Infectious Disease Compendium

Aggregatibacter

Microbiology

Aggregatibacter actinomycetemcomitans (formally Actinobacillus actinomycetemcomican),   Aggregatibacter aphrophilus (was Haemophilus aphrophilus)  and  Aggregatibacter segnis (was Haemophilus segnis) (as of 2006).

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.