文档介绍：会计学
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肠道杆菌
Enterobacteriaceae (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。
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All bacilli belonging to Enterobacteriaceae are short gram-negative rods, either mobile or non-mobile.
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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.
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Lactose（乳糖） fermentation
Mechanism: 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 slants
Basic components: lactose and a pH indicator
The identification of Enterobacteriaceae is largely depend on biochemical reactions
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Results
SS plate
red colonies
non-pathogenic/非致病菌
white colonies
pathogenic/致病菌
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Enterobacteriaceae have complex antigenic structures.
H Ag (flagella)
somatic O Ag (lipopolysaccharide)
K/Vi Ag (capsule)
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Common pathogenic materials for Enterobacteriaceae include:
bacterial structures (pili, capsule)
toxins (enterotoxin, endotoxin)
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Infections outside the intestines caused by bacterial translocation
Opportunistic infection
including septicemia, pneumonia, meningitis and urinary tract infections
Community-acquired infection
urinary tract infections
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E. coli associated urinary tract infection
E. coli causes urinary tract infections such as acute cystitis（急性膀胱炎） and pyelonephritis（肾盂肾炎）.
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