Colstridum Flashcards
Characteristics of cl.difficile
gram + bacilli with ……
Anareobic
Motile
No capsulated
Proteolytic
Disease of cl difficile
antibiotic-associated pseudomembranous colitis
Virulence factors of cl.difficile
- Exotoxin A (enterotoxin):
Cause diarrhea and abdominal pain.
- Exotoxin B (cytotoxin) death of the enterocytes, inflammation and fibrosis which as pseudo membrane.
Pathogenesis of cl.difficile
Uncontrolled antibiotic therapy (specially lincomycin and clindamycin)
Diagnosis diff
- ELISA
- PCR
- Cytotoxicity test
Treatment of diffic
( 1. Stop the causative antibiotic.
- Drug against Clostridium Difficile.
● Metronidazole (can be used against any anaerobic bacteria)
● Oral Vancomycin (The only indication for the oral vancomycin is for Clostridium Difficile)
- Fidaxomicin (prevents the disease and the relapse of the disease)
- Fecal bacteriotherapy 5. If the person has toxic megacolon -> Surgical resection of the colon
Characteristics of Clostridium Perfringens
● Obligate anaerobe
● Gram +ve bacilli
● Spore-forming
● Non-motile
● capsulated
disease caused perfri.
- Food poisoning
- Gas Gangrene
➢Virulence Factors perfri.
- Alpha toxin
- Alpha and beta hemolysin
➢Predisposing Factors perfri
- Diabetes
- Wounds
- Accidents
- Atherosclerosis
Culture perifri
● Blood agar (double zone of hemolysis)
● Egg-yolk agar (contains phospholipids)
● RCMM
➢Treatment perfri
- Complete surgical debridement of the wound until bleeding occurs
- Administer Antitoxins
- Administer antibiotics (Metronidazole or Penicillin G)
Clostridium Botulinum characteristics
● Gram +ve bacilli
● Spore-forming
● Obligate anaerobes
● Motile
● Uncapsulated
disease caused in botu
Botulism (food poisoning but has neurological manifestations.)
- Adult (food borne) botulism.
- Infantile botulism
- Wound botulism
The food associated with adult botulism, infantile botulism
canned food, honey
➢Pathogenesis of botu
Prevention of Acetylcholine release in NMJ
➢Treatment of botu
- Respiratory support
- Trivalent antitoxin. To Adult Botulinum (No bacteria)
- Infantile botulism -> Penicillin (Bacteria)
1Cause of infantile botulism
2Cause of wound and food borne botulism
1organism
2toxin
Clostridium tetani Characteristics
Anaerobic, gram +ve rod+ terminal spore
Motile, non-capsulated Mainly proteolytic
Virulence factors of tetani
. Tetanus toxin (tetanospasmin)
- Tetanolysin (Hemolysin)
Transmission of tetani
Wound or skin popping ممكن زول سكري برضو
يكون ضربو مسمار في رجلو 😂😂
Pathogenesis of tetani
- Descending (faster) :
Toxin -> Blood -> Brain -> Spinal Cord
- Ascending: Toxin ->Nerve -> Brain
➢Mechanism of action of Tetanus Toxin
The toxin binds ganglioside receptors and block the release of inhibitory mediators (Glycine and GABA) = excitation -> contraction
➢
Signs and symptoms of tetani
Spastic paralysis (hypertonia)
- Locked Jaw (trismus)
- Risus Sardonicus (masked face)
- Hyperexcitability (hyperreflexia)
- Opisthotonos (Arching of the back)
- Convulsions
- Respiratory Failure
1 .Treatment of tetani
2.Prevention
- Maintain the airways and respiratory support
- Isolate the patient in quite room (without light) to avoid hyperexitability.
- Sedation (e.g., diazepam / Valium) should be given to prevent spasms & hyperexitability
- Surgical debridement of the affected wound
- Tetanus immunoglobulin is given to neutralize the toxin.
- Benzyl penicillin or Metronidazole is also given
➢
Prevention
- immunization with tetanus toxoid in childhood and every 10 years thereafter
- When trauma or injury occurs, the wound should be cleaned, and tetanus toxoid booster should be given.
- If the wound is grossly contaminated, tetanus immune globulin, as well as the toxoid booster, should be given and penicillin administered
What antibiotics has been moot frequently implicated in the production of the pseudomembranous enterocolitis?
lincomycin and clindamycin
