Microbiology Basics Flashcards
What causes failure of the body to function normally?
Disease
There are many types of diseases, not all caused by germs.
What is a leading cause of disease in humans?
Pathogens
What are disease-producing microorganisms?
Pathogens
What is the invasion of the body by a pathogen and the symptoms that develop in response to this invasion?
Infection
Which type of infection is restricted to a small area?
Local
What type of infection is widespread throughout the body?
Systemic
Which type of infection is spread by the blood; it affects the entire body and generally makes you feel sick?
Systemic
What is often differentiated in regard to a wound, where there is a distinction between growth of microorganisms and infection?
Colonization
What are microorganisms present and growing but not causing illness?
Colonization
What are the six groups of microorganisms (some of which are pathogens)?
Bacteria
Viruses
Fungi
Protozoa
Worms
Arthropods
What are the single-celled organisms found everywhere?
Bacteria
Which microbe was first observed under the microscope by van Leeuwenhoek, who called them “little beasties?”
Bacteria
Which microbe considers living conditions within the human body to be ideal?
Bacteria
Which microbe performs useful roles such as synthesizing needed substances like vitamin K?
Bacteria
Which microorganism (that normally and harmoniously lives in or on the human body without causing disease) prevents the overgrowth of other organisms, keeping them under control?
Normal Flora
Which microbe makes up the largest group of pathogens?
Bacteria
In which two ways do bacteria cause damage when they successfully invade the human body?
1) Entering and growing in the human cell.
2) Secreting toxins that damage the cell.
Which three groups are bacteria classified into based on shape?
Which other two groups (4 & 5) are also classified as bacteria, although they differ in several important ways from the three referenced above?
Coccus (Round)
Bacillus (Rod-Shaped)
Curved Rod
Rickettsiae
Chlamydiae
Which bacteria are round cells and are arranged in patterns?
Cocci
Which type of cocci are arranged in pairs?
Diplococci
Which type of cocci are arranged in chains, like a chain of beads?
Streptococci
Which type of cocci looks like bunches of grapes and are arranged in clusters?
Staphylococci
Which bacteria group cause many diseases, including gonorrhea, meningitis, and pneumonia?
Cocci
Which bacteria group are long and slender cells shaped like a cigar?
Bacilli
Which bacteria group causes diseases including tetanus, diphtheria, and tuberculosis (TB)?
Bacilli
Which group of bacteria includes the vibrio, the spirillum, and the spirochete?
Curved Rods
What is cholera caused by?
Vibrio
Which type of curved rod has a slight curve and resembles a comma?
Vibrio
Which type of curved rod is a long cell that coils like a corkscrew?
Spirillum
What are coiled spirilla that are capable of waving and twisting motions?
Spirochete
Which famous curved rod, also known as Treponema pallidum, causes syphilis?
Spirochete
What are the two clinically important characteristics of bacteria?
1) Cell Wall
2) Ability to Form Spores
Which two structures are the bacterial cell surrounded by?
Cell Membrane
Cell Wall
What is a rigid wall that protects the underlying cell membrane from bursting?
Cell Wall
What needs to be damaged for the cell membrane of the bacterium to burst, killing the bacterium?
Cell Wall
What does Penicillin cause to burst, causing the bacterium to die and preventing cell wall synthesis in the bacterium?
Cell Membrane
What do human cells lack, leaving them undamaged by penicilln?
Cell Wall
What do viruses lack, leaving them unaffected by penicillin?
Cell Wall
What does bacteria form that allows them to survive harsh environmental conditions such as drying, heating, and exposure to certain disinfectants?
Spores
What enables the bacteria to exist in a “sleepy,” or dormant, state until conditions improve?
Spores
How does Clostridium botulinum, the organism that causes a deadly form of food poisoning (botulism), withstand several hours of exposure to boiling water?
Spores
Which two bacteria groups are smaller than most bacteria and must reproduce within the living cells of a host?
