1、Case study and question,A 31-year-old woman with face pain came to the hospital. She was unable to open her mouth because of facial muscle spasms and had been unable to eat for 4 days because of severe pain in her jaw. The doctor found the patient trismus牙关紧闭 and risus sardonicus苦笑面容. Her husband co
2、mplained that 1 week before, she had incurred a puncture刺伤 wound to her toe while walking in her garden.,1.How should this diagnosis be confirmed？ 2. What is the procedure for treating this patient？ 3.Should management wait until the lab results are available？ 4.What is the long term prognosis预后for
3、this patient？,She had cleaned the wound and removed a mall pieces of wood from it, but she had not sought medical attention,Category,Clostridium Species,diseases including gas gangrene气性坏疽, tetanus破伤风and botulism肉毒杆菌中毒. pseudomembranous colitis假膜的结肠炎(PC) and food poisoning. Main pathogensis factors
4、are exotoxins. perfringens, tetani, botulinum, difficile,Biochemical Characteristics,Gram(+); long and slender菌体细长;,peritrichous flagella周鞭毛, no capsule无荚膜,terminal located round spore(drum-stick apperance使细菌呈鼓槌状)芽胞正圆，位于菌体顶端its diameter greater than vegetative cell.,Morphology,BIOCHEMICAL CHARACTERI
5、STICS,Culture:obligate anaerobic; swarming occures on blood agar, faint hemolysis血平板上，有微弱溶血. does not ferment any carbohydrate and proteins.,BIOCHEMICAL CHARACTERISTICS,Resistance: tolerate boiling for 60 min.alive several ten years in soil. Classification and Antigenic Types: C tetani is the only s
6、pecies. There are no serotypes,General introduction,C tetani is found worldwide. Ubiquitous in soil, it is occasionally found in intestinal flora of humans and animals C.tetani is the cause of tetanus,or lockjaw. When spores are introduced into wounds by contaminated soil or foreign objects such as
7、nails or glass splinters,Pathogenic condition 致病条件,Wound need form anaerobic microenvironment伤口需形成厌氧微环境 Wound narrow and deep（刺伤puncture ），soil stain泥土污染 extensive wound大面积创伤、 suffer burns烧伤，much necrotic tissue坏死组织多，local deficiency blood局部组织缺血 Aerobe and facultative anaerobemixed infection; polyin
8、fection有需氧菌或兼性厌氧菌混合感染的伤口Only local multiply,non-nvasive ,main exotoxin effect 无侵袭力，仅在局部繁殖，其致病作用完全有赖于病菌所产生的外毒素,Clostridium Tetani,Pathogenesis of tetanus caused by C tetani,Pathogenicity,No invasiveness; toxemia毒血症 produces two exotoxins: tetanolysin破伤风溶血毒素, and tetanospasmin破伤风痉挛毒素(a kind of neuroto
9、xin, toxicity strong毒性极强,对人致死量1g) The actions of tetanospasmin,retrograde transport 逆向运转to (CNS) Delitescence潜伏期：a few days to several weeks The two animal species most susceptible to this toxemia are horses and humans.,tetanospasmin破伤风痉挛毒素,结构 菌体：一条多肽 释出菌体：轻链（A链）-S-S-重链（B链） B链：神经节苷脂结合的单位,可提纯制疫苗 A链：活
10、性亚单位毒性作用,Clostridium tetani -Tetanospasmin,disseminates播散systemically binds to ganglioside神经甘脂 receptors inhibitory neurones in CNS glycine 甘氨酸 Neurotransmitter神经递质 stops nerve impulse to muscles spastic paralysis痉挛性麻痹 severe muscle contractions and spasms can be fatal,Mechanisms of tetanospasmin,sp
11、astic paralysis (rigid paralysis),破伤风痉挛毒素作用机制,膜的转位 通过重链N端的介导产生膜的转位使轻链进入胞质溶胶 胞质溶胶中作用靶的改变 A链发挥毒性作用，使储存抑制性神经介质小泡膜蛋白发生改变，阻止抑制性神经介质-氨基丁酸的释放，使肌肉活动的兴奋与抑制失调，造成麻痹性痉挛,破伤风痉挛毒素作用机制,与神经系统的结合 B链识别运动神经元外胞浆膜上的受体并结合，促使毒素进入细胞内小泡中 内在化作用 小泡从外周神经末稍沿神经轴突逆行向上，到达运动神经元细胞体，进入传入神经末稍，最终进入中枢神经系统,典型的症状,苦笑面容,muscles(trismus or lo
