Microbiology (MCB 221)

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Questions and Answers

Where can the idea that microorganisms could cause disease be traced to

It can be traced back to ancient cultures such as Egyptians and greeks who had some understanding of infections and sanitation

What is the miasma theory

For many centuries diseases were believed to be caused by bad air or miasma

The miasma theory was prevalent until when?

19 century

What century did the advent of microscopy happen

17th century Signup and view all the answers

Who was often called the father of microbiology

Antonie van leuwenhoek Signup and view all the answers

Who crafted lenses that allowed observation of single celled organisms, what year did he do it and what did he term it

Antonie van leuwenhoek, 1670, animalcules Signup and view all the answers

What was Pasteur experiment about and what year did it take place

Pasteur's experiment debunked the theory of spontaneous generation and demonstrated that microorganisms were responsible for fermentation and spoilage . ( 1860's) Signup and view all the answers

What did Pasteur's experiment lead to

It led to the development of pasteurization Signup and view all the answers

What did Robert Koch do and what year did he do then

He established systematic methods of linking specific microorganisms to specific diseases, introducing Koch postulate. He also worked on cholera anthrax and tuberculosis. (1876) Signup and view all the answers

What did Joseph lister do

He promoted surgical cleanliness and reduced infection rate Signup and view all the answers

Who created the small pox vaccine and what year was it created

Edward Jenner in 1796 Signup and view all the answers

Who developed vaccines for rabies and anthrax

Louis Pasteur Signup and view all the answers

What years were the golden age of microbiology

1880's - 1940's Signup and view all the answers

Who developed the first effective treatment of syphilis and what did it contribute to

Paul Ehrlich and it contributed to the field of chemotherapy Signup and view all the answers

In what years did the discovery of antibiotics take place

1920's - 1940's Signup and view all the answers

Who discovered penicillin, what year did he discover it and how did it affect the development of antibiotics

Alexander Fleming, 1928 and it lead to the development of antibiotics Signup and view all the answers

Define sterilization

It is the complete destruction of all microbial life, including bacteria, viruses, fungi, and spores. Signup and view all the answers

What is the goal of sterilization

To Achieve a sterile environment or instrument, ensuring no viable microorganisms are present. Signup and view all the answers

What is disinfection

Is The reduction of pathogenic microorganisms to a level that is not harmful to health; does not necessarily eliminate all microbes. Signup and view all the answers

What is the goal of disinfection

To Decrease the risk of infection in non-living surfaces and objects. Signup and view all the answers

What are the key differences between sterilization and disinfection

Goal Level of Efficacy Application Methods Signup and view all the answers

What are the methods of sterilization

Physical and chemical method Signup and view all the answers

Sterilization and disinfection are essential practices in where

Healthcare microbiology and sanitation Signup and view all the answers

Sterilization and disinfection are aimed at?

Controlling the spread of pathogens Signup and view all the answers

What is autoclaving

It is a physical method of sterilization that uses steam under pressure to kill microorganisms and spores ( standard condition is 121 degree Celsius for 15-29 minutes) Signup and view all the answers

What is dry heat sterilization

It is a physical method of sterilization that uses hot air to sterilize ( e.g oven ) , it requires higher temperatures ( 160-180 degree Celsius for 1-2 hours) Signup and view all the answers

What is filtration

It is a physical method of sterilization that physically removes microorganisms from liquid or air using filter with specific pore sizes Signup and view all the answers

What is radiation

It is a physical method of sterilization that uses ultraviolet (UV) or gamma rays to inactive or kill microorganisms Signup and view all the answers

What is ethylene oxide

(it is a chemical form of sterilization) it is gas that is used to sterilize haet sensitive objects or materials Signup and view all the answers

What is hydrogen peroxide

It is a chemical method of sterilization that sterilizes objects through oxidative process Signup and view all the answers

What are the methods of disinfection

Chemical and physical disinfection Signup and view all the answers

List the physical method of sterilization

Autoclaving, dry heat sterilization, filtration, radiation Signup and view all the answers

List examples of Chemical disinfectant

<ol> <li>Alcohol ( e.g ethanol and isopropanol) effective against bacteria and viruses usually at 70% concentration. 2. Chlorine compound (e.g bleach) effective against board spectrum used for surface disinfection. 3. Phenolic compounds ( e.g Lysol) effective against bacteria and fungi used, in healthcare settings 4. Quatemary ammonium compound , effective against some gram positive bacteria and some fungi , used for surface disinfection</li> </ol> Signup and view all the answers

List the physical method of disinfection

<ol> <li>Heat: boiling water at 100 degree Celsius (10-30 min) can disinfect items but may not sterilize them 2. Ultraviolet light: effective for disinfecting air, water and surfaces by damaging the microbial DNA</li> </ol> Signup and view all the answers

What is the difference between sterilization and disinfection in terms of level of efficacy

Sterilization is 100% but disinfection varies ( variable effectiveness) Signup and view all the answers

What is the difference between sterilization and disinfection in terms of goals

Sterilization: complete destruction of all microbes, disinfection: reduction or deduction of pathogens Signup and view all the answers

What is the difference between sterilization and disinfection in terms of application

Sterilization: surgical equipment and laboratory tools. Disinfection: surfaces and skins Signup and view all the answers

What is the difference between sterilization and disinfection in terms of methods

Sterilization: physical and chemical. Disinfection: primarily chemical, some physical Signup and view all the answers

What are the factors affecting sterilization and disinfection

<ol> <li>Concentration of agent. 2. Contact time. 3. Temperature. 4. Type of microorganisms</li> </ol> Signup and view all the answers

What are the importance of sterilization and disinfection

<ol> <li>Infection control: essential in healthcare to prevent hospital acquired infection . 2. Laboratory safety: critical in the lab to maintain aseptic come for microbiological work . 3. Public health: to prevent the spread of infectious diseases in community settings</li> </ol> Signup and view all the answers

What is culture of microorganisms

It is the growth and maintainance of microbial cells in a controlled condition typically a nutrient medium Signup and view all the answers

What are the factor to consider for a controlled condition for microbial culture

<ol> <li>PH level. 2. Temperature. 3. Water. 4. Nutrient</li> </ol> Signup and view all the answers

What are the types of microbial culture

<ol> <li>Pure culture: a culture that contains a single type of microorganisms ( useful for studying specific characteristics and behaviors of a single species). 2. Mixed culture: a culture that contains 2 or more species of microorganisms ( useful for studying interaction between different species and understanding community dynamics. 3. Enrichment culture: a culture that is designed to enhance the growth of species from a mixed population (useful for isolation of rare and slow growing microorganisms). 4. Continuous culture: a culture where fresh medium is continuously ( it maintains exponential growth of microorganisms by extended period of time)</li> </ol> Signup and view all the answers

Flashcards

Microbial Cause of Disease

Ancient cultures like Egyptians and Greeks recognized some connection between infections and sanitation, hinting at the idea that microorganisms could cause diseases.

Miasma Theory

The common belief for centuries, that diseases were caused by bad air (miasma).

Miasma Theory Era End

The understanding of diseases as caused by bad air or miasma predominantly held until the 19th century.