Module 12: Infection & Microbiology Flashcards
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
Protozoa are eukaryotic or more complex organisms. They are unicellular, motile, and lack a cell wall. The pathogen‘s are usually parasites. What are 3 diseases caused by a protozoan infection?
Trichomoniasis, malaria, amebic dysentery
Trichomoniasis Causes what?
STI of the reproductive tracts of men and women, causing inflammation
Malaria is caused by microbes found where?
RBCs. Acute illness when these RBCs rupture to release new microbes and toxins; transmitted by specific type of mosquito
Amebic dysentery Is a severe form of? How is it spread?
Diarrhea, and liver abscesses if portal circulation is penetrated; spread by the fecal–oral route (improper handwashing)
Helminths or worms are not microorganisms, but are often included with microbes because they are parasites and cause infection in humans worldwide. How is one affected by helminths? What type of effects do they have?
May enter through the skin, transmitted by infected insects, or ingested in contaminated food or water.
Systemic effects, such as severe anemia, can develop with a large number of worms in the body
Prions are protein-like agents. How are they transmitted? What kind of disease do they cause? Give example of human prion and animal prion
By consumption of contaminated tissues (muscle) or the use of contaminated donor tissues.
Causes degenerative disease of the CNS
Human prion infection - CJD, animal prion infection - mad cow disease
*Some areas of the body lack resident flora or are sterile under normal circumstances. What are some examples?
Lungs, bladder, Kidney, uterus/fallopian tubes/ovary, blood/CSF
*Where is resident flora present?
Skin, nose, pharynx, mouth, colon, rectum, vagina, distal urethra and perineum
*What is an endemic infection?
Refers to a disease or condition regularly found among particular people or in a certain area
*A widespread occurrence of an infectious disease in a community at a particular time is referred to as?
Epidemics
*What is a pandemic infection?
A disease becomes pandemic when it spreads beyond a region to infect large numbers of people worldwide
*What are nosocomial infections?
Infections that occur in healthcare facilities, including hospitals, nursing homes, doctors offices, and dental offices
An infection/disease occurring in single individuals is referred to as?
Sporadic
What infection is resistant to penicillin like antibiotics?
MRSA - Methicillin-resistant staphylococcus aureus infection
*Standard/universal precautions for infection control are used when?
In all settings with everybody when body fluids may be exchanged
*Specific precautions for infection control are used when?
In clients with a specific infection – used in addition to standard precautions
*What is the incubation period?
Time between entry of organism and appearance of clinical signs of disease
*What is the prodromal period?
Early symptom stage – feel fatigue, loss of appetite, headache. “i’m coming down with something”
*What is the acute period Of infection?
Infectious disease developed fully, clinical manifestations reach a peak
Septicemia means?
Multiplication of pathogenic organisms in the blood, causing sepsis
systemic infection: what is bacteremia?
Presence of bacteria in the blood
Systemic infection: What is toxemia?
Presence of toxin in the blood
What is viremia?
Presence of virus in the blood
*Leukocytosis, or an increase in white blood cells is common in what type of infection?
Bacterial infection
*Leukopenia, A reduction in the number of leukocytes in the blood is often caused by what type of infection?
Viral infection
Fungi reproduce by
Budding, extension of hyphae, proDuction of spores
