''Eikenella corrodens'' is a
Gram-negative facultative anaerobic bacillus that can cause severe invasive disease in humans. It was first identified by
M. Eiken
( ; ; pl. ; ; 1512, from Middle French , literally "my lord") is an honorific title that was used to refer to or address the eldest living brother of the king in the French royal court. It has now become the customary French title of resp ...
in 1958, who called it ''Bacteroides corrodens''. ''E. corrodens'' is a rare pericarditis associated pathogen. It is a
fastidious, slow growing, human
commensal bacillus, capable of acting as an opportunistic pathogen and causing abscesses in several anatomical sites, including the liver, lung, spleen, and submandibular region. ''E. corrodens'' could independently cause serious infection in both immunocompetent and immunocompromised hosts.
Microbiology
''Eikenella corrodens'' is a
pleomorphic bacillus that sometimes appears
coccobacillary and typically creates a depression (or "pit") in the agar on which it is growing. Only half produce the pitting of the agar considered characteristic.. It is slow-growing, facultative, anaerobic and a gram-negative bacillus.
It grows in aerobic and anaerobic conditions, but requires an atmosphere enhanced by 3–10%
carbon dioxide.
The colonies are small and greyish, they produce a greenish discoloration of the underlying agar, and smell faintly of bleach (
hypochlorite
In chemistry, hypochlorite is an anion with the chemical formula ClO−. It combines with a number of cations to form hypochlorite salts. Common examples include sodium hypochlorite (household bleach) and calcium hypochlorite (a component of ble ...
).
They are
oxidase-positive,
catalase
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting t ...
-negative,
urease-negative, and
indole-negative, and reduce
nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
to
nitrite
The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name ...
.
In 2006, Azakami ''et al'' reported that the periodontal pathogen ''E. corrodens'' have
ortholog of ''
luxS'', the gene required for
quorum sensing (QS) signal molecule
AI-2 synthesis and ''E. corrodens'' can produce AI-2 signal for cell-to-cell communication and AI-2 has a role on
biofilm formation by ''E. corrodens''. Karim ''et al'' reported that this bacterium can produce AI-2 inactivation enzyme during its stationary phase. Karim ''et al'' also reported that ''LuxS''-mediated QS may facilitate the maturation and detachment of biofilm formation in ''E. corrodens'', which can leads to progression of
periodontal disease.
Medical importance
''Eikenella corrodens'' is a
commensal of the human mouth and upper respiratory tract. It is an unusual cause of infection and when it is cultured, it is most usually found mixed with other organisms. Infections most commonly occur in patients with cancers of the head and neck, but can occur in human bite infections, especially "
reverse bite", "
fight bite", or "
clenched fist injuries". It can also cause infections in
insulin-dependent diabetics and
intravenous drug user
Drug injection is a method of introducing a drug into the bloodstream via a hollow hypodermic needle, which is pierced through the skin into the body (usually intravenously, but also at an intramuscular or subcutaneous location). Intravenous t ...
s who lick their needles ("needle-licker's osteomyelitis"). It is one of the
HACEK
The HACEK organisms are a group of fastidious Gram-negative bacteria that are an unusual cause of infective endocarditis, which is an inflammation of the heart due to bacterial infection. HACEK is an abbreviation of the initials of the genera o ...
group of infections which are a cause of culture-negative
endocarditis. In general, the HACEK organisms are responsible for approximately 3% of all cases of infective endocarditis (IE). IE due to ''E. corrodens'' is usually a result of poor oral hygiene and or periodontal infection. Manipulation of the gingival or oral mucosa for dental procedures also can predispose patients to infection since ''E. corrodens'' is a constituent of the human oral flora. ''E. corrodens'' can coexists and is frequently detected with other pathogens including ''Staphylococcus'' and ''Streptococcus''.
''Eikenella corrodens'' infections are typically indolent (the infection does not become clinically evident until a week or more after the injury). They also mimic
anaerobic infection in being extremely foul-smelling.
''Eikenella corrodens'' was mentioned in an episode of ''
Forensic Files'', in which a hotel employee punched a woman in the mouth, knocking out two of her teeth. The tooth bacteria caused a major infection in the man's hand.
Treatment
For accurate diagnoses, a high degree of suspicion is required in order to properly attribute an infection to ''Eikenella corrodens.'' The identification of ''E. corrodens'' may be delayed because of its slow growth in the absence of . ''E. corrodens'' can be treated with
penicillins,
cephalosporins, or
tetracyclines, however due to the resistant nature of the bacteria ongoing and recurring symptoms can be expected despite rigorous and prolonged antibiotic treatment. Submandibular and peritonsillar abscesses caused by ''E. corrodens'' can be treated by incision and drainage. Earlier diagnosis and proper drainage surgery with effective antibiotics treatment may improve the prognosis. First-choice drugs for ''E. corrodens'' infections should be third-generation
cephems,
carbapenems, or new
quinolone
Quinolone may refer to:
* 2-Quinolone
* 4-Quinolone
* Quinolone antibiotic
A quinolone antibiotic is a member of a large group of broad-spectrum bacteriocidals that share a bicyclic core structure related to the substance 4-quinolone. They ...
s. It is innately resistant to
macrolides (e.g.,
erythromycin
Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used duri ...
),
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 infec ...
, and
metronidazole. It is susceptible to
fluoroquinolones (e.g.,
ciprofloxacin) ''in vitro'', but no clinical evidence is available to advocate their use in these infections.
References
External links
*
''Eikenella corrodens''at the NCBI Taxonomy Browser
{{Taxonbar, from=Q3039103
Neisseriales