Morphology
i)
Shape – It is diplococcus , arranged in pair with flat
surface apposed ( plano-convex ) . It resembles like the letterb “D”
ii)
Size – It is about 1 μ in length and 0.8 μ in breadth .
iii)
Arrangement – It is arranged usually in pair and single
form or group may be found . It may be intracellular or extracellular .
iv)
It is non-sporing .
v)
There is ab sence of flagellum , so non-motile .
vi)
It is Gram negative diplococcus .
vii)
It is non-acid fast coccus .
Pathology produced by Nisseria Meningtidis –
Nesseria meningitides is a human pathogens and it will
produce cerebrospinal meningitis or spotted fever . It may produce chronic
meningococcal septicaemia in which the meninges are not involved usually . The
organism may spread when the defence mechanism of the body is lowered by
fatigue , in case of soldier . When there is lowering of general resistance ,
there may be increased tendency to over crowding .
Pathology ----
a) The
organism usually is present is nasopharynx .
b) From
nasophrynx , The organism reaches the sub arachnoid space and produces acute
inflammation of meninges and brain . ( Meningo – encephalitis ). In case of
children , it may produce posterior basal meningitis . In case of adult , it
may produce blockage of sub arachnoid space producing high rise of
cerebrospinal fluid pressure and intense headache . There may be the
formation of exudates in sub arachnoid space
and from the sub arachnoid space , the exudates may reach to the perivascular
space of brain .
c) There
may be dilation of ventricle producing internal hydrocephalus .
d) Congestion
of brain may be produced due to dilation of cerebral vessels .
e) Septicaemia
may be produced and it may affect meninges , heart and joints .
