scholarly journals Elevated Linezolid Resistance in Clinical cfr-Positive Staphylococcus aureus Isolates Is Associated with Co-Occurring Mutations in Ribosomal Protein L3

2010 ◽  
Vol 54 (12) ◽  
pp. 5352-5355 ◽  
Author(s):  
Jeffrey B. Locke ◽  
Gracia Morales ◽  
Mark Hilgers ◽  
Kedar G. C. ◽  
Shahad Rahawi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
23S Rrna ◽  
Hospital Outbreak ◽  
Linezolid Resistance ◽  
Ribosomal Protein L3

ABSTRACT Resistance to linezolid (LZD) occurs through mutations in 23S rRNA and ribosomal proteins L3 and L4 or through methylation of 23S rRNA by Cfr. Here we report novel L3 mutations, ΔSer145/His146Tyr and ΔMet169-Gly174, co-occurring with cfr in LZD-resistant Staphylococcus aureus isolates recovered from a hospital outbreak in Madrid, Spain. LZD MIC values (16, 32, or 64 μg/ml) correlated with the presence and severity of the L3 mutation. All isolates had TR-700 (torezolid) MIC values of ≤2 μg/ml.

scholarly journals First Report ofcfr-Carrying Plasmids in the Pandemic Sequence Type 22 Methicillin-Resistant Staphylococcus aureus Staphylococcal Cassette ChromosomemecType IV Clone

2016 ◽  
Vol 60 (5) ◽  
pp. 3007-3015 ◽  
Author(s):  
Anna C. Shore ◽  
Alexandros Lazaris ◽  
Peter M. Kinnevey ◽  
Orla M. Brennan ◽  
Gráinne I. Brennan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ribosomal Proteins ◽  
Resistance Mechanisms ◽  
Sequence Type ◽  
23S Rrna ◽  
Methicillin Resistant ◽  
Content Type ◽  
First Report ◽  
Type Iv ◽  
Linezolid Resistance

ABSTRACTLinezolid is often the drug of last resort for serious methicillin-resistantStaphylococcus aureus(MRSA) infections. Linezolid resistance is mediated by mutations in 23S rRNA and genes for ribosomal proteins;cfr, encoding phenicol, lincosamide, oxazolidinone, pleuromutilin, and streptogramin A (PhLOPSA) resistance; its homologuecfr(B); oroptrA, conferring oxazolidinone and phenicol resistance. Linezolid resistance is rare inS. aureus, andcfris even rarer. This study investigated the clonality and linezolid resistance mechanisms of two MRSA isolates from patients in separate Irish hospitals. Isolates were subjected tocfrPCR, PhLOPSAsusceptibility testing, 23S rRNA PCR and sequencing, DNA microarray profiling,spatyping, pulsed-field gel electrophoresis (PFGE), plasmid curing, and conjugative transfer. Whole-genome sequencing was used for single-nucleotide variant (SNV) analysis, multilocus sequence typing, L protein mutation identification,cfrplasmid sequence analysis, andoptrAandcfr(B) detection. Isolates M12/0145 and M13/0401 exhibited linezolid MICs of 64 and 16 mg/liter, respectively, and harbored identical 23S rRNA and L22 mutations, but M12/0145 exhibited the mutation in 2/6 23S rRNA alleles, compared to 1/5 in M13/0401. Both isolates were sequence type 22 MRSA staphylococcal cassette chromosomemectype IV (ST22-MRSA-IV)/spatype t032 isolates, harboredcfr, exhibited the PhLOPSAphenotype, and lackedoptrAandcfr(B). They differed by five PFGE bands and 603 SNVs. Isolate M12/0145 harboredcfrandfexAon a 41-kb conjugative pSCFS3-type plasmid, whereas M13/0401 harboredcfrandlsa(B) on a novel 27-kb plasmid. This is the first report ofcfrin the pandemic ST22-MRSA-IV clone. Differentcfrplasmids and mutations associated with linezolid resistance in genotypically distinct ST22-MRSA-IV isolates highlight that prudent management of linezolid use is essential.

