肠道杆菌Enterobacteriaceae Enterobacteriaceae ( (肠杆菌科肠杆菌科) )肠杆菌科目前有44个菌属、170多个种。多为肠道正常菌群，但可成为条件致病菌；少数为致病菌。A.All bacilli belonging to Enterobacteriaceaeare short gram-negative rods, either mobile or non-mobile. B.All bacilli belonging to Enterobacteriaceae are facultative anaerobes. They grow in common media. Most of the enteric bacilli form round, convex, smooth colonies with distinct edges.Lactose（乳糖）（乳糖） fermentationMechanism: Non-pathogenic enteric bacilli can ferment lactose while pathogenic enteric bacilli such as Shigella and Salmonella can not.Media: SS-plate or EMB plate , TSI agar slantsBasic components: lactose and a pH indicator C.The identification of Enterobacteriaceae is largely depend on biochemical reactions Results ResultsSS platered coloniesred coloniesnon-pathogenic/non-pathogenic/非致病菌非致病菌非致病菌非致病菌white colonieswhite colonies pathogenic/ pathogenic/致病菌致病菌致病菌致病菌D.Enterobacteriaceae have complex antigenic structures.H Ag (flagella) somatic O Ag (lipopolysaccharide)K/Vi Ag (capsule) E.E.Common pathogenic materials for Enterobacteriaceae Common pathogenic materials for Enterobacteriaceae include:include:bacterial structures (pili, capsule)bacterial structures (pili, capsule) toxins (enterotoxin, endotoxin) toxins (enterotoxin, endotoxin)Infections outside the intestines caused by bacterial translocation Opportunistic infection including septicemia, pneumonia, meningitis and urinary tract infections Community-acquired infectionurinary tract infectionsE. coli associated urinary tract infectionE. coli causes urinary tract infections such as acute cystitis（急急性性膀膀胱胱炎炎） and pyelonephritis（肾盂肾炎肾盂肾炎）.Infections inside the intestines caused by pathogenic E. coliCommon symptoms include Gastroenteritis（肠胃炎肠胃炎）, diarrhea（腹泻）（腹泻） and dysentery（痢疾）（痢疾）. Disease transmission is by fecal-oral route （粪口途径）（粪口途径）. EnteroEnterot toxigenic oxigenic E. coli E. coli ( (ETEC/ETEC/肠产毒性大肠杆菌肠产毒性大肠杆菌肠产毒性大肠杆菌肠产毒性大肠杆菌) ) Entero Enterop pathogenic athogenic E. coli E. coli ( (EPEC/EPEC/肠致病性大肠杆菌肠致病性大肠杆菌肠致病性大肠杆菌肠致病性大肠杆菌) ) Entero Enteroi invasive nvasive E. coli E. coli ( (EIEC/EIEC/肠侵袭型大肠杆菌肠侵袭型大肠杆菌肠侵袭型大肠杆菌肠侵袭型大肠杆菌) ) Entero Enteroh hemorrhagic emorrhagic E. coli E. coli ( (EHEC/EHEC/肠出血性大肠杆菌肠出血性大肠杆菌肠出血性大肠杆菌肠出血性大肠杆菌) ) Entero Enteroa aggregative ggregative E. coli E. coli ( (EAEC/EAEC/肠集聚性大肠杆菌肠集聚性大肠杆菌肠集聚性大肠杆菌肠集聚性大肠杆菌) )Cause travellers diarrhea. Two types of plasmid-encoded toxins are produced: Heat labile toxins (LT/耐热肠毒素耐热肠毒素)activate adenyl cyclase（腺苷环化酶）（腺苷环化酶） which catalyze ATP to cAMP Heat stable toxins (ST/不耐热肠毒素不耐热肠毒素)activate guanyl cyclase（鸟苷环化酶）（鸟苷环化酶） to catalyze GTP to cGMP cAMP/cGMP are the intracellular second messagers. The former increases the secretion of water and ions, and the latter inhibits ionic uptake. Clinical signs: watery diarrhea, fever and nausea.EnteroEnterot toxigenic oxigenic E. coli E. coli ( (ETEC/ETEC/肠产毒性大肠杆菌肠产毒性大肠杆菌肠产毒性大肠杆菌肠产毒性大肠杆菌) ) Commonly associated with infant diarrhea. Characteristic lesion with destruction of microvilli without invasion Clinical signs: fever, diarrhea with non-bloody stools, vomiting and nausea.Enteropathogenic E. coli (EPEC/肠致病性大肠杆菌肠致病性大肠杆菌) Associated with elder children and adult diarrhea. Without flagella High virulence: a small number of EIEC can cause serious illness Clinical signs: Acute inflammatory responses and tissue destruction. Produce diarrhea with little fluid, much blood and mucus containing polymorphonuclear cells. EnteroEnteroi invasive nvasive E. coli E. coli ( (EIEC/EIEC/肠侵袭型大肠杆菌肠侵袭型大肠杆菌肠侵袭型大肠杆菌肠侵袭型大肠杆菌) )EHEC produces bacteriophage-mediated exotoxin. This toxin is called Vero toxin (VT) because of its cytotoxicity to cultured Vero cells. The