scholarly journals Linezolid Resistance in Staphylococcus aureus: Gene Dosage Effect, Stability, Fitness Costs, and Cross-Resistances

2008 ◽  
Vol 52 (4) ◽  
pp. 1570-1572 ◽  
Author(s):  
Silke Besier ◽  
Albrecht Ludwig ◽  
Johannes Zander ◽  
Volker Brade ◽  
Thomas A. Wichelhaus
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Dosage ◽  
Single Point ◽  
23S Rrna ◽  
Cross Resistance ◽  
Single Point Mutation ◽  
Rrna Gene ◽  
Gene Dosage Effect ◽  
Linezolid Resistance ◽  
23S Rrna Gene

ABSTRACT Linezolid resistance in Staphylococcus aureus is typically associated with mutations in the 23S rRNA gene. Here we show that the accumulation of a single point mutation, G2576T, in the different copies of this gene causes stepwise increases in resistance, impairment of the biological fitness, and cross-resistance to quinupristin-dalfopristin and chloramphenicol.

scholarly journals Explaining the Bias in the 23S rRNA Gene Mutations Associated with Clarithromycin Resistance in Clinical Isolates ofHelicobacter pylori

1998 ◽  
Vol 42 (10) ◽  
pp. 2749-2751 ◽  
Author(s):  
Y. J. Debets-Ossenkopp ◽  
A. B. Brinkman ◽  
E. J. Kuipers ◽  
C. M. J. E. Vandenbroucke-Grauls ◽  
J. G. Kusters
Keyword(s):  
Growth Rate ◽  
Single Point ◽  
Gene Mutations ◽  
23S Rrna ◽  
Single Point Mutation ◽  
Rrna Gene ◽  
Clarithromycin Resistance ◽  
23S Rrna Gene ◽  
Stability Of Resistance ◽  
H Pylori

ABSTRACT A single point mutation in the 23S rRNA gene of Helicobacter pylori is known to confer resistance to clarithromycin. Most prevalent among clarithromycin-resistant clinical H. pyloriisolates are the mutations from A-2142 to G and A-2143 to G in the 23S rRNA gene. The bias in the 23S rRNA gene mutations conferring clarithromycin resistance may result from the higher MIC, stability of resistance, and growth rate found for the strains with the above-mentioned mutations.

scholarly journals Intrinsic Macrolide Resistance in Mycobacterium smegmatis Is Conferred by a Novel erm Gene, erm(38)

2003 ◽  
Vol 47 (10) ◽  
pp. 3053-3060 ◽  
Author(s):  
Kevin A. Nash
Keyword(s):  
Mycobacterium Smegmatis ◽  
Sequence Data ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
Rrna Gene ◽  
Mycobacterium Fortuitum ◽  
Knockout Mutant ◽  
23S Rrna Gene ◽  
High Level

ABSTRACT High-level, acquired macrolide resistance in mycobacteria is conferred by mutation within the 23S rRNA gene. However, several mycobacteria are naturally resistant to macrolides, including the Mycobacterium smegmatis group and Mycobacterium tuberculosis complex. Thus, the aim of this study was to characterize this resistance. Intrinsic macrolide resistance in M. smegmatis was inducible and showed cross-resistance to lincosamides but not to streptogramin B (i.e., ML resistance). A similar phenotype was found with Mycobacterium microti and macrolide-resistant Mycobacterium fortuitum. A search of the DNA sequence data for M. smegmatis strain mc2155 identified a novel erm gene, erm(38), and expression analysis showed that erm(38) RNA levels increased >10-fold after a 2-h incubation with macrolide. Inducible ML resistance was not expressed by an erm(38) knockout mutant, and complementation of this mutant with intact erm(38) in trans resulted in high-level ML resistance (e.g., clarithromycin MIC of >512 μg/ml). Thus, the results indicate that erm(38) confers the intrinsic ML resistance of M. smegmatis. Southern blot analysis with an erm(38)-specific probe indicated that a similar gene may be present in macrolide-resistant M. fortuitum. This finding, with the presence of the erm(37) gene (Rv1988) in the M. tuberculosis complex, suggests that such genes are widespread in mycobacteria with intrinsic macrolide resistance.

scholarly journals The reduced prevalence of macrolide resistance in Mycoplasma pneumoniae clinical isolates from pediatric patients in Beijing in 2016

2018 ◽  
Author(s):  
Xiujun Tian ◽  
Ran Wei ◽  
Junyan Shao ◽  
Hong Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Cross Resistance ◽  
Rrna Gene ◽  
Older Children ◽  
Infection Susceptibility ◽  
23S Rrna Gene ◽  
Beijing China ◽  
Different Levels

