Shared Flashcard Set

Details

Vuck Path/Pharm Test 4
Infectious Processes
61
Pathology
Professional
02/03/2012

Additional Pathology Flashcards

 


 

Cards

Term
Breaking the chain: Transmission of Infection
Definition
Destroying: Reservoir
Blocking: Mode of Transmission, Portals of Entry and Exit
Reducing: Victim's Susceptibility
Term
Infection risk factors
Definition
Nutritional status
Chronic illness
Age
Immunosuppression
Term
Direct transmission
Definition
Direct contact between reservoir and new host
-Physical
-Fecal contamination
-Airborne droplets
Term
Indirect transmission
Definition
Reservoir deposits organism on fomite (inanimate object), which transmits pathogen to new host
Term
Colonization
Definition
Microorganism does not cause disease in host, but can be transmitted to others
Term
Infection control
Definition
Requires breaking chain of transmission
-Use antimicrobials
-Destroy nonhuman reservoirs/vectors
-Block portal exit
-Improve immune system
Term
Most cost-effective method of altering pathogen susceptibility
Definition
Immunization
Term
2 Goals of Immunization
Definition
Confer immunity to host by direct exposure to pathogen

Decrease number of susceptible hosts in the population (herd immunity)
Term
Nosicomial Infection
Definition
Acquired while hospitalized

48,000 deaths annually

catheters & ventilators

MRSA
Term
Opportunistic Infections
Definition
Normal flora may become pathogenic when immune system is compromised
Term
Microbial Adherence
Definition
Ability of a microorganism to latch onto and gain entrance into its host
-Direct penetration
-Sticks to tissue surface
-Slime layer (glycocalyx) also facilitates adherence
Term
____ help microorganism to spread or invade tissues
Definition
Bacterial enzymes
Term
Encapsulation
Definition
-Prevents opsonization by antibodies
-Prevents microorganism from being phagocytized
Term
Endospore formation
Definition
Allows microorganism to survive under harsh environmental conditions
Term
Microorganism Characteristics
Definition
[image]
Term
Virulence
Definition
-Microorganism consistently causes disease in all infected hosts
-Interaction between host/pathogen harms host
Term
Antimicrobial resistance
Definition
-Microorganism’s ability to mutate in response to environment changes in host
-Mutation allows successful host infection
Term
Chemotaxis
Definition
Movement of microorganisms toward favorable environment, usually toward sugar or amino acid concentrations.
Term
Antibiotic Resistance
Definition
-Individuals treated with antibiotics taking only part of prescribed dose
-Overprescription of antibiotics
Term
Exotoxins
Definition
-Polypeptides produced and released by organisms
-Very toxic
Term
Endotoxins
Definition
-Immunogenic part of bacterial cell wall that triggers a massive immune response when bacterium lyses
-Associated with gram neg. bacteria
Term
Septic Shock
Definition
Immune response leads to cell shock and multiple organ failure
Term
3 types of spirochete
Definition
Borrelia: spaghetti
Treponema: corkscrew
Spirilla: flatter
Term
4 major groups of bacteria
Definition
1. Gliding bacteria
2. Spirochetes
3. Mycoplasmas
4. Rigid bacteria
Term
Bacilli
Definition
Rod shaped
Escherichia coli
Term
Gram Stain
Definition
4 step process: stain, fixation, extraction, counterstain

Gram positive bacteria are already stained with crystal violet and remain purple.

Gram negative bacteria are stained pink
Term
Identifying micoorganisms
Definition
-Are they Gram positive or negative? 
-What is the morphology (rod, coccus, spiral, pleomorphic [variable form] etc)? 
-Do cells occur singly or in chains, pairs etc? 
-How large are the cells?
Term
Bacterial infection results in death when
Definition
If they overwhelm lymph nodes, bacterial emboli can cause bacteremia, microabscesses, sepsis, septic shock
Term
Sepsis
Definition
Systemic blood borne illness
Term
Fungi
Definition
-Disseminated through environment
-Reproduce by either
--Dividing (asexually)
--Combining genetic information before dividing (sexually)
-Mycoses
--Infections caused by fungi
Term
3 location for fungi
Definition
1. Superficial
2. Subcutaneous
3. Systemic
Term
Antibiotic
Definition
Strictly speaking – a chemical that is produced by one microbe and has the ability to harm other microbes
Term
Antimicrobial agent
Definition
Any agent that has the ability to kill or suppress microorganisms
Term
Selective Toxicity
Definition
-Disruption of bacterial cell wall
--Rigid cell wall/high bacterial intracellular osmotic pressure

-Inhibition of an enzyme unique to bacteria
--Sulfonamide inhibition of bacterial folic acid synthesis

-Disruption of bacterial protein synthesis
--Ribosomal differences between human and bacterial cells
Term
Antimicrobial Drugs work on:
Definition
Cell wall synthesis
Cell membrane permeability
Protein synthesis (lethal)
Nonlethal inhibitors of protein synthesis
Synthesis of nucleic acids
Antimetabolites
Viral enzyme inhibitors
Term
Four basic microbial mechanisms
Definition
1. Decrease the concentration of a drug at its site of action
2. Inactivate a drug
3. Alter the structure of drug target molecules
4. Produce a drug antagonist
Term
Organisms With Microbial Drug Resistance
Definition
MRSA: Methicillin-resistant S. aureus *
VRE: vancomycin-resistant Enterococcus
MDRTB: multidrug-resistant tuberculosis
Term
Mechanisms for Acquired Resistance
Definition
Spontaneous mutation
-random changes to microbe’s DNA
-Single drug resistance

Conjugation
-extra-chromosomal DNA is transferred from one bacterium to another
-Most common-gram neg. bacteria
-Multiple drug resistance
Term
Suprainfection
Definition
Overgrowth of normal microbes due to treating other infection.
Term
CDCs Campaign to Prevent Antimicrobial Resistance: 12 Steps to Prevent Antimicrobial Resistance Among Hospitalized Adults
Definition
[image]
Term
Selection of Antibiotics
Definition
-Identify organism
-Drug sensitivity of organism
-Host factors
Drug may be ruled out due to:
-Allergy
-Inability to penetrate the site of infection
-Patient variables
Term
Empiric Therapy
Definition
Antibiotic therapy for patients before causative organism is positively identified
(Emergency for sepsis, pre-surgery)
Term
Identifying the Infection Organism
Definition
-Match the drug with the bug
-Gram-stained preparation
-Determining drug susceptibility
--Disk diffusion test
--Broth dilution procedure (more precise).
Term
Minimum inhibitory concentration
Definition
prevents growth
Term
Minimum bacteriocidal concentration
Definition
destroys bacteria
Term
Antimicrobial effects of antibiotic combinations
Definition
Additive: 1 + 1 = 2
potentiative (synergistic): 1 + 1 = 3
antagonistic: decrease in effectiveness of 1 due to other
Term
Prophylactic Use of Antimicrobials
Definition
Agents given to prevent infection rather than to treat an established infection
-Surgery
-Bacterial endocarditis
-Neutropenia
-Other indications
Term
Endocarditis
Definition
inflammatory bacterial infection of the heart
Term
Mechanisms of Bacterial Resistance to Penicillin
Definition
-Inability of penicillins to reach their targets
-Inactivation of penicillins by bacterial enzymes
-Production of penicillin-binding proteins (PBPs) that have a low affinity for penicillins (MRSA)
Term
Gram-negative vs gram-positive cell envelope
Definition
Gram-negative cell envelope
-Three layers
-Thin cell wall and an additional outer membrane that is hard to penetrate