Gadeberg O V, Orskov I, Rhodes J M
Infect Immun. 1983 Jul;41(1):358-64. doi: 10.1128/iai.41.1.358-364.1983.
The alpha-hemolytic Escherichia coli strain C134-73 Hly+ was primarily cytocidal to human blood monocytes and granulocytes in vitro in the presence of fresh autologous plasma. Monocytes and granulocytes underwent marked morphological changes during incubation with the bacteria, and the percentages of intact phagocytes decreased progressively with the time of incubation. The cytotoxic effect increased with the number of bacteria per phagocyte and was produced by log-phase microorganisms only. Neither free hemolysin nor free cytotoxic activity to leukocytes could be detected in the incubation medium if the bacteria were removed from the test system. Bacteria-free culture supernatants containing alpha-hemolysin were cytotoxic to monocytes, granulocytes, and lymphocytes, monocytes and granulocytes being the most sensitive. However, this effect was abolished by fresh autologous plasma. Two nonhemolytic strains, a mutant derivative of C134-73 Hly+ and strain X43, were not cytotoxic. These observations suggest that alpha-hemolysin associated with the bacterial cells may enhance the virulence of E. coli by injuring phagocytes, whereas free alpha-hemolysin may be of minor importance because its cytotoxic effect is neutralized by host plasma.
α溶血大肠杆菌菌株C134 - 73 Hly +在新鲜自体血浆存在的情况下，体外对人血单核细胞和粒细胞具有主要的细胞杀伤作用。单核细胞和粒细胞在与细菌孵育期间经历了明显的形态变化，完整吞噬细胞的百分比随着孵育时间逐渐降低。细胞毒性作用随着每个吞噬细胞的细菌数量增加而增强，并且仅由对数期微生物产生。如果从测试系统中去除细菌，则在孵育培养基中检测不到游离溶血素和对白细胞的游离细胞毒性活性。含有α溶血素的无细菌培养上清液对单核细胞、粒细胞和淋巴细胞具有细胞毒性，单核细胞和粒细胞最为敏感。然而，这种作用被新鲜自体血浆消除。两个非溶血菌株，C134 - 73 Hly +的突变衍生物和X43菌株，没有细胞毒性。这些观察结果表明，与细菌细胞相关的α溶血素可能通过损伤吞噬细胞来增强大肠杆菌的毒力，而游离α溶血素可能不太重要，因为其细胞毒性作用被宿主血浆中和。
