This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'All of the following statements about Botulism are true except : \nSelect and explain. \nA. Botulism is caused by endotoxin, B. Honey ingestion causes infant botulism, C. Constipation is seen, D. Detection of antitoxin in the serum can aid in diagnosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cl. botulinum produce exotoxin (since endotoxin is usually produced by gram-negative bacteria) which differs from other exotoxin in that it is produced intracellularly and appears in the medium only on death/autolysis of cell.\nToxin production is determined by bacteriophage at least in types C and D toxin.\nAll toxin are neurotoxin except C toxin, which is cytotoxin.\nToxin acts by blocking production or release of Ach\xa0at synapse and Neuromuscular junction (= parasympatholytic = effect of atropine) so cause constipation, paralysis, etc.\nHuman disease is caused by type A, B, E and rarely F.\nMC Type of botulism is ‘Infant botulism’ which is produced by eating of honey containing spores so toxin is produced inside.\nFoodborne botulism and wound botulism are produced by preformed toxin.\nDiagnosis may be confirmed by demonstration of bacillus or toxin in food or feces.\nA retrospective diagnosis may be made by detection of antitoxin in the patient serum but it may not be seen in all cases.', 'role': 'assistant'}]