Pasteurella bettyae infection requiring finger amputation due to rapid deterioration and tissue damage

We report a case of infection of the middle finger of a 69-year-old man who visited our hospital. Pus was collected from the erythematous and swollen area of the nail cage of the left-hand middle finger and evaluated in our microbiology laboratory. Gram staining of the specimen revealed multinucleated leukocytes and abundant gram-negative bacilli. Isolated colonies were identified as Pasteurella bettyae using VITEK MS and 16 S ribosomal RNA (rRNA) gene sequencing. The patient's blood test results improved after treatment with penicillin, but the local factors affecting the finger did not improve, and amputation of the middle finger had to be performed. This case represents a report of a very rare hand infection caused by P. bettyae. Polymorphic identification methods, such as MALDI-TOF MS and 16 S rRNA gene sequencing, are needed for members of the genus Pasteurella isolated from severe infections and abnormal sites, and further studies are warranted.