Rickettsia
Chlamydia
Which two bacterial groups are parasites?
Rickettsia
Chlamydia
What are microbes that require a living host?
Parasites
Which bacterial group is often carried by fleas, ticks, and body lice?
Rickettsiae
Which bacterial group causes Rocky Mountain spotted fever (RMSF), carried by the tick?
Rickettsiae
Which bacterial group is responsible for epidemic typhus, carried by body lice?
Rickettsiae
Which bacterial parasite is the smallest and causes several major human diseases?
Chlamydiae
Which bacterial group is the cause of one of the most prevalent sexually transmitted diseases in the United States today?
Chlamydiae
Which bacterial group is responsible for trachoma, a serious eye infection that is a leading cause of blindness in the world?
Chlamydiae
What are bacterial infections such as rickettsial and chlamydial treated with?
Antibiotics
What is the translation of the latin word meaning “poison”?
Virus
Which microbe group is the smallest?
Virus
What infectious agents are not cells and consist of either ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) surrounded by a protein shell?
Virus
Which microbe can only reproduce within the living cells of a host, making them parasites?
Virus
What are diseases such as measles, mumps, influenza, poliomyelitis, COVID-19, and AIDS classified?
Virus
Because of the intimacy of the virus - host relationship, the development of nontoxic antiviral agents has been slow and difficult. This point is well illustrated by the drug zidovudine (AZT), used in the treatment of AIDS. While exerting antiviral effects, the drug also causes widespread damage to the ___ cells.
host
What causes most upper respiratory infections, making them unresponsive to antibiotic therapy?
Virus
What is a plantlike organism, such as a mushroom, that grows best in dark, damp places?
Fungus
What are yeasts and molds (such as bread mold) classified?
Fungus
What causes mycotic infections?
Fungus
What does myco mean?
Fungus
What are localized infections including athlete’s foot, ringworm, thrush, and vaginitis classified?
Fungus
What is yeast-like Candida albicans that normally inhabits the mouth, digestive tract, and vagina classified?
Fungus
When Candida overgrows, it can cause an infection in the mouth (thrush), intestinal symptoms, or vaginitis.
Which microbe infection is rarely systemic, but when they occur, are life-threatening and difficult to cure?
Fungus
What are the are single-celled, animal-like microbes?
Protozoa
What are the four main types of protozoa?
Always - Amebas
Carry - Ciliates
Fruit - Flagellates
Snacks - Sporozoa
Which microbes are found in the soil and in most bodies of water?
Protozoa
Which type of parasite causes Amebic dysentery and giardiasis?
Protozoa
The parasites are ingested in contaminated water and food and cause severe diarrhea.
Which protozoa, called plasmodium, causes malaria?
Sporozoa
Plasmodium malariae is carried by a mosquito, which is capable of spreading malaria over a wide region.
Which protozoa, including Pneumocystis jiroveci and Cryptosporidium, pose a serious health threat to persons with impaired immune systems?
Sporozoa
Pneumocystis jiroveci and Cryptosporidium cause infections in persons with AIDS and other immunocompromised persons.
Which two disease-causing, multicellular organisms are larger than microorganisms?
Worms
Arthropods
What are parasitic worms?
Helminths
What are the multicellular animals that are parasitic and pathogenic to humans?
Worms
Which two groups are worms (helminths) categorized?
Roundworms
Flatworms
Which worm includes ascarides, pinworms, hookworms, trichinae, and the tiny worms that cause filariasis or elephantiasis?
Roundworms
Which worm infestation is common in children and is very hard to control?
Pinworm
Which organism infestation is transmitted by the fecal–oral route (in which hands contaminated by feces introduce the organism, eggs, or larvae into the mouth)?
Worm
Which worm includes tapeworms and flukes?
Flatworms
Tapeworms that live in the intestines may grow from 5 to 50 feet in length. Imagine hosting a 50-foot tapeworm!
