Escherichia coli and Enterococcus spp. in Rainwater Tank Samples: Comparison of Culture-Based Methods and 23S rRNA Gene Quantitative PCR Assays

2012 ◽  
Vol 46 (20) ◽  
pp. 11370-11376 ◽  
Author(s):  
W. Ahmed ◽  
K. Richardson ◽  
J. P. S. Sidhu ◽  
S. Toze
Keyword(s):  
Escherichia Coli ◽  
Quantitative Pcr ◽  
23S Rrna ◽  
Rrna Gene ◽  
Rainwater Tank ◽  
Enterococcus Spp ◽  
23S Rrna Gene ◽  
Pcr Assays

scholarly journals Two New Point Mutations at A2062 Associated with Resistance to 16-Membered Macrolide Antibiotics in Mutant Strains ofMycoplasma hominis

2001 ◽  
Vol 45 (10) ◽  
pp. 2958-2960 ◽  
Author(s):  
Pio Maria Furneri ◽  
Giancarlo Rappazzo ◽  
Maria Pia Musumarra ◽  
Patrizia Di Pietro ◽  
Lucrezia S. Catania ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Mycoplasma Hominis ◽  
23S Rrna ◽  
Macrolide Antibiotics ◽  
Rrna Gene ◽  
In Vitro Exposure ◽  
Mutant Strains ◽  
23S Rrna Gene

ABSTRACT We describe two mutants of Mycoplasma hominis PG-21 which show resistance to 16-membered macrolides but susceptibility to lincosamides, obtained by in vitro exposure to increasing doses of josamycin. The 23S rRNA gene showed that each had a mutation (A2062G and A2062T) corresponding to nucleotide 2062 in Escherichia coli, which was associated with the acquired phenotype.

scholarly journals Intraspecific Diversity of the 23S rRNA Gene and the Spacer Region Downstream in Escherichia coli

1999 ◽  
Vol 181 (14) ◽  
pp. 4442-4442
Author(s):  
Ana I. Antón ◽  
Antonio J. Martínez-Murcia ◽  
Francisco Rodríguez-Valera
Keyword(s):  
Escherichia Coli ◽  
Intraspecific Diversity ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene

scholarly journals Mutations in a 23S rRNA Gene of Chlamydia trachomatis Associated with Resistance to Macrolides

2004 ◽  
Vol 48 (4) ◽  
pp. 1347-1349 ◽  
Author(s):  
O. Y. Misyurina ◽  
E. V. Chipitsyna ◽  
Y. P. Finashutina ◽  
V. N. Lazarev ◽  
T. A. Akopian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chlamydia Trachomatis ◽  
Gene Mutations ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
In Vitro Susceptibility ◽  
23S Rrna Gene ◽  
Mixed Populations

ABSTRACT For six clinical isolates of Chlamydia trachomatis, in vitro susceptibility to erythromycin, azithromycin, and josamycin has been determined. Four isolates were resistant to all the antibiotics and had the mutations A2058C and T2611C (Escherichia coli numbering) in the 23S rRNA gene. All the isolates had mixed populations of bacteria that did and did not carry 23S rRNA gene mutations.

scholarly journals Intraspecific Diversity of the 23S rRNA Gene and the Spacer Region Downstream in Escherichia coli

1999 ◽  
Vol 181 (9) ◽  
pp. 2703-2709 ◽  
Author(s):  
Ana I. Antón ◽  
Antonio J. Martínez-Murcia ◽  
Francisco Rodríguez-Valera
Keyword(s):  
Escherichia Coli ◽  
Gene Families ◽  
Intraspecific Diversity ◽  
Rrna Genes ◽  
23S Rrna ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Enzyme Electrophoresis ◽  
Single Mutation ◽  
23S Rrna Gene

