Microbiology Flashcards
Include all organisms that are too small to be seen by the unaided eye.
Microorganisms (Microbes)
Can be beneficial agents in the fields of biotechnology and medicine. However, some can infect humans and cause diseases.
Microbes
Discase-Causing Microbes
Pathogens
The scientific discipline that carefully studies, identifies, and characterizes microorganisms.
Microbiology
Carries out laboratory procedures for the detection and identification of pathogens from human samples.
Microbiology Section
These are not made up of true cells. They cannot reproduce independently and are considered non-living. Include viruses and prions.
Acellular Infectious Agents
Do not have nuclear membranes and membrane-bound organelles. Hence, it can be said that these cells do not have ‘true nucleus’. Include the bacteria and archaea.
Prokaryotic Cells
Has a ‘true nucleus’ that is bound by a nuclear membrane. These cells are also characterized by presence of membrane-bound organelles such as mitochondria and endoplasmic reticulum. Include protozoa, microscopic fungi, and the microscopic algae.
Eukaryotic Cell
Internal Mechanisms of Cells
Core
External Mechanisms of Cells
Capsid
Unit made up of the nucleic acid core and the proteinaceous capsid.
Nucleocapsid
Not present in all viruses unlike the core and the capsid. Made up of glycoproteins and lipids
Envelope
Viruses that do not have envelopes.
Naked Viruses
Viruses that are equipped with envelopes.
Enveloped Viruses
Proteinaceous material that protects the nucleic acid core. Made up of structural subunits known as capsomeres
Capsid
Structural Subunits
Capsomeres
TRUE OR FALSE: Some textbooks do not consider viruses as true microbes because of their acellular nature.
True
Unicellular, prokaryotic microbes
Include the eubacteria (true bacteria) and the cyanobacteria (formerly known as
the blue-green algae)
Bacterial cell wall is unique due to presence of peptidoglycan
Taxonomic classification: Kingdom Monera, Domain Bacteria
Bacteria
Unicellular, prokaryotic microbes that live in extreme conditions (environments with extreme heat, extreme cold, extremely high/ low pH, etc.)
Taxonomic classification: Kingdom Monera, Domain Archaea
Archaea
Unicellular, eukaryotic organisms
Non-photosynthetic
Taxonomic classification: Kingdom Protista, Domain Eukarya
Protozoa (Protozoan)
Non-photosynthetic, eukaryotic organisms
Microscopic fungi include the unicellular yeasts and the multicellular molds
Microscopic fungi are capable of carrying out both sexual & asexual reproduction
Cell wall is predominantly made up of chitin
Taxonomic classification: Kingdom Fungi, Domain Eukarya
Fungi
Reproduce via Budding
Yeast
Grow via Apical Extension
Molds
Photosynthetic eukaryotic organisms
Some are unicellular while others are multicellular
Cell wall is predominantly made up of cellulose
Taxonomic classification: The microscopic, unicellular algae are placed under Kingdom Protista; Domain Eukarya
Algae
Focuses on the study of bacteria. As mentioned earlier, not all microorganisms do not cause infectious diseases. The same can be said for this, as not all bacteria are pathogenic.
Bacteriology
The subject that deals with the bacteria that infect humans and the diseases that they cause.
Clinical Bacteriology
The discipline that studies viruses and virus-like agents, including their classification, structure, and their disease-causing properties.
Virology
The discipline that studies the microscopic yeasts and molds.
Mycology
Also known as the study of algology, is the scientific study of algae. Within the context of microbiology, phycology is only concerned with the algae that are too small to be observed by the naked human eyes.
Phycology
The subject that studies the eukaryotic and unicellular protozoans. Take note that some of the protozoans are parasitic in nature.
Protozoology
Completely dependent on another organism (host) for shelter and nourishment while simultaneously harming the host in the process of being dependent.
Protozoans
One of the several individuals who discovered that if two convex lenses (two-lens instrument) were put together, it can be used to make small objects appear larger.
Zacharias Janssen
Coined the term ‘microscopio’ or microscope to refer to the two-lens system.
Giovanni Faber
Used a 25x microscope. In 1665, he published the book Micrographia which detailed his studies using the 25x
microscope.
Robert Hooke
Studied a piece of cork using the 25x microscope: He used the word “cella” to describe the ‘great many little boxes’ he observed. He became the first person to describe and draw a microorganism (mold).
Robert Hooke
Came up with a 200x microscope. Described hundreds of tiny, living animals (probably protozoa and algae) which he
called animalcules.
Anton van Leeuwenhoek
The study of the distribution and determinants of a disease in a specified population.
Epidemiology
Believed in the theory of miasma (“bad air”) which stated that the origin of epidemics such as cholera, malaria, and plague were due to ‘bad air’, emanating from rotting organic matter.
Naturalists
Was a Hungarian obstetrician. Observed the mortality of pregnant women due to puerperal fever (childbed fever). He also compared the performance between Medical Students and Midwifery Students.
Ignaz Semmelweis
“Father of Epidemiology”. Investigated the 1854 London cholera epidemic, concluded that cholera was
waterborne and not spread by miasma.
