Two Clinical Cases of Feline Hemoplasmosis in Korea

Abstract

Feline hemotropic mycoplasmosis (hemoplasmosis) is an infection of the red blood cells caused by the Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm), and Candidatus Mycoplasma turicensis (CMt). The existence of Mhf, CMhm, and CMt has been demonstrated in feral cats in Korea using molecular methods, but no clinical cases have yet been reported. This study reports 2 clinical cases of hemotropic mycoplasmosis caused by CMhm and CMt in 2 anemic cats. The first case was a client-owned intact female domestic shorthair cat that presented with fever, pale mucous membranes, and normocytic normochromic non-regenerative anemia. Prior to referral, an immunosuppressive prednisolone dose was administered at the local veterinary clinic for 1 month. The cat was diagnosed with high-grade alimentary lymphoma. Organisms were found on the surface of the red blood cells on blood smear examination. The second case was of a rescued cat that presented with dehydration and fever. The cat had normocytic normochromic non-regenerative anemia. Necropsy revealed concurrent feline infectious peritonitis. Polymerase chain reaction assay targeting 16S rRNA revealed CMhm infection in case 1 and dual infection of CMhm and CMt in case 2. Normocytic normochromic non-regenerative anemia was observed in both cats before and during the management of the systemic inflammation. This is the first clinical case report in Korea to demonstrate CMhm and CMt infections in symptomatic cats.

Keywords: Candidatus Mycoplasma haemominutum; Candidatus Mycoplasma turicensis; Feline hemoplasmosis; PCR; hemolytic anemia.

Fig. 1

Blood smear examination of case 1. Organisms are seen on the surface of the erythrocytes (arrow). (A) Organisms are seen as single dark purple and blue dots on the surface of erythrocytes with Diff-Quik staining. (B) Some erythrocytes have many distinct organisms on their surface, visualized with New Methylene Blue staining.

Fig. 2

Molecular phylogenetic analysis by the Maximum Likelihood Estimation Method. Phylogenetic relationships for 402 bp-long Candidatus Mycoplasma haemominutum (A) and 271 bp-long Candidatus Mycoplasma turicensis (B), based on partial nucleotide sequences of the 16S rRNA gene fragments. The Maximum Likelihood Estimation Method based on the Kimura 2-parameter model was used for constructing the phylogenetic tree. The numbers at the nodes are the proportions of 1,000 bootstrap iterations that support the topology shown. Bolded letters indicate the Mycoplasma sequences obtained from the cats in this study.