[Septic arthritis byAggregatibacteraphrophilus: Case report]

Septic arthritis by Aggregatibacter aphrophilus is an uncommon entity, so it's important to diagnose it early, to avoid serious consequences. In adults, the knee is the most affected site.

We present a case of a 17-year-old boy, with pain in the left knee since one month ago. It shows an increase in local temperature, erythema and movement inability. A nuclear magnetic resonance (NMR) was performed and empirical treatment was given with cephalothin and clindamycin. A knee arthrotomy was realized, and intramedullary secretion and bone tissue was sent to study.

the NMR images were suggestive of an infectious process. In the culture gram-negative coccobacilli were isolated, later identified like as Aggregatibacter aphrophilus. According to this diagnostic, the treatment was changed to ceftriaxone

the rapidity and certainty in the choice of antimicrobial therapy is the most important step for a well evolution of this infection, therefore is very important to emphasize the importance of a correct identification of these rare microorganisms