Yonsei Med J.  1969 Dec;10(2):181-191. 10.3349/ymj.1969.10.2.181.

Virulence of Entamoeba histolytica according to the Strains in Korea II. Studies on the Pathogenicity of Entamoeba histolytica Strains in Rats

• Soh CT
• Cho KM
• Lee JY

• KMID: 1107460
• DOI: http://doi.org/10.3349/ymj.1969.10.2.181

Abstract

The experimental infection of rats with seven strains of Entamoeba histolytica were carried out according to animal ages, number of inoculated amebae, rat strain differences and rat-culture passages. The rat cecal scoring technique of Neal (1951) was utilized to measure the invasiveness of the parisite. The results are summarized and concluded as follows; 1. In the infection of Sprague-Dawley strain rat with YS9-strain and NAMRU II-stran amebae, which wem confirmed highly invasive to the membrane of cecum of rabbits in the previous reports (Cho,1968; Cross,1968), remarkab1e invasiveness was observed in the 30-day-old rat groups with the average cecal score above 5.0. Although no statistical differences of virulence by the number of inoculations showed in rat groups, the cecal scores were markedly reduced in the 50,000 amebae inoculated rats. 2. The hybrid albino rats were considered unsuitable for virulence study of E. histolytica, since the invasiveness of the amabae was inconsistant. 3. The virulences of YS 14 and YS16-strains from cyst carrier showed no virulence, YS 15 from cyst carrier and YS 24 from liver abscess were moderately invasive, and only YS25 from liver abscess showed highly invasive as with YS 9 and NAMRU II-strain amebae. By rat-culture passage, YS14-strain and YS24-strain amebae showed marked increase of invasiveness. It was presumed that the rat-culture passage should be indispensably supplememed in the studies on the virulence of E. histolytica.

MeSH Terms

Adult
Animals
Cecum/microbiology
Entamoeba histolytica/*pathogenicity
Female
Human
Korea
Male
Middle Aged
Rats
Virulence