Bacterial diseases (4.3.1.3) — AQA GCSE Biology Revision Notes

Revision notes for AQA GCSE Biology specification point 4.3.1.3, Bacterial diseases.

Bacterial Diseases

Bacteria are very small LIVING CELLS that can REPRODUCE RAPIDLY inside the body. They make you ill by producing TOXINS that damage your cells and tissues. Bacterial infections can usually be treated with ANTIBIOTICS.

Salmonella

  • Pathogen: BACTERIUM

  • How it spreads: Eating CONTAMINATED FOOD, especially undercooked CHICKEN/POULTRY AND EGGS, or food prepared in unhygienic conditions.

  • Symptoms: Caused by the TOXINS the bacteria release: FEVER, ABDOMINAL CRAMPS, VOMITING and DIARRHOEA.

  • Treatment: Usually rest and rehydration; ANTIBIOTICS in severe cases.

  • Prevention: In the UK, poultry are VACCINATED against Salmonella. Also: good FOOD HYGIENE — cook food thoroughly, wash hands, and keep raw meat separate from ready-to-eat food.

Gonorrhoea

  • Pathogen: BACTERIUM — a SEXUALLY TRANSMITTED DISEASE (STD).

  • How it spreads: By UNPROTECTED SEXUAL CONTACT.

  • Symptoms: A THICK YELLOW OR GREEN DISCHARGE from the vagina or penis, and PAIN ON URINATING.

  • Treatment: Originally treated with the antibiotic PENICILLIN, but many ANTIBIOTIC-RESISTANT STRAINS have appeared, making it harder to treat.

  • Prevention: Using BARRIER METHODS OF CONTRACEPTION (CONDOMS), and treating infected people quickly to prevent further spread.

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