Role of alpha-toxin in Clostridium perfringens infection determined by using recombinants of C. perfringens and Bacillus subtilis.
Clostridium perfringens type A strains which differed in alpha-toxin (phospholipase C [PLC]) productivity were inoculated intraperitoneally or intravenously into mice, and then their 50% mouse lethal doses (LD50) were determined. Strain NCTC 8237 produced ninefold higher PLC activity than strain 13. The mean LD50 for the former was 1 log unit lower than that for the latter. Two isogenic strains were constructed from strain 13: strain 13(pJIR418 alpha) (pJIR418 alpha contains the plc gene), which produced ninefold higher PLC activity than strain 13; and strain 13 PLC-, which showed no PLC productivity at all because of transformation-mediated gene disruption. The mean LD50 for strain 13(pJIR418 alpha) was 1 log unit lower than those for strain 13 PLC- and strain 13. These results indicate that PLC functions as a virulence-determining factor when it is produced in a sufficient amount. Such a difference in LD50 was also observed between Bacillus subtilis with and without the cloned plc gene. Inoculation of B. subtilis PLC+ intravenously into mice caused marked thrombocytopenia and leukocytosis. Mice inoculated with B. subtilis at 2 LD50 died because of circulatory collapse. Histological examination revealed that intravascular coagulation and vascular congestion occurred most prominently in the lungs. These results suggest that PLC plays a key role in the systemic intoxication of clostridial myonecrosis, probably by affecting the functions of platelets and phagocytes.
Ninomiya
M
M
Department of Hospital Pharmacy, Kagawa Medical School, Japan.
Matsushita
O
O
Minami
J
J
Sakamoto
H
H
Nakano
M
M
Okabe
A
A
D000818:Animals; D001412:Bacillus subtilis; D001427:Bacterial Toxins / Q000378:metabolism / Q000633:toxicity*; D002135:Calcium-Binding Proteins; D003015:Clostridium Infections / Q000473:pathology / Q000503:physiopathology*; D003016:Clostridium perfringens / Q000472:pathogenicity*; D004906:Erythrocyte Count; D005738:Gas Gangrene / Q000503:physiopathology; D006460:Hemolysin Proteins; D017737:Macrophages, Peritoneal / Q000382:microbiology; D008297:Male; D051379:Mice; D010976:Platelet Count; D014170:Transformation, Genetic; D010738:Type C Phospholipases / Q000378:metabolism
D001427:Bacterial Toxins; D002135:Calcium-Binding Proteins; D006460:Hemolysin Proteins; C020452:Clostridium perfringens theta-toxin; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens