Principles

Providing clinicians with pathogen identification and information about antibiotic resistance – within the first crucial hours of sepsis diagnosis
  • Detects 99% of all sepsis-relevant pathogens - 33 bacteria and 6 fungi
  • Identifies 4 antibiotic resistant genes (vanA, vanB, blaSHV, mecA)
  • Results within the working day
  • Enables detection of non-cultivable pathogens

VYOO has been developed and validated in close collaboration with leading international microbiologists. Each VYOO kit contains all reagents, consumables and step-by-step instructions. The protocol outlined here has been technically validated in more than 150000 separate reactions during development work, ongoing case studies and investigator-initiated studies.

Control concept

VYOO is the first test in the market with an internal control running through all steps - from sample to result. By excluding errors of the test protocol, the control gives you the definite security that results are valid." 

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Workflow and Principles




Effective access to pathogens

A glass-bead based lysis step ensures disruption of even the most robust pathogen cells, e.g. Candida spp. and Streptococcus pyogenes. Total DNA is isolated by passing lysate through a DNA purification column from which the DNA is then eluted.

 

 

Increased sensitivity downstream, reducing time to result

Whole blood of sepsis patients contains complex DNA mixtures with a high human DNA content resulting in a very low bacterial and/or fungal/human DNA ratio (1:2 x109). After DNA extraction, the proprietary sample preparation process, LOOXSTER, isolates and concentrates bacterial and fungal genomic DNA. This affinity chromatography step utilizes a DNA binding protein that recognizes unmethylated CpG motifs.

 


These motifs are predominantly present in bacterial and fungal genomes at significantly lower frequencies than in human [DNA enrichment render] genomes (bacteria: 1:50, fungi: 1:160, human: 1:2,200). Consequently, most human DNA washes through the affinity cartridge and bound bacterial/fungal DNA is eluted in concentrated form. With more than 90% of human DNA removed, the bacterial and/or fungal/human DNA ratio is significantly higher.

 

 

 

Primers selected to target sepsis pathogens and antibiotic resistance markers

A routine multiplex PCR method amplifies these highly specific gene targets. Using a limited number of PCR cycles ensures robust results.

 

Pathogens identified, antibiotic resistance revealed

Gel electrophoresis separates the amplified gene targets (amplicons) to reveal the pathogens and present information about antibiotic resistance.

Validation control

The internal process control covers each step of the protocol. Samples are spiked with endospores of Bacillus subtilis included in in cell lysis, genomic nucleic acid isolation and DNA enrichment. If the B. subtilis-specific amplicon is clearly visible in the evaluation of the PCR results, technical validity of the assay is ensured. 

 

 

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VYOO is approved for diagnostic and research use within Europe. VYOO provides solely qualitative diagnostic information. The relevance of this information to diagnosis of infection and the selection of a directed anti-infective therapy must be evaluated by a clinician together with other clinical and diagnostic findings. VYOO is for research use only in USA.