illness is characterized by serious abdominal pain and diarrhea which is initially watery but then becomes bloody. In children, the disease may be progressed to a systemic stage called as hemolytic uremic syndrome (kidney injury) with 10% death rate.Enterohemorrhagic E. coli (EHEC/肠出血性大肠杆菌肠出血性大肠杆菌) A dominant serotype of EHEC is E. coli O157:H7 It causes a persistent, mucus-watery diarrhea with vomiting and dehydration in infants. It produces enteroaggregative heat-stable toxin (EAST) similar to the heat stable toxins of ETEC. It produces mucous associated autoagglutinin which causes aggregation of the bacteria and formation of biofilm. EnteroEnteroa aggregative ggregative E. coli E. coli ( (EAEC/EAEC/肠集聚性大肠杆菌肠集聚性大肠杆菌肠集聚性大肠杆菌肠集聚性大肠杆菌) )E. coli Enterobacter AerogenesIMViC testIndole testMethyl red (MR) testVoges-Proskauer (VP) testCitrate utilization test 枸橼酸盐试验吲哚试验甲基红试验产气肠杆菌微生物学检测微生物学检测防治原则防治原则菌毛疫苗菌毛疫苗QUIZ 1主要引起婴儿和旅行者腹泻的大肠埃主要引起婴儿和旅行者腹泻的大肠埃希菌是：希菌是：A.肠产毒型大肠埃希菌肠产毒型大肠埃希菌B.肠致病型大肠埃希菌肠致病型大肠埃希菌C.肠侵袭型大肠埃希菌肠侵袭型大肠埃希菌D.肠出血型大肠埃希菌肠出血型大肠埃希菌人类细菌性痢疾的最常见病原菌人类细菌性痢疾的最常见病原菌人类细菌性痢疾的最常见病原菌人类细菌性痢疾的最常见病原菌（急性细菌性痢疾，慢性细菌性痢疾）（急性细菌性痢疾，慢性细菌性痢疾）（急性细菌性痢疾，慢性细菌性痢疾）（急性细菌性痢疾，慢性细菌性痢疾）痢疾发病总数在前五位，死亡在前十位（传染病）痢疾发病总数在前五位，死亡在前十位（传染病）革兰氏阴性短小杆菌，无鞭毛，有菌毛，无芽胞，革兰氏阴性短小杆菌，无鞭毛，有菌毛，无芽胞，无荚膜无荚膜O抗原是分类依据，可以分为抗原是分类依据，可以分为4群（种），群（种），40余个余个血清型（包括亚型）血清型（包括亚型）致病性：黏附、侵袭、胞内繁殖、细胞间扩散致病性：黏附、侵袭、胞内繁殖、细胞间扩散Shigella志贺菌属Salmonella 沙门菌属 急性消化道传染病，我国乙类传染病急性消化道传染病，我国乙类传染病 Enteric fever (typhoid fever) is the most serious form of salmonella infection which only occurs in human Carrier state is common In untreated patients, the death rate is 7% to 14% Antibiotic therapy is essential, vaccines are not effective and not widely used肠热症肠热症 (伤寒、副伤寒伤寒、副伤寒)1.The microbe initially invades intestinal mucosal epithelium and propagate at the local. 2.The microbe penetrates into the bloodstream to cause the first round of bacteremia with symptoms of fever, general discomfort and pain. 3.The microbe enters many organs such as liver, spleen, kidney, gall and marrow for further propagation. 4.The microbe penetrates into the bloodstream again to cause the second round of bacteremia with serious symptoms of high fever, swell of spleen and liver, rose-colored spots in skin, and tissue injury.enteric fever development1. 致病菌致病菌S. typhi （伤寒沙门菌）（伤寒沙门菌）S. paratyphi A （甲型副伤寒杆菌）（甲型副伤寒杆菌）S. schottmuelleri （肖式沙门菌）（肖式沙门菌）S. hirschfeldii （希式沙门菌）（希式沙门菌）enteric fever Diagnosis 2. 标本采集标本采集 Blood first week Stool and urine from the second week on Marrow can be considered because of its high and permanent positive results.enteric fever diagnosis3. Widal test （肥达试验）（肥达试验）a quantitative agglutination test using the known O antigen of S.typhi , and H antigens of S. typhi and S. paratyphi A/B to detect specific serum antibodies. For one single serum sample, The titers of anti-O antigen IgM 1:80 and/or anti-H antigen IgG 1:160. For two serum samples that collected with an interval of 57 days, 4-fold increase in titers of specific antibody.沙门菌引起的其它疾病沙门菌引起的其它疾病急性胃肠炎急性胃肠炎(食物中毒，Gastroenteritis /food-poisoning)败血症败血症It is the most common Salmonella infection and usually transmitted from contaminated food. However, only a few of food poisoning-causing salmonella serotypes can produce enterotoxin.Many Salmonella serotypes can cause septicemia. This disease is commonly found in children or adult with low immunity. QUIZ 2肠热症发病一周内，进行病原性诊断肠热症发病一周内，进行病原性诊断应选择：应选择：A.尿培养尿培养B.血培养血培养C.粪便培养粪便培养D.肥达试验肥达试验Helicobacter pylori 幽门螺杆菌慢性胃炎，消化性溃疡，胃癌慢性胃炎，消化性溃疡，胃癌2005诺贝尔奖获得者诺贝尔奖获得者Barry Marshall，Robin Warren于于1983年，从胃炎组织标本年，从胃炎组织标本中分离出幽门螺杆菌，并证实该菌是胃炎及消中分离出幽门螺杆菌，并证实该菌是胃炎及消化道溃疡的病原菌化道溃疡的病原菌一端有2-6根鞭毛鞭毛，运动活泼的革兰氏阴性螺杆菌主要生化鉴定依据：脲素酶脲素酶、过氧化氢酶、氧化酶均为阳性