Published on

Published in: Business, Technology
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  2. 2. <ul><li>G+,lanceolate diplococcus </li></ul><ul><li>Formly classified as Diplococcus pneumoniae </li></ul><ul><li>Reclassified to streptococcus pneumoniae-genetic relation with strept. </li></ul><ul><li>Differs from strpt in- </li></ul><ul><li>1.morphology </li></ul><ul><li>2.bile solubility </li></ul><ul><li>3.optachin sensitivity </li></ul><ul><li>4.sp.polysach.capsule </li></ul>
  3. 3. <ul><li>First noticed –pasteur &Sternberg </li></ul><ul><li>Realtion betwn pneumococci &pneumonia –Frankel &Weichsalbaum </li></ul><ul><li>Morphology </li></ul><ul><li>Small-1 micron –slightly elongatd—one end broad ,other pointd,flame shaped /lanceolate shaped. </li></ul><ul><li>Occurs in pairs-with broad ends in apposition long axis of the coccus parellel to the line joining the two cocci in a pair.CAPSULATED-capsule enclosing each pair. </li></ul>
  4. 4. <ul><li>Capsules—bst seen in materials taken bst from exudates-may b lost onb repeatd cultivation NONMOTILE,NONSPORING </li></ul><ul><li>In culture typical morph—not apparent—cocci r more rounded tending to occur in short chains </li></ul><ul><li>Staind with Anilline dyes---G+ </li></ul><ul><li>Capsule-clear halo –inidan ink </li></ul>
  5. 5. <ul><li>Cultural chr. </li></ul><ul><li>Grow only in enriched media.—aerobes+fac.anero.Temp-37C---PH 7.8—growth is improcved by 5-10%Co2 </li></ul><ul><li>Blood agar-inc-18 hrscolonies-small,dome shaped,glistening,with an area of green discolouration(alpha hemolysis) </li></ul><ul><li>Resemble colonies of str. Viridans— </li></ul><ul><li>Furthr inc—colonies become flat—with raised edges and central umbonation---so concentric rings r seen on the surface whn viewd frm above—”Draughtsman/Carrom Coin appearance” </li></ul><ul><li>Sm strains that dvlp abundnt capsular material(3 &7)---form large mucoid colonies </li></ul>
  6. 7. <ul><li>Under anerobic condition---colonies in blood agar –sorrondd by zone of beta hemolysis due to—O2 labile hemolysin O </li></ul><ul><li>Liquid media(gluc broth)-growth occurs as uniform turbidity </li></ul><ul><li>Cocci readily undergoes autolysis in cultures due to activity of intracellular enzymes.,enhancd by bile salts,Na lauryl suphate,and other surface active antigens </li></ul><ul><li>Heat killd cultures do not undergo autolysis </li></ul>
  7. 8. <ul><li>Biochemical reactions </li></ul><ul><li>Fermnt---acid </li></ul><ul><li>Ferm.-testd in HISS’s serum water/srum agar slopes.inulin f-+(diff strp.) </li></ul><ul><li>-bile soluble— </li></ul><ul><li>1ml culture+drops of 10% sodium deoxycholate=lysis overn8 </li></ul><ul><li>Loopful of deoxycholate—lysis in few min </li></ul><ul><li>Bile/Bile salts--+ts---amidase---cleavs the bond between alanine &muramic acidin the peptidoglycan.---lysis of organism---soluble </li></ul><ul><li>Tst at nuetral PH using deoxycholate &youn culture </li></ul><ul><li>C-….O- </li></ul>
  8. 9. <ul><li>Resistance </li></ul><ul><li>Delicate—destroyd by 52C 15 min and antiseptics </li></ul><ul><li>Ic culture –destroyd on prolongd inc—accumulation of toxic peroxidase—strains maintaind in semisolid blood agar/by lyophilisation </li></ul><ul><li>Penicilline DOC </li></ul><ul><li>Resistance—intermediate(MIC 1micgm),high(2micgm)---due o mutation /gene transfer—by alteration penicillin binding proteinson surface—resistant to multiple strains—DRSP-Drug Resistant Streptococcus Pnuemoniae </li></ul>
  9. 10. <ul><li>sensitivity to Optochin—1/5lakh—diffr.from strp. </li></ul><ul><li>Antigenic properies </li></ul><ul><li>Most imp-Type specific capsular polsacharid/SSS/specific soluble substances-diffuse into cultural medium/infective exudates and tissues </li></ul><ul><li>Clas.of pneumococci-antigenic nature of capsular polysach. </li></ul><ul><li>From lobar pneumoniae—Types 1,2,3. and a heterogenus grp 4 </li></ul>
  10. 11. <ul><li>Typing done by </li></ul><ul><li>1.agglutinaion of cocci with type specific aniserum </li></ul><ul><li>2.Precipitation of SSS with specific serum </li></ul><ul><li>3.Capsule swelling reaction by Neufeld(quelling Reaction)—Suspn.pnuem+antiseum+loopful of methylene blue---in presence of homologous antiserum capsule becomes apparently swollen,sharply delineatd and refractile.can b done directly with spuum from a/c pneumoniae---antigencty varies in sp.—antegenic in humans-no resp in mice in large quantity(immunological paralysis)---small quatities---resp+ </li></ul>
