salmonids and other fish, resulting in substantial economic losses in aquaculture worldwide. The mechanisms uses to cause disease are poorly understood. Despite considerable effort, most strains of have resisted attempts at genetic manipulation.
View Article and Find Full Text PDFCells
December 2024
Molecular and Cellular Microbiology Laboratory, Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA.
Within mammalian cells, diverse endocytic mechanisms, including phagocytosis, pinocytosis, and receptor-mediated endocytosis, serve as gateways exploited by many bacterial pathogens and toxins. Among these, caveolae-mediated endocytosis is characterized by lipid-rich caveolae and dimeric caveolin proteins. Caveolae are specialized microdomains on cell surfaces that impact cell signaling.
View Article and Find Full Text PDFViral Immunol
January 2025
Department of Microbiology, Basic Science Center, Autonomous University of Aguascalientes, Aguascalientes, Mexico.
Respiratory syncytial virus (RSV) is one of the most important etiologies of acute respiratory infections that cause bronchiolitis in children under 5 years of age. Treatments are expensive, no vaccine is available, and this is an important cause of hospitalization. Costimulatory molecules have been reported to be good inducers of antiviral type 1 immune response.
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