scholarly journals Verbascoside Protects Mice From Clostridial Gas Gangrene by Inhibiting the Activity of Alpha Toxin and Perfringolysin O

2020 ◽  
Vol 11 ◽  
Author(s):  
Jian Zhang ◽  
Shui Liu ◽  
Lining Xia ◽  
Zhongmei Wen ◽  
Naiyu Hu ◽  
...  
2002 ◽  
Vol 184 (7) ◽  
pp. 2034-2038 ◽  
Author(s):  
Milena M. Awad ◽  
Julian I. Rood

ABSTRACT The pathogenesis of Clostridium perfringens-mediated gas gangrene or clostridial myonecrosis involves the extracellular toxins alpha-toxin and perfringolysin O. Previous studies (T. Shimizu, A. Okabe, J. Minami, and H. Hayashi, Infect. Immun. 59:137-142, 1991) carried out with Escherichia coli suggested that the perfringolysin O structural gene, pfoA, was positively regulated by the product of the upstream pfoR gene. In an attempt to confirm this hypothesis in C. perfringens, a pfoR-pfoA deletion mutant was complemented with isogenic pfoA+ shuttle plasmids that varied only in their ability to encode an intact pfoR gene. No difference in the ability to produce perfringolysin O was observed for C. perfringens strains carrying these plasmids. In addition, chromosomal pfoR mutants were constructed by homologous recombination in C. perfringens. Again no difference in perfringolysin O activity was observed. Since it was not possible to alter perfringolysin O expression by mutation of pfoR, it was concluded that the pfoR gene product is unlikely to have a role in the regulation of pfoA expression in C. perfringens.


2020 ◽  
Vol 11 ◽  
Author(s):  
Shui Liu ◽  
Xiaofeng Yang ◽  
Hong Zhang ◽  
Jian Zhang ◽  
Yonglin Zhou ◽  
...  

2001 ◽  
Vol 69 (12) ◽  
pp. 7904-7910 ◽  
Author(s):  
Milena M. Awad ◽  
Darren M. Ellemor ◽  
Richard L. Boyd ◽  
John J. Emmins ◽  
Julian I. Rood

ABSTRACT To examine the synergistic effects of alpha-toxin and perfringolysin O in clostridial myonecrosis, homologous recombination was used to construct an alpha-toxin deficient derivative of a perfringolysin O mutant of Clostridium perfringens. The subsequent strain was complemented with separate plasmids that carried the alpha-toxin structural gene (plc), the perfringolysin O gene (pfoA), or both toxin genes, and the resultant isogenic strains were examined in a mouse myonecrosis model. Synergistic effects were clearly observed in these experiments. Infection with the control strain, which did not produce either toxin, resulted in very minimal gross pathological changes, whereas the isogenic strain that was reconstituted for both toxins produced a pathology that was clearly more severe than when alpha-toxin alone was reconstituted. These changes were most apparent in the rapid spread of the disease, the gross pathology of the footpad and in the rate at which the mice had to be euthanatized for ethical reasons. Elimination of both alpha-toxin and perfringolysin O production removed most of the histopathological features typical of clostridial myonecrosis. These effects were restored when the mutant was complemented with the alpha-toxin structural gene, but reconstituting only perfringolysin O activity produced vastly different results, with regions of coagulative necrosis, apparently enhanced by vascular disruption, being observed. Reconstitution of both alpha-toxin and perfringolysin O activity produced histopathology most similar to that observed with the alpha-toxin reconstituted strain. The spreading of myonecrosis was very rapid in these tissues, and coagulative necrosis appeared to be restricted to the lumen of the blood vessels. The results of these virulence experiments clearly support the hypothesis that alpha-toxin and perfringolysin O have a synergistic effect in the pathology of gas gangrene.


