🦠NEISSERIA:
আমরা জানি এটা একটা gram(-) cocci.
📌classification of Neisseria:
👉pathogenic:
1.Neisseria gonorrhoeae
2.Neisseria meningitidis
👉Non-pathogenic:
1. Neisseria flava
2.Neisseria subflava
3.Neisseria mucosa
4.Neisseria lacti
5.Neisseria sica
🦠Neisseria Gonorrhoeae:
Imp. properties :
1.Gm(-)ve diplocococcus(মানে জোড়ায় জোড়ায় থাকে)
2.kidney shaped (each having concave margin & convex margin, concave sides are adjacent)
3. oxidase positive
4.এরা সাধারনত intracellular within neutrophil in lesions &exudates
5. Non-flagellated,Non-spore forming,Non-capsulated
📌Virulence factor of N.gonorrhoeae:
1.pili: এটা pillinn protein দিয়ে তৈরী। N.gonorrhoeae ১০০ টা serotypes আছে এই pillin protein এর antigenicity উপর ভিত্তি করে। ফলে তারা সহজেই reinfection করতে পারে।
2.Endotoxin(Lipo-oligosaccharide)
3.Por protein
4.IgA 1 protease : it cleaves IgA that defends mucosal surface.
5. Ferric binding protein
🗣️Nice to know:
👉প্রায় সকল gm(-)ve bacteria এর endotoxin হলো lipo-ploysaccharide(LPS),কিন্ত N.gonorrhoeae এর endotoxin lipo-oligosaccharide(LOS)
👉Other IgA producing bacteria :
1 S.pneumoniae
2 N.meningitidis
3 H.influenzae
📢CLINICAL FEATURES :
👉In Male:
1.Acute case:
-urethritis
-dysuria
-yellow purulent discharge.
2.chronic case:
-prostatitis
-epididymitis
-seminal vesiculitis
👉In Female:
1. Acute case:
-cervicitis
-purulent vaginal discharge
2.chronic case
-salphingitis
-fibrosis
-pelvic peritonitis
👉New born
-Opthalmia neonatorum: এটা সাধারনত develop করে যখন new born infant কোন infected birth canal দিয়ে pass করে।
🗣️Some viva questions :
👉why N.gonorrhoeae don't cause vaginitis?
N.gonorrhoeae শুধুমাত্র infect করে columner epithelium কে,আবার urethra,cervix এর lining columner epithelium,কিন্ত vagina এর lining squamous epithelium.তাই এরা vaginitis করে না।
👉 N.gonorrhoeae দিয়ে আক্রান্ত patient কি protective immunity develop korbe?? উত্তর না। why?
-patient কোন protective immunity develop করবে না। কারন N.gonorrhoeae
antigenically heterogeneous তাই তারা এদের surface structures পরিবর্তন করতে সক্ষম।
⚗️Laboratory diagnosis:
🔹 Specimen:
(a)Male:
-Acute case: urethral discharge
-chronic case: prostatic secretion by prostatic massage(early morning before passing urine)
( b)Female:
-endocervical swab(both acute &chronic case).
(c)New born: conjunctival swab.
♦️Microscopic Examination :
Gram staining : gm(-)ve diplococci within polymorphonuclear leukocytes.
🧫Culture:
▪️chocolate agar media: এখানে sterile specimen ব্যবহার করা হয়।e.g. blood
▪️Thayer martin media: Non-sterile specimen ব্যবহার করা হয়।e.g. cervical sawb
এই media তে কিছু antibiotics থাকে।যেমন: vancomycin,colistin,Amphotricin-B, trimethoprim.মনে রাখার জন্য VANT.
▪️Modified New york city media:
incubation temp 37,incubation period 18-24 hour,incubation environment 5-10% CO২.
🧪Biochemical test:
▪️oxidase positive
▪️Fermemts only glucose.
🧬Nucleic acid amlification test:PCR
this is higly specific &sensitive.
🔹serological tests: ELISA,DNA probe assay.
🗣️ viva:
what is the role of antibiotics in Thayer martin media?
👉vancomycin-inhibit gm(+)ve bacteria
👉Amphotericin-B
inhibit fungul growth.
👉colistin-kills gm(-)ve bacteria except Neisseria.
👉Trimethoprim-
prevent swarming growth of proteus.
🦠Neisseria Meningitidis
🔹 also Known as meningococus.
♦️properties :
▪️Gm(-)ve diplococci.
▪️oval shape with flattened apposed surface.
▪️Usually intrecellular within neutrophil.
▪️polysaccharide capsule present.
▪️Have endotoxin composed of lipcpolysaccharide.
▪️Non spore forming,Non flagellated.
♦️Virulence factor
▪️polysaccharide capsule
▪️Endotoxin
▪️IgA protease.
♦️Pathogenesis of meningococcal meningitis:
🔹Route of infection: direct transmission by air borne droplets.
🔹steps : organism দেহে প্রবেশ করে air borne droplet দিয়ে →যা nasopharynx এর membrane এ colonize করে→ become a part of normal flora →blood stream এ প্রবেশ করে, spread করে meninges, joints or disseminated throughout the body(meningococcemia)→ পরবর্তীতে blood brain barrier cross করে এবং তা sub-arachniod space এ পৌছায়→meningitis
🗣️Viva:
♦️what are the clinical findings?
▪️Fever,headache
stiff neck,progress to coma within a few hours.
▪️Arthritis
▪️petechial hemorrhages in skinn
▪️Intestinal myocarditis.
♦️what are the organisms respnsible for meningitis?
▪️please follow pictures
📢Nice to know:
♦️waterhouse friderichen syndrome:
🔹it is fulminant form of meningococcemia যেখানে adrenal gland failure হয়, adrenal gland এ bleeding এর জন্য।
🔹characteristic:
▪️High fever
▪️circulatory failure
▪️Hypotension
♦️Laboratory diagnosis :
🔹specimen :
▪️CSF
▪️Blood
▪️Nasopharyngeal swab.
🔹Microscopic examination :
▪️Gm(-)ve diplicocci with plenty of polymorhonuclear
leukocytes with plenty of pus cell.
🔹Culture:
▪️chocolate agar media
▪️Thayer martin media.
🔹Biochemical test:
▪️fermentation reaction→ferments both glucose & maltose
▪️oxidase (+)ve
🔹Serological test:
▪️Latex agglutinatiom test
▪️Haemaglutination
test.
🔹Examination of CSF:
▪️physical :
→Appearance : turbid
→color: purulent
→pressurer:⬆️
▪️Biochemical:
→sugar:⬇️
→protein: ⬆️
→chloride:⬇️
▪️cytological test:
→WBC count :⬆️
(predominantly neutrophil)
🗣️Viva:
♦️why N.gonorrhoeae & N. meningitidis can't be cultured in blood agar media?
▪️কারন blood agar plate এর toxic trace metal আর fatty acids organism এর growth inhibit করে।
♦️CSF findings in different type of meningitis
