background: in this study, erythromycin resistance isolates from the students with aged 12-15 yr old were studied and the mutations in the 23s rrna were identified by sequencing. methods: throat samples of 327 students with 12-15 years old from 3 schools of tehran were cultured on the selective strep­tococ­cus pyogenes medium and 23 strains were primarily selected as s. pyogenes . results: all ...

Background: Clarithromycin resistance in Helicbacter pylori has been found to be associated with point mutations in 23s rRNA gene leads to reduced affinity of the antibiotic to its ribosomal target or changing the site of methylation. The aim of this study was to determine the most important point mutations in 23s rRNA gene in H. pylori that are closely related to clarith-romycin resistance amo...

background:  aeromonas spp. can cause diarrhea and various infections in humans. access to rapid techniques with a high sensitivity and specificity is strongly needed for the identification of aeromonas species. the aim of this study was to evaluate two different methods including api 20e bacterial identification tests and the molecular detection using pcr primers specific for 16s-rrna and 23s-...

background: clarithromycin resistance in helicbacter pylori has been found to be associated with point mutations in 23s rrna gene leads to reduced affinity of the antibiotic to its ribosomal target or changing the site of methylation. the aim of this study was to determine the most important point mutations in 23s rrna gene in h. pylori that are closely related to clarith-romycin resistance amo...

Ribosomal RNA (rRNA) isolated from Wolinella recta and seven related bacteria was examined by agarose gel electrophoresis. The 23S rRNA molecule could not be detected in W. recta, Wolinella curva, Bacteroides gracilis, or Bacteroides ureolyticus. In place of the 23S molecule, there were three smaller molecules of approximately 1700, 650, and 600 bases designated 23S alpha, 23S beta, and 23S del...

We have previously shown that the 23S rRNA of Salmonella strains is highly fragmented by specific enzyme cleavages. In this article, we report that 23S rRNA of Salmonella strains is rapidly degraded as the cells enter the stationary phase. More than 90% of the 23S rRNA is degraded when the cells reach the stationary phase. The rate of degradation of 23S rRNA correlated with its degree of fragme...

RNase III makes the initial cleavages that excise Escherichia coli precursor 16S and 23S rRNA from a single large primary transcript. In mutants deficient in RNase III, no species cleaved by RNase III are detected and the processing of 23S rRNA precursors to form mature 23S rRNA fails entirely. Instead, 50S ribosomes are formed with rRNAs up to several hundred nucleotides longer than mature 23S...

BACKGROUND The concept of ribosomal constraints on rRNA genes is deduced primarily based on the comparison of consensus rRNA sequences between closely related species, but recent advances in whole-genome sequencing allow evaluation of this concept within organisms with multiple rRNA operons. METHODOLOGY/PRINCIPAL FINDINGS Using the 23S rRNA gene as an example, we analyzed the diversity among ...

Salmonella typhimurium LT2 contains intervening sequences (IVSs) of 90-110 nt within all its 23S rRNA that are cleaved out by RNase III, resulting in rRNA fragmentation. In order to determine the functionality of 23S rRNA that contains unexcised IVSs, we constructed an S. typhimurium RNase III (rnc) deficient strain by transducing a mini-Tn10 (rnc-14::Tn10) from Escherichia coli K-12. The resul...

Pasteurella multocida is known as an important heterogenic bacterial agent causes some severe diseases such as fowl cholera in poultry and haemorrhagic septicaemia in cattle and buffalo. A polymerase chain reaction (PCR) assay was developed using primers derived from conserved part of 16S-23S rRNA gene. The PCR amplified a fragment size of 0.7 kb using DNA from nine avian P. multocida  isolates...