আজকে আমাদের পড়াশুনার টপিক – Clostridium tetani. Clostridium tetani causes tetanus.
👉প্রথমেই জেনে নিই Morphology:
📌 1. Anaerobic, spore forming, gram positive.
2. Rod shaped with rounded ends.
3. Produce a spherical,terminal spore which is larger than the bacillary body.(এর জন্যই gram staining এ “tennis racket” appearance দেখা যায়)
4. Non-capsulated, motile with peritrichous flagella(slow and steady movement), non-acid fast.
👉Tetenus এর types কি কি আছে?
♦ 1. Otogenic tetanus.
2. Tetanus neonatorum.
3. Post-operative tetanus.
4. Cryptogenic tetanus.
👉Transmission কিভাবে হয়❓
💠 এই bacteria এর spore mainly soil এ থাকে [ specially barnyard and garden soil], portal of entry হচ্ছে wound site. Spore can also be introduced during “skin-popping”. Neonatal tetanus এর ক্ষেত্রে contaminated umbilicus or circumcision wound এর মাধ্যমে ছড়ায়।
👉 Clinical findings / features কি কি হবে❓
🚩 Tetanus is characterized by strong muscle spasms ( spastic paralysis)
- Lock jaw ( Trismus) : due to rigid contraction of the jaw muscles.( ফলে মুখ খোলা যায় না/ বড় করে হা করা যায় না)
- Risus sardonicus : A characteristic grimace.
- Opisthotonos : A pronounced arching of the back due to spasm of the strong extensor muscles of the back.(মানে হচ্ছে শরীর ধনুকের মত বেঁকে যায়)
👉 Clostridium tetani কি কি toxins produce করে?
⭕ 1. Tetanoplasmin (potent neurotoxin)
2. Tetanolysin.
👉Pathogenesis of tetanus:
💠 Spores of Cl.tetani are widespread in the soil.
⏬
এই spore যেকোন wound site ( like deep penetrated/lacerated wound, burn, umbilical stump, surgical suture) দিয়ে body তে ঢুকবে।
⏬
Traumatized tissue তে organism টা germimate করে এবং turn into vegetative form.
⏬
Multiplication হবে এবং toxin (tetanospasmin and tetanolysin) liberate করে। এই liberated toxin টা absorbed হয় motor nerve ending এ।
⏬
এই neurotoxin peripheral motor nerve দিয়ে anterior horn cell of the spinal cord এ যায় ( যাকে বলে retrograde transmission). তারপর tetanospasmin ganglioside receptor এর সাথে bind করে এবং inhibitory neurotransmitters release কে block করে দেয়।
⏬
Prevents inhibition of lower motor neuron by upper motor neuron..and exaggerated action of lower motor neuron on the muscles –
- increased muscle tone.
- Exaggerated muscular response.
- Hyper-excitability of voluntary muscles.
- Involuntary contraction( spastic contraction)
👉Laboratory diagnosis of tetanus কি হবে?
1. Specimen collection : Wound swab.
2. Microscopic examination : Gram staining – gram positive bacilli (tennis racket appearnce)
3. Culture :
🚩Robertson’s cooked meat media.
Finding – turbidity of medium and blackening of meat.
🚩Blood agar (finding- swarming growth)
👉 Prevention কি হবে?
⭕ Vaccine 😊
pre-exposure :
1st dose – at 6 weeks of age.
2nd dose – after 4-6 weeks.
3rd dose – after 4-6 weeks.
Booster dose – (4-6) years of age.
Additional – every 10 years after last dose.
Post -exposure prophylaxis:
- Tetanus immunoglobulin. (TIG)- 250 units in intravenous route.( gives immediate protection by passive immunization.)
- Tetanus Toxoid – intramuscular ( Gives long term protection by active immunization).
👉Treatment of tetanus:
⭕১. Treatment বলতে প্রথমেই মাথায় আসে TIG। মানে হচ্ছে TIG দিতে হবে patient কে।
২. Antibiotic এর মধ্যে Penicillin G or Metronidazole দিব।
৩. Anticonvulsant therapy : Diazepam(IV) দিতে পারি symptoms কে minimize করতে।
৪. Respiratory support, If needed.
🔴 Reference : Lange review of medical microbiology and immunology, 15th edition, page :134.
Lippincott’s Illustrated reviews, 3rd edition. Page : 156-157🔴
Platform Academic/ Tamanna Sultana
PAHMC
2016-17