Wohlfahrtiimonas chitiniclastica Infections in two patients with osteomyelitis, China

This report presents two cases of human infection caused by Wohlfahrtiimonas chitiniclastica, a pathogen associated with chronic osteomyelitis and soft tissue infections. Case 1 involves a 75-year-old male with a long-standing, chronic wound following a right lower leg fracture, which worsened due to inappropriate treatments like "moxibustion" and leech therapy, leading to a severe infection. Despite initial antibiotic therapy with cefoxitin sodium, the infection progressed, resulting in amputation. Case 2 describes a patient with a refractory right plantar ulcer complicated by calcaneal osteomyelitis, who was treated with surgical debridement, followed by antimicrobial therapy based on bacterial culture and susceptibility testing. Both cases were associated with polymicrobial infections, including W. chitiniclastica, and required targeted antibiotic therapy. The diagnosis was confirmed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing, highlighting the importance of advanced diagnostic techniques. W. chitiniclastica is capable of causing life-threatening infections, including osteomyelitis and myiasis, particularly in patients with poor hygiene or chronic wounds. This study underscores the challenges in identifying emerging pathogens and the necessity for comprehensive diagnostic approaches, including whole-genome sequencing, to improve clinical outcomes and develop effective therapeutic strategies.