Question

Food poisoning is caused by:
(a)Clostridium botulinum
(b)Salmonella typhi
(c)Escherichia coli
(d)Bacillus megaterium

Answer 1

Hint Food poisoning is a food borne disease. Ingestion of food contaminated by pathogens causes food poisoning. The pathogens may include bacterium, viruses or parasites.

Complete solution:
Clostridium botulinum is a Gram-positive, anaerobic, spore forming motile bacillus which has the ability of producing the neurotoxin, botulinum. Under certain conditions, these bacteria may grow in food items and produce toxins. When the food containing these toxins are ingested, it results in a severe form of food poisoning called Botulism. This food illness is rare but its mortality rate is high.
Salmonella typhi is a Gram-negative, non-spore forming bacillus that causes typhoid fever or simply typhoid. When this bacterium grows in the intestine and blood it causes typhoid. Typhoid spreads by eating or drinking food or water which is contaminated with the feces of an infected person. Humans are the only carriers of this bacteria.
E.coli or Escherichia coli is a Gram-negative, facultative anaerobic, coliform bacillus which is commonly found in the lower intestine of endothermic organisms. Most E.coli strains are harmless but some can cause serious food poisoning in their hosts.The harmless strains aid in the host in production of vitamin K2 which helps in clotting of blood.
Bacillus megaterium is a Gram-positive, aerobic spore forming bacillus. It is the one of the biggest known bacteria and was the main model organism for intensive studies on biochemistry, sporulation and bacteriophages. B.megaterium has been recognised as a potential biocontrol agent against plant diseases.

Additional information:
The initial symptoms of botulism include weakness, blurred vision, tiredness and trouble in speaking which may increase up to weakness of arms, chest, muscle and legs. Vomiting, swelling of abdomen and diarrhea may also occur.The spores of the bacteria are found in both soil and water. These spores when exposed to low oxygen levels and certain temperatures produce the botulinum toxin. This toxin when present in food causes foodborne botulism.

So, the correct answer is ‘Clostridium botulinum’.

Note:
-Although some strains of E.coli also cause food poisoning, C.butylicum is the main bacterium causing food poisoning.
-There are several other bacteria that cause food poisoning. They include Salmonella, Campylobacter, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus etc.