Bacteria and Disease: Transmission, Pathogenicity

Edited by Jamie (ScienceAid Editor), Taylor (ScienceAid Editor), Chameleon

Transmission of Bacteria and Disease

We often assume that all bacteria are harmful, but there are many uses for bacteria, and every healthy person has natural flora - bacteria lining the skin the gut and digestive tract.

Bacteria that cause harm are described as pathogenic. There are numerous ways that pathogenic bacteria can be transmitted to us. In the table below we will take a two examples.

Bacteria Transmission Discussion
Salmonella Food - mainly eggs and egg products. This bacteria infects the colon and lower intestine. The response to this is to increase fluid production which results in diarrhoea. This can cause dehydration, so sufferers must drink a lot of water and replace salts, it also makes absorbing antibiotics difficult.
Escherichia coli Water contaminated with faeces. E. coli is a bacteria naturally occurring in the human gut, but some strains are pathogenic. This also results diarrhoea, and can be fatal. In developing countries, over 5 million children die a year from diarrhoea because of poor sanitation.

Contamination of food and water can be prevented by basic hygiene. Food-borne infection is prevented:

  1. 1
    Inspecting farms to ensure animals do not carry disease
    Advertisement
    Was this step helpful? Yes | No| I need help
  2. 2
    Washing food properly.
    Was this step helpful? Yes | No| I need help
  3. 3
    Cooking food thoroughly.
    Was this step helpful? Yes | No| I need help
  4. 4
    Wear protective clothing where food is being both produced and prepared.
    Was this step helpful? Yes | No| I need help

Water-borne infections are prevented by treating the water before it is ingested by people. To reduce the millions of deaths in developing countries, infrastructure to provide clean water is desperately needed.

Was this helpful? Yes | No| I need help

Pathogenicity

Pathogenicity is the ability of the bacteria to cause disease. The most dangerous bacteria have a high pathogenicity. There are a number of features that can make a bacteria more pathogenic.

  1. 1
    How easily the bacteria can attach and enter the host is important
    .
    Molecules in their cell wall can bind to molecules on the host's cell membranes.
    Was this step helpful? Yes | No| I need help
  2. 2
    Receptors vary from individual to individual, so some people may be more susceptible to diseases than others.
    Was this step helpful? Yes | No| I need help
  3. 3
    Many pathogenic bacteria produce toxins - chemicals that have a harmful effect on the body
    .
    Was this step helpful? Yes | No| I need help
  4. 4
    Exotoxins are produced by living bacteria and can have varying affects
    .
    Was this step helpful? Yes | No| I need help
  5. 5
    Tetanus is caused by Clostridium tetani which releases toxins in to the nervous system that cause involuntary muscle contractions
    .
    Was this step helpful? Yes | No| I need help
  6. 6
    'Endotoxins are compounds in bacterial cell walls that only have an effect when the cell dies and is broken down
    .
    These are what cause fever and aches.
    Was this step helpful? Yes | No| I need help
  7. 7
    Large numbers of bacteria may be required to cause infection, as is the case with Salmonella enteritidis (10 million), however another species of salmonella only needs be present in small numbers to cause typhoid fever.
    Was this step helpful? Yes | No| I need help
  8. 8
    The invasiveness of a bacteria is its ability to spread within the host
    .
    A bacterium that can break into one of the body's major transport systems (blood or lymphatic, will be very invasive.
    Was this step helpful? Yes | No| I need help

Milk

Milk is vulnerable to contamination during collection and storage, and is an excellent medium for growth. The flash pasteurization method is the most common for destroying micro-organisms. Milk is heated to 72o C for 15 seconds, then rapidly cooled to 3oC. The heat kills many pathogens and the rapid cooling prevents those resistant to heat, from dividing rapidly. The milk now must be kept refrigerated and can last for several days. The flash pasteurization process has little effect on the flavour or nutritional value of milk.

Was this helpful? Yes | No| I need help

Another method of heat treating milk is ultra-high temperature processing, where the milk is heated to 135°C for 1 or 2 seconds. This is more effective and means the milk can be stored for several months. This treatment, however, has more of an effect on the nutritional content of the milk (mainly vitamins).

Was this helpful? Yes | No| I need help



Questions and Answers

Can you discuss in details,pathogenic bacteria as a threat to public health?

Discuss pathogenic bacteria as a public threat to human health

ScienceAid QnA. This section is not written yet. Want to join in? Click EDIT to write this answer.

Referencing this Article

If you need to reference this article in your work, you can copy-paste the following depending on your required format:

APA (American Psychological Association)
Bacteria and Disease: Transmission, Pathogenicity. (2017). In ScienceAid. Retrieved Dec 15, 2018, from https://scienceaid.net/biology/micro/disease.html

MLA (Modern Language Association) "Bacteria and Disease: Transmission, Pathogenicity." ScienceAid, scienceaid.net/biology/micro/disease.html Accessed 15 Dec 2018.

Chicago / Turabian ScienceAid.net. "Bacteria and Disease: Transmission, Pathogenicity." Accessed Dec 15, 2018. https://scienceaid.net/biology/micro/disease.html.

If you have problems with any of the steps in this article, please ask a question for more help, or post in the comments section below.

Comments

ScienceAid welcomes all comments. If you do not want to be anonymous, register or log in. It is free.

Article Info

Categories : Micro

Recent edits by: Taylor (ScienceAid Editor), Jamie (ScienceAid Editor)

Share this Article:

Thanks to all authors for creating a page that has been read 384 times.

x

Thank Our Volunteer Authors.

Would you like to give back to the community by fixing a spelling mistake? Yes | No