Bacterial Culture, Diseases, and Biotechnology Uses
Bacterial Culture Media, Mutation, and Strain
Bacteria can grow in artificial culture media, which serve to isolate and identify them. There are two types of culture media:
- Solid: Contains water, sodium chloride, proteins, and a solidifying substance called agar. The advantage of solid media is that it allows us to distinguish different bacterial colonies.
- Liquid: Contains water, sodium chloride, and proteins. In liquid media, bacteria grow uniformly.
Mutation and Strain: A mutation is an alteration in the DNA that can be produced by various factors. When a mutation occurs in different bacteria, all the individuals of the mutant bacteria form the strain.
Bacterial Diseases
1. Salmonella
Salmonella are gram-negative bacteria that can cause different infections depending on the species. The most common are:
Typhoid Fever
The mechanism of transmission is poor hygiene, especially through the consumption of unpasteurized dairy products (milk, cheese) contaminated by birds.
Symptoms: Fever, headache, abdominal pain, and a pink rash on the skin.
Treatment: Antibiotics.
Gastroenteritis
Inflammation of the stomach and intestine. It is spread through food handled by carriers of the disease without proper hygienic measures.
Symptoms: Nausea, diarrhea, fever, and vomiting.
Treatment: Bland diet and fluid intake. Usually, medical treatment is not necessary.
Prevention: Proper food cooking and refrigeration of eggs.
2. Cholera
Cholera is caused by a large, motile, gram-negative bacterium with a flagellum. The disease is spread through contaminated water or fish.
Symptoms: When the bacteria reach the intestine, they produce a toxin that causes very liquid diarrhea. If not treated in time, the patient may die from dehydration. It also causes vomiting and cramps.
Treatment: Treatable with antibiotics administered intravenously along with fluids. Hydration helps the patient recover and eliminate the bacteria spontaneously.
Prevention: Boil water, cook food thoroughly, and maintain proper hygiene.
3. Tetanus
Tetanus is caused by a large, gram-negative bacterium that is very serious but easily preventable. This bacterium is found in soil, the feces of some animals, and especially in rusty metal. The disease is spread through wounds.
Symptoms: This bacterium produces a toxin that attacks the nervous system, generating muscle spasms, difficulty swallowing, neck stiffness, fever, and headache. It can paralyze the facial muscles, forming a fixed smile.
Prevention: A vaccine that is reapplied regularly or after a wound.
4. Tuberculosis
Tuberculosis is a very serious disease that was once controlled but is now spreading again. It is caused by a large, non-motile, gram-negative bacterium.
Spread: It is spread through the air via sneezing, coughing, and sputum.
Symptoms: The bacterium attacks and may even destroy lung tissue, causing bloody sputum and significant weight loss.
Treatment: Antibiotics.
Prevention: A test called tuberculin helps detect the disease.
Bacteria, Agencies, and Biotechnology
Colonies of bacteria live in different parts of our bodies and obtain benefits from this symbiotic relationship. For example, bacterial flora live on the skin and mucous membranes. If this equilibrium is broken, infection occurs.
Applications of Bacteria
Biotechnology refers to industrial processes that use microorganisms to obtain their products.
Environmental Applications
Bacteria are used in wastewater purification. They are also used to remove oil spills, as some bacteria feed on these hydrocarbons and can therefore eliminate them from the water.
Applications in Genetic Engineering
One of the applications of genetic engineering is the manufacture of drugs. Bacteria divide rapidly and are used to produce human proteins through the manipulation of their genetic material.