Isolation of Lancefieldella parvula in Secondary Infection from Human Bite: A Rare Occurrence

Abstract

Background: Human bite infections most commonly manifest as skin and soft tissue infections with lower infection rates than animal bites. Lancefieldella parvula is an anaerobe Gram-positive coccus found in human oral mucosa.

Case presentation: We present the case of a 28-year-old healthy woman who suffered a deep skin and soft tissue infection in the left hand after a human bite. She presented with signs and symptoms of infection unresponsive to antibiotics, requiring admission for surgical debridement. Microbiological cultures were taken from the wound and empirical treatment was initiated with ciprofloxacin and clindamycin. Cultures were positive for Lancefieldella parvula by Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) which was genetically confirmed by 16S sequencing. The patient required two surgical debridements and digit amputation; and was treated with levofloxacin for five days recovered, achieving complete resolution of symptoms.

Conclusions: Timely surgical management and targeted antimicrobial therapy in severe human bite infections is crucial. The identification of Lancefieldella parvula using advanced tools like MALDI-TOF emphasizes the need to consider uncommon microorganisms in the differential diagnosis.

Keywords: Human bite; Lancefieldella parvula; amputation; skin and soft tissue infection.