scholarly journals Amplification and Direct Sequence Analysis of the 23S rRNA Gene from Thermophilic Bacteria

BioTechniques ◽  
2001 ◽  
Vol 30 (2) ◽  
pp. 414-420 ◽  
Author(s):  
Ashraf Ibrahim ◽  
Jacob Hofman-Bang ◽  
Birgitte K. Ahring
1999 ◽  
Vol 37 (3) ◽  
pp. 575-580 ◽  
Author(s):  
Karin D. E. Everett ◽  
Linda J. Hornung ◽  
Arthur A. Andersen

Few identification methods will rapidly or specifically detect all bacteria in the order Chlamydiales, familyChlamydiaceae. In this study, three PCR tests based on sequence data from over 48 chlamydial strains were developed for identification of these bacteria. Two tests exclusively recognized theChlamydiaceae: a multiplex test targeting theompA gene and the rRNA intergenic spacer and a TaqMan test targeting the 23S ribosomal DNA. The multiplex test was able to detect as few as 200 inclusion-forming units (IFU), while the TaqMan test could detect 2 IFU. The amplicons produced in these tests ranged from 132 to 320 bp in length. The third test, targeting the 23S rRNA gene, produced a 600-bp amplicon from strains belonging to several families in the order Chlamydiales. Direct sequence analysis of this amplicon has facilitated the identification of new chlamydial strains. These three tests permit ready identification of chlamydiae for diagnostic and epidemiologic study. The specificity of these tests indicates that they might also be used to identify chlamydiae without culture or isolation.


2009 ◽  
Vol 47 (4) ◽  
pp. 1281-1282 ◽  
Author(s):  
R. Zarrilli ◽  
M. Giannouli ◽  
A. Di Popolo ◽  
F. Tomasone ◽  
Y.-W. Chu ◽  
...  

2007 ◽  
Vol 57 (2) ◽  
pp. 213-218 ◽  
Author(s):  
H. Moyaert ◽  
A. Decostere ◽  
P. Vandamme ◽  
L. Debruyne ◽  
J. Mast ◽  
...  

Gram-negative, curved, motile bacteria (strains EqF1T and EqF2) were isolated from faecal samples from two clinically healthy horses. Both strains possessed a single, monopolar, sheathed flagellum and were urease-negative. The novel strains grew at 37 °C under microaerobic conditions and were positive for oxidase, catalase and alkaline phosphatase activities. The isolates reduced nitrate to nitrite, but γ-glutamyl transpeptidase activity was not detected. The novel isolates did not grow at 42 °C or on media containing 1 % glycine. They were resistant to cephalotin and nalidixic acid and susceptible to metronidazole. Analysis of the 16S and 23S rRNA gene sequences of the two novel strains identified them as representing a single species within the genus Helicobacter. In terms of 16S rRNA gene sequence similarity, Helicobacter pullorum and Helicobacter canadensis were the most closely related species (98 % similarity). 23S rRNA gene sequence analysis also classified strains EqF1T and EqF2 within the enterohepatic division of the genus Helicobacter, but only 94 % similarity was detected with H. pullorum and H. canadensis, which are helicobacters with unsheathed flagella. The most closely related species in terms of 23S rRNA gene sequence similarity was Helicobacter canis (95 %). Numerical analysis of whole-cell protein extracts by SDS-PAGE was performed and the novel isolates were clearly differentiated from H. pullorum, H. canadensis, H. canis and other species of the genus Helicobacter. This finding was also confirmed by sequence analysis of the hsp60 gene. On the basis of these genetic, biochemical and protein data, the isolates are classified as representing a novel species, for which the name Helicobacter equorum sp. nov. is proposed (type strain EqF1T=LMG 23362T=CCUG 52199T).


Author(s):  
J G E Laumen ◽  
S S Manoharan-Basil ◽  
E Verhoeven ◽  
S Abdellati ◽  
I De Baetselier ◽  
...  

Abstract Background The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide. Objectives To characterize the genetic pathways leading to high-level azithromycin resistance. Methods A customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. We tracked stepwise evolution of resistance by whole genome sequencing. Results Within 26 days, all cultures evolved high-level azithromycin resistance. Typically, the first step towards resistance was found in transitory mutations in genes rplD, rplV and rpmH (encoding the ribosomal proteins L4, L22 and L34 respectively), followed by mutations in the MtrCDE-encoded efflux pump and the 23S rRNA gene. Low- to high-level resistance was associated with mutations in the ribosomal proteins and MtrCDE efflux pump. However, high-level resistance was consistently associated with mutations in the 23S ribosomal RNA, mainly the well-known A2059G and C2611T mutations, but also at position A2058G. Conclusions This study enabled us to track previously reported mutations and identify novel mutations in ribosomal proteins (L4, L22 and L34) that may play a role in the genesis of azithromycin resistance in N. gonorrhoeae.


Sign in / Sign up

Export Citation Format

Share Document