2004 ◽  
Vol 72 (9) ◽  
pp. 5204-5215 ◽  
Author(s):  
David K. O'Brien ◽  
Stephen B. Melville

ABSTRACT Clostridium perfringens is the most common cause of clostridial myonecrosis (gas gangrene). Polymorphonuclear cells (PMNs) appear to play only a minor role in preventing the onset of myonecrosis in a mouse animal model of the disease (unpublished results). However, the importance of macrophages in the host defense against C. perfringens infections is still unknown. Two membrane-active toxins produced by the anaerobic C. perfringens, alpha-toxin (PLC) and perfringolysin O (PFO), are thought to be important in the pathogenesis of gas gangrene and the lack of phagocytic cells at the site of infection. Therefore, C. perfringens mutants lacking PFO and PLC were examined for their relative cytotoxic effects on macrophages, their ability to escape the phagosome of macrophages, and their persistence in mouse tissues. C. perfringens survival in the presence of mouse peritoneal macrophages was dependent on both PFO and PLC. PFO was shown to be the primary mediator of C. perfringens-dependent cytotoxicity to macrophages. Escape of C. perfringens cells from phagosomes of macrophage-like J774-33 cells and mouse peritoneal macrophages was mediated by either PFO or PLC, although PFO seemed to play a more important role in escape from the phagosome in peritoneal macrophages. At lethal doses (109) of bacteria only PLC was necessary for the onset of myonecrosis, while at sublethal doses (106) both PFO and PLC were necessary for survival of C. perfringens in mouse muscle tissue. These results suggest PFO-mediated cytotoxicity toward macrophages and the ability to escape macrophage phagosomes may be important factors in the ability of C. perfringens to survive in host tissues when bacterial numbers are low relative to those of phagocytic cells, e.g., early in an infection.


RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 19676-19685 ◽  
Author(s):  
Dongneng Jiang ◽  
Liqun Zhang ◽  
Fei Liu ◽  
Chang Liu ◽  
Linlin Liu ◽  
...  

Gas gangrene is a bacterial infection that produces gas in tissues in gangrene.C. perfringenswith alpha-toxin plays a key role in gas gangrene. Detection ofC. perfringensis highly important in clinical diagnosis of gas gangrene.


2014 ◽  
Vol 10 (1) ◽  
pp. 32 ◽  
Author(s):  
Evy Goossens ◽  
Stefanie Verherstraeten ◽  
Leen Timbermont ◽  
Bonnie R Valgaeren ◽  
Bart Pardon ◽  
...  

1999 ◽  
Vol 67 (9) ◽  
pp. 4902-4907 ◽  
Author(s):  
Darren M. Ellemor ◽  
Rebecca N. Baird ◽  
Milena M. Awad ◽  
Richard L. Boyd ◽  
Julian I. Rood ◽  
...  

ABSTRACT A hallmark of gas gangrene (clostridial myonecrosis) pathology is a paucity of leukocytes infiltrating the necrotic tissue. The cause of this paucity most likely relates to the observation of leukocyte aggregates at the border of the area of tissue necrosis, often within the microvasculature itself. Infecting mice with genetically manipulated strains of Clostridium perfringens type A (deficient in either alpha-toxin or theta-toxin production) resulted in significantly reduced leukocyte aggregation when alpha-toxin was absent and complete abrogation of leukocyte aggregation when theta-toxin was absent. Thus, both alpha-toxin and theta-toxin are necessary for the characteristic vascular leukostasis observed in clostridial myonecrosis.


2019 ◽  
Vol 10 ◽  
Author(s):  
Kiyonobu Yamamura ◽  
Hiroshi Ashida ◽  
Tokuju Okano ◽  
Ryo Kinoshita-Daitoku ◽  
Shiho Suzuki ◽  
...  

1968 ◽  
Vol 14 (6) ◽  
pp. 705-709 ◽  
Author(s):  
A. H. W. Hauschild ◽  
F. S. Thatcher

Classical and food-poisoning strains of Clostridium perfringens type A were tested for their capacity to produce gas gangrene in guinea pigs.The virulence of food-poisoning strains producing heat-sensitive spores and showing beta hemolysis on sheep-blood agar was comparable to that of the classical strains. The most virulent strains of both groups produced fatal infection with only three to five vegetative cells. Of 13 food-poisoning, heat-sensitive strains showing no beta hemolysis, only three were lethal when a minimum of 4 × 104 to 4 × 108 cells was injected. None of the food-poisoning, heat-resistant strains produced fatal infection with cell numbers up to 4 × 108. The groups of strains showed a correlation between virulence and formation of alpha toxin in liquid culture.It is concluded that a number of heat-sensitive, beta-hemolytic strains of C. perfringens may cause gas gangrene as well as food poisoning, and that the current subdivision of C. perfringens type A strains into classical and food-poisoning groups is no longer tenable.


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