Objectives: The aim of this study was to determine the occurrence of 16S rRNA mutations associated with low-level tetracycline resistance in Helicobacter pylori isolates from adult dyspeptic patients in South West Nigeria.
Methods: Susceptibility testing to tetracycline of 50 H. pylori isolates was performed by Etest. The 535-bp conserved region of the H. pylori tetracycline-binding site of 16S rRNA was amplified by PCR, followed by sequencing and multiple sequence alignment for all 50 clinical isolates.
Results: Of the 50 clinical isolates examined, DNA sequence analysis revealed nucleotide substitutions in 7 isolates at positions 926-928. Of the seven isolates, two demonstrated reduced susceptibility to tetracycline with Etest minimum inhibitory concentrations (MICs) of 0.75-1.0mg/L, whilst the other five isolates were resistant with MICs of 1.5-24mg/L (resistance breakpoint >1mg/L). The two isolates with reduced susceptibility had single nucleotide substitution of AG, whilst the five resistant isolates demonstrated double base pair substitutions of GT/AC and AG/AC and a single nucleotide substitution of AG.
Conclusions: This study shows that low-level tetracycline resistance amongst H. pylori-positive dyspeptic patients is associated with reduced susceptibility and resistance to tetracycline. This is the result of 1-bp and 2-bp differences in positions 926 and 926-928, respectively, in the 16S rRNA of H. pylori.
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http://dx.doi.org/10.1016/j.jgar.2018.01.003 | DOI Listing |
Infect Dis Now
January 2025
CHU Poitiers, Department of Infectious Agents, Bacteriology Department, Poitiers, France; University of Poitiers, U1070 INSERM Pharmacology of Antimicrobial Agents and Antibiotic Resistance, Poitiers, France.
Introduction: The increasing resistance of Helicobacter pylori to clarithromycin leads to an ongoing adaptation of empirical first-line treatment for H. pylori infections.
Patients And Methods: Prospective study (2022-2023) of 364 patients with no previous treatment for H.
Dermatol Clin
January 2025
Department of Dermatology, Brigham and Women's Hospital, 41 Avenue Louis Pasteur, 317A, Boston, MA 02115, USA. Electronic address:
Although many treatments are available for acne, these can be limited by lack of effectiveness, patient tolerance and adherence, and accessibility. This review provides a comprehensive summary of the latest developments in acne management, exploring a range of topical, systemic, and procedural treatments. The mechanisms of action, pivotal trial data, and potential role in clinical practice are reviewed for emerging therapies such as 1726 nm laser, sarecycline, clascoterone, trifarotene, minocycline foam, and fixed-dose combination topicals.
View Article and Find Full Text PDFFoods
October 2024
Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Institutes of Agricultural Science and Technology Development, Yangzhou University, Yangzhou 225009, China.
The emergence of inactivation enzyme-encoding genes (X), , and challenges the effectiveness of tetracyclines, β-lactams, and macrolides. This study aims to explore the concurrence and polymorphism of their variants in sp. strains from food-producing animals and surrounding environments.
View Article and Find Full Text PDFToxicol Lett
November 2024
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan; Laboratory of Biochemistry and Molecular Biology, School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan; Laboratory of Functional Organoid for Drug Discovery, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka 567-0085, Japan; Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan; Global Center for Medical Engineering and Informatics, Osaka University, Osaka 565-0871, Japan; Center for Infectious Disease Education and Research (CiDER), Osaka University, Osaka 565-0871, Japan. Electronic address:
Caco-2 cells, a human colorectal adenocarcinoma cell line, are widely used to model small intestinal epithelial cells in the drug development process because they can predict drug absorption with high accuracy. However, Caco-2 cells have several issues. First, Caco-2 cells have little expression of cytochrome P450 3A4 (CYP3A4), which is a major drug-metabolizing enzyme in the human intestine.
View Article and Find Full Text PDFEnviron Int
August 2024
Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China. Electronic address:
Natural environments play a crucial role in transmission of antimicrobial resistance (AMR). Development of methods to manage antibiotic resistance genes (ARGs) in natural environments are usually limited to the laboratory or field scale, partially due to the complex dynamics of transmission between different environmental compartments. Here, we conducted a nine-year longitudinal profiling of ARGs at a watershed scale, and provide evidence that restrictions on livestock farms near water bodies significantly reduced riverine ARG abundance.
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