scholarly journals Retapamulin Inhibition of Translation and 50S Ribosomal Subunit Formation in Staphylococcus aureus Cells

2007 ◽  
Vol 51 (9) ◽  
pp. 3385-3387 ◽  
Author(s):  
W. Scott Champney ◽  
Ward K. Rodgers
Keyword(s):  
Staphylococcus Aureus ◽  
16S Rrna ◽  
Cell Viability ◽  
Protein Biosynthesis ◽  
Ribosomal Subunit ◽  
Inhibitory Effect ◽  
23S Rrna ◽  
Specific Inhibition ◽  
Methicillin Resistant

ABSTRACT Retapamulin inhibited protein biosynthesis and cell viability in methicillin-sensitive and methicillin-resistant Staphylococcus aureus organisms. A specific inhibitory effect on 50S ribosomal subunit formation was also found. Pulse-chase labeling experiments confirmed the specific inhibition of 50S subunit biogenesis. Turnover of 23S rRNA was found, with no effect on 16S rRNA amounts.

scholarly journals Solithromycin Inhibition of Protein Synthesis and Ribosome Biogenesis in Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae

2013 ◽  
Vol 57 (4) ◽  
pp. 1632-1637 ◽  
Author(s):  
Ward Rodgers ◽  
Ashley D. Frazier ◽  
W. Scott Champney
Keyword(s):  
Staphylococcus Aureus ◽  
Protein Synthesis ◽  
Streptococcus Pneumoniae ◽  
Haemophilus Influenzae ◽  
Ribosome Biogenesis ◽  
Antimicrobial Agents ◽  
Protein Biosynthesis ◽  
Ribosomal Subunit ◽  
23S Rrna ◽  
Content Type

ABSTRACTThe continuing increase in antibiotic-resistant microorganisms is driving the search for new antibiotic targets and improved antimicrobial agents. Ketolides are semisynthetic derivatives of macrolide antibiotics, which are effective against certain resistant organisms. Solithromycin (CEM-101) is a novel fluoroketolide with improved antimicrobial effectiveness. This compound binds to the large 50S subunit of the ribosome and inhibits protein biosynthesis. Like other ketolides, it should impair bacterial ribosomal subunit formation. This mechanism of action was examined in strains ofStreptococcus pneumoniae,Staphylococcus aureus, andHaemophilus influenzae. The mean 50% inhibitory concentrations (IC50s) for solithromycin inhibition of cell viability, protein synthesis, and growth rate were 7.5, 40, and 125 ng/ml forStreptococcus pneumoniae,Staphylococcus aureus, andHaemophilus influenzae, respectively. The net formation of the 50S subunit was reduced in all three organisms, with IC50s similar to those given above. The rates of 50S subunit formation measured by a pulse-chase labeling procedure were reduced by 75% in cells growing at the IC50of solithromycin. Turnover of 23S rRNA was stimulated by solithromycin as well. Solithromycin was found to be a particularly effective antimicrobial agent, with IC50s comparable to those of telithromycin and significantly better than those of azithromycin and clarithromycin in these three microorganisms.

scholarly journals Genetic Environment and Stability ofcfrin Methicillin-Resistant Staphylococcus aureus CM05

2011 ◽  
Vol 56 (1) ◽  
pp. 332-340 ◽  
Author(s):  
Jeffrey B. Locke ◽  
Shahad Rahawi ◽  
Jacqueline LaMarre ◽  
Alexander S. Mankin ◽  
Karen Joy Shaw
Keyword(s):  
Staphylococcus Aureus ◽  
Recombination Event ◽  
Sequence Similarity ◽  
Ribosomal Subunit ◽  
23S Rrna ◽  
Broad Host Range ◽  
Chromosomal Locus ◽  
Methicillin Resistant ◽  
Content Type ◽  
Fitness Advantage

