Morphological and Cultural Characteristics of Microorganisms: General Characteristics of Streptococcus :

Morphological and Cultural Characteristics of Microorganisms: General Characteristics of Streptococcus :: 1.      Streptococcus: General  Characteristics of Streptococcus :       a. Gram Positive coccus. b. Arranged in short chain or...

General Characteristics of Bacillus

Figure: Bacillus Spp.

1.     Bacillus:

General  Characteristics of Bacillus: 

 a. Gram positive rods & arranged in chains.

 b.  Obligate aerobe & facultative anaerobe,

c. Capsulated & endospore-forming bacteria ,

d. Non-flagellated, non-motile,

e. Grows on ordinary media.

Habitat:

They are common in soil worldwide at mesophilic                

temperatures and only a few are pathogenic to

humans, Bacillus anthracis primarily infects herbivores,

Diseases Produced by Bacillus:

a. Anthrax ,

b. Respiratory granulomatous infection,

   c.Tubercular diseases.

General Characteristics of Staphylococcus

1.     Staphylococcus:

General  Characteristics of Staphylococcus:

a. Gram Positive coccus, arranged in grape-like clusters forms,

b. Spherical or rounded in shape, about 0.7-1.2 µm in diameter,

c. Capable of growing in ordinary media, like blood agar & Nutrient agar.

d. Some species are highly pathogenic,  

e. Many of are aerobic & Facultative anaerobes.

f. Produce golden yellow, lemon yellow or white colors of colony,

g. Non-flagellated , non-sporing, non-motile,

h. Catalase, Coagulase, Phosphatase, & DNAse positive,

Habitat:
i)  Reside on mucous membranes and skin of mammals (60% intermittent carriers)

ii) Anterior nares and on mucous membranes of about 30% of the population

iii) Carriage rate in considerably higher among hospital personnel

 iv) Source of infection - individual's own microflora (or from hospital staff)

  v) Can survive on inanimate objects (lab coats, gloves, bedding)

Diseases Produced by Staphylococcus:

a. Cellulitis ,

Fig: Staphylococcus 

b. Impetigo contagiosa ,

c. Pneumonia

d. Infective endocarditis,     

e. Otitis media,

f. Meningitis,

g. Septicemia,

h. Toxic shock syndrome,   

i. Osteomyelitis,

j. Perianal abscess,       

k. Carbuncles ,

l. Enterocolitis .

General Characteristics of Streptococcus :

1.     Streptococcus:

General  Characteristics of Streptococcus :      

a. Gram Positive coccus.

b. Arranged in short chain or long chain,

c. Spherical or oval in shape,

d. About 1 µm in diameter,

e.   Many are facultative anaerobes.

f. Grow better in enriched media,

g. Non-flagellated , non-sporing, non-motile, usually

non-capsulated but one more virulent,

h. Catalase negative,

Habitat:

a. Found on the skin and inside the naso-pharynx, mouth and throat in small numbers ,

b. In Pyogenic lesions,

c. Rectum.

Diseases Produced by Streptococcus :

a.      Pyogenic diseases:

i)                   Respiratory tract:

● Cellulitis

Figure : Streptococcus

●Tonsilitis

●Pharyngitis

●Peritonsillar abscess

ii)                Skin & soft tissue:

●Erysipelas

●Impetigo

●Pyoderma

                                                                                  

iii)              Ear infection:

●Otitis media                                                    

●Mastoiditis

                                                                                 

iv)               Genital tract:                                                       

●Puerperal sepsis

v)                  Deep infection:

●Lymphangitis

●Acute endocarditis

● Septicaemia

b)Toxigenic diseases:

i)                   Scarlet fever,

ii)                Toxic shock syndrome

c) Immunogenic diseases/post streptococcal disease:

i)                   Acute rheumatic fever (ARF),

ii)                Acute glomerulonephritis (AGN),