Nippon Saikingaku Zasshi

Mice were injected subcutaneously with live staphylococci suspended in Freund's incomplete adjuvant, and effect of the infection on their susceptibility to lethal action of staphylococcal alpha-toxin was examined. The LD₅₀ of the alpha-toxin decreased in the mice of one week after infection as compared with those in non-infected ones, suggesting that the susceptibility to the alpha-toxin increased by the infection.
On the other hand, the LD₅₀ of the alpha-toxin increased in the mice of two and three weeks after infection, possibly due to the decrease of their susceptibility to lethal action of alpha-toxin.
The increase in the susceptibility of the infected mice to alpha-toxin was prevented by the pretreatment of the mice with staphylococcal toxoid or vaccine.

View full abstract

Show abstractHide abstract

Toxic glycolipid showing delayed lethal toxicity for mice was isolated from the firmly bound lipids of virulent human Mycobacterium tuberculosis, strain H₃₇Rv. Its chemical and biological properties were studied.
M. tuberculosis H₃₇Rv was extracted successively with methanol-ether (2:1, v/v) and chloroform. The resulting partially defatted bacterial residue was treated 5 times with 0.1N HCl at 37C overnight and then extracted with methanol-ether (2:1, v/v) and chloroform. The chloroform extract was subjected to a successive chromatographic purification on magnesium silicate-celite (chromatography I), on silica gel (chromatography II), and again on magnesium silicate-celite column (chromatography III).
The fractions of chromatography III containing glycolipid which exhibited an anthrone-positive spot (Rf:0.26) by thin layer chromatography with chloroform-methanol (85:15, v/v) as developing solvent were further submitted to chromatography on silica gel H column emploing chloroform-methanol (85:15, v/v) as eluent. When the eluate was subjected to preparative thin layer chromatogrophy [silica gel H; chloroform-methanol (85:15, v/v)], it showed a single spot on a thin layer chromatogram with several solvent systems.
Five repeated intraperitoneal injections with glycolipid (100μg) caused a heavy loss of body weight and deaths (70% in 5 weeks) in mice. The toxicity of this glycolipid was slow in occurrence and closely resembled that of cord factor (trehalose-6, 6'-dimycolate). The glycolipid showed a higher melting point (155-160C) and optical rotation ([α]D=+41.5±1.0°)than the cord factor. It contained neither nitrogen nor phoshorus. The purified toxic glycolipid contained trehalose and mycolic acid at an equimolecular ratio. These data suggest that the toxic glycolipid in the firmly bound lipids may be trehalose monomycolate.

View full abstract

Download PDF (2670K)

Register with J-STAGE for free!