Arcanobacterium haemolyticum is a gram positive rod with a matchbox or Chinese letter orientation. It was first discovered and described in 1946 in servicemen and people from the South Pacific. When plated out, the colony is small with a narrow zone of beta hemolysis and pits the agar. This organism has been a topic of controversy due to its resemblance to Corynebacterium pyogenes; because of this resemblance, A. haemolyticum was originally classified within the Corynebacterium genus with the subspecies hominis. Since this bacteria resembles Streptococcus pyogenes, the two are often confused and can be differentiated by the gram stain, inverse CAMP, and catalase reaction. This confusion was later resolved in 1982 when a new genus was created and this organism was renamed. The genus Arcanobacterium means secretive bacteria and is based on the characteristics of its fatty acid, peptidoglycan, and DNA.
Arcanobacterium haemolyticum typically infects teenagers and young adults aged 15 to 25 and is usually found in immunocompromised people. It is transmitted person to person through respiratory droplets and is found in the pharynx as well as the skin but there are no known risk factors. This bacteria causes pharyngitis, tonsillitis, and cellulitis. A rash believed to be caused by an exotoxin may be seen on the chest, abdomen, neck, and extremities in 20-25% of cases and can lead to diagnostic errors. The most common symptoms associated with A. haemolyticum are sore throat, pruritus, fever, pharyngeal erythema, and a nonproductive cough.
Arcanobacterium haemolyticum typically infects teenagers and young adults aged 15 to 25 and is usually found in immunocompromised people. It is transmitted person to person through respiratory droplets and is found in the pharynx as well as the skin but there are no known risk factors. This bacteria causes pharyngitis, tonsillitis, and cellulitis. A rash believed to be caused by an exotoxin may be seen on the chest, abdomen, neck, and extremities in 20-25% of cases and can lead to diagnostic errors. The most common symptoms associated with A. haemolyticum are sore throat, pruritus, fever, pharyngeal erythema, and a nonproductive cough.
Arcanobacterium haemolyticum is usually treated with erythromycin, clindamycin, gentamicin, or cephalosporins. Serious infections may be treated with parenteral antimicrobial drugs.
Great info, I am sure as technology progresses, confusing bacteria would be less of an issue. Also emergence of better tests can help to identify organisms better, faster and more efficient.
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