Older children especially from seven to thirteen years old are more prone to develop Mycoplasma pneumoniae (MP) infection; in winter children are more susceptible to infect with MP. In Beijing, China in 2016 the rates of macrolide resistance of MP were 69.48% (in total children), 61.59% (in outpatients) and 79.28% (in hospitalized patients), respectively. All the macrolide resistant isolates harbored A2063G or A2064G mutation in the 23S rRNA gene. Seven isolates showed a mixed infection. Susceptibility results showed that 73 isolates with the A2063G mutation demonstrated different levels resistance to erythromycin (MIC=8 to>256μg/ml), azithromycin (MIC=8 to>64μg/ml) and josamycin (MIC=2 to 8μg/ml). No cross-resistance was observed in the in the antibiotics of levofloxacin and tetracycline against MP.

scholarly journals Delayed Development of Linezolid Resistance in Staphylococcus aureus following Exposure to Low Levels of Antimicrobial Agents

2008 ◽  
Vol 52 (6) ◽  
pp. 1940-1944 ◽  
Author(s):  
Keith Miller ◽  
Alexander J. O'Neill ◽  
Mark H. Wilcox ◽  
Eileen Ingham ◽  
Ian Chopra
Keyword(s):  
Staphylococcus Aureus ◽  
Homologous Recombination ◽  
Antimicrobial Agents ◽  
Suppressive Effect ◽  
23S Rrna ◽  
Rrna Gene ◽  
Selection Window ◽  
23S Rrna Gene ◽  
Resistant Mutants ◽  
Selection Of

ABSTRACT The development of resistance to linezolid (LZD) in gram-positive bacteria depends on the mutation of a single 23S rRNA gene, followed by homologous recombination and gene conversion of the other alleles. We sought to inhibit this process in Staphylococcus aureus using a range of antibacterial agents, including some that suppress recombination. A model for the rapid selection of LZD resistance was developed which allowed the selection of LZD-resistant mutants with G2576T mutations in all five copies of the 23S rRNA gene following only 5 days of subculture. The emergence of LZD-resistant isolates was delayed by exposing cultures to low concentrations of various classes of antibiotics. All antibiotic classes were effective in delaying the selection of LZD-resistant mutants and, with the exception of fusidic acid (FUS) and rifampin (RIF), prolonged the selection window from 5 to ∼15 days. Inhibitors of DNA processing were no more effective than any other class of antibiotics at suppressing resistance development. However, the unrelated antimicrobials FUS and RIF were particularly effective at preventing the emergence of LZD resistance, prolonging the selection window from 5 to 25 days. The enhanced suppressive effect of FUS and RIF on the development of LZD resistance was lost in a recA-deficient host, suggesting that these drugs affect recA-dependent recombination. Furthermore, FUS and RIF were shown to be effective inhibitors of homologous recombination of a plasmid into the staphylococcal chromosome. We suggest that RIF or FUS in combination with LZD may have a role in preventing the emergence of LZD resistance.

scholarly journals Linezolid Resistance in SequentialStaphylococcus aureusIsolates Associated with a T2500A Mutation in the 23S rRNA Gene and Loss of a Single Copy of rRNA

2004 ◽  
Vol 190 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Venkata G. Meka ◽  
Satish K. Pillai ◽  
George Sakoulas ◽  
Christine Wennersten ◽  
Lata Venkataraman ◽  
...  
Keyword(s):  
Single Copy ◽  
23S Rrna ◽  
Rrna Gene ◽  
Linezolid Resistance ◽  
23S Rrna Gene

scholarly journals Rapid Detection and Estimation by Pyrosequencing of 23S rRNA Genes with a Single Nucleotide Polymorphism Conferring Linezolid Resistance in Enterococci

2003 ◽  
Vol 47 (11) ◽  
pp. 3620-3622 ◽  
Author(s):  
Alistair Sinclair ◽  
Catherine Arnold ◽  
Neil Woodford
Keyword(s):  
Fragment Length Polymorphism ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Linezolid Resistance ◽  
Gene Copies ◽  
23S Rrna Gene ◽  
23S Rrna Genes

ABSTRACT Pyrosequencing was used to detect rapidly and estimate the number of 23S rRNA genes with a G2576T mutation in 43 linezolid-resistant and -susceptible clinical isolates of enterococci. The method showed 100% concordance with PCR-restriction fragment length polymorphism for detecting isolates homozygous for either G2576 or T2576 or heterozygous for this mutation. A good correlation was found between linezolid MICs and the number of 23S rRNA gene copies carrying the mutation.

