The micro-organisms that causes Typhoid disease is

Step 1: Analyze the question The question asks which micro-organism causes typhoid fever.

Step 2: Explain the concept Different diseases are caused by different types of pathogens:

• Bacteria cause typhoid, cholera, tuberculosis, and gonorrhoea.
• Protozoans cause malaria, amoebic dysentery, and sleeping sickness.

Typhoid fever is a bacterial disease. It spreads through food and water contaminated with faeces or urine from an infected person (the faecal-oral route). Poor sanitation and unsafe water are the main risk factors.

Step 3: Go through the options

• A. Trypanosoma gambiense: a protozoan that causes sleeping sickness, spread by the tsetse fly. ❌
• B. Salmonella typhi: a bacterium that causes typhoid fever. ✅
• C. Entamoeba histolytica: a protozoan that causes amoebic dysentery. ❌
• D. Plasmodium sp: a protozoan that causes malaria, spread by the female Anopheles mosquito. ❌

Step 4: Answer The correct answer is B. Salmonella typhi.

💡 Exam tip: Match each disease to its organism by the name. Salmonella typhi contains "typhi", which points to typhioid. For protozoan diseases, remember the trio: Plasmodium is malaria, Trypanosoma is sleeping sickness, and Entamoeba is amoebic dysentery.