Clostridium tetani
Cause tetanus.
Clostridium tetani is gram positive spore forming strict anaerobic bacilli, drumstick appearance.
Clostridium tetani spore found in soil, in dust, air, intestinal tract, feces, object in hospital environment like plaster of peris, clothing and wall plaster, rusty wire.
Morphology
Non capsulated, rod shaped, motile, anaerobic.
Size; 0.3-0.5 micrometer in width and 2-2.5 micrometer in length.
Characteristics
Cannot grow in presence of O2.
Resistance to dry heat.
Can grow at optimum temperature 37 degree Celsius and PH 7.4
On blood agar medium after 24 to 48 hours incubation. It produces haemolysis.
Unable to ferment sugar.
Source and Mode of Transmission
It enters through puncture wound and cuts such as;
1. By splinter
2. After severe burn
3. Surgery
4. Contaminated injection
Pathogenesis
Clostridium tetani causes tetanus in human being.
Tetanus is caused by exotoxin " tetanus toxin".
It is made up of two fragments;
1. Heavy fragment
(B) binds to neurons.
2. Light fragment
(A) penetrates the target cell.
In alearly stage of disease, jaw muscle are affected, mouth cannot open thus also known as lockjaw.
Paralysis of chest, muscles leading to respiratory failure.
Clinical types of tetanus are;
1. Cephalic tetanus
Head injury or ear infection.
2. Post abortion and puerperal tetanus
Infection in female genital tract through unsterile instrument and dressing while abortion.
3. Generalized tetanus
Affect all skeletal muscles of individual, most severe and common form of tetanus.
4. Local tetanus
Site of infected wound.
5. Neonatal tetanus
Affect neonate due to unhygienic practices after delivery.
Placing cow dung on umbilical stump lead tetanus.
Neonate infection due to contaminated instrument of cut umbilical cord
Laboratory Diagnosis
Specimen collection
Wound, swab or tissue
Microscopic examination
Smears from wound material after gram staining show gram +ve bacilli with drum stick appearance.
Cultural characteristics
Strict anaerobic can grow in absence of O2, optimum temperature 37 degree Celsius, PH 7.4
Culture
On blood agar medium.
Biochemical reaction
Breakdown protein but unable to ferment sugar.
Treatment
Human tetanus immunoglobulin (TIG) give to neutralize toxin produce.
Prevention
Active immunization with tetanus toxoid prevent tetanus.
Triple vaccine with DPT.
0 Comments