Evaluation of the MRSA/SA ELITe MGB assay for the detection of Staphylococcus aureus in bone and joint infections

2021 ◽  
Author(s):  
R. Labetoulle ◽  
J. Rigaill ◽  
M. Lleres-Vadeboin ◽  
F. Grattard ◽  
B. Pozzetto ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
16S Rrna ◽  
Molecular Detection ◽  
Limit Of Detection ◽  
Joint Infections ◽  
Efficient Management ◽  
Therapeutic Decisions ◽  
Synovial Fluids ◽  
Amplification Assay ◽  
One Year

Bone and joints infections represent a potentially devastating complication of prosthetic orthopaedic joint replacement, thus requiring both rapid and appropriate antibiotic treatment. Staphylococcus aureus is one of the most frequent pathogens involved in this pathology. Being able to assert its presence is the first step of patients’ efficient management. This monocenter study was aimed at evaluating the MRSA/SA ELITe MGB assay for the molecular detection of S. aureus and methicillin-resistant S. aureus (MRSAin bone and joint biopsies and synovial fluids. This test together with conventional techniques including standard cultures and 16S rRNA amplification assay were performed on 208 successive perioperative samples collected prospectively for one year from 129 patients. Using conventional techniques, a microbial pathogen was detected in 76 samples from 58 patients, out of which 40 were identified as S. aureus . The limit of detection (LODof the MRSA/SA ELITe MGB assay was experimentally determined for bone and joint biopsies and synovial fluids using negative samples spiked with S. aureus ATCC43300. The sensitivity of S. aureus detection with the MRSA/SA ELITe MGB assay was 82.5% (33/40 samplesand 97.5% (39/40 samplesusing manufacturer’s LOD and experimentally determined LOD respectively. Interestingly using the osteo-articular specific LOD, 15 additional samples were detected positive for S. aureus DNA with the MRSA/SA ELITe MGB assay; in all cases, those samples were taken from patients considered to be infected with S. aureus according to their clinical and microbiological records. The results were available within 24h, which could help to shorten the therapeutic decisions.

scholarly journals First insights into molecular basis identification of 16 s ribosomal RNA gene of Staphylococcus aureus isolated from Sudan

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Manal A. Gumaa ◽  
Abeer Babiker Idris ◽  
N. E. Bilal ◽  
Mohamed A. Hassan
Keyword(s):  
Staphylococcus Aureus ◽  
16S Rrna ◽  
Ribosomal Rna ◽  
Molecular Basis ◽  
Molecular Detection ◽  
Rrna Gene ◽  
Wound Infections ◽  
Resistant Phenotype ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Abstract Objective In this study, we analyzed the molecular evolution of Staphylococcus aureus isolates using 16S rRNA gene and phylogenetic analysis to detect the prevalence of S. aureus infections in Sudan. Results Molecular detection of S. aureus has shown that 20 (43.47%) of patients were positive for S. aureus. The phylogenetic tree of 16S rRNA sequences was divided into three lineages of S. aureus isolates detected from wound infections in Sudan. Nucleotides base-pair substitution was appeared at position 249. This mutation do not linked with Macrolides, Lincosamides and Streptogramines b resistant phenotype. Further studies should investigate the effect of that mutation on resistance to other antibiotics.

scholarly journals First insights into Molecular basis Identification of 16s Ribosomal RNA Gene of Staphylococcus aureus Isolated from Sudan

2021 ◽  
Author(s):  
Manal Abdalla Gumaa ◽  
Abeer Babiker Idris ◽  
Nasr aldin Bilal Mohamed ◽  
Mohamed Ahmed Hassan
Keyword(s):  
Staphylococcus Aureus ◽  
16S Rrna ◽  
Ribosomal Rna ◽  
Molecular Detection ◽  
Rrna Gene ◽  
Wound Infections ◽  
Resistant Phenotype ◽  
16S Ribosomal Rna Gene ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Abstract Objective: In this study, we analyzed the molecular evolution of Staphylococcus aureus isolates using 16S rRNA gene and phylogenetic analysis to detect the prevalence of S. aureus infections in Sudan. Results: Molecular detection of S.aureus has shown that 20(43.47%) of patients were positive for S.aureus. The phylogenetic tree of 16S rRNA sequences was divided into three lineages of S.aureus isolates detected from wound infections in Sudan. Nucleotides base-pair substitution was appeared at position 249. This mutation do not linked with Macrolides, Lincosamides and Streptogramines b resistant phenotype. Further studies should investigate the effect of that mutation on resistance to other antibiotics.

