ENTEROBACTERIACEAE ENTERIC GRAM NEGATIVE RODS - PowerPoint PPT Presentation

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ENTEROBACTERIACEAE ENTERIC GRAM NEGATIVE RODS

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ENTEROBACTERIACEAE ENTERIC GRAM NEGATIVE RODS Dr.Indumathi Gokula Metropolis Clinical laboratory FEATURES LARGE HETEROGENOUS GROUP : NATURAL HABITAT : HUMAN/ANIMAL ... – PowerPoint PPT presentation

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Title: ENTEROBACTERIACEAE ENTERIC GRAM NEGATIVE RODS


1
ENTEROBACTERIACEAEENTERIC GRAM NEGATIVE RODS
  • Dr.Indumathi
  • Gokula Metropolis Clinical laboratory

2
FEATURES
  • LARGE HETEROGENOUS GROUP
  • NATURAL HABITAT HUMAN/ANIMAL INTESTINE
  • MORE THAN 25 GENERA AND 110 SPECIES
  • 20-25 CLINICALLY SIGNIFICANT SPECIES
  • FACULTATIVE ANAEROBES, FERMENT CARBOHYDRATES,
    COMPLEX ANTIGENIC STRUCTURE
  • PRODUCE TOXINS AND VIRULENCE FACTORS

3
CHARACTERISTICS
  • GRAM NEGATIVE BACILLI
  • NON SPORING
  • MOTILE(PERITRICHOUS FLAGELLA)/NON MOTILE
  • CAPSULATED/NON CAPSULATED
  • NON FASTIDIOUS
  • FERMENT GLUCOSE WITH ACID/GAS
  • REDUCE NITRATES TO NITRITES
  • OXIDASE NEGATIVE/CATALASE POSITIVE
  • BIOCHEMICAL TESTS DONE TO DIFFERENTIATE THE
    VARIOUS SPECIES

4
CLASSIFICATION
  • COMPLEX
  • CHANGING TAXONOMY

LACTOSE FERMENTERS (LF) LATE LACTOSE FERMENTER (LLF) LACTOSE NON FERMENTERS NLF
E.COLI KLEBSIELLA ENTEROBACTER SERRATIA CITROBACTER ARIZONA PROVIDENCIA SHIGELLA SALMONELLA PROTEUS
5
ANTIGENIC STRUCTURE
  • COMPLEX
  • 3 ANTIGENS
  • O (SOMATIC)
  • H(FLAGELLAR)
  • K(CAPSULAR)

6
O ANTIGEN (SOMATIC)
  • MOST EXTERNAL PART OF CELL WALL LPS
  • REPEAT POLYSACCHARIDE UNITS
  • HEAT AND ALCOHOL RESISTANT
  • DETECTED BY AGGLUTINATION
  • ANTIBODIES TO O ARE IgM
  • GENUS SPECIFIC
  • CROSS SHARING
  • ASSOCIATED WITH DISEASE (UTI OR DIARRHOEA CAUSING
    E.COLI)
  • MORE THAN 150 TYPES

7
H ANTIGENS(FLAGELLAR)
  • LOCATED ON FLAGELLA
  • HEAT AND ALCOHOL LABILE
  • ANTIBODIES FLUFFY CLUMPS MAINLY IgG TYPE
  • MORE THAN 50 TYPES

8
K ANTIGENS (CAPSULAR)
  • EXTERNAL TO O ANTIGEN
  • MORE THAN 100 TYPES
  • PRESENT IN SOME GENERA
  • POLYSACCHARIDE/PROTEINS
  • ASSOCIATED WITH VIRULENCE
  • E.G.K1 OF E.COLI MENINGITIS, UTI
  • KLEBSIELLA UTI 8,9,10,24
  • Vi ANTIGENS IN SALMONELLA
  • INHIBITS PHAGOCYTOSIS
  • ANTIGENIC FORMULA E.COLI 055K5H21

9
ESCHERICHIA COLI
  • NORMAL INTESTINAL FLORA
  • DETECTION IN WATER INDICATES RECENT FECAL
    CONTAMINATION
  • ONLY ONE SPECIES
  • SEVERAL SEROTYPES AND BIOTYPES
  • MA LF
  • IMVIC --

10
PATHOGENICITY
  • URINARY TRACT INFECTION
  • DIARRHOEA
  • PYOGENIC INFECTION
  • SEPTICAEMIA

11
UTI
  • COMMON CAUSE OF ASCENDING INFECTION
  • PREGNANCY, SEXUALLY ACTIVE FEMALES, OTHER
    PREDISPOSING FACTORS LIKE OBSTRUCTION
  • PYELONEPHRITIS
  • UROPATHOGENIC STRAIN
  • VIRULENCE FACTOR HAEMOLYSIN
  • P PILUS
  • K ANTIGEN
  • O1,2,4,6,7,75 K SEROTYPES K1,2,3,5,12,13

12
E.COLI DIARRHOEA
  • 5 STRAINS
  • ENTEROPATHOGENIC(EPEC)
  • ENTEROTOXIGENIC(ETEC)
  • ENTEROINVASIVE(EIEC)
  • ENTEROHAEMORRHAGIC(EHEC)
  • ENTEROAGGREGATIVE(EAEC)/
  • DIFFUSE AGGREGATIVE

13
DIARRHOEA
  • WATERY STOOLS
  • ABDOMENAL CRAMPS
  • VOMITING
  • WITH OR WITHOUT FEVER
  • WITH OR WITHOUT BLOOD AND MUCUS
  • SELF LIMITING 5-10 DAYS

14
EPEC
  • INFANTILE DIARRHOEA SPORADIC CASES/INSTITUTIONAL
    OUTBREAK
  • INCUBATION 1-2 DAYS
  • O26B6,055B5 STRAINS
  • VIRULENCE FACTOR PILI (Bfp) intimin(adhesin)
    Tir ( translocated intimin receptor)
  • BACTERIAL ATTACHMENT TO MICROVILLI AND EFFACING
    (DISTRUPTION) MECHANISM

15
ENTEROPATHOGENIC E.COLI
16
EPEC DIAGNOSIS
  • ISOLATION
  • SEROTYPING WITH POLYVALENT SERA
  • TISSUE CULTURE ADHESION FLUORESCENT ACTIN STAIN
  • DNA BASED DETECTION FOR VIRULENCE GENES

17
ETEC
  • TRAVELLERS DIARRHOEA
  • BOTH ADULTS AND CHILDREN
  • CONSUMPTION OF WATER CONTAMINATED WITH SEWAGE
  • IP 1-7 DAYS NO FEVER
  • SELF LIMITING 2-6 DAYS
  • O6, 08, 025, 027

18
ETEC
  • VIRULENCE FACTOR
  • ENTEROTOXIN LT AND ST GENETIC CONTROL
  • PILI OR K PROTEINS
  • LT CHOLERA LIKE TOXIN, ACTIVATES
  • CYCLIC AMP PATHWAY FLUID HYPERSECRETION
    INTENSE PROLONGED
  • ST ACTIVATES CYCLIC GMP PATHWAY SHORT ONSET OF
    ACTION

19
ETEC
  • DIAGNOSIS
  • CULTURE FAECES
  • DETECT LT/ST TOXIN
  • LT TOXIN BY IN VIVO
  • IN VITRO
  • IN VIVO LIGATED RABBIT ILEAL LOOP (6-18HRS)
  • ADULT RABBIT SKIN TEST
  • IN VITRO ELISA
  • RIA
  • TISSUE CULTURE (CHO CELL LINES)

20
EIEC
  • DYSENTRY/FEVER
  • OLDER CHILDREN AND ADULTS
  • O124, 136, 144
  • IP 3 DAYS DURATION 7-10DAYS
  • VIRULENCE FACTOR PLASMID CODED OMP
  • INVASIVE ENDOCYTOSIS?INFLAMMATION?
  • NECROSIS?ULCERATION
  • DETECTION SERENY TEST
  • HeLA CELL INVASION

21
EHEC
  • DEVELOPED COUNTRIES
  • CONTAMINATED BEEF AND UNPASTEURIZED MILK
  • HAEMORRHAGIC COLITIS/HUS
  • IP 3-4 DAYS
  • DURATION 5-10 DAYS
  • O157H7
  • VEROTOXIN CYTOTOXINSHIGA LIKE TOXIN
  • DETECTION OF VERO TOXIN BY GENETIC PROBES
  • GROWTH ON MA SORBITOL AGAR

22
EAEC
  • ACUTE OR CHRONIC DIARRHOEA
  • gt14DAYS DURATION
  • DEVELOPING COUNTRIES
  • FOOD BORNE
  • CHARACTERISTIC ATTACHMENT TO CELLS STACKED
    BRICK FORMATION
  • VIRULENCE FIMBRIA, HEAT LABILE ENTEROTOXIN AND
    CYTOTOXIN

23
EAEC
24
SEPSIS/MENINGITIS
  • INADEQUATE NORMAL DEFENSES
  • SUSCEPTIBLE NEW BORN
  • UROSEPSIS
  • MENINGITIS K1 ANTIGEN IN NEONATES
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