صفات عمومي انتروباكترياسه ها باسيل هاي گرم منفي مي باشند. - اكسيداز آن ها منفي است. - هوازي - بي هوازي اختياري مي باشند. - گلوكز را تخمير مي كنند. - قادر به احياي نيترات به نيتريت هستند. - در انواع متحرك فلاژل از نوع پري تريش دارند.

باسیل های گرم منفی هوازی بیهوازی اختیاری رشد در شرایط هوازی دربلاد ومک کانکی ↓ ( + ) تست اکسیداز ( - ) TSIتخمیر گلوکز در ( + ) → ← ( - ) اسینتوباکتر Enterobacteriaceae

IMVIC

11/27/2018 Dr.M.Sharifi

ONPG test

β- galactosidase & ONPG test ο-Nitrophenyl-β-D-galactopyranoside is structurally similar to lactose : exception, glucose replaced by a ο-Nitrophenyl group This test detects the enzyme β-galactosidase far more quickly than does the test for lactose fermentation 11/27/2018 Dr.M.Sharifi

ο-Nitrophenol is a chromophore : colorless when bounded , yellow in its free form 11/27/2018 Dr.M.Sharifi

ONPG test tablets that can be easily reconstituted by adding a small amount of water are available commercially and are convenient for use in the laboratory. Organisms with strong β-galactosidase activity may produce a positive test within a few minutes after inoculation of the medium 11/27/2018 Dr.M.Sharifi

11/27/2018 Dr.M.Sharifi

Escherichia coli (cont’d) Characteristics Dry, pink (lactose positive) colony with surrounding pink area on MacConkey

Escherichia coli (cont’d) Ferments glucose, lactose, trehalose, & xylose Positive indole and methyl red tests Does NOT produce H2S or phenylalanine deaminase Simmons citrate negative Usually motile Voges-Proskauer test negative

کلبسیلا تست های بیوشیمیایی فلور طبیعی روده اما بیماریزا زمانی که به بافت های دیگر راه یابد TSI A/A + gas Urea + Citrate + MR-, VP+ Motility – دارای هر دو آنتی ژن O و K

Klebsiella species (cont’d) Significant biochemical reactions Lactose positive Most are urease positive Non-motile

Klebsiella species Usually found in GI tract Four major species K. pneumoniae is mostly commonly isolated species Possesses a polysaccharide capsule, which protects against phagocytosis and antibiotics AND makes the colonies moist and mucoid Has a distinctive “yeasty” odor Frequent cause of nosocomial pneumonia

Enterobacter species Comprised of 12 species; E. cloacae and E. aerogenes are most common Isolated from wounds, urine, blood and CSF Major characteristics Colonies resemble Klebsiella Motile MR negative; VP positive

Enterobacter species (cont’d)

Enterobacter species Comprised of 12 species; E. cloacae and E. aerogenes are most common Isolated from wounds, urine, blood and CSF Major characteristics Colonies resemble Klebsiella Motile MR negative; VP positive

Serratia species (cont’d) Major characteristics Ferments lactose slowly Produce characteristic pink pigment, especially when cultures are left at room temperature S. marscens on nutrient agar →

Hafnia species Hafnia alvei is only species Has been isolated from many anatomical sites in humans and the environment Occasionally isolated from stools Delayed citrate reaction is major characteristic

Proteus, Morganella & Providencia species All are normal intestinal flora Opportunistic pathogens Deaminate phenylalanine All are lactose negative

Proteus species P. mirabilis and P. vulgaris are widely recognized human pathogens Isolated from urine, wounds, and ear and bacteremic infections Both produce swarming colonies on non-selective media and have a distinctive “burned chocolate” odor Both are strongly urease positive Both are phenylalanine deaminase positive

Proteus species (cont’d) A exhibits characteristic “swarming” B shows urease positive on right

11/27/2018 Dr.M.Sharifi

Morganella species Morganella morganii is only species Documented cause of UTI Isolated from other anatomical sites Urease positive Phenylalanine deaminase positive

Providencia species Providencia rettgeri is pathogen of urinary tract and has caused nosocomial outbreaks Providenicia stuartii can cause nosocomial outbreaks in burn units and has been isolated from urine Both are phenylalanine deaminase positive

Citrobacter species Citrobacter freundii associated with nosocomial infections (UTI, pneumonias, and intraabdominal abscesses) Ferments lactose and hydrolyzes urea slowly Resembles Salmonella sp.