Question

The ratio of the radiiof h atom and its nucleus me s 10*10*10*10*10

Answer 1

The differences and similarities between salmonella and shigella are as follows: -

(1) Gram’s nature- Both organisms are gram negative.

-Salmonella

-Shigella

(2) Motility- Shigella is non motile whereas Salmonella is motile with peritrichous flagella.

(3) Shape of microbe- Salmonella is rod shaped microbe while Shigella is slender bacilli microbe.

(4) Differential media- is Hektoen agar. In which Shigella colonies will appear green in colour while Salmonella colonies appear in black in colour.

(5) H2S production- Shigella don't produces H2S while Salmonella produces H2S.

(6) Mainly causes disease- Shigella causes Shigellosis while Salmonella causes Salmonellosis.

(7) Route of transmission- Disease can be transmitted through contaminated food and water, personal contact even from animals. But Salmonella is transmitted by raw food while Shigella by person to person contact.

(8) Major pathogen- Shigella= Shigella dysenteriae

Salmonella = Salmonella typhi

(9) Reservoir of organism- For Shigella= Human and primates only.

For Salmonella = Human and animal.

(10) Toxin production- Shigella produces heat labile toxin called Shiga toxin while Salmonella produces enterotoxin.

(11) Organism affect human organs-

Salmonella affect small and large intestine whereas Shigella affects colon.

(12) Incubation period- Shigella = 1-2 days

Salmonella =6-72 hours.

(13) Dosage- Salmonella required larger infective dosage than for Shigella.

(14) Other factors- Both are facultative anaerobic and non-spore forming organisms.