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Bacteriologysgu
Quiz Two
Question | Answer |
---|---|
Large, Gram-positive rods | Clostridium |
Produce endospores | Clostridium |
Anaerobic | Clostridium |
Catalase-negative, oxidase-negative | Clostridium |
Enriched media required for growth | Clostridium |
Motile (except C. perfringens | Clostridium |
Present in soil & alimentary tracts of animals & in feces | Clostridium |
Neurotoxic Clostridia | Clostridium tetaniClostridium botulinum (types A - G) |
Causative agent of tetanus | Clostridium tetani |
Straight, slender, anaerobic, Gm +ve rod with special terminal endospores, giving characteristic “drumstick” appearance | Clostridium tetani |
Endospores resistant to chemicals & boiling but killed by autoclaving at 121 deg. C for 15 mins | Clostridium tetani |
Has swarming growth & hemolytic on blood agar | Clostridium tetani |
Ten serologic types based on flagellar antigens | Clostridium tetani |
Cross-neutralizing antibodies to neurotoxins between all serotypes | Clostridium tetani |
Infection occurs by entry of endospores into traumatized tissues (abrasions & wounds | Clostridium tetani |
Mode of action is by synaptic inhibition | Clostridium tetani |
Incubation period is 5 to 7 days, may extend to 3 weeks | Clostridium tetani |
Clinical effects of neurotoxins are similar in all domestic animals | Clostridium tetani |
Nature & severity of clinical signs are dependent on anatomical site of the replicating bacteria, amount of toxin produced & species susceptibility | Clostridium tetani |
Clinical signs include stiffness, localized spasms, altered facial expression, spasm of mastigatory muscles (“lock jaw”), generalized muscle stiffness (“saw-horse”) stance, especially in horses | Clostridium tetani |
Recovered animals are not necessarily immune (toxin concentration that induce clinical disease is usually below threshold required to stimulate production of neutralizing antibodies | Clostridium tetani |
Serious & fatal disease | Botulism |
cause most outbreaks in domestic animals | C. botulinum types C and D |
Inactivated by boiling for 20mins | C. botulinum |
Gm +ve rod with sub-terminal endospores | C. botulinum |
Occurs most commonly in waterfowl, cattle, horses, sheep, mink, poultry & farmed fish | C. botulinum |
Pigs & dogs are relatively resistant & rare in domestic cats | C. botulinum |
Poor quality baled silage & silage or hay containing rodent carcasses have been linked to outbreaks in horses & ruminants | C. botulinum |
the most potent biological toxin known | Neurotoxins of C. botulinum |
C. botulinum Mode of action is by | inhibition of neuro-muscular transmission |
Botulism Clinical signs Develops | 3 to 17 days after ingestion of toxin in all species of animals |
Acute disease of cattle & sheep caused by C. chauvoei | Blackleg |
bomasitis in sheep caused by C. septicum | Braxy |
Manifests as cellulitis with minimal gas gangrene & gas formation | Malignant edema |
Acute disease affecting sheep & occasionally cattle, caused by C. novyi type B | Infectious necrotic hepatitis |
Occurs primarily in cattle & occasionally in sheep, caused by C. haemolyticum | Bacillary hemogl |
Neuro disorder in newborn foals under 2 months, due to stress in dam, high level of corticosteroids in milk, high mortality | Shaker foal symptom |
Cattle & Sheep: Gangrenous cellulitis & myositis caused by exotoxins, leading to rapid death | Blackleg |
Large muscle masses of limbs, back & neck are frequently affected | Blackleg |
Manifests as cellulitis with minimal gas gangrene & gas formation | Malignant edema |
Clinical features of toxemia are similar to malignant edema | Gas gangrene |
Hemoglobinuria: major clinical feature as a result of extensive red cell destruction | Bacillary hemogl |
Histotoxic clostridia | Vaccination: Adjuvanted bacterin & toxoid is most effective |
is the causative agent of Gas gangrene in human & domestic animals. | C. perfringens type A |
C. perfringens type B | Lamb dysentery |
Many animals die suddenly & high susceptibility of this group is attributed to the absence of microbial competition and the low proteolytic activity in the neonatal intestine | C. perfringens type B |
Occurs in sheep at pasture, usually manifests as sudden death | perfringens type C:perfringens type C |
Sudden death in goats & feedlot catle | Clostridia |
Necrotic enteritis in chickens | Enteropathogenic & Enterotoxaemia-producing Clostridia |
Haemorrhagic enteritis in neonatal pigs | Enteropathogenic & Enterotoxaemia-producing Clostridia |
Neuro disorder in newborn foals under 2 months, due to stress in dam, high level of corticosteroids in milk, high mortality | Shaker foal symptom |
Vax available | immunize dam and passive transfer of neutralizing antitoxin to foal, or give antitoxin serum to foal |