Lesson 3- Bacteriology Flashcards
What is bacteriology?
Study of micro organisms called bacteria, germs, or microbes.
What is bacteria?
- One celled vegetable, microscopic organisms which exist in air, ground and human skin surface, indicate matter, and body fluids, and clothes and under nails
- Have both plant and animal characteristics
- Summer harmful and some are harmless
- some bacteria is carried by animals, some by humans, and some by insects
- Others are transferred by water, food and soil
Define microorganism
Any organism of microscopic or sub microscopic size
Name the classifications of bacteria
Non-pathogenic organisms which can be beneficial and harmless. And pathogenic which can be harmful and cause disease and infection if they invade the body.
Describe nonpathogenic organisms/bacteria
- Constitutes the majority of all bacteria
- Beneficial to indigestion, processing yogurt, and penicillin etc.
- They perform useful function such as decomposing and improving the fertility of soil
- Safe to come in contact with
- Beneficial and harmless
Describe pathogenic bacteria
- Can cause disease and infection if they invade the body
- These parasites require living matter for their growth
- Also known as microbes are germs
- Salons, spas, medical facilities and schools must maintain strict standards for cleaning and disinfecting
- are classified into three main groups according to their shape
How many classifications, or shapes, are there to identify bacteria strains?
Three
Name the three classifications, or shapes of pathogenic bacteria
- Cocci – round, which appear singular or in groups
- Bacilli. - Short and rod shaped
- Spirilla – spiral or screws shaped
Describe cocci bacteria
- Staphylococci
- these pyogenic or pus forming organisms grow in bunches or clusters. They usually are responsible for pilosebaceous infections such as abscesses, pustules and boils, pimples.
- Staff Areus can live for two weeks on hard household surfaces - Streptococci- 000
- Pyogenic/pus forming bacteria which grow in chains. They are found in blood poisoning and strep throat. - Diplococci- 00 00
- Grow in pairs and cause pneumonia
Describe bacilli bacteria
Bacilli bacteria are rod shaped organisms. They are the most common with some able to survive with oxygen and others without oxygen. They caused diseases such as tetanus, typhoid fever, tuberculosis, and diphtheria.
Describe spirilla bacteria
Spirilla bacteria is curved or corkscrew shaped and divided into many groups. The most important of which is treponema pallidum, the causative agent in syphilis, chlamydia etc.
Describe the movement of bacteria
Different bacteria move in different ways. Cocci bacteria rarely show active motility (self movement). They are transmitted in the air, and dust, or within the substance in which they settle.
Bacilli and Spirilla bacteria are both motile and use slender hair like extensions known as flagella or cilia for movement. A whip like motion of this hair moves the bacteria in liquid.
Describe bacterial growth and reproduction
Bacteria consist of an outer cell wall and an internal protoplasm. They manufacture their own food from the surrounding environment, give off waste products [toxin], grow and reproduce. Under a microscope bacteria looks like tiny bags. Bacteria may exhibit 2 distinct phases in their life cycle which are the active or vegetative stage and the in active or spore forming stage.
Describe the two distinct life phases of a bacteria’s life cycle
- Active or vegetative bacteria
- this is the stage where bacteria is most active, grows and reproduces. In this stage growth division and separation is very fast if conditions are favorable. Bacteria multiply best in warm, dark, damp, or dirty places where food is available. As many as 16 million germs may develop in half a day from one bacterium.
- Cell division happens every 20 to 60 minutes depending on the bacteria. The infectious pathogen staphylococcus aureus undergoes cell division every 20 to 30 minutes
- If conditions become unfavorable, bacteria either die or become an active
- Inactive or spore forming bacteria
- Some bacteria such as anthrax and tetanus bacilli put themselves in a wax like shell
- Certain bacteria form spores with tough outer coverings to withstand periods of famine, dryness and climate change.
- in this stage spores can be blown about in the dust on flakes of skin and are not harmed by disinfectants, heat or cold
- when favourable conditions are restored spores change into the active or vegetative form and then start to grow and reproduce again
Define aerobes
Microorganism which grows in the presence of air. They need oxygen to exist.
Define anaerobes
Cannot reproduce or exist in the presence of oxygen. Anaerobic organisms may out number aerobic ones 10 to one especially in areas of the skin supplied with large sebaceous glands as staphylococci and diptheroids thrive and lipids [fats].