2. The genus Escherichia is named after
Escherich who first described as Bacterium
coli commune
Parasite, living only in the human or
animal intestine
Detection of E coli in drinking water,
therefore, is taken as evidence of pollution
with human feces
Introduction
3. Gram negative
Straight rod measuring 1-3 X 0.4-0.7 m
arranged singly or in pairs
Capsule & fimbriae are found in some
strains
Morphology
4. Aerobe & facultative anaerobe
Temp: 10- 40 0 C
May be hemolytic on blood agar
Pink colonies on MacConkey’s agar
(lactose fermentation)
Growth
characteristics
6. Somatic 0 (LPS) - Endotoxic activity
Capsular K - protects against the
phagocytosis
Flagella H - Fimbriae promote virulence
( important in UTI)
Antigenic structure
7. Four main types:
UTI
Diarrhea
Pyogenic infections including meningitis
Septicemia (urosepsis & SIRS- systemic
inflammatory response syndrome)
Pathogenic diseases
8. Mid stream sample/semi quantitative culturing (Kass et
al ) >_ 1.00,000/ml of urine. ( significant Bacteriuria )
Urine should not be kept in wards for > 2 hours and to be
preserved at 4 c
Culture by standard loop method.
Fixed volume cultured on MacConkey agar Lactose
fermenters I M Vi C
Antibiotic sensitivity tested
Lab diagnosis
11. Also called as Friedlander’s
bacillus mucosus capsulatus
First isolated by Fried lander from
fatal cases of pneumonia
Introduction
12. Gram negative
Capsulated
Non-motile bacillus
Measures about 1-2
m X0.5- 0.8 m in
size
Morphology Culture
• Grows well on
ordinary media
• Opt. temp: 37 0 C
• Mucoid nature of
colonies are found
in the medium
due to the
accumulation of
slime produced
by Klebsiella
14. { {Pathogenesis
Second most popular
aerobic bacterial flora of
colon
Causes:
severe
bronchopnumonia
UTI’s
Nosocomial infections
Wound infections
Septicemia
Meningitis
Rarely diarrhea
Lab diagnosis
Cultures on blood agar
and MacConkey agar
Gram staining
Biochemical reactions
17. Belongs to the tribe protecae & LNF, hence
donot belong strictly to family
Enterobacteraceae
Normal intestinal commensals and
oppurtunistic pathogens like coliforms
The name “Proteus” refers to their
pleomorphism, after the Greek god Proteus
INTRODUCTION
18. Gram negative rod
Size 1 to 2 X 0.5-0.8 m
Exhibit swarming motility
Filamentous or granular
Non- sporing & non- capsulated
MORPHOLOGY
19. Aerobe & facultative anaerobe
Grow on ordinary medium
emitting putrefactive odor (fishy or
seminal)
Forms smooth, pale or colorless
colonies on MacConkey’s agar
CULTURE
20. Deamination of phenyl alanine (PPA
reaction)
Hydrolysis of urea
MR +ve
VP –ve
Ferments glucose by producing acid or gas
BIOCHEMICAL REACTIONS
