ABSTRACT. Detection of hemotropic Mycoplasma spp. infection was attempted in cats by PCR using whole blood without DNA extraction. A total 46 of 54 (85%) cats with suspected Mycoplasma spp. infection showed a positive reaction, corresponding completely with the results of standard PCR testing. The direct PCR assay was sensitive enough to detect more than 0.0061% parasitemia for 'C. M. haemominutum' and 0.0075% parasitemia for M. haemofelis. These data indicate that the direct PCR assay might be sufficient for use as a tool in clinical examinations. KEY WORDS: blood, feline, hemoplasma.J. Vet. Med. Sci. 70(10): 1095-1099, 2008 Mycoplasma (M.) haemofelis, 'Candidatus (C.) Mycoplasma haemominutum' and 'C. Mycoplasma turicensis' are minute, gram-negative, epicellular bacteria infecting the feline erythrocyte and causing hemolytic anemia, thrombocytopenia, fever and jaundice [12,16]. Definitive diagnosis of hemotropic Mycoplasma spp. infection is made by examination of a thin Wright-Giemsa-stained blood smear, but this method is unreliable because the tiny organisms often resemble stain debris, protein precipitates and HowellJolly bodies. Furthermore, parasitemic episodes are recurrent, and so examination under a microscope sometimes cannot detect the organism in some clinical cases. Recently, some reports have indicated that molecular detection of Mycoplasma spp. infection using polymerase chain reaction (PCR) based on the 16S rRNA gene of hemotropic Mycoplasma spp. is more sensitive and specific than cytological examination [5,7,8,15]. Therefore, PCR analysis has come to prevail as a useful and sensitive examination in veterinary laboratories in Japan. However, the cost of examination is high, and the time needed is not short. The complicated procedure and time required for the PCR assay are suspected as being the main reasons for these problems. So, it is important that these cost and time problems will be resolved in order to extend the PCR assay further into the veterinary field. A highly capable Taq polymerase has been developed that enables more efficient amplification of DNA [4]. Furthermore, several reports have revealed that direct PCR using a template such as whole blood and feces is able to detect various gene abnormalities and infectious diseases [3,10,11]. It is necessary to confirm the capacity of direct PCR to detect hemotropic Mycoplasma spp. infection by analyzing a specific population. Both the M. haemofelis and 'C. Mycoplasma haemominutum' strains were widespread in domestic cats in Japan, but sole infection with 'Candidatus Mycoplasma turicensis' has not been confirmed [6]. Therefore, direct PCR analysis to detect M. haemofelis and 'C. Mycoplasma haemominutum', was carried out in a total of 59 blood samples derived from cats with a suspected Mycoplasma spp. infection and healthy cats, and the results were compared with the standard method described previously [15].A total of 59 blood specimens from 54 cats with a suspected Mycoplasma spp. infection, based on clinical signs and haematological abno...

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