''Clostridium cadaveris'' is an

enteric The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...

, gas-forming,

motile Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...

, strictly

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic ad ...

gram-positive bacterium In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

of the genus ''

Clostridium ''Clostridium'' is a genus of anaerobic, Gram-positive bacteria. Species of ''Clostridium'' inhabit soils and the intestinal tract of animals, including humans. This genus includes several significant human pathogens, including the causative ...

''. First described by Klein in 1899, it was noted to be the most prominent bacteria during

human decomposition Decomposition is the process in which the organs and complex molecules of animal and human bodies break down into simple organic matter over time. In vertebrates, five stages of decomposition are typically recognized: fresh, bloat, active decay, a ...

; historically it was described as "putrefying flora". ''Clostridium cadaveris'' is usually considered non-pathogenic; unlike other species of ''Clostridium'', it does not produce toxins. ''Clostridium cadaveris'' is found in soil, water, and is a normal component of the human intestinal tract. The genus ''Clostridium'' is large and phylogenetically diverse, comprising over 150 species. Clostridia are found extensively in nature predominantly as benign soil saprophytes. A number of ''Clostridium'' species are pathogenic to humans. Members including ''C.botulinium'', ''C. perfringens'', and ''C.septicum'' are spore forming and the cause of botulism and gas gangrene respectively. ''Clostridium cadaveris'' is closely related phylogenetically to ''Clostridium fallax'' and ''Clostridium intestinale''. Infections in humans due to ''C. cadaveris'' are rare and the organism is seldom found is clinical specimens. Most cases reported in medical literature document infections in immunocompromised patients, but isolated cases in immunocompetent hosts have been reported.

Colony characteristics

Primary isolation media is blood agar incubated anaerobically at 35-37 degrees Celsius for 40–48 hours. Microscopic appearance shows gram positive rods with both smooth and rough colony types and further spore staining technique may be utilized to determine spore shape and position. Currently the standard to identify clostridial species such as ''C. cadaveris'' is via molecular techniques utilizing ribosomal RNA gene sequencing.

Infections

Infections due to ''C. cadaveris'' are rare and present predominantly as bacteremia of gastro-intestinal origin and may occur endogenously. Associated risk factors for bacteremia due to ''C. cadaveris'' include a compromised immune system, trauma, recent surgical procedures, diabetes, and perforated bowel. Bacteremia and sepsis caused by ''Clostridium cadaveris'' have been implicated following orthopedic procedures, in patients undergoing oncological treatment, and in cases of necrotic decubitus. Due to the rare clinical manifestation of bacteremia attributed to ''C. cadaveris'', the organism's susceptibility to antibiotic treatment is not well documented. Case reports indicate a susceptibility to most antibiotics including metronidazole and

penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

as well as resistance to

clindamycin Clindamycin is an antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media (middle ear infe ...

and possibly beta-lactams. Infections may be persistent due to the organisms ability to sporulate.

In the human gut

''Clostridium cadaveris'' normally colonizes in the gastrointestinal tract.

Microbiota Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been fou ...

(gut flora) contain between 400 and 800 bacterial species and are usually classified in two divisions:

Bacteroidota The phylum Bacteroidota (synonym Bacteroidetes) is composed of three large classes of Gram-negative, nonsporeforming, anaerobic or aerobic, and rod-shaped bacteria that are widely distributed in the environment, including in soil, sediments, and ...

and

Bacillota The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the ea ...

; ''Clostridium cadaveris'' are Bacillota. Species diversity of human microbiota is unique and microbiota display unequal distribution in the digestive tract. Smaller populations are found in the small intestines, whereas populations one hundredfold are found in the ileum, colon, and rectum. Imbalance of the ratio between Bacillota and Bacteroidota levels are connected to obesity,

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension, ...

, and other health complications. Antibiotic treatment can also alter the balance of microbiota causing pathogenic bacterial growth.

In human decomposition

In humans, one of the first signs of decomposition is a yellow-green discolorization of the abdomen in the area of the cecum due to the build up of gases from bacteria and autolysis of cells. ''Clostridium cadaveris'', ''C. welchii'', ''E. coli'', and ''B. aerogenes'' are found in large numbers after death due to nutrient supply for anaerobic bacteria allowing for optimal organismal growth. In initial stages of decomposition bacteria feed on both intestinal contents and intestinal tissues, prolific colonization occurs allowing digestive enzymes and anaerobic bacteria such as ''C. cadaveris'' to breach the intestinal tract invading other tissues and organs. Translocation and proliferation of gut flora such as ''C. cadaveris'' allow for these organisms to serve as bacterial indicators for time of death in individuals.

References

External links

* *
Type strain of ''Clostridium cadaveris'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q3681024 Gram-positive bacteria Bacteria described in 1957 cadaveris