A review of the benefits of using Doctors Data for comprehensive microbiology testing


Culture Growth Testing

Doctor’s Data utilises culture growth testing, which remains the international standard for clinical microbiology testing. Culture growth testing enables identification of living, metabolically active organisms. This allows susceptibility testing to be performed on any pathogenic strains identified (a stand out feature of culture growth testing).

Traditionally in Microbiology there are 3 different growth conditions considered. Doctors Data looks at 10 different growth conditions.

  • 5x Aerobic- 1 has enrichment broth for enteric pathogens.
  • 3x Anaerobic- sensitive to O2= bifido, lacto, bacteroides, Clostridia spp.
  • Microaerophic- low tolerance to O2 campylobacter.
  • Yeast specific- 170 species, 65 Candida


 MALDI-TOF Technology (Not PCR)

 KEY MALDI-TOF FEATURES

  • Shared the 2002 Nobel Prize in Chemistry
  • 3rd in Cleveland Clinic’s Top Ten medical innovations that will improve patient care
  • Used by NASA to search for life on Mars
  • ‘Will eventually be used by all hospitals and laboratories’ (College of American Pathologists, 2013)
  • MALDI-TOF is being purchased by numerous laboratories world wide, however, expertise around its use is crucial

 THE DOCTORS DATA MALDI-TOF ADVANTAGE

  • Doctor’s Data introduced the revolutionary proteomic technology known as MALDI-TOF Mass Spectrometry to the functional medicine industry.
  • During this they have made groundbreaking discoveries, technological advances and developed an unrivaled expertise for clinically relevant assessment of the gastrointestinal (GI) microbiome.
  • Doctors Data receives 1000’s of samples weekly from around the world. Being leaders in CSA, Doctors Data utilise MALDI-TOF technology with an international identification reference database of 1200+  GI species.
  • An advantage of using the expansive open reference library is that the database remains in a continual state of growth as they are able to uncover new findings.
  • Doctors Data is a a global company that receives more than 1400 samples daily from around the world.
  • The Department Manager of Microbiology at Doctor’s Data, Hope Beilfuss, published a peer-reviewed paper on the first definitive identification of the Laribacter hongkongensis species in the United States. This particular organism is misidentified by other phenotypic methods and undetectable by more limited MALDI-TOF databases, further demonstrating the advanced capabilities and use of an open library.
  • It is important to note that all MALDI-TOF technology is not created equal. It is of the utmost importance that clinicians understand that experience matters when it comes to such sophisticated technology. You can read more on this here.

 WHAT ABOUT PCR?

  • Polymerase chain reaction (pCR) is a relatively old biochemical technology that is used in molecular biology to amplify (exponentially) select segments of DNA and has been recognized by a share of the 1993 Noble prize in Chemistry.
  • pCR-based platforms have significant limitations in the context of clinical medicine, especially for Complementary and Integrative medicine.
  • pCR requires a primer for identification of every genus (let alone species). Therefore, a reliable pCR based evaluation of microorganisms in a stool specimen that is even 1/10th as comprehensive as that of the culture/MALDITOF MS approach would be absolutely cost prohibitive (if possible).
  • For more information, see Proteomics: a Revolution in the evaluation of gastrointestinal Microflora 12-page information guide


 Sample Stability

Doctors Data sample collection uses advanced transport mediums to ensure viability of sample in transit.

  • Transport media (Cary-Blair) is buffered to prevent shifts in pH and has a very low nutrient content that suspends the growth of present bacteria and inhibits the growth of others
  • The media has a low agar content to enhance viability of pathogenic species
  • A reducing agent markedly lowers the oxygen content and favours anaerobes
  • When properly collected and shipped, beneficial and pathogenic species may be successfully recovered quantitatively from the transport media for up to 14 days (see graph below)

stool-transport


 Reporting Bacterial Numbers

To simplify reading the results, each organisim family or species is reported as 1+ (Rare), 2+ (Few), 3+ (Moderate), or 4+ (Many). Refer to the scientific notations in the table below.

Research Nutrition provides the below guide alongside test results:

csa-bacerial-numbers

Furthermore, EVERY SINGLE PATIENTS sample is tested using the diffusion method for advanced detection of bacteria – evaluated for phenotypic expression. IV susceptibility testing is also performed for yeast detection.

csa-webinar

References

Lagier et. al   Microbial culturomics: paradigm shift in the human gut microbiome study. Clin Microbiol Infect. 2012 Dec;18(12):1185-93.

Tan KE, Ellis BC, Lee R, Stamper PD, Zhang SX, Carroll KC. Prospective evaluation of a matrix-assisted laser desorption ionization-time of flight mass spectrometry system in a hospital clinical microbiology laboratory for identification of bacteria and yeasts: a bench-by-bench study for assessing the impact on time to identification and cost-effectiveness.  J Clin Microbiol. 2012 Oct;50(10):3301-8

Manz, Michael;  Burri, Emanuel;  Rothen, Claude;  Tchanguizi, Nuschin;  Niederberger, Christian et al. (2012)  Value of fecal calprotectin in the evaluation of patients with abdominal discomfort: an observational study. BMC Gastroenterol. 2012 Jan 10;12:5.

Beilfuss HA, Quig D, Block MA, Schreckenberger PC. 2015. Definitive identification of Laribacter hongkongensis acquired in the United States. J Clin Microbiol 53:2385–2388.