Module 12: Infection & Microbiology Flashcards
(50 cards)
Many microorganisms are nonpathogenic or pathogenic?
non-pathogenic - they do not usually cause disease, in fact they are usually beneficial.
Some are pathogenic “germs”; infection due to pathogenic microbes entering and multiplying in the host
What are Pathogen’s?
The disease causing microbes often referred to as germs
Micro organisms include?
Bacteria, fungi, viruses, protozoa
Bacteria is classified as what?
Prokaryotes,
What is culture and sensitivity?
A culture is a process of growing a micro organism in a lab so it can be identified
Sensitivity – involves testing various antimicrobial medications on the organism that has been cultured, and identifying which ones will kill or inhibit growth of the microorganism
Describe antibiotic
A type of anti-microbial substance active against bacteria and is the most important type of antibacterial agent for fighting bacterial infections
Describe bacteria
Unicellular organisms that do not require living tissue to survive
What is a virus?
A very small obligate intracellular parasite that requires a living host cell for replication
What are the three major groups of bacteria based on cellular shape?
Bacilli (rod), spirals, cocci (spherical)
What are four factors affecting bacterial growth?
Nutrients, oxygen, pH, temperature
Bacteria duplicates by?
Binary fission (two daughter cells identical to the parent bacterium)
What is the function of the outer rigid cell wall of bacteria?
Protects the microbe and provides a specific shape
A bacterium has one of two types of cell walls, gram–positive or Gram–negative, which differ in their chemical composition. What is this classification useful for?
For selecting appropriate antimicrobial therapy
Penicillin acts on gram- positive or negative?
Gram-positive
Some bacteria secrete toxic substances, toxins, and enzymes. Toxins consist of two types, exotoxins and endotoxins. Exotoxins are usually produced by gram-________ bacteria and diffuse through body fluids. They often interfere with ___________
Gram-positive, interfere with nerve conduction
Exotoxin stimulate what?
antibody or antitoxin production, which after being processed to reduce the toxic affect, can be used as toxoid to induce an immune response
Endotoxins are present in the cell wall of gram-______and are released after the bacterium dies. They may cause what? And could affect what system?
Negative
- fever and general weakness; Could affect circulatory system
Enzymes are produced by some bacteria and damage what?
Post tissues or cells
Viruses are difficult to control – one type of virus exist in many similar forms or strains and they tend to mutate during replication (ex. Cold or influenza viruses). Some viruses can alter host cell chromosome which can lead to the development of what disease?
Cancer
Chlamydia is related to bacteria and leads to common STD that causes what?
Pelvic inflammatory disease and sterility in woman
Rickettsia is transmitted by insects (ticks, lice), they are gram-_______ bacteria, And attack what?
Gram-negative,
Attack blood vessel walls (rash, small hemorrhage); can cause typhus fever
Mycoplasmas Are the smallest cellular microbes, what do they lack which makes them unaffected by many anti-microbial drugs? Mycoplasmal infection is a common cause of?
Lack cell walls
Common cause of pneumonia
Where is fungi found?
Everywhere – common contaminants found on surfaces and in food, but also frequently considered beneficial (production of foods, source of antibiotics)
Fungal or mycotic infection results from single-celled _______ or multicellular _______. These organisms are classified as?
Single-cellular: yeast, multicellular: mold
Eukaryotic
