Presentation on theme: "2001 -- A letter containing anthrax spores is mailed to NBC one week after the September 11 terrorist attacks on the Pentagon and World Trade Center. It."— Presentation transcript:
2001 -- A letter containing anthrax spores is mailed to NBC one week after the September 11 terrorist attacks on the Pentagon and World Trade Center. It was the first of a number of incidents around the country. In Florida, a man dies after inhaling anthrax at the offices of American Media Inc.
1What is Anthrax? Anthrax is blamed for several devastating plagues that killed both humans and livestock. Soon after scientists learned more about it in the late 1800s, it emerged in World War I as a biological weapon.
1. What is anthrax? Morphology Morphology -----observation under microscope Culture Culture ------observation of colonies
Morphology -----Observation under microscope 1-1.2um in width 3-5 um in length Gram positive Sporeforming rod Squared ends Endospore: ellipsoidal shaped centrally
Squared ends Morphology -----Observation under microscope Morphology -----Observation under microscope Endospore (resistant to staining)
Culture ----Observation of colonies aerobic Optimal condition: 37 C PH: 7.2-7.4 Blood plate Common plate Nutrient broth
Observation of colonies Diameter:2-4mm Colour:grayishwhite Rough colony : irregular, curving outgrowths from the margin. Colony of anthrax
Observation of colony Enhance production of poly -D-glutamyl capsule Incresed CO2 tension to 5% Mucoid colony type(thick capsule)
Pathogenicity of B.Anthracis Pathogenicity of B.Anthracis Disease Disease
Pathogenicity of B.Anthracis Poly-D-glutamyl capsule Poly-D-glutamyl capsule important important Anthrax toxin Anthrax toxin Polysaccharide of bacterium Antigen of spore
Poly-D-glutamyl capsule All virulent strains of B.Anthracis form this capsule anti-phagocytosis capsule
Anthrax Toxin Consist of 3 components : EF(edema factor) A fragment LF(lethal factor) (toxicity) PA(protective antigen) B fragment (non-toxicity,binding receptor)
Anthrax Toxin There are 3 active combing forms: EF+PA LF+PA EF+LF+PA EF+LF inactive
Disease multiply at the site of the lesion get into the circulation systemic pathology
Cutaneous anthrax :Less lethal forms include cutaneous infections, which occur if anthrax spores come in contact with a cut or other opening in the skin Pulmonary anthrax: If inhaled, anthrax spores can germinate and lead to infection within one to 60 days. This is pulmonary anthrax, which usually causes death. Gastrointestinal anthrax :Another form of anthrax develops in the intestine of those who eat improperly cooked meat of animals that have been infected with anthrax
Epilogue Naturally seldom get Anthrax from animals No chance from person to person transmation Treatment : antibiotics eg.penicillin
Anthrax as a biological weapon? Use your knowledge to conquer the disease,but not to destroy our life !
PA+LF lethal activity LF:Zn dependent protease that can include cytokine production in macrophage and lymphocyte MAPKK mitogen-activated protein kinase disrupt cellular signal
PA+LF+EF edema,necrosis,lethal Both the function of PA+EF and PA+LF Others to neutrophil: EF+LF engulfment of bacteria susceptibility to infection
Skin anthrax Less lethal forms include cutaneous infections, which occur if anthrax spores come in contact with a cut or other opening in the skin
Pulmonary anthrax If inhaled, anthrax spores can germinate and lead to infection within one to 60 days. This is pulmonary anthrax, which usually causes death. 肺炭疽胸片
intestinal anthrax Another form of anthrax develops in the intestine of those who eat improperly cooked meat of animals that have been infected with anthrax
1876 -- Robert Koch confirms bacterial origin of anthrax 1880 -- First successful immunization of livestock against anthrax. 1915 -- German agents in the United States believed to have injected horses, mules, and cattle with anthrax on their way to Europe during World War I 1937 -- Japan starts biological warfare program in Manchuria, including tests involving anthrax 1942 -- United Kingdom experiments with anthrax at Gruinard Island off the coast of Scotland. It was only recently decontaminated. 1943 -- United States begins developing anthrax weapons 1945 -- Anthrax outbreak in Iran kills 1 million sheep