Pneumoccoccus is a gram positive coccus . It exhibitis a
marked tendency to arrangement as lanceolate diplococcus . It can grow poorly
or ordinay media . It usually ferments insulin . It is soluble in bile and is
frequent pathgens to man . Pneumococcus may be termed as Diplococcus pneumoniae
or streptococcus pneumoniae because it closely resembles to Streptococcus
viridans .
Morphology
i)
Shape and size – oval or lanceolate diplococcus in
pairs . It is 1 μ in length .
ii)
Usually it is arranged in pair . Short chain of three
to four may be present on artificial media particularly in fluid variety .
iii)
Each pair is enclosed in a single capsule .
iv)
Non sporing .
v)
Non motile .
vi)
Gram positive and non-acid fast diplococcus .
Pathology produced by Pneumococcus –
1. The
organism usually present in throat enters along nasopharynx → to nose ( Rhinitis ) → transverse along
nasoclear duct → to lacrimal sac (
dacrocystis ) . It may often be found in cornea ( corneal ulcer ) .
2. From
throat , the organism will enter into Eustachian tube → to middle ear ( otitis media ) .
3. From
throat ,, the organism wil enter into lower respiratory tract producing → Laryngitis
→ Bronchitis and Broncho pneumonia
→ Lobar pneumonia → Seticaemia and from blood , the organism
localises in different serous sacs like pleura ( pleurisy ) , pericardium (
pericarditis ) , peritoneum ( peritonitis ) , meninges (meningitis ) synovial
membrane ( arthritis ) may invade serious sacs directly .
4. From
throat , the organism may enter into mastoid bone ( Mastoditis ) and it will
lead to osteomyelitis of mastoid bone and inflammation of Mastoid air
sinus → leads to subdural abscess → when abscess bursts , the organism will
enter into the meninges ( pneumococcal meningitis ) .