ABSTRACTThe Cfr methyltransferase confers resistance to many 50S ribosomal subunit-targeted antibiotics, including linezolid (LZD), via methylation of the 23S rRNA base A2503 in the peptidyl transferase center. Methicillin-resistantStaphylococcus aureusstrain CM05 is the first clinical isolate documented to carrycfr. Whilecfris typically plasmid borne, in CM05 it is located on the chromosome and is coexpressed withermBas part of themlroperon. Here we evaluated the chromosomal locus, association with mobile genetic elements, and stability of thecfrinsertion region in CM05. Thecfr-containingmlroperon is located within a 15.5-kb plasmid-like insertion into 23S rRNA allele 4. The region surrounding thecfrgene has a high degree of sequence similarity to the broad-host-range toxin/antitoxin multidrug resistance plasmid pSM19035, including a secondermBgene downstream of themlrlocus andistAS-istBS. Analysis of several individual CM05 colonies revealed two distinct populations for which LZD MICs were either 8 or 2 μg/ml. In the LZDscolonies (designated CM05Δ), a recombination event involving the twoermBgenes had occurred, resulting in the deletion ofcfrand the 3′ flanking region (cfr-istAS-istBS-ermB). The fitness advantage of CM05Δ over CM05 (though not likely due to thecfrdeletion itself) results in the predominance of CM05Δ in the absence of selective pressure. Minicircles resulting from theermBrecombination event and the novel association ofcfrwith the pSM19035 plasmid system support the potential for the continued dissemination ofcfr.

scholarly journals A bacteriocin-based antimicrobial formulation to effectively disrupt the cell viability of methicillin-resistant Staphylococcus aureus (MRSA) biofilms

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Christian Kranjec ◽  
Kirill V. Ovchinnikov ◽  
Torstein Grønseth ◽  
Kumar Ebineshan ◽  
Aparna Srikantam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Viability ◽  
Cell Damage ◽  
Penicillin G ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Lactam Antibiotic ◽  
Mrsa Strains ◽  
Therapeutic Tools

AbstractAntibiotic-resistant and biofilm-associated infections brought about by methicillin-resistant Staphylococcus aureus (MRSA) strains is a pressing issue both inside as well as outside nosocomial environments worldwide. Here, we show that a combination of two bacteriocins with distinct structural and functional characteristics, garvicin KS, and micrococcin P1, showed a synergetic antibacterial activity against biofilms produced in vitro by S. aureus, including several MRSA strains. In addition, this bacteriocin-based antimicrobial combination showed the ability to restore the sensitivity of the highly resilient MRSA strain ATCC 33591 to the β-lactam antibiotic penicillin G. By using a combination of bacterial cell metabolic assays, confocal and scanning electron microscopy, we show that the combination between garvicin KS, micrococcin P1, and penicillin G potently inhibit cell viability within S. aureus biofilms by causing severe cell damage. Together these data indicate that bacteriocins can be valuable therapeutic tools in the fight against biofilm-associated MRSA infections.

Polymerase Chain Reaction for the Rapid Detection of Cerebrospinal Fluid Shunt or Ventriculostomy Infections

Neurosurgery ◽  
2005 ◽  
Vol 57 (6) ◽  
pp. 1237-1243 ◽  
Author(s):  
Jason T. Banks ◽  
Suman Bharara ◽  
R Shane Tubbs ◽  
Charles L. Wolff ◽  
G Yancey Gillespie ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Cerebrospinal Fluid ◽  
16S Rrna ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Propionibacterium Acnes ◽  
Chain Reaction ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Polymerase Chain