John Snow
Snow interviewed the sick and healthy Londoners and plotted the location of each cholera case on a district map. He later found out that most cholera cases were clustered and were getting their water source from the street pump in Broad Street. Requested the parish Board of Guardians to remove the street pump handle, effectively breaking the spread of the disease
Spot-Mapping
Considered by many as the “father of bacteriology”. Was the first to correctly explain that fermentation involves converting sugar into alcohol (wine)by yeasts in the absence of oxygen. Concluded that souring and spoilage of wine and dairy products is caused by the presence of bacteria. Came up with the pasteurization technique as a practical solution for the “wine disease” (wine souring).
Louis Pasteur
Specific pathogens are responsible for specific infectious disease.
Germ Theory of Disease by Louis Pasteur
Verified the germ theory of disease by coming up with postulates. His postulates are used as the formalized standards when relating a specific organism to a specific disease.
Robert Koch
POSTULATES: Microorganisms from the pure culture are inoculated into a healthy, susceptible animal. The disease (same disease in postulate 1) is reproduced.
Postulate 3
POSTULATES: The suspected pathogen must be re-isolated from the tissue specimens of the experimental animal and shown to be the same as the original.
Postulate 4
POSTULATES: The microorganisms are isolated from the tissues of a dead animal and a pure culture is prepared. (The microorganisms are then later identified).
Postulate 2
POSTULATES: The same microorganisms are present in every case of the disease.
Postulate 1
A population of cells or multicellular organism growing in the absence of other species of type.
Pure Culture
Marked by many discoveries and innovations that were brought about by the healthy competition between the Pasteur Laboratory headed by Louis Pasteur and the Koch Laboratory headed by Robert Koch.
Classical Golden Age of Microbiology
Focused on mechanism of infection & immunity.
The Pasteur Lab
Attenuated (weakened) the bacterial cells of chicken cholera.
Louis Pasteur with Charles Chamberland
Applied the principle of attenuation to anthrax and demonstrated that he could protect sheep against the disease.
Louis Pasteur
Began testing of an experimental rabies vaccine against dogs.
Emile Roux
Gave the untested (in humans) rabies vaccine to a 9-year-old boy, Joseph Meister, who had been bitten and mauled by a rabid dog. The boy recovered and remained healthy.
Louis Pasteur
Identified the diphtheria toxin.
Alexander Yersin & Emile Roux
Discovered Phagocytosis.
Elie Metchnikoff
Focused on procedural methods for isolation, cultivation, & identification of pathogens.
The Koch Lab
Identified and cultured Mycobacterium tuberculosis
Discovered Bacillus anthracis. Isolated Vibrio cholerae and confirmed John Snow’s suspicion that water is the key to transmission.
Robert Koch
Isolated Corynebacterium diphtheriae (diphtheria bacillus).
Friedrich Loeffler
Cultivated the typhoid bacillus.
George Gaffky
Suggested some dyes might control bacterial infections.
Paul Ehrlich
Isolated Clostridium tetani.
Shibasaburo Kitasato
Developed the diphtheria antitoxin.
Emil von Behring
Observed bacterial cells in leprosy patients.
Gerhard Hansen
Discovered Neisseria gonorrhoeae.
Albert Neisser
Discovered that malaria is caused by a protozoan.
Charles Laveran
Discovered the bacterium responsible for infant diarrhea.
Theodore Escherich
Identified a bacterial causative agent of meningitis (Haemophilus influenzae).
Richard Pfeiffer
Independently discovered the bacterium causing plague
(Yersinia pestis).
Shibasaburo Kitasato and Alexander Yersin
Cultivated Bordetella pertussis (pertussis bacillus).
Jules Bordet and Octave Gengou
Credited as the inventor of this indispensable test. It is performed to classify bacteria according to their cell wall structure.
Hans Christian Gram
This technique will also allow the microscopic observation and classification of bacteria according to shape.
Gram Staining (GS)
Spherical-Shaped Bacteria
Cocci
Rod-Shaped Bacteria
Bacilli
Purple Color Stain
Gram-Positive Bacteria
Pink/Red Color Stain
Gram-Negative Bacteria
This technique is used mainly for the differentiation of acid fast organisms (which will appear with a red stain after acid-fast staining) from non-acid fast organisms. This technique is most useful in the detection of Mycobacterium tuberculosis.
Acid Fast Stain (AFS)
This technique utilizes 10% potassium hydroxide which dissolves the keratin of skin scrapings, nails and hair in order to detect fungal elements such as spores and hyphae.
KOH (Potassium Hydroxide) Preparation
The isolation of the bacterium from the actual site of infection and allowing the organism to grow in vitro using an artificially feasible environment. It allows the microbiologist to come up with a sufficient population of the pathogen which will eventually be used for identification of the pathogen.
Culture
Done after culture in order to determine the most appropriate antibiotics that can be used to treat the infection caused by the pathogen.
Sensitivity Testing/ Antimicrobial Susceptibility Testing (AST)
The most routinely used technique in the Microbiology Section.
Kirby-Bauer Technique (Disk Diffusion Susceptibility Test).
