Case summary: A 2-year-old female spayed domestic shorthair cat was presented for a progressive subcutaneous nasofacial swelling. Histology of biopsy tissue revealed pyogranulomatous inflammation and large numbers of gram-negative capsulated bacterial coccobacilli within macrophages. The isolate was fastidious and grew after 6 days under microaerophilic conditions in a candle jar. The molecular identity of the isolate, from comparative sequence analysis of the 16s rRNA gene, is an as yet to be classified bacterial species within a novel genus of Neisseria. Infection resolved after 7 months of antimicrobial therapy with doxycycline and trimethoprim sulfamethoxazole. There has been no further recurrence of clinical signs in a 3 year follow-up period.
Relevance and novel information: Cats are susceptible to nasofacial infections as a result of traumatic inoculation of environmental bacteria, fungi and protozoa. We report a novel pathogen in the Neisseriaceae family, identified by 16 sRNA comparative sequence analysis, as a cause of nasofacial infection in a cat, and its subsequent successful treatment with combination antimicrobial therapy.