PROTEUS SPECIES

(proteus species) Mode of transmission,mechanisms by which microorganisms cause disease and diagnosis

Define proteus

A Gram negative rod.Its an enterobactericeae

 List the species of proteus 

·         Proteus mirabilis

·         Proteus vulgaris

 Mention the species of medical importance

·         Proteus mirabilis

·         Proteus vugaris

Describe the normal habitat

• Proteus species are found in the intestines of humans and animals in soil sewage and water. They are frequent contaminants of cultures

Describe the morphology Proteus 

• Proteus species are
•  actively motile,
• Non-capsulated Gram negative
• pleomorphic rods (wide rage in shape and size) vary from an almost coccal form to very long filaments (proteus a Greek god who often changed his shape).

.

 Describe the mode of transmission and pathogenicity of Salmonella species

TRANSMISSION

•  Through contact to the urethra or wound

PATHOGENICITY-

Proteus mirabilis causes:-

1.      Urinary infections, especially following catheterisation or cystoscopy. Infections are also associated with the presence of stones. Proteus infected urine has an alkaline reaction.

2.      Abdominal and wound infections. Proteus is often a secondary invader of ulcers, pressure sore burns and damaged tissues.

3.      Septicaemia and occasionally meningitis and chest infections

Proteus vulgaris occasionally isolated from urine pus and other specimens

 Describe the laboratory diagnosis Salmonella 

1.SPECIMENS

Depending on the site of infection, these include urine, pus and sputum

2.CULTURE CHARACTERISTICS

Media for growth are;-

• Blood agar-swarming is seen
• DCA-    Swarming inhibited
• SSA--    Swarming inhibited
• Macconkey agar--       Swarming inhibited

·         When cultured aerobically, most proteus strains produce a characteristic swarming growth over the surface of blood agar and several other culture  Media.

·         Swarming however, is inhibited on media containing bile salts such as Mac Conkey agar, DCA, XLD agar and SS agar.

·         On these media individual non – lactose-fermenting colonies are produced after overnight incubation at 35 – 37 ⁰c.

·          proteus cultures has a distinctive smell.

Culture on various enrichment and selective media.The media include:-

• Selenite F
• XLD agar
• DCA
• SS agar
• Blood agar(sub culture)

3.BIOCHEMICAL TESTS

·         Proteus mirabilis can be differentiated from proteus vulgaris by the indole test.

·          Proteus mirabilis is indole negative.

·         Proteus Vulgaris are indole positive

·         Proteus rapidly hydrolyzes urea (with 4 hours) this is an important early screening test in differentiating enteric pathogens from proteus.  Serology

·         Motility is positive in MIU

·         Methyl red positive

·         Citrate pisitive

·         Some of the antigen of proteus strains (OX19,) OXK and OX2) agglutinate with sera from patients with rickettsial disease . These reactions form the basis of the Weil – Felix test .

·         NB:It produces an enzyme known as Beta lactamase

PREVENTION AND CONTROL:

• Eliminating the source of infection, particularly by control of carriers.
• When sanitary control of the environment is difficult, active immunization with typhoid vaccine.
• Treating the infected cases

Key Points 

Define proteus

A Gram negative rod in the Genus enterobactericiae

·          Proteus mirabilis

·         Proteus vulgaris

Mention the species of medical importance(5 minutes)

·         Proteus mirabilis

·         Proteus vugaris

:Describe the normal habitat

• Proteus species are found in the intestines of humans and animals in soil sewage and water. They are frequent contaminants of cultures

Evaluation

• List 2species of proteus
• Mention 3 Biochemical tests
• Mention the appearance of colonies on blood Agar
• Mention on how to prevent swarming