Isothermal amplification assay for visual on-site detection of Staphylococcus aureus in Chevon

2021 ◽  
pp. 1-16
Author(s):  
Govindarajan Bhuvana Priya ◽  
Ravi Kant Agrawal ◽  
Arockiasamy Arun Prince Milton ◽  
Sanjod Kumar Mendiratta ◽  
Bhoj Raj Singh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Isothermal Amplification ◽  
Amplification Assay

scholarly journals Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine Modified Surface

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1929
Author(s):  
Alexander Rodríguez ◽  
Francisco Burgos-Flórez ◽  
José D. Posada ◽  
Eliana Cervera ◽  
Valtencir Zucolotto ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Neuronal Damage ◽  
Charge Transfer Resistance ◽  
Single Frequency ◽  
Response Analysis ◽  
Transfer Resistance ◽  
Therapeutic Decisions

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.

scholarly journals SaQuant: a real-time PCR assay for quantitative assessment of Staphylococcus aureus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Colin Wood ◽  
Jason Sahl ◽  
Sara Maltinsky ◽  
Briana Coyne ◽  
Benjamin Russakoff ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Pathogen Detection ◽  
Limit Of Detection ◽  
Future Research ◽  
Limit Of Quantification ◽  
Pathogen Prevalence ◽  
Single Well ◽  
Effective Public Health ◽  
Detection And Quantification

Abstract Background Molecular assays are important tools for pathogen detection but need to be periodically re-evaluated with the discovery of additional genetic diversity that may cause assays to exclude target taxa or include non-target taxa. A single well-developed assay can find broad application across research, clinical, and industrial settings. Pathogen prevalence within a population is estimated using such assays and accurate results are critical for formulating effective public health policies and guiding future research. A variety of assays for the detection of Staphylococcus aureus are currently available. The utility of commercial assays for research is limited, given proprietary signatures and lack of transparent validation. Results In silico testing of existing peer-reviewed assays show that most suffer from a lack of sensitivity and specificity. We found no assays that were specifically designed and validated for quantitative use. Here we present a qPCR assay, SaQuant, for the detection and quantification of S. aureus as might be collected on sampling swabs. Sensitivity and specificity of the assay was 95.6 and 99.9 %, respectively, with a limit of detection of between 3 and 5 genome equivalents and a limit of quantification of 8.27 genome equivalents. The presence of DNA from non-target species likely to be found in a swab sample, did not impact qualitative or quantitative abilities of the assay. Conclusions This assay has the potential to serve as a valuable tool for the accurate detection and quantification of S. aureus collected from human body sites in order to better understand the dynamics of prevalence and transmission in community settings.

scholarly journals Bactericidal Action of Daptomycin against Stationary-Phase and Nondividing Staphylococcus aureus Cells

2007 ◽  
Vol 51 (12) ◽  
pp. 4255-4260 ◽  
Author(s):  
Carmela T. M. Mascio ◽  
Jeff D. Alder ◽  
Jared A. Silverman
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Bactericidal Activity ◽  
Direct Action ◽  
Metabolic Inhibitor ◽  
Log Reduction ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections ◽  
Lipopeptide Antibiotic

ABSTRACT Most antibiotics with bactericidal activity require that the bacteria be actively dividing to produce rapid killing. However, in many infections, such as endocarditis, prosthetic joint infections, and infected embedded catheters, the bacteria divide slowly or not at all. Daptomycin is a lipopeptide antibiotic with a distinct mechanism of action that targets the cytoplasmic membrane of gram-positive organisms, including Staphylococcus aureus. Daptomycin is rapidly bactericidal against exponentially growing bacteria (a 3-log reduction in 60 min). The objectives of this study were to determine if daptomycin is bactericidal against nondividing S. aureus and to quantify the extent of the bactericidal activity. In high-inoculum methicillin-sensitive S. aureus cultures in stationary phase (1010 CFU/ml), daptomycin displayed concentration-dependent bactericidal activity, requiring 32 μg/ml to achieve a 3-log reduction. In a study comparing several antibiotics at 100 μg/ml, daptomycin demonstrated faster bactericidal activity than nafcillin, ciprofloxacin, gentamicin, and vancomycin. In experiments where bacterial cell growth was halted by the metabolic inhibitor carbonyl cyanide m-chlorophenylhydrazone or erythromycin, daptomycin (10 μg/ml) achieved the bactericidal end point (a 3-log reduction) within 2 h. In contrast, ciprofloxacin (10 μg/ml) did not produce bactericidal activity. Daptomycin (2 μg/ml) remained bactericidal against cold-arrested S. aureus, which was protected from the actions of ciprofloxacin and nafcillin. The data presented here suggest that, in contrast to that of other classes of antibiotics, the bactericidal activity of daptomycin does not require cell division or active metabolism, most likely as a consequence of its direct action on the bacterial membrane.

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