In order to evaluate the pathogenicity of Korean strains of Trichomonas vaginalis, an experimental inoculation of T. vaginalis into mouse peritoneal cavity was performed. Fifteen strains of T. vaginalis were selected from 53 infected cases and were cultured axenically in Roiron-Rattner medium at 37C for 48 hours. Each strain, at the dose of 0.5 ml of 1x10(6)/ml trichomonads, was inoculated intraperitoneally to a group of 10 mice, respectively. A total of 15 groups, consisted of 150 mice, were sacrificed on the 8th day of inoculation, and then they were thoroughly examined for the detection of the lesion. The results obtained in present study were summarized as follows: Prior to inoculation, the positive rates in 2 kinds of media cultivating T. vaginalis were compared. In Johnson's CPLM medium, 65 percent of positive rate was obtained, and 94.2 percent of positive rate, the better result, was shown in the culture of Roiron-Rattner medium. Overall death rate of 150 inoculated mice was 7.3 percent (range 0-40 percent), and 7 strains (46.7 percent) out of 15 inoculated strains were proved as fatal strain. The intraperitoneal lesions produced by the inoculation of T. vaginalis were observed in the liver (20 percent), intestinal wall and mesentery (14 percent), peritoneal wall (9.3 percent), wall of the stomach (6.0 percent), and the spleen (5.3 percent) of 150 inoculated mice. Occasionally, the lesions were also found in the pancreas and wall of the urinary bladder. In 11.3 percent of inoculated mice, purulent ascites with living trichomonads could be seen. Thirteen strains (86.7 percent) out of the 15 inoculated strains produced the T. vaginalis-associated pathological lesions. On the histopathological investigation of those lesions, intraperitoneal inoculation was characterzed by a necrotizing granulomatous inflammation, i.e., acutely necrotizing process with areas of encircling granuloma formation. Numerous free lying trichomonads were seen along the expanding margin of the lesion. Where there were free trichomonads, the reaction was usually of necrotizing. And these organisms directly eroded the vascular wall and often provoked thrombosis. From the above findings, it is considered that the Korean strains of T. vaginalis are highly pathogenic.
