The mechanisms of intrinsic resistance of Mycoplasma hominis to 14- and 15-membered macrolides were investigated in comparison with those of M. pneumoniae, which is naturally susceptible to macrolides. Radiolabeled erythromycin was not accumulated by M. hominis PG21, but addition of an ABC transporter inhibitor increased the level of erythromycin uptake more than two times, suggesting the exist...

OBJECTIVES Macrolide resistant Treponema pallidum strains, caused by mutations in the 23S ribosomal RNA (23S rRNA) gene, are widespread and increasingly prevalent. The authors aimed to establish the strain types of T pallidum isolated from patients in a London sexual health centre and to determine the frequency of macrolide resistance. METHODS T pallidum DNA from blood and ulcer samples were ...

BACKGROUND AND AIMS Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies. PATIENTS AND METHODS We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy...

To elucidate the organization of the transcription units encoding the 16S, 23S and 5S rRNAs in the archaebacterium Thermoplasma acidophilum, the nucleotide sequences flanking the three rRNA genes were determined, and the 5' and 3' termini of the rRNA transcripts were mapped by primer extension and nuclease S1 protection. The results show that each of the rRNAs is transcribed separately, consist...

Peptide bond formation by the ribosome requires 23S rRNA and its interaction with the 3'-CCA end of tRNA. To investigate the possible evolutionary development of the peptidyl transfer reaction, we tried to obtain peptide bond formation without the ribosome or rRNA simply by using a piece of tRNA--an aminoacyl-minihelix--mixed with sequence-specific oligonucleotides that contained puromycin. Pep...

OBJECTIVES To study mutations at positions A2058, A2503 and U2504 (Escherichia coli numbering) of 23S rRNA and their relationship to resistance to antibiotics that target the large ribosomal subunit. METHODS Single and dual mutations at positions 2058, 2503 and 2504 of 23S rRNA were introduced into a Mycobacterium smegmatis strain with a single functional rRNA operon. MICs of macrolide, pleur...

A phytoplasma was detected in golden beard grass (Chrysopogon acicalatus) displaying white leaf symptoms near vegetative fields at the Tatkone region in Myanmar, 2011. Based on restriction fragment length polymorphism analysis of PCR-amplified 16S rRNA genes, including the 16S-23S spacer region and part of the 23S rRNA gene, the phytoplasma was identified as a member of the Bermuda grass white ...

The sarcin-ricin loop (SRL) of 23S rRNA in the large ribosomal subunit is a factor-binding site that is essential for GTP-catalyzed steps in translation, but its precise functional role is thus far unknown. Here, we replaced the 15-nucleotide SRL with a GAAA tetraloop and affinity purified the mutant 50S subunits for functional and structural analysis in vitro. The SRL deletion caused defects i...

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of th...

DUF177 proteins are nearly universally conserved in bacteria and plants except the Chlorophyceae algae. Thus far, duf177 mutants in bacteria have not established a function. In contrast, duf177a mutants have embryo lethal phenotypes in maize and Arabidopsis. In maize inbred W22, duf177a mutant embryos arrest at an early transition stage, whereas the block is suppressed in the B73 inbred backgro...