Burchard G D, Mirelman D
Department of Biophysics, Weizmann Institute of Science, Rehovot, Israel.
Exp Parasitol. 1988 Aug;66(2):231-42. doi: 10.1016/0014-4894(88)90095-1.
The pathogenic potential of four Entamoeba histolytica isolates obtained from asymptomatic carriers and possessing nonpathogenic zymodemes was compared to four E. histolytica strains obtained from invasive cases of amebiasis and having pathogenic zymodemes. Both xenic and axenic cultures of a number of strains were tested. Determinations of cytopathogenicity were done in vitro by measuring the rates of destruction of tissue cultured monolayers of baby hamster kidney cells by intact amebae or by its cell-free extracts. The in vivo virulence was tested by assessing their capacity to form hepatic abscesses in hamsters or cecal ulcerations in rats. The results obtained show that two of the isolates from asymptomatic carriers (strains SAW 1734R clAR and WI:0385:191) were as virulent as three of the invasive ones (HM-1:IMSS, 200:NIH, and SAW 408). Two other isolates from asymptomatic carriers and one from a dysentery case were avirulent. All the E. histolytica isolates tested were similarly sensitive to metronidazole and emetine (IC50 1-10 micrograms/ml). The results indicate that the pathogenic potential of E. histolytica varies between isolates and can be affected by culture conditions and by the presence or absence of bacterial cells. These findings suggest that virulence does not necessarily correlate with a pathogenic zymodeme.
将从无症状携带者分离得到的、具有非致病酶谱型的4株溶组织内阿米巴的致病潜力，与从侵袭性阿米巴病病例分离得到的、具有致病酶谱型的4株溶组织内阿米巴菌株进行了比较。对多个菌株的共生培养物和无菌培养物都进行了测试。通过测量完整的阿米巴或其无细胞提取物对幼仓鼠肾细胞组织培养单层的破坏率，在体外测定细胞致病性。通过评估它们在仓鼠中形成肝脓肿或在大鼠中形成盲肠溃疡的能力，来测试体内毒力。所获得的结果表明，来自无症状携带者的2株分离株（菌株SAW 1734R clAR和WI:0385:191）与3株侵袭性分离株（HM-1:IMSS、200:NIH和SAW 408）的毒力相当。另外2株来自无症状携带者的分离株和1株来自痢疾病例的分离株无毒力。所有测试的溶组织内阿米巴分离株对甲硝唑和吐根碱的敏感性相似（IC50为1 - 10微克/毫升）。结果表明，溶组织内阿米巴的致病潜力在不同分离株之间存在差异，并且可能受到培养条件以及细菌细胞的存在与否的影响。这些发现表明，毒力不一定与致病酶谱型相关。
