Resistance of Helicobacter pylori to clarithromycin is the most common cause of treatment failure in patients with H. pylori infections. This study describes the MICs and the presence of 23S rRNA mutations of H. pylori isolates from Bogotá, D.C., Colombia. H. pylori were isolated from gastric biopsies from patients with functional dyspepsia. Clarithromycin susceptibility was investigated by agar dilution and strains were considered resistant if the MIC was ≥ 1 μg/ml. DNA sequences of the 23S rRNA gene of strains resistant and sensitive to clarithromycin were determined to identify specific point mutations. Clarithromycin resistance was present in 13.6% of patients by agar dilution. The A2143G, A2142G and A2142C mutations were found in 90.5, 7.1, and 2.4% of H. pylori strains with resistance genotype.The resistant phenotype was associated with 23S rRNA resistance genotype in 85.7% of isolates. The point mutations in 23S rRNA were well correlated with MICs values for clarithromycin.
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http://dx.doi.org/10.1007/s12275-013-2465-6 | DOI Listing |
Nat Commun
January 2025
Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.
The proline-rich antimicrobial designer peptide Api137 inhibits protein expression in bacteria by binding simultaneously to the ribosomal polypeptide exit tunnel and the release factor (RF), depleting the cellular RF pool and leading to ribosomal arrest at stop codons. This study investigates the additional effect of Api137 on the assembly of ribosomes using an Escherichia coli reporter strain expressing one ribosomal protein per 30S and 50S subunit tagged with mCherry and EGFP, respectively. Separation of cellular extracts derived from cells exposed to Api137 in a sucrose gradient reveals elevated levels of partially assembled and not fully matured precursors of the 50S subunit (pre-50S).
View Article and Find Full Text PDFMicrobiol Spectr
January 2025
Department of Laboratory Medicine, National University Hospital, Singapore, Singapore.
Unlabelled: The complex (MAC) is a common causative agent causing nontuberculous mycobacterial (NTM) pulmonary disease worldwide. Whole-genome sequencing was performed on a total of 203 retrospective MAC isolates from respiratory specimens. Phylogenomic analysis identified eight subspecies and species.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
January 2025
International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark.
Four novel nontuberculous mycobacteria were discovered from a historical strain collection at the International Reference Laboratory of Mycobacteriology at Statens Serum Institut in Copenhagen, Denmark. Phylogenetic analysis combining the 16S , internal transcribed spacer and 23S elements, as well as a single-copy core-gene (, , and ) analysis of these freeze-dried mycobacteria, clinically isolated from gastric lavage samples between 1948 and 1955, showed to be associated with type strains grouping within the Terra and Fortuitum-Vaccae clade. Phenotypic characteristics, biochemical properties and fatty acid and mycolic acid profiles supported the classification as novel strains.
View Article and Find Full Text PDFPathogens
November 2024
The Davies Livestock Research Centre, School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, Adelaide, SA 5005, Australia.
, an important cause of enzootic pneumonia in pigs in many countries, has recently been shown to exhibit reduced susceptibility to several antimicrobial classes. In the present study, a total of 185 pig lung tissue samples were collected from abattoirs in Australia, from which 21 isolates of were obtained. The antimicrobial resistance profile of the isolates was determined for 12 antimicrobials using minimum inhibitory concentration (MIC) testing, and a subset ( = 14) underwent whole-genome sequence analysis.
View Article and Find Full Text PDFMikrobiyol Bul
October 2024
Hacettepe University Faculty of Medicine, Department of Infectious Diseases and Clinical Microbiology, Ankara, Türkiye.
A sexually transmitted bacterium, Mycoplasma genitalium has varying rates of reported resistance to macrolide and some fluoroquinolone group antimicrobials recommended for the treatment of its infections. It is currently recommended that the treatment of these must be planned according to macrolide resistance status. The aim of this study was to determine the presence of macrolide resistance associated mutations (MRM) and fluoroquinolone resistance associated mutations (QRM) in patients infected with M.
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