ABSTRACT The molecular microevolution of the 23S rRNA gene (rrl) plus the spacer downstream has been studied by sequencing of different operons from some representative strains of the Escherichia coli ECOR collection. The rrl gene was fully sequenced in six strains showing a total of 67 polymorphic sites, a level of variation per nucleotide similar to that found for the 16S rRNA gene (rrs) in a previous study. The size of the gene was highly conserved (2902 to 2905 nucleotides). Most polymorphic sites were clustered in five secondary-structure helices. Those regions in a large number of operons were sequenced, and several variations were found. Sequences of the same helix from two different strains were often widely divergent, and no intermediate forms existed. Intercistronic variability was detected, although it seemed to be lower than for the rrs gene. The presence of two characteristic sequences was determined by PCR analysis throughout all of the strains of the ECOR collection, and some correlations with the multilocus enzyme electrophoresis clusters were detected. The mode of variation of the rrl gene seems to be quite similar to that of therrs gene. Homogenization of the gene families and transfer of sequences from different clonal lines could explain this pattern of variation detected; perhaps these factors are more relevant to evolution than single mutation. The spacer region between the 23S and 5S rRNA genes exhibited a highly polymorphic region, particularly at the 3′ end.

scholarly journals Detection and Quantification of Macrolide Resistance Mutations at Positions 2058 and 2059 of the 23S rRNA Gene by Pyrosequencing

2005 ◽  
Vol 49 (1) ◽  
pp. 457-460 ◽  
Author(s):  
Marjo Haanperä ◽  
Pentti Huovinen ◽  
Jari Jalava
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Streptococcus Pyogenes ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Resistance Mutations ◽  
23S Rrna Gene ◽  
Pyrosequencing Method ◽  
Detection And Quantification

ABSTRACT A pyrosequencing method for detection and quantification of macrolide resistance mutations at positions 2058 and 2059 (Escherichia coli numbering) of the 23S rRNA gene is described. The method was developed and tested for Streptococcus pneumoniae, Streptococcus pyogenes, Mycobacterium avium, Campylobacter jejuni, and Haemophilus influenzae.

scholarly journals Panel of 23S rRNA Gene-Based Real-Time PCR Assays for Improved Universal and Group-Specific Detection of Phytoplasmas

2009 ◽  
Vol 75 (9) ◽  
pp. 2945-2950 ◽  
Author(s):  
Jennifer Hodgetts ◽  
Neil Boonham ◽  
Rick Mumford ◽  
Matthew Dickinson
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Nested Pcr ◽  
Multiplex Assay ◽  
The Other ◽  
23S Rrna ◽  
Rrna Gene ◽  
Specific Detection ◽  
23S Rrna Gene ◽  
Pcr Assays

ABSTRACT Primers and probes based on the 23S rRNA gene have been utilized to design a range of real-time PCR assays for routine phytoplasma diagnostics. These assays have been authenticated as phytoplasma specific and shown to be at least as sensitive as nested PCR. A universal assay to detect all phytoplasmas has been developed, along with a multiplex assay to discriminate 16SrI group phytoplasmas from members of all of the other 16Sr groups. Assays for the 16SrII, 16SrIV, and 16SrXII groups have also been developed to confirm that the 23S rRNA gene can be used to design group-specific assays.

scholarly journals Molecular pathways to high-level azithromycin resistance in Neisseria gonorrhoeae

2021 ◽  
Author(s):  
J G E Laumen ◽  
S S Manoharan-Basil ◽  
E Verhoeven ◽  
S Abdellati ◽  
I De Baetselier ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Ribosomal Proteins ◽  
Efflux Pump ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene ◽  
Evolution Of Resistance ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance

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.

scholarly journals Molecular characterization of a ceftriaxone-resistant Neisseria gonorrhoeae strain found in Switzerland: a case report

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Konrad Egli ◽  
Anna Roditscheff ◽  
Ursula Flückiger ◽  
Martin Risch ◽  
Lorenz Risch ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Rrna Gene ◽  
Limited Information ◽  
Specific Pcr ◽  
Appropriate Treatment ◽  
23S Rrna Gene ◽  
Allele Type ◽  
Ciprofloxacin Resistance

Abstract Background The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones. Case presentation A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance. Conclusion The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.

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