A macrolide-resistant clinical isolate of Streptococcus pneumoniae with 23S rRNA mutations showed a heterogeneous phenotype and genotype. The mutant 23S rRNA genes from this isolate transformed susceptible strain R6 to resistance. Culture of resistant strain R6 in the absence of antibiotic pressure showed gene conversion to occur between the four 23S rRNA alleles, resulting in reversion to susc...

The termini of rRNA processing intermediates and of mature rRNA species encoded by the 3' terminal region of 23S rDNA, by 4.5S rDNA, by the 5' terminal region of 5S rDNA and by the 23S/4.5S/5S intergenic regions from Zea mays chloroplast DNA were determined by using total RNA isolated from maize chloroplasts and 32P-labelled rDNA restriction fragments of these regions for nuclease S1 and primer...

Data are presented consistent with the notion that the 23s ribosomal ribonucleic acid (rRNA) of Anacystis nidulans undergoes specific endonucleolytic cleavage in vivo, to produce two fragments with molecular weights of 0.88 x 10(6) and 0.17 x 10(6) daltons. Cleavage occurred at random after 23s rRNA formation and was stimulated by light in this organism, an obligately photoautotrophic unicellul...

Phytoplasma phylogenetics has focused primarily on sequences of the non-coding 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (16-23S ISR), and primers that enable amplification of these regions from all phytoplasmas by PCR are well established. In this study, primers based on the secA gene have been developed into a semi-nested PCR assay that results in a sequence of the expected ...

Characterization of the rRNA operon from the obligate intracellular bacterium Coxiella burnetii has determined the order of the rRNA genes to be 16S-23S-5S. A 444-bp intervening sequence (IVS) was identified to interrupt the 23S rRNA gene beginning at position 1176. The IVS is predicted to form a stem-loop structure formed by flanking inverted repeats, and the absence of intact 23S rRNA molecul...

A set of forty-nine Lactobacillus isolates recovered from the faecal swabs of different dog breeds viz. Pomeranian (12), Labrador (15) and mongrel/indigenous dogs (22) were subjected to Lactobacillus group-specific multiplex PCR corresponding to the 16S-23S rRNA intergenic spacer region (ISR) and its flanking 23S rRNA gene. Twenty-three (46.9%) isolates were found to be positive for Group IV; s...

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...

OBJECTIVES Clarithromycin is the key drug in the various treatment regimens of Mycobacterium avium complex (MAC) diseases, and is the only drug for which drug susceptibility has been shown to correlate with clinical response in these diseases. A point mutation at either positions 2058 or 2059 of the 23S rRNA gene has been reported to occur in high-level clarithromycin-resistant isolates. In thi...

In prokaryotes, the ribosomal gene locus contains three rRNA species: 16S, 23S and 5S. The potential of sequencing 16S rDNA of bacteria and archaea for establishing phylogenetic relationships and for use in molecular diagnostics is well-documented. Currently, over 3000 16S rRNA sequences are available in the databases. However, the potential of the 23S rRNA gene as a diagnostic tool has not bee...

OBJECTIVES This study was conducted to examine the role of the CmeABC efflux pump in decreasing the susceptibility of Campylobacter coli to macrolides and ketolides in the context of absence or presence of mutations in the 23S rRNA genes. METHODS The cmeB gene was inactivated in strains of C. coli showing two different patterns of erythromycin resistance (low or high level of resistance) asso...