Flukes are flat, leaf-shaped worms that invade the blood and organs such as the liver, lungs, and intestines. Because these large flatworms feed on the human host, infestation causes weight loss, anemia, and generalized debilitation.
Infestation by worms is treated with drugs called anthelmintics (which means “against worms”).
What are the animals with jointed legs and include insects?
Arthropod
Since mites and lice are ectoparasites, meaning they live on the surface of the body, skin, and mucous membranes, which organism are they classified?
Arthropods
Ectoparasites cause itching and discomfort but are not life-threatening.
What do arthropods such as mosquitoes, biting flies, fleas, and ticks act as?
Vectors
What is an object, living or nonliving, that transfers a pathogen from one organism to another?
Vector
The bite of the arthropod vector introduces pathogens into the host (the person or organism that is infected by a pathogen), causing infection. For example, the mosquito (arthropod vector) can carry the pathogens for malaria and encephalitis. The tick can carry the pathogens that cause Lyme disease and RMSF.
Pathogens: Microorganisms and Larger Disease-Causing Organisms
Which two laboratory procedures and techniques are used to identify pathogens?
Staining
Culture
Which technique involves the use of dyes?
Staining
How are bacteria identified?
Staining
Gram or Acid - Fast
Dye
Which bacterium is one that stains purple or blue?
Gram - Positive
Which gram stain is Streptococcus?
Gram - Positive
Which gram stain is a bacterium such as Escherichia coli?
Gram - Negative
What result causes bacteria to pick up a pink or red gram stain?
Gram - Negative
Does not absorb the purple Gram stain.
What is an important first step in the identification of the causative organism of an infection?
Gram Staining
Most bacteria are gram-positive or gram-negative.
Which procedure first includes staining the bacterium with a red dye and then washing with an acid?
Acid-Fast
Which test is undergone when bacteria retains a red stain?
Acid-Fast
Most bacteria lose the red stain when washed with acid. However, several bacteria retain the red stain and are therefore called acid-fast.
How does the most famous bacteria of its type, Mycobacterium tuberculosis (the causative organism of TB) stain?
Acid-Fast
Red
This organism is commonly called the acid-fast bacillus.
Which two bacteria do not stain with any of the commonly used dyes?
Spirochetes
Rickettsiae
They must be stained with special dyes and techniques.
Sometimes the physician wants to identify the specific pathogen growing in an infected wound and orders a wound ___ to be done. A sample of the wound exudate (pus) is placed on ___ medium. The pathogens are incubated and allowed to grow and multiply. The pathogens can then be stained and identified.
culture x 2
What is food that supports the growth of pathogens?
Medium
What term is assigned to the growth of pathogens in a medium?
Culture
What test is undergone when the cultured pathogens are tested for their susceptibility to various antibiotics?
Culture and Sensitivity
What is placed in a culture to verify whether a pathogen is responsive or sensitive (if the growth stops) to its effects?
Antibiotic
How do pathogens enter the body?
Portals of Entry
What are the six portals of entry?
Respiratory Tract
Gastrointestinal Tract
Genitourinary Tract
Parenteral Route
Eyes
Skin
Which entry portal includes those injuries that penetrate the skin or mucous membranes, such as bites, cuts, and surgery?
Parenteral
Which entry portal exists when body fluids contaminated with the AIDS or hepatitis viruses enter through tiny cuts or abrasions on ungloved hands?
Parenteral
Which two entry portals do most pathogens enter the body through?
Respiratory
Gastrointestinal
Which entry portal exists when one inhales droplets of water and dust?
Respiratory
Which entry portal exists when eating spoiled food or placing contaminated hands in the mouth?
Gastrointestinal
How do pathogens leave the body of an infected person?
Portals of Exit
What are the six portals of exit?
