DDI White

Key Advantages

  • Extensive anaerobic culture
    (optimised for Clostridium species)
  • Identification of ALL Clostridium species
    (including C. botulinum , C. tetani, C. perfringens , and C. difficile)
  • Toxins A and B indentification (performed when C. difficile is identified) 

(Stand alone test or add-on to CSA)


Clostridium is a genus of bacteria that includes over one hundred distinct species, many of which are abundant and normal inhabitants of the gastrointestinal tract. Many of the Clostridium species are beneficial, some are virulent and several have been implicated as possible factors in the development of some cases of autism.   Due to the biodiversity within the Clostridium genus, it may be helpful to identify the prevalence of Clostridium species in symptomatic patients.

Clostridium is a diverse genus of bacteria, many of which are abundant and normal inhabitants of the human gastrointestinal tract (GIT).   Many of the Clostridium species can have beneficial effects on the metabolism and health of the GIT in part by breakdown of polysaccharides, saccharolytic fermentation of carbohydrates to short chain fatty acids, and regulation of immune function.

While non-pathogenic Clostridium species are predominantly saccharolytic, toxin-producing species tend to be strongly proteolytic.

Proteolytic fermentation produces toxic metabolites such as ammonia, amines, volatile phenols and indoles which are pharmacologically active and affect a variety of physiological functions; including adverse effects in the central nervous system.

Aside from the well-established pathogenic Clostridium species such as C. botulinum, C. tetani, C. perfringens and C. difficile, other species may have yet-to-be-elucidated roles in health and disease.   For example, they may be involved as mediators in the gut-brain connection, in the evolution of psychiatric neurodevelopmental delay (e.g. autism and the autism spectrum disorders).

Clostridium species that produce neurotoxins and potentially toxic metabolic byproducts have been reported to be more prevalent in autistic children compared to neurotypical controls; most notable were greater quantities of C. bolteae and members of the C. hystolyticum group.

Clostridia are anaerobic Gram-positive bacteria that do not grow in the more aerobic environment of the distal colon.   However Clostridia produce extremely durable endospores as a means of proliferation; the spores are resistant to air, antibiotics, heat, drying and disinfectants.

Doctor’s Data uses growth media optimally suited for growth of Clostridium species and anaerobic culture conditions to germinate the spores to metabolically active bacteria that are sub-cultured for positive identification (speciation).   If  C. difficile is detected, the culture is directly analyzed for toxins A and B because C. difficile associated disease is not overtly expressed unless the bacteria actively produce toxins.

Clostridia generally are resistant to antibiotics and treatment of an overgrowth of C. difficile, especially in asymptomatic carriers and infants <2, generally is not warranted.   Additionally, since plasmids have a potential rise in transferring various capacities, including antibiotic resistance, from one organism to another, the use of antibiotics in the treatment of clostridia overgrowth should be considered carefully.

Consider in:

  • Persistent diarrhoea after hospital visit
  • High clostridia species count (3+ or 4+) within CSA/Bacteriology stool testing and no other pathogens – yet persistent digestive or neurological symptoms
  • Persistent neurological pathologies without identifiable cause. (Eg. ASD).

Clostridium Species With Established Pathogenicity

Commonly Isolated

  • C. difficile
  • C. perfringens
  • C. septicum
  • C. tertium

Rarely Isolated

  • C. novyii type A
  • C. sordellii

Very Rarely Isolated

  • C. tetani
  • C. histolyticum
  • C. botulinum

“Non-Pathogenic” Clostridium Species

Commonly Isolated

  • C. sporogenes
  • C. ramosum
  • C. innocuum
  • C. paraputrificum
  • C. cadaveris
  • C. bifermentans
  • C. fallax
  • C. clostridioforme

Rarely Isolated

  • C. hathewayi
  • C. limosum
  • … About 100 Clostridium Species have been identified in total


Sample Report

Collection Instructions

Gastrointestinal Testing Options

Interpretation Guide 

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