Infectious Disease Compendium

Aggregatibacter

Microbiology

Aggregatibacter actinomycetemcomitans (formally Actinobacillus actinomycetemcomican),   Aggregatibacter aphrophilus (was Haemophilus aphrophilus)  and  Aggregatibacter segnis (was Haemophilus segnis) (as of 2006). A gram-negative coccobacillus.

Syndromes

A. actinomycetemcomicans is a cause of endocarditis (it puts the A in HACEK), head and neck infections and part of aspiration pneumonia with or without empyema.

A. aprophilus causes endocarditis. Part of any disease where spit is an issue.

Treatment

Third-generation cephalosporins, ciprofloxacin, gentamicin, tetracyclines. Endocarditis is usually treated with penicillin PLUS an aminoglycoside.

Notes

Sloooooow growers and can take > 48 h to pop positive in blood cultures.

Last update: 05/05/18