  11. 12. <ul><li>Othr antigens-nucleoprotein,somatic C cho antigen </li></ul><ul><li>In a/c pneumonia case’s sera—an abnl protein—”btea globulin”---tht ppts somatic C r found---but dissappears during convalescnce </li></ul><ul><li>B-globulin—C reactive protein-(CRP)-not an antbody—a/c phase substance produced in hepatocytes—production stimulated by bac.inf.inflm.,malignancy, tissue destrrction---disappear whn infl.reactions subside </li></ul><ul><li>CRP-index - response to t/t in Rheumatic fever </li></ul>
  12. 13. <ul><li>Variation </li></ul><ul><li>On repeatd subculture—S-R variation. </li></ul><ul><li>R-colonies-rough-noncaps-autoaggluable-avirulent—as spontaneous mutants and outgrow the S type-in tissues they r eliminated by phagocytsR form +DNA---Transformation—Griffith </li></ul><ul><li>Toxin &virulent factors </li></ul><ul><li>O2labile hemolysin+lecocidin---weak---no virulence </li></ul><ul><li>Virulence depends on capsule and production of a toxin calld “pneumolysin” </li></ul>
  13. 14. <ul><li>Capsular poly sach-not phagocytosd effectvly---but suscepatble to surface Phagocyosis—being engulfd against a firm surface.(fibrin clot/epithelium) </li></ul><ul><li>Enhanced virulence of Type3-abundance of capsulr mat. </li></ul><ul><li>Noncapsular –avirulent </li></ul><ul><li>antibody to capsular polys..provides protection against inf. </li></ul><ul><li>Pneumolysin-a membrane damaging toxin by pneumococci-has cytotoxic+ complement activating property.virulnt fctr-immunogenic— </li></ul><ul><li>Pneumococcal autolysins by releasin bacterial components in infectd tissues, may also contribut to virulence </li></ul>
  14. 15. <ul><li>Pathogenicity </li></ul><ul><li>Colonise in human nasopharynx—infection in middle ear-paranasal sinus-and respiratory tract by direct spreadalso meninges---pneumococcal bacteremia—distant infections as heart,peritonium joints.inf-mostly endogenous—also exo </li></ul><ul><li>---commonst—otitis media & sinusitis </li></ul><ul><li>Most common bac causing pneumonia—both lobar and broncho..+a/c tracheobronchitis and empyema </li></ul><ul><li>Aspiaration from nasophryngl scrn---lower RT---nl evn during sleep—nl mucosl defence mech-entrapmnt,expulsion and cough reflex-+ciliary escalator effect prvnt establishmnt of infection </li></ul>
  15. 16. <ul><li>Whn compromised—viral inf.,anaesthesia,chilling/---penetrate bronchial mucosa—spread thru lung along peribranchial tissues and lymphatics—bacteremia is common during the early stages of lobar pneumonia—toxemia—due todiffusion of caps.polysach—into blood and tissues </li></ul><ul><li>Fall of temp by crisis &relief of symptoms coinside wth neutralisation os SSS by anticapsular antibodies </li></ul>
  16. 17. <ul><li>50% fatality is due to pneumococcal bactermia </li></ul><ul><li>Bronchopneumonia –always secondary inf.—caused by any serotype of pneumococcus—due to primarly damaged epi+increasd bronchial secrn----termilnla evnt in agd and debilitatad ones </li></ul><ul><li>---exacerbated by c/c bronchitis-also haemophilus influenzaeass. Wth this codition </li></ul><ul><li>Meningitis –most serius of pneumococcal inf.---secondry to pneumonia,otits media, all ages…with antibiotics—fatality rate 25% </li></ul>
  17. 18. <ul><li>Other suppurative lesions </li></ul><ul><li>Empyema,pericarditis otitis medis,sinusitis,conjunctivits,,, </li></ul><ul><li>Epidemiology </li></ul><ul><li>Respiratory tract of carriers.-source—Ds-only whn host’s resistance lowerd+viral inf./pulmon.congestion/stress/malnutrition/immunodefficincy/alcoholism </li></ul><ul><li>*splenectomy and sickle cell ds.---predispose to it </li></ul>
  18. 19. <ul><li>Lab dg </li></ul><ul><li>a/c phase of lobar pneumonia—Rusty sputum—pneumococci in large no. with hardly any othr kind of bacteria,G+inoc-Blood ag.over n8 -37C,5-10%Co2---laryngal swabs can b used </li></ul><ul><li>Scanty-intraperitoneal inoculation into mice --+--dies in 1-3 days </li></ul><ul><li>Isolation of pneumococci frm blood indicates bad prognosis </li></ul><ul><li>a/c otits media-pneum-fluid of inner ear..---meningitis---CSF—and culture---if negetive---do Demonstration of SSS in CSF by ppting with atisera </li></ul><ul><li>Capsular polysach—demon-blood,urine,CSF—by counter immuno electrophoresi---antibodies can b demonstratd by agglutination pptn,mouse protection test,bactericidal test eith whole blood </li></ul>
  19. 20. <ul><li>Prophylaxis </li></ul><ul><li>Polyvalent polysach vaccine for 23 most prevelnt serotypes -80-90% protection </li></ul><ul><li>T/t </li></ul><ul><li>Parenteral penicilline </li></ul><ul><li>Serious-amoxycillin </li></ul><ul><li>Third gen cephalosporin </li></ul><ul><li>Vancomycin-life threatning illness </li></ul>