12、ckjaw牙关紧闭, risus sardonicus苦笑,in neonates; infection typically originates from umbilical切断脐带stump残端;very poor prognosis in infants预后不良,the body extremely rigid, and opisthotonos角弓反张(a spasm in which the head and heels足跟 are bent backward and the body bowed forward),cramping痉挛 and twitching抽搐 of musc
13、les,the neck and jaw muscles (trismus).,Clinical Manifestations,no fever but sweats profusely 多汗 pain, especially in the area of the wound Complications include fractures骨折, bowel impaction肠嵌塞, intramuscular hematoma血肿, muscle ruptures肌肉撕裂, and pulmonary, renal, and cardiac problems,Immunity免疫性,Humo
14、ral immunity(antitoxin抗毒素) The disease does not produce immunity in the patient.病后不会获得牢固免疫力 Active immunity人工免疫follows vaccination with tetanus toxoid类毒素 破伤风免疫属外毒素免疫，主要是发挥中和作用（毒素与中枢神经组织结合非常牢固，一旦结合即非抗毒素所能中和）,Epidemiology,In some developing countries, tetanus is still one of the ten leading causes of
15、death, and neonatal tetanus accounts for approximately one-half of the cases worldwide. In the US, intravenous drug abusers have become another population with an increasing incidence of clinical tetanus In untreated tetanus, the fatality rate is 90% for the newborn and 40% for adults.,Diagnosis,Dia
16、gnosis is primarily by the clinical symptoms (above). The wound may not be obvious. It is important for the clinician to be aware that toxigenic strains of C tetani can grow actively in the wound of an immunized person. Numerous syndromes, including rabies and meningitis, have symptoms similar to th
17、ose of tetanus and must be considered in the differential diagnosis.,infantDPT (diptheria, pertussis, tetanus)三联疫苗tetanus toxoid 破伤风类毒素antigenicno exotoxic activity 免疫程序：3、4、5月 3次 2、7岁加强 2次特殊情况 1次,Vaccination,Control,The offending organism must be removed by local debridemen清创术,防止创口厌氧微环境的形成 toxoid 紧
18、急预防TAT （tetanus antitoxin破伤风抗毒素）; Metronidazole甲硝唑 (For more serious wounds) AIDS patients may not respond to prophylactic预防 injections of tetanus toxoid,扎耳引起破伤风案例,Case-2,The patient，53-years-old， because road accident, limb serious crush injury 挤压伤，go to hospital .,Case-2,After 2 days he with fever
19、 and pain in the wound, local tissue necrosis. Infected muscle is discolored (purple mottling斑纹) and edematous水肿 and produces a foul-smelling exudate; gas bubbles form. Question Your diagnosismay be What do you must control the disease.,C. perfringens,soil, fecal contamination gas gangrene气性坏疽 swell
20、ing of tissues gas release fermentation products wound contamination 两端平切粗大杆菌 芽胞位于次极端，呈椭圆形，不大于菌体 无鞭毛 体内有明显的荚膜,lecithinase 卵磷脂酶 production,Laboratory identification,Double Hemolysis Circles,Nagler reaction 菌落周围乳白色浑浊圈,Virulence factors toxin produced by all strains acts as a lecithinase卵磷脂酶 diagnosis:
21、 Nagler reaction-egg yolk agar,C. perfringens - Pathogenicity,接种血平板或庖肉培养基，镜检及生化反应鉴定 动物实验 如怀疑食物中毒，在发病后一日内，检出大于105病菌/克食品或106病菌/克粪便可确立诊断,分离培养,庖肉培养基 牛乳“汹涌发酵”,Stormy fermentation,Toxins,产气荚膜梭菌主要和次要毒素及其分型,Toxins,The alpha toxin - a lecithinase卵磷脂酶that lyses erythrocytes, platelets leukocytes endothelial c
22、ells. The theta toxin has similar hemolytic and necrotizing effects. DNAase, hyaluronidase,Enterotoxin,Many strains of type A produce enterotoxin, which is a heat-labile protein and destroyed immediately at 100 . Trypsin胰酶 treatment enhances the toxin activity threefold. The toxin is produced primar
23、ily by type A strains but also by a few type C and D strains. It disrupts ion transport in the ileum回肠(primarily) and jejunum空肠 by inserting into the cell membrane and altering membrane permeability. As superantigen.,Without treatment death occurs within 2 days,effective antibiotic therapy debrideme