Respiratory Tract
Gastrointestinal Tract
Genitourinary Tract
Eyes (tears)
Skin (intact and broken)
Breasts (milk)
Which are the most common portals of exit?
Respiratory
Gastrointestinal
Which portal of exit exists when the common cold virus is released by sneeze or cough into a room?
Respiratory
Which exit portal exists when the Salmonella organism in a person with typhoid fever exits the body?
Gastrointestinal
Which exit portal exists when discharge spreads infection (sexually transmitted diseases)?
Genitourinary
What is the most important procedure in preventing the spread of infection?
Handwashing
In which three modes are pathogens spread?
Person to Person
Environment to Person
“Tiny Animals” (insects) to Person
Which transmission mode occurs when someone with a cold virus sneezes, spraying the virus into the air in tiny droplets of nasal discharge, and these droplets are inhaled by others?
Person to Person
- Droplet Contact
- Object contamination (doorknobs, handshaking, etc.)
What term is assigned to an object, living or nonliving, that transfers a pathogen from one organism to another?
Vector
What term is assigned to a nonliving vector?
Fomite
What is a contaminated doorknob considered?
Vector & Fomite
What are soiled handkerchiefs and contaminated eating utensils considered to be?
Vectors & Fomites
Which transmission mode includes contact with contaminated water, air, food, or soil?
Environment to Person
Which transmission mode exists when developing typhoid fever from drinking a glass of water contaminated by S. typhi?
Environment to Person
Which transmission mode exists when one develops food poisoning by eating food contaminated with E. coli?
Environment to Person
Which transmission mode includes the use of insects (and other “crawling critters”) in the spread of disease?
“Tiny Animal” to Person
What are the tiny animals used in the spreading of disease considered?
Vectors
Which transmission mode exists when a mosquito bites a person with malaria, the malaria-causing plasmodium matures in the stomach of the mosquito, and then the plasmodium-loaded mosquito bites another person?
“Tiny Animal” to Person
Which transmission mode exists when flies hop from dog feces to food on a picnic table, the pathogens from the dog feces are transferred by the fly feet to the food, and the food is eaten?
“Tiny Animal” to Person
Note that the mosquito and fly both spread disease. The mosquito, however, plays a more complicated and biological role. The plasmodium (causative organism of malaria) requires the mosquito as part of its life cycle; it matures in the stomach of the mosquito. Because of this role, the mosquito is called a biological vector. The lowly fly does not participate in the life cycle of the pathogen; it merely walks on the dog feces, and the germs stick to the feet of the fly. The fly then flies onto your food and deposits the germs on your food. The fly is only a mechanical vector but a very effective germ spreader.
Spread of Infection
What is a hospital-acquired infection that is most often transmitted from patient to patient by direct contact?
Nosocomial
Which infection type is transmitted by health professionals who do not wash their hands?
Nosocomial
What are permanent microbes residents that do not produce disease when present in normal amounts?
Normal Flora
What is the population of microbes within the vagina?
Normal Flora
What are the diverse population of microbes in body cavities or areas such as the skin, large intestine, mouth, and respiratory tract considered?
Normal Flora
What is an organism who has become infected with a pathogen?
Host
What is an organism that transmits a pathogen such as rickettsia?
Animal Vector
A tick acts as an arthropod vector for Rocky Mountain Spotted Fever (RMSF).
What is a tick harboring pathogens?
Resivoir
Which disease type can be transmitted from one person, animal, or organism to another?
Communicable
- Vectors
- Contaminated food or water
- Airborne particles
- Indirect contact
Non-communicable diseases (like diabetes or cancer) are not spread between individuals.
Which disease type can easily spread from host to host like a common cold or impetigo?
Contagious
- Chickenpox
- Measles
Which disease type includes animal diseases that are transmissible to humans?
Zoonosis
- Malaria
- Endemix typhus
What is an organism that transmit a disease to other organisms, typically without showing symptoms of the disease?
Carrier
Key Microbiological Terms
