Acute appendicitis caused by Arcanobacterium haemolyticum

Arcanobacterium haemolyticum is known for causing pharyngitis in young adults and skin/soft tissue infections in older and immunocompromised people. We report here the case of a 25-year-old patient admitted to the emergency room for pain in the right iliac fossa. Abdominal computed tomography (CT) scan showed acute uncomplicated appendicitis. The biological assessment revealed an inflammatory syndrome with CRP at 124 mg/L. The patient underwent an appendectomy by laparotomy. The cytobacteriological analysis of deep pus revealed an important leukocyte reaction to neutrophils, and the growth of Arcanobacterium haemolyticum in culture. Antibiotic susceptibility testing showed that the bacterium was susceptible to clindamycin, tetracycline, linezolid, and rifampicin, and resistant to penicillin G, sulfamethoxazole/trimethoprim, moxifloxacin, ciprofloxacin, and vancomycin. Most studies have shown that this bacterium is susceptible to all classes of antibiotics except sulfamethoxazole-trimethoprim, however, in our case and like certain recent studies, other resistances are emerging.