''Corynebacterium ulcerans'' is a rod-shaped, aerobic, and

Gram-positive 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 bac ...

bacterium. Most ''Corynebacterium'' species are harmless, but some cause serious illness in humans, especially in immunocompromised humans. ''C. ulcerans'' has been known to cause

diphtheria Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and s ...

and diphtheria-like infections in patients. Previously thought to simply be contaminants recovered from diphtheria patients, “ coryneform” or “diphtheroids” are now believed to be the ''cause'' of such infections.

Disease

Increasingly over the past few decades, ''C. ulcerans'' has been recognized as an emerging pathogen in over six countries across the globe including the United States, the United Kingdom, and Japan. ''

C. diphtheriae ''Corynebacterium diphtheriae'' is the pathogenic bacterium that causes diphtheria. It is also known as the Klebs–Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs (1834–1912) and Friedrich Lö ...

'' is the causative agent of classical diphtheria, and ''C. ulcerans'' has been found to carry the same gene that codes for the diphtheria toxin. After swabbing lesions on a 53-year-old woman in Germany who experienced swelling of her pharynx and who developed a whitish pseudomembrane, doctors were able to grow ''C. ulcerans.'' This made it the first documented case of classical diphtheria caused by ''C. ulcerans'' in Germany. ''C. ulcerans'' can also cause zoonotic infections. In 2003, A 47-year-old woman in Le Kremlin-Bicêtre, France was admitted to the intensive care unit for labored breathing. It was found that as a result of a kidney graft received the previous year, the patient was

immunocompromised Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

and vulnerable to ''C. ulcerans'', which was found growing from a swab of her throat. After many tests, the patient was found to have contracted the disease from her dog, which was found to have chronic labial ulcerations that provided an easy way to transmit the bacteria to the patient. In addition to classical diphtheria, ''C. ulcerans'' can also cause skin infections that resemble classical cutaneous diphtheria as a result of production of the diphtheria toxin. By contracting this skin infection, patients become more vulnerable to contracting infections from other bacteria that exist naturally in the patient's environment that can cause life-threatening diseases.

Treatment

Patients who contract diphtheria and diphtheria-like symptoms as a result of ''C. ulcerans'' require treatment with diphtheria antitoxin and

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

. Surgery and other more extreme measures must be taken if not treated immediately.

References

External links

Type strain of ''Corynebacterium ulcerans'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q3694963 Corynebacterium Gram-positive bacteria Bacteria described in 1995