Presentation on theme: "A Brief Synopsis of “HACEK” organisms"— Presentation transcript:
1A Brief Synopsis of “HACEK” organisms Michael Addidle
2HACEK ORGANISMS H-H. parainfluenzae A-Aggregatibacter actinomycetecomitans- Aggregatibacter aphrophilus and paraphrophilus.C-Cardiobacterium hominusE-Eikenella corrodensK-Kingella species
3What do HACEK organisms have in common? Gram negativeCommensals in oropharyngeal areaRelatively fastidiousPrefer CO2 enriched atmosphereAll have a propensity to cause endocarditis, usually secondary to rotten teeth or recent dental treatment or combination of both.Endocarditis- long interval between first symptoms and dx.Frequent embolisationMay be large vegetations on left sided valves.Can all cause non-endocardial infections also.
4Haemophilus parainfluenzae H. aphrophilus and H. paraphrophilus have movedCause endocarditis more commonly than H. influenzae but all endocarditis caused by Haemophilus is rare.
5A-Aggregatibacter actinomycetecomitans Common cause of periodontitisMost endocarditis caused by this bacteria have underlying heart disease.Star-shaped colonies
6Cardiobacterium hominis In contrast to other members of the group, almost exclusively associated with endocarditisMay also be commensal of GI tractCharacteristic Gram stain: bulbous ends and irregular staining. May have a rosette pattern..
7Eikenella corrodens Oral commensal. May implicated in bite infections. May cause infections at several different sites within the body.Slightly yellow colonies after a few daysBleach like odourPit into agar.Beta-lactamase strains are not infrequent.
9Kingella species K. kingae, K dentrificans, K.oralis, K. potus Square ends, uneven decolorisation on Gram stain.May be mildly haemolytic on blood agarColonise pharynx of many children 6 months to 4 years.Common cause of septic arthritis in this age group.Infections in adults usually in immunocompromised.Injection of aspirate into BC media improves detection rates.
12Molecular detectionIn modern blood culture systems, HACEK organsims grow within 5 days.16s PCRMost useful for heart valvesMay also be useful for negative blood cultures where high index of suspicion.