24、nt清创术; 扩创术(即清除伤口腐肉的手术) anti-toxin Amputation截肢术 & death is rare,Associayed diseases of C. perfringens,Gas gangrene 气性坏疽 Food poisoning 食物中毒Enterotoxin Cellulitis蜂窝织炎, Fasciitis筋膜炎,三、肉毒梭菌,（Cbotulinum）,Biological Features,Anaerobic Gram-positive rod-shaped sporeformer produces a protein neurotoxic. so
25、il, sediments沉积物 of lakes, ponds池塘, decaying vegetation. intestinal tracts of birds, mammals and fish.,Botulinum toxin,binds peripheral nerve receptors acetylcholine neurotransmitter作用于外周神经肌肉接头处，抑制神经介质乙酰胆碱的释放 inhibits nerve impulses flaccid paralysis迟缓性麻痹 death respiratory cardiac failure,Mechanisms
26、 of botulinum toxin,flaccid paralysis,Botulinum toxin,Bio terrorism 生物恐怖/生物战剂 not an infection resembles a chemical attack 10 ng can kill a normal adult,-18-36 hours: -weakness, dizziness眩晕,dryness of the mouth口干. -Nausea,vomiting. -Neurologic features: blurred vision视力模糊, inability to swallow不能吞咽,
27、difficulty in speech说话吃力, descending weakness of skeletal muscles肌力下降, respiratory paralysis.,Clinical syndromes,Botulism(肉毒中毒),food poisoning rare fatalgermination of spore inadequately sterilized canned food home not an infection,Diagnosis,-by clinical symptoms alone -differentiation difficult. -
28、most direct and effective: serum or feces. -most sensitive and widely used: mouse neutralization test. 48h. Culturing of specimens 5-7d.,Treatment,Individuals known to have ingested food with botulism should be treated immediately with antiserum. antibiotic therapy (if infection) Vaccination will no
29、t protect hosts from botulism, however passive immunisation with antibody is the treatment of choice for cases of botulism.,Prevention,-proper food handling and preparation. - spores survive boiling (100 degrees at 1 atm) 1h. -toxin heat-labile, boiling or intense heating, inactivate the toxin. -bul
30、ge膨胀, gas, spoiled.,所致疾病,食物中毒 进食污染食物（多为罐头、肉制品、豆制品）发生食物中毒-食入毒素 临床表现：少见胃肠道症状，主要为神经末梢麻痹（松驰型） 乏力、头痛眼肌麻痹：复视、斜视、眼睑下垂咽部肌肉麻痹：吞咽、咀嚼困难、口齿不清膈肌麻痹，呼吸困难窒息死亡 神志清楚 病死率高,Medicine,Blepharospasm眼睑痉挛,Crows feet prior to BOTOX injection,Crows feet following BOTOX treatment,botulinum toxin injections are targeted at the
31、muscles around the eye.,Clostridium Difficile Infection Dra. Merle VAMC San Juan,（ Cdifficile）艰难梭菌,Pathogenicity 致病性,Neonat intestinal tract新生儿肠道中normal flora正常菌群 Enterotoxin, cytotoxin 肠毒素和细胞毒素,C. difficile,After antibiotic use使用抗生素后 Intestinal normal flora -greatly decreased导致菌群失调可引起内源性感染或院内交叉感染 C
32、olonization occurs Enterotoxin secreted Pseudomembanous colitis假膜性肠炎,Pseudomembranous Colitis,Pseudomembranous colitis (PC) results predominantly as a consequence of the elimination of normal intestinal flora through antibiotic therapy. Symptoms include abdominal pain with a watery diarrhea and leuk
33、ocytosis. “Pseudomembranes“ consisting of fibrin, mucus and leukocytes can be observed by colonoscopy. Untreated pseudomembranous colitis can be fatal in about 27-44%.,Therapy,Discontinuation of initial antibiotic (e.g. ampicillin)Specific antibiotic therapy (e.g. vancomycin万古霉素),no oxidative phosph
34、orylation fermentation killed by oxygen lack certain enzymes superoxide dismutase O2-+2H+ H2O2 catalase H2O2 H20 + O2 peroxidase H2O2 H20 /NAD to NADH,Obligate (strict) anaerobes,过氧物酶,Non-spore-forminganaerobic bacteria 无芽胞厌氧菌,Bacterial Flora of the Body,Site Total Bacteria Ratio(per/ml or gm) Anaer