scholarly journals Dissemination of cfr-mediated linezolid resistance among Staphylococcus species isolated from a teaching hospital in Beijing, China

2018 ◽  
Vol 46 (9) ◽  
pp. 3884-3889 ◽  
Author(s):  
Jiyong Jian ◽  
Liang Chen ◽  
Zeqiang Xie ◽  
Man Zhang
Keyword(s):  
Staphylococcus Aureus ◽  
Teaching Hospital ◽  
Ribosomal Rna ◽  
Ribosomal Proteins ◽  
Methicillin Resistant ◽  
Linezolid Resistance ◽  
Ribosomal Protein L3 ◽  
Domain V ◽  
23S Ribosomal Rna ◽  
Beijing China

Objective The aim of the present study was to report the dissemination of cfr and fexA genes mediated by linezolid resistance among Staphylococcus species. Methods Three methicillin-resistant staphylococci that were collected from a teaching hospital in Beijing were identified as linezolid-resistant. These three staphylococci were Staphylococcus aureus, S. haemolyticus, and S. cohnii. Mutations in domain V of 23S ribosomal RNA, ribosomal proteins, and the cfr, fexA, and optrA genes were analysed. Results The three isolates had no mutations of 23S ribosomal RNA, but showed mutations in the cfr and fexA genes. Mutations in the gene for ribosomal protein L3, which resulted in the amino acid exchanges Gly108Glu, Ser158Phe, and Asp159Tyr, were identified in S. cohnii X4535. Conclusions This is the first report of the cfr gene in clinical linezolid-resistant methicillin-resistant S. aureus isolated from Beijing. L3 mutations coupled with the cfr and fexA genes may act synergistically. Potential transmissibility of this agent, even without prior exposure to linezolid, may have serious epidemiological repercussions.

scholarly journals First Report of cfr-Mediated Resistance to Linezolid in Human Staphylococcal Clinical Isolates Recovered in the United States

2008 ◽  
Vol 52 (6) ◽  
pp. 2244-2246 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Lalitagauri M. Deshpande ◽  
Mariana Castanheira ◽  
Joseph DiPersio ◽  
Michael A. Saubolle ◽  
...  
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Ribosomal Protein ◽  
Staphylococcus Epidermidis ◽  
The United States ◽  
Human Infection ◽  
Clinical Isolates ◽  
23S Rrna ◽  
First Report ◽  
Linezolid Resistance

ABSTRACT Linezolid resistance has dominantly been mediated by mutations in 23S rRNA or ribosomal protein L4 genes. Recently, cfr has demonstrated the ability to produce a phenotype of resistance to not only oxazolidinones, but also other antimicrobial classes (phenicols, lincosamides, pleuromutilins, and streptogramin A). We describe the first detection of cfr-mediated linezolid resistance in Staphylococcus aureus and Staphylococcus epidermidis recovered from human infection cases monitored during the 2007 LEADER Program.

scholarly journals Halobacterium cutirubrum ribosomes. Properties of the ribosomal proteins and ribonucleic acid

1972 ◽  
Vol 130 (1) ◽  
pp. 103-110 ◽  
Author(s):  
L. P. Visentin ◽  
C. Chow ◽  
A. T. Matheson ◽  
M. Yaguchi ◽  
F. Rollin
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Soluble Fraction ◽  
Ribosomal Subunit ◽  
23S Rrna ◽  
Core Particle ◽  
Fractionation Procedure ◽  
Additional Protein ◽  
70S Ribosome ◽  
Low Ionic Strength