scholarly journals Deletion of One 23S rRNA Gene (rrl) Copy Contributes to the Development of Linezolid Resistance in Staphylococcus warneri

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Caroline Rouard ◽  
Florence Doucet-Populaire ◽  
Christelle Guillet-Caruba ◽  
Millie Villet ◽  
Nadège Bourgeois-Nicolaos
Keyword(s):  
23S Rrna ◽  
Rrna Gene ◽  
Staphylococcus Warneri ◽  
Linezolid Resistance ◽  
23S Rrna Gene

scholarly journals Improved Multiplex Polymerase Chain Reaction for Rapid Staphylococcus Aureus Detection in Meat and Milk Matrices

2016 ◽  
Vol 15 (1) ◽  
pp. 65-76
Author(s):  
Zuzana Šramková ◽  
Barbora Vidová ◽  
Andrej Godány
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Food Poisoning ◽  
Detection Sensitivity ◽  
23S Rrna ◽  
Rrna Gene ◽  
Chain Reaction ◽  
23S Rrna Gene ◽  
Polymerase Chain ◽  
Toxic Shock Syndrome Toxin

Abstract Staphylococcal food poisoning represents one of the most frequently occurring intoxications, caused by staphylococcal enterotoxins (SE-s) and staphylococcal enterotoxin-like proteins (SEl-s). Therefore, there is a need for rapid, sensitive and specific detection method for this human pathogen and its toxin genes in food matrices. The present work is focused on Staphylococcus aureus detection by a nonaplex polymerase chain reaction, which targets the 23S rRNA gene for identification of S. aureus at the species level, genes for classical SE-s (SEA, SEC, SED), new SE-s (SEH, SEI), SEl-s (SEK, SEL) and tsst-1 gene (toxic shock syndrome toxin). Primers were properly designed to avoid undesirable interactions and to create a reliably identifiable profile of amplicons when visualized in agarose gel. According to obtained results, this approach is able to reach the detection sensitivity of 12 colony forming units from milk and meat matrices without prior culturing and DNA extraction.

Characterization of Staphylococcus aureus Isolates from White-Brined Urfa Cheese

2011 ◽  
Vol 74 (11) ◽  
pp. 1788-1796 ◽  
Author(s):  
KURSAT KAV ◽  
RAMAZAN COL ◽  
MUSTAFA ARDIC
Keyword(s):  
Staphylococcus Aureus ◽  
Tandem Repeats ◽  
Genetic Relatedness ◽  
Food Poisoning ◽  
Rflp Analysis ◽  
23S Rrna ◽  
Enzyme Linked Immunosorbent Assay ◽  
Toxin Gene ◽  
Rrna Gene ◽  
23S Rrna Gene

The aim of this study was to investigate the presence of Staphylococcus aureus and staphylococcal enterotoxin (SE) genes in Urfa cheese samples and to characterize the enterotoxigenic potential of these isolates. From a total of 127 Urfa cheese samples, 53 isolates (from 41.7% of the samples) were identified by a species-specific PCR assay as S. aureus. Of these isolates, 40 (75.5%) gave positive PCR results for the 3′ end of the coa gene. The coa-positive S. aureus strains were characterized for their population levels and enterotoxigenic properties, including slime factor, β-lactamase, antibiotic susceptibilities, production of the classical SEs (SEA through SEE), in both cheese and liquid cultures by enzyme-linked immunosorbent assay (ELISA) and for the presence of specific genes, including classical SE genes (sea through see), mecA, femA, and spa, by PCR. The genetic relatedness among the coa-positive S. aureus isolates was investigated by PCR-based restriction fragment length polymorphism (RFLP) analysis and the 23S rRNA gene spacer. The 23S rRNA gene spacer and coa RFLP analysis using AluI and Hin6I revealed 14 different patterns. SEB, SEC, and SEA and SEE were detected by ELISA in three cheese samples. Fourteen S. aureus strains harbored enterotoxin genes sea through see, and three strains carried multiple toxin genes. The most commonly detected toxin gene was sec (25% of tested strains). Of the 40 analyzed S. aureus strains, 3 (7.5%) were mecA positive. Based on tandem repeats, four coa and spa types were identified. The results of this study indicate that S. aureus and SEs are present at significant levels in Urfa cheese. These toxins can cause staphylococcal food poisoning, creating a serious hazard for public health.

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