35、obes:AerobesUpper AirwayNasal Washings 103-104 3-5:1Saliva 108-109 1:1Tooth Surface 1010-1011 1:1 Gingival Crevice牙龈缝 1011-1012 1000:1 Gastrointestinal TractStomach 102-105 1:1Small Bowel 102-104 1:1Ileum 104-107 1:1Colon 1011-1012 1000:1Female Genital Tract Endocervix子宫颈口区 108-109 3-5:1Vagina阴道 108
36、-109 3-5:1,与人类疾病相关的主要无芽胞厌氧菌,*70-80% infection of oral, intestinal tract, urogenital tract are caused by non-spore-forming anaerobic bacteria,I. Biological characteristics:,G+ bacilli : polymorphic, no- motile, growing slow,biochemical react slowly* Bifidobacterium双歧杆菌* Lactobacillus乳酸菌,I. Biological
37、 characteristics,2. G- bacilli : capsul, pili, no motile, *Bacteroides- B. fragilis; B. melaninogenicus*Fusobacterium-F. nucleatum 3. G+ cocci: *peptococcus *peptostreptococcuscause infection with other bacteria 4.G- cocci:*Veillonella韦荣球菌，咽喉部主要厌氧菌cause infection with other bacteria,临床上最常见的无芽胞厌氧菌分离株
38、,乳杆菌,Strict anaerobe infectious disease,Sites throughout body Muscle, cutaneous/sub-cutaneous necrosis Abscesses,disease,endogenous infection内源性感染， nonspecific infection无特定病型， purulent local inflammation, abscess,大多为化脓性感染，tissue necrosis excreta分泌物或脓液ropiness粘稠，乳白色、粉红色、血色或棕黑色，foul smell有恶臭，有时有gas气体
39、aminoglycoside antibiotics invalid使用氨基糖苷类抗生素无效,临床上遇到以下情况，应考虑有无厌氧菌感染,Clues to Anaerobic Infection,Infections in continuity to mucosal surfaces Infections with tissue necrosis and abscess formation Putrid odor恶臭味 Gas in tissues Polymicrobial flora,II. Pathogenesis致病性:,*Infection mixed with other aerob
40、es*Anaerobic environment厌氧微环境pathogenic condition感染条件： immunity function lower宿主免疫力下降 radiotherapy, chemotherapy， diabetes, chronic consumptive disease maligmant tumor barrier destruction：enterobrosis肠穿孔, open fracture开放骨折, dental extraction拔牙 local anaerobic environment：ischemia局部缺血 tissue necrosis
41、 flora disequlibrium菌群失调*Pathogenic factors: LPS, capsule, enzymes,Virulence Factors,Anti-phagocytic capsule Also promote abscess formation Tissue destructive enzymes B. fragilis produces variety of enzymes (lipases, proteases, collagenases) that destroy tissue Abscess Formation Beta-lactamase produ
42、ction B. fragilis protect themselves and other species in mixed infections Superoxide dismutase production Protects bacteria from toxic O2 radicals as they move out of usual niche,Characteristics of Anaerobic Infections,Most pathogenic anaerobes are usually commensals共生体 Originate from our own flora
43、 Predisposing Conditions Breeches in the mucocutaneous barrier displace normal flora Compromised vascular supply Trauma with tissue destruction Antecedent infection,Characteristics of Anaerobic Infections,3. Complex Flora Multiple species Abdominal Infection Avg of 5 species 3 anaerobic 2 aerobic Le
44、ss complex then nl flora Fecal flora 400 different species Those predominant in stool are not infecting species Veillonella, Bifidobacterium rarely pathogenic Species uniquely suited to cause infection predominate,4. Synergistic Mixture of Aerobes & Anaerobes E. coli Consume O2 Allow growth of anaer
45、obes Anaerobes promote growth of other bacteria by being antiphagocytic and producing B-lactamases,所致疾病,septicemia，败血症 中枢神经系统感染 呼吸道感染 口腔牙齿感染 腹部会阴部感染 女性生殖道感染,III. Laboratory diagnosis:,标本采取 Direct smear;直接涂片镜检 Anaerobic culture分离培养与鉴定,Failure to grow in the lab on common media BIOCHEMICAL KITS e.g. API SYSTEM GAS CHROMATOGRAPHY volatile fermentation products,