AbstractOBJECTIVE:Infection after cerebrospinal fluid (CSF) shunts or ventriculostomies is a common complication associated with significant morbidity and mortality. Polymerase chain reaction (PCR) is a powerful molecular technique that allows rapid and precise amplification of bacterial deoxyribonucleic acid (DNA) and has proven a powerful tool in the detection of a wide variety of clinically important infectious diseases. We analyzed specimens of CSF derived from ventriculoperitoneal shunts or external ventricular drains by using both conventional cultures and PCR and report herein our preliminary results.METHODS:We selected 86 CSF samples from adult patients who underwent either shunt tap or routine surveillance cultures of their ventriculostomy. These specimens were chosen from a larger group of 300 specimens that were routinely collected (many serially) in our clinical practice. They were chosen because clinical suspicion of infection was increased because of either patient signs and symptoms (fever, stiff neck, lethargy, worsening neurological examination) or preliminary laboratory analysis of CSF data (increased white blood cell count, increased protein level, decreased glucose). We considered this subgroup optimal to efficiently initiate our investigation of the correlation of PCR and culture results. CSF was increased by using standard culture techniques and by using PCR. Samples of CSF that were to undergo PCR had DNA extracted, purified, and amplified for 16S rRNA using primers 16S-Forward and 16S-Reverse of conserved sequence regions of all bacteria. DNA was PCR-amplified for 30 cycles. One microliter of the first PCR product was subjected to nested PCR using primers specific for gram-positive and gram-negative bacteria. Samples were also subjected to PCR amplification for specific detection of Propionibacterium acnes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus using specific primers for 16S rRNA Propionibacterium, nuclease gene of Staphylococcus, and Mec gene of methicillin-resistant Staphylococcus aureus.RESULTS:For 18 of 86 specimens (21%), both the culture and PCR were positive. For 30 of 86 specimens (35%), both the PCR and culture results were negative. For 42 of 86 specimens (49%), cultures were negative and PCR was positive. There were no positive culture results with negative PCR results. Most negative culture/positive PCR cases occurred after prolonged intravenous antibiotics. Of the 56 PCR-positive specimens, 30 were positive for Propionibacterium acnes, whereas 40 were positive for Staphylococcus aureus. Of the Staphylococcus aureus-positive specimens, two were positive for methicillin resistant-Staphylococcus aureus. Among the 56 PCR-positive specimens, 30 were positive for both Propionibacterium acnes and Staphylococcus aureus; gram-negative organisms were not detected by any method in these specimens.CONCLUSION:These preliminary data suggest that PCR is a highly sensitive, rapid, and potentially promising modality for the detection and treatment of CSF shunt ventriculostomy infection.

scholarly journals Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Agathe Boudet ◽  
Pauline Sorlin ◽  
Cassandra Pouget ◽  
Raphaël Chiron ◽  
Jean-Philippe Lavigne ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Ring Test ◽  
Methicillin Resistant ◽  
Lung Dysfunction ◽  
Chronic Colonization ◽  
Strain Dependent

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.

scholarly journals Identifikasi Molekuler Bakteri Staphylococcus sp. dan Staphylococcus aureus Penyebab Mastitis Subklinis pada Ternak Kambing Perah

2021 ◽  
Vol 39 (2) ◽  
pp. 151
Author(s):  
Clara Ajeng Artdita ◽  
Fatkhanuddin Aziz ◽  
Nurulia Hidayah ◽  
Achmad Fauzi ◽  
Triastuti Septi Wulandari ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
23S Rrna ◽  
Chain Reaction ◽  
Methicillin Resistant ◽  
Polymerase Chain

Mastitis merupakan radang pada glandula mammae (ambing) ternak perah. Mastitis tipe subklinis sering dikaitkan pada kejadian mastitis di peternakan ruminansia kecil seperti kambing perah (kambing Peranakan Etawah, Saanen, dan Sapera). Patogen utama yang berperan dalam kejadian mastitis ini adalah genus Staphylococcus. Tujuan penelitian adalah untuk melakukan identifikasi bakteri Staphylococcus sp. dan Staphylococcus aureus sebagai penyebab mastitis subklinis pada kambing perah dengan menggunakan metode polymerase  chain reaction (PCR). Tahapan metode yang dilakukan adalah ekstraksi DNA dengan teknik spin-collumn system terhadap 26 isolat bakteri yang telah dilakukan uji biokimia sebelumnya dan amplifikasi gen spesifik 23s rRNA Staphylococcus sp. dan Staphylococcus aureus, serta methicillin resistant Staphylococcus aureus (MRSA), dilanjutkan dengan visualisasi menggunakan UV-transluminator. Hasil menunjukkan bahwa sebanyak 12 isolat sampel teridentifikasi Staphylococcus sp. dan 1 diantaranya teridentifikasi Staphylococcus aureus. Isolat yang teridentifikasi Staphylococcus aureus bukan termasuk MRSA. 

scholarly journals PSV-32 Influence of chlorate and chlorate plus molybdate on the growth of multi-drug resistant staphylococci

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 295-295
Author(s):  
Oscar Ruiz ◽  
Yamicela Castillo-Castillo ◽  
Robin Anderson ◽  
Michael E Hume ◽  
Claudio Arzola ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Nitrate Reductase ◽  
Growth Rates ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Specific Growth ◽  
Brain Heart Infusion ◽  
Inhibitory Effect ◽  
Drug Resistant ◽  
Methicillin Resistant ◽  
Specific Growth Rates

Abstract This study was conducted to determine the effects of chlorate, a metabolic precursor of the bactericide chlorite, when administered without or with molybdate, an essential component of a co-enzyme contributing to nitrate reductase conversion of chlorate to chlorite, against methicillin-resistant staphylococci, important mastitic-pathogens of livestock. Two methicillin-resistant Staphylococcus aureus (strains CP and 49521) were individually cultured for 12 h at 39o C in nitrate-supplemented (5 mM) ½-strength Brain Heart Infusion broth (10 mL/tube) treated without (control) or with 5 mM chlorate (CL) or 5 mM chlorate plus 1 mM molybdate (CLMO). Control and treated cultures were incubated anaerobically in triplicate and growth was measured via absorbance at 600 nm. An analysis of variance revealed an inhibitory effect of treatments (P < 0.05) on maximum absorbances observed after the 12-h incubation, with maximum absorbances for CP (1.22, 0.10, and 0.46; SEM = 0.12) and 49521 (1.24, 0.22 and 0.06, SEM = 0.09) being higher in controls than in CL- and CLMO-treated cultures, respectively. Similarly, mean specific growth rates of S. aureus CP and 49521 were inhibited (P < 0.05) by both treatments during the first 6 h of growth, with rates being most rapid in control cultures, intermediate in CLMO-treated cultures and slowest in CL-treated cultures (0.68, 0.27 and 0.03 h-1, SEM= 0.15; and 0.92, 0.47 and 0.09 h-1, SEM = 0.08; for CP and 40521, respectively). Growth rates did not differ (P > 0.05) between controls or treatments during the last 6 h of incubation, averaging 0.74 and 0.75 h-1 for both CP and 49521 (SEM = 0.20 and 0.22, respectively). These results confirm that chlorate treatment inhibits methicillin-resistant Staphylococcus aureus strains CP and 49521 although moderate adaption by these strains began to occur after 6 h incubation which, contrary to expectation, was not overcome by co-treatment with molybdate.

scholarly journals Linezolid-Resistant Staphylococcus aureus Strain 1128105, the First Known Clinical Isolate Possessing thecfrMultidrug Resistance Gene

2014 ◽  
Vol 58 (11) ◽  
pp. 6592-6598 ◽  
Author(s):  
Jeffrey B. Locke ◽  
Douglas E. Zuill ◽  
Caitlyn R. Scharn ◽  
Jennifer Deane ◽  
Daniel F. Sahm ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
Aureus Strain ◽  
23S Rrna ◽  
Surveillance Program ◽  
Rrna Gene ◽  
Multidrug Resistance Gene ◽  
Content Type

ABSTRACTThe Cfr methyltransferase confers resistance to six classes of drugs which target the peptidyl transferase center of the 50S ribosomal subunit, including some oxazolidinones, such as linezolid (LZD). The mobilecfrgene was identified in European veterinary isolates from the late 1990s, although the earliest report of a clinicalcfr-positive strain was the 2005 Colombian methicillin-resistantStaphylococcus aureus(MRSA) isolate CM05. Here, through retrospective analysis of LZDrclinical strains from a U.S. surveillance program, we identified acfr-positive MRSA isolate, 1128105, from January 2005, predating CM05 by 5 months. Molecular typing of 1128105 revealed a unique pulsed-field gel electrophoresis (PFGE) profile most similar to that of USA100,spatype t002, and multilocus sequence type 5 (ST5). In addition tocfr, LZD resistance in 1128105 is partially attributed to the presence of a single copy of the 23S rRNA gene mutation T2500A. Transformation of the ∼37-kb conjugative p1128105cfr-bearing plasmid from 1128105 intoS. aureusATCC 29213 background strains was successful in recapitulating the Cfr antibiogram, as well as resistance to aminoglycosides and trimethoprim. A 7-kbcfr-containing region of p1128105 possessed sequence nearly identical to that found in the Chinese veterinaryProteus vulgarisisolate PV-01 and in U.S. clinicalS. aureusisolate 1900, although the presence of IS431-like sequences is unique to p1128105. Thecfrgene environment in this early clinicalcfr-positive isolate has now been identified in Gram-positive and Gram-negative strains of clinical and veterinary origin and has been associated with multiple mobile elements, highlighting the versatility of this multidrug resistance gene and its potential for further dissemination.

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.

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