Streptococcus

Monday, January 12, 2015

Streptococcus

  Strepto means chain and Coccus means seed . Any of a group of bacter  Strepto means chain and Coccus means seed . Any of a group of bacteria which as they remain attached after fission are usually found in chains .



     Morphology

i)                    Shape and size – These are spherical or ovoid cocci , average diameter is 0.5 to 1 μ
ii)                   Arrangement – Arrranged in chain usually but streptococcus faecalis which is present in the intestinal tract is usually arranged in pairs or short chains .
iii)                 Non motile due to absence of flagellum .
iv)                 Non – sporing
v)                  Non-capsulated .



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Disease produced by streptococcus

  ( A) By Streptococcus haemololyticus –

  1.. Infection of skin subcutaneous tissue and lymphatics
  
a)      Impetigo contagiosa
b)      Paronychia- infection of semilunar fold at the base of the nail
c)      Erysipelas- Spread through lymphatic and tissue spaces of cutis and septicaemia may occur .
d)      Cellulitis .
e)      Ludwing’s angina – a type of cellulites of the  floor of mouth . It may extend to the neck or throat .
f)        Wound infection .
g)      Lymphangitis – inflammation of lymphatic vessels .


  2.. Infection of respiratory tract with mouth and throat …

a)      Epidemic sore throat
b)      Acute follicular tonsillitis
c)      Lungs – broncho pneumonia
d)      Scarlet fever .

   3… Infection of Genito urinary tract

a)      Kidney -  Acute nephritis .
b)      Lesion of endometrium – endometritis
c)      Testes and epididymes – epididymo-orchitis will produce .
4…   Heart – Acute bacterial endocarditis and pericarditis .
5..  Brain -  Meningitis may occur due to septicaemia or from otitis media and mastoiditis .





(B)….   By Streptococcuus viridans ---

a)      Teeth – Pyorrhoea , alveolitis and apical absecess .
b)      Throat – chronic tonsillitis and pharyngitis .
c)      Appendix – Appendicitis .
d)      Stomach – peptic ulcer
e)      Heart – sub acute bacterial endocarditis .,

f)        Gall bladder – Chronic chole cystitis .




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