1. The 30S ribosomal subunit of the extreme halophile Halobacterium cutirubrum is unstable and loses 75% of its ribosomal protein when the 70S ribosome is dissociated into the two subunits. A stable 30S subunit is obtained if the dissociation of the 70S particle is carried out in the presence of the soluble fraction. 2. A fractionation procedure was developed for the selective removal of groups of proteins from the 30S and 50S subunits. When the ribosomes, which are stable in 4m-K+ and 0.1m-Mg2+, were extracted with low-ionic-strength buffer 75–80% of the 30S proteins and 60–65% of the 50S proteins as well as the 5S rRNA were released. The proteins in this fraction are the most acidic of the H. cutirubrum ribosomal proteins. Further extraction with Li+–EDTA releases additional protein, leaving a core particle containing either 16S rRNA or 23S rRNA and about 5% of the total ribosomal protein. The amino acid composition, mobility on polyacrylamide gels at pH4.5 and 8.7, and the molecular-weight distribution of the various protein fractions were determined. 3. The s values of the rRNA are 5S, 16S and 23S. The C+G contents of the 16S and 23S rRNA were 56.1 and 58.8% respectively and these are higher than C+G contents of the corresponding Escherichia coli rRNA (53.8 and 54.1%).

scholarly journals In Vitro Selection of Resistance in Haemophilus influenzae by Amoxicillin-Clavulanate, Cefpodoxime, Cefprozil, Azithromycin, and Clarithromycin

2002 ◽  
Vol 46 (9) ◽  
pp. 2956-2962 ◽  
Author(s):  
Catherine Clark ◽  
Bülent Bozdogan ◽  
Mihaela Peric ◽  
Bonifacio Dewasse ◽  
Michael R. Jacobs ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
In Vitro Selection ◽  
Fold Increase ◽  
Single Step ◽  
23S Rrna ◽  
Gene Encoding ◽  
Amoxicillin Clavulanate

ABSTRACT Abilities of amoxicillin-clavulanate, cefpodoxime, cefprozil, azithromycin, and clarithromycin to select resistant mutants of Haemophilus influenzae were tested by multistep and single-step methodologies. For multistep studies, 10 random strains were tested: 5 of these were β-lactamase positive. After 50 daily subcultures in amoxicillin-clavulanate, MICs did not increase more than fourfold. However, cefprozil MICs increased eightfold for one strain. Clarithromycin and azithromycin gave a >4-fold increase in 8 and 10 strains after 14 to 46 and 20 to 50 days, respectively. Mutants selected by clarithromycin and azithromycin were associated with mutations in 23S rRNA and ribosomal proteins L4 and L22. Three mutants selected by clarithromycin or azithromycin had alterations in ribosomal protein L4, while five had alterations in ribosomal protein L22. Two mutants selected by azithromycin had mutations in the gene encoding 23S rRNA: one at position 2058 and the other at position 2059 (Escherichia coli numbering), with replacement of A by G. One clone selected by clarithromycin became hypersusceptible to macrolides. In single-step studies azithromycin and clarithromycin had the highest mutation rates, while amoxicillin-clavulanate had the lowest. All resistant clones were identical to parents as observed by pulsed-field gel electrophoresis. The MICs of azithromycin for azithromycin-resistant clones were 16 to >128 μg/ml, and those of clarithromycin for clarithromycin-resistant clones were 32 to >128 μg/ml in multistep studies. For strains selected by azithromycin, the MICs of clarithromycin were high and vice versa. After 50 daily subcultures in the presence of drugs, MICs of amoxicillin-clavulanate and cefpodoxime against H. influenzae did not rise more than fourfold, in contrast to cefprozil, azithromycin, and clarithromycin, whose MICs rose to variable degrees.

scholarly journals Resistance to Linezolid Caused by Modifications at Its Binding Site on the Ribosome

2011 ◽  
Vol 56 (2) ◽  
pp. 603-612 ◽  
Author(s):  
Katherine S. Long ◽  
Birte Vester
Keyword(s):  
Binding Site ◽  
Ribosomal Proteins ◽  
Resistance Mechanism ◽  
Ribosomal Subunit ◽  
Resistance Mechanisms ◽  
Drug Binding ◽  
23S Rrna ◽  
Detailed Knowledge ◽  
Linezolid Resistance ◽  
Almost All

ABSTRACTLinezolid is an oxazolidinone antibiotic in clinical use for the treatment of serious infections of resistant Gram-positive bacteria. It inhibits protein synthesis by binding to the peptidyl transferase center on the ribosome. Almost all known resistance mechanisms involve small alterations to the linezolid binding site, so this review will therefore focus on the various changes that can adversely affect drug binding and confer resistance. High-resolution structures of linezolid bound to the 50S ribosomal subunit show that it binds in a deep cleft that is surrounded by 23S rRNA nucleotides. Mutation of 23S rRNA has for some time been established as a linezolid resistance mechanism. Although ribosomal proteins L3 and L4 are located further away from the bound drug, mutations in specific regions of these proteins are increasingly being associated with linezolid resistance. However, very little evidence has been presented to confirm this. Furthermore, recent findings on the Cfr methyltransferase underscore the modification of 23S rRNA as a highly effective and transferable form of linezolid resistance. On a positive note, detailed knowledge of the linezolid binding site has facilitated the design of a new generation of oxazolidinones that show improved properties against the known resistance mechanisms.

scholarly journals Mutations within therplDGene of Linezolid-Nonsusceptible Streptococcus pneumoniae Strains Isolated in the United States

2014 ◽  
Vol 58 (4) ◽  
pp. 2459-2462 ◽  
Author(s):  
W. Dong ◽  
S. Chochua ◽  
L. McGee ◽  
D. Jackson ◽  
K. P. Klugman ◽  
...  
Keyword(s):  
United States ◽  
Streptococcus Pneumoniae ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Structural Changes ◽  
Binding Pocket ◽  
The United States ◽  
Target Site ◽  
23S Rrna ◽  
Content Type

ABSTRACTThree invasiveStreptococcus pneumoniaestrains nonsusceptible to linezolid were isolated in the United States between 2001 and 2012 from the CDC's Active Bacterial Core surveillance. Linezolid binds ribosomal proteins where structural changes within its target site may confer resistance. Our study identified mutations and deletions near the linezolid binding pocket of two of these strains within therplDgene, which encodes ribosomal protein L4. Mutations in the 23S rRNA alleles or therplVgene were not detected.

scholarly journals Inactivation of the Indigenous Methyltransferase RlmN in Staphylococcus aureus Increases Linezolid Resistance

2011 ◽  
Vol 55 (6) ◽  
pp. 2989-2991 ◽  
Author(s):  
Jacqueline M. LaMarre ◽  
Benjamin P. Howden ◽  
Alexander S. Mankin
Keyword(s):  
Staphylococcus Aureus ◽  
23S Rrna ◽  
Potential Mechanism ◽  
Content Type ◽  
Clinical Strains ◽  
Linezolid Resistance

ABSTRACTThe indigenous methyltransferase RlmN modifies A2503 in 23S rRNA. A recently describedrlmNmutation in a clinicalStaphylococcus aureusisolate decreases susceptibility to linezolid and was thought to increase the extent of A2503 modification. However, we show that the mutation in fact abolishes RlmN activity, resulting in a lack of A2503 modification. Since many mutations could inactivate therlmNgene, our findings unveil a potential mechanism for future linezolid resistance in clinical strains.

scholarly journals Control of Ribosomal Protein L1 Synthesis in Mesophilic and Thermophilic Archaea

Genetics ◽  
1999 ◽  
Vol 152 (4) ◽  
pp. 1363-1372
Author(s):  
Alexander Kraft ◽  
Christina Lutz ◽  
Arno Lingenhel ◽  
Peter Gröbner ◽  
Wolfgang Piendl
Keyword(s):  
Ribosomal Protein ◽  
Binding Site ◽  
Structural Gene ◽  
Ribosomal Proteins ◽  
Halophilic Archaea ◽  
Peptide Bond ◽  
Target Site ◽  
Start Codon ◽  
23S Rrna ◽  
Ribosomal Protein Synthesis

Abstract The mechanisms for the control of ribosomal protein synthesis have been characterized in detail in Eukarya and in Bacteria. In Archaea, only the regulation of the MvaL1 operon (encoding ribosomal proteins MvaL1, MvaL10, and MvaL12) of the mesophilic Methanococcus vannielii has been extensively investigated. As in Bacteria, regulation takes place at the level of translation. The regulator protein MvaL1 binds preferentially to its binding site on the 23S rRNA, and, when in excess, binds to the regulatory target site on its mRNA and thus inhibits translation of all three cistrons of the operon. The regulatory binding site on the mRNA, a structural mimic of the respective binding site on the 23S rRNA, is located within the structural gene about 30 nucleotides downstream of the ATG start codon. MvaL1 blocks a step before or at the formation of the first peptide bond of MvaL1. Here we demonstrate that a similar regulatory mechanism exists in the thermophilic M. thermolithotrophicus and M. jannaschii. The L1 gene is cotranscribed together with the L10 and L11 gene, in all genera of the Euryarchaeota branch of the Archaea studied so far. A potential regulatory L1 binding site located within the structural gene, as in Methanococcus, was found in Methanobacterium thermoautotrophicum and in Pyrococcus horikoshii. In contrast, in Archaeoglobus fulgidus a typical L1 binding site is located in the untranslated leader of the L1 gene as described for the halophilic Archaea. In Sulfolobus, a member of the Crenarchaeota, the L1 gene is part of a long transcript (encoding SecE, NusG, L11, L1, L10, L12). A previously suggested regulatory L1 target site located within the L11 structural gene could not be confirmed as an L1 binding site.

scholarly journals Emergence of cfr-Mediated Linezolid Resistance in Staphylococcus aureus Isolated from Pig Carcasses

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 769
Author(s):  
Hee Young Kang ◽  
Dong Chan Moon ◽  
Abraham Fikru Mechesso ◽  
Ji-Hyun Choi ◽  
Su-Jeong Kim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ribosomal Proteins ◽  
Meca Gene ◽  
Animal Products ◽  
Chloramphenicol Resistance ◽  
Linezolid Resistance ◽  
Pig Carcasses ◽  
High Level ◽  
23S Ribosomal Rna ◽  
Encoding Genes

Altogether, 2547 Staphylococcus aureus isolated from cattle (n = 382), pig (n = 1077), and chicken carcasses (n = 1088) during 2010–2017 were investigated for linezolid resistance and were further characterized using molecular methods. We identified linezolid resistance in only 2.3% of pig carcass isolates. The linezolid-resistant (LR) isolates presented resistance to multiple antimicrobials, including chloramphenicol, clindamycin, and tiamulin. Molecular investigation exhibited no mutations in the 23S ribosomal RNA. Nevertheless, we found mutations in ribosomal proteins rplC (G121A) and rplD (C353T) in one and seven LR strains, respectively. All the LR isolates carried the multi-resistance gene cfr, and six of them co-carried the mecA gene. Additionally, all the LR isolates co-carried the phenicol exporter gene, fexA, and presented a high level of chloramphenicol resistance. LR S. aureus isolates represented 10 genotypes, including major genotypes ST433-t318, ST541-t034, ST5-t002, and ST9-t337. Staphylococcal enterotoxin and leukotoxin-encoding genes, alone or in combination, were detected in 68% of LR isolates. Isolates from different farms presented identical or different pulsed-field gel electrophoresis patterns. Collectively, toxigenic and LR S. aureus strains pose a crisis for public health. This study is the first to describe the mechanism of linezolid resistance in S. aureus isolated from food animal products in Korea.

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