Cytologic diagnosis of Mycoplasma in a recurrent abscess from a cat

Abstract

A 10‐year‐old, neutered male, indoor/outdoor domestic shorthair cat was presented for a mass on the right front paw. The mass was treated as an abscess, and despite initial resolution, the mass recurred and ruptured approximately 1 month later. This mass successfully resolved with intense management as an open wound. Several days later, the cat developed vomiting and inappetence, and a new mass was noted on the lateral aspect of the right rear limb. Aspirates from the new mass were submitted for cytologic evaluation and bacterial cultures. Anaerobic and aerobic bacterial cultures were negative. Cytologic evaluation revealed septic neutrophilic inflammation with small rod, cocci, curved, and ring forms of bacteria seen, and Mycoplasma spp. infection was suspected based on the morphology of the bacteria. Polymerase chain reaction followed by gene sequencing revealed 86% similarity for Mycoplasma elephantis. The cat was treated with a fluoroquinolone antibiotic and clinically improved, with resolution of the abscess. This case highlights the importance of recognizing the morphologic appearance of Mycoplasma spp. on cytologic examination to help guide additional testing choices and therapeutic planning.

Mycoplasmafelis abscess infection and lymphadenomegaly in a cat

“…A thorough cytological examination of samples in order to recognise Mycoplasma spp. morphology has been shown to be important in the diagnosis, 14 as appeared to be important in this case where the pathologist identified accumulation of pale grey‐brown material lacking identifiable structure within some neutrophils. Mycoplasma spp.…”

“…Additionally, as the patient improved clinically after being treated with doxycycline, it seems very likely that Mycoplasma spp. was the cause of the clinical signs 14,15,17 …”

“…associated with the cleaning of the wound. It is interesting that there was not a full response to marbofloxacin, as the use of a fluoroquinolone would have been expected to be effective 14,16,17 . It is possible that this medication had not been administered appropriately, due to the difficulty in administering tablet medications to cats.…”

“…However, they have been associated with disorders of the conjunctiva, 8 respiratory 9–11 or urinary systems. Mycoplasma has been sporadically reported in bite abscesses in cats, 5,12–14 presumably due to the fact that Mycoplasma spp. are part of the normal flora of the mouth.…”

“…have also been reported to respond to tetracyclines or fluoroquinolones. 14,16,17 Due to the difficulty of culturing Mycoplasma spp., there is a risk of misdiagnosis of this infectious agent in cat bite abscesses. Veterinarians should consider requesting a polymerase chain reaction (PCR) test or a specific culture in order to diagnose the presence of Mycoplasma spp.…”