1. Proteus-Providencia-Morganella group
@ Gram negative rods, motile, aerobic and
facultatively anaerobic
@ Catalase positive, oxidase negative,
@ Attack sugars fermentatively with gas
production, phenylalanine positive
@ Urea positive, citrate positive, gelatin
positive.

3. PROVIDENCIA:
@ Gram negative rods, motile, aerobic and
facultatively anaerobic
@ Catalase positive, oxidase negative,
@ Attack sugar fermentatively with gas
production, citrate positive
@ Gelatin positive, urease negative,
phenylalanine positive.

5. MORGANELLA:
@ Gram negative rods, motile, aerobic and
facultatively anaerobic.
@ Catalase positive, oxidase negative,
@ Glucose fermented with production of
gas, phenylalanine positive
@ urease positive, citrate negative, gelatin
negative.

7. PROTEUS SPECIES:
@ P. mirabilis.
@ P. vulgaris.
PROVIDENCIA SPECIES:
@ P. rettgeri
@ P. stuartii
MORGANELLA SPECIES:
@ M. morganii: The only one species of medical importance. No swarming

9. ANTIGENIC STRUCTURE:
@ The cell wall (O) antigens of Proteus
strains: OX-2, OX-19, & OX-K cross
react with Rickettsia antigens and so
are used in diagnosis of rickettsial
infections by the Weil-­Felix test.

11. PATHOGENSIS:
@ All group members are:
# Very motile, Hence invade the tissue
directly and seriously.
# Proteus and Morganella are urease
positive. This enzyme hydrolyses urea in
urine, form ammonia, and leads to rise in
urine pH. This causes:
Formation of stones
Multiplication of bacteria & renal failure

13. EPIDEMIOLOGY:
@ Normal habitat: human colon, water, soil.
@ From the colon they enter the urethra,
specially in women.
Diseases:
@ UTI caused by all.
@ Pneumonia, wound infections and
septicaemia are caused by Proteus.
@ Nosocomial and hospital infections are
caused by P. mirabilis and Prov. rettgerii.

15. LABORATORY DIAGNOSIS:
Specimens:
@ Urine, sputum, swabs, blood.
Microscopy:
@ Gram negative rods, motile, no capsule.
Culture:
@ On Mac Conkey, blood and CLED agar.
@ Proteus produces swarming on blood
agar & inhibited by bile salts (Mac Conkey).

17. Biochemical Reactions:
a) Lactose negative, glucose positive.
b) Catalase positive, oxidase negative.
c) Phenylalanine positive.
d) Urea positive (Proteus & Morganella).
e) Citrate positive (Proteus & Providencia
f) Gelatin positive (Proteus only)--- API

19. Biochemical reactions of Proteus, Morganella, and Providencia species
Urea
Cit
Ind
Suc
H2S
PDA GG
P.mirabilis + D -
P.vulgaris
M.morgani
P.rettgeri
P.stuarti
Key: Urea = Urease test, Cit = Citrate test, Ind = Indole test,
Suc = Sucrose fermentation, H2S = Hydrogen sulphide
production, PDA = Phenylalanine deaminase test, GG = Gas
from glucose fermentation, D = Different strains give
different results

21. TREATMENT
@ Antibiotic sensitivity is needed.
@ Prot. mirabilis is treated by ampicillin
@ Indole-positive species (Prot. vulgaris,
Prov. rettgeri, Morg. morganii) are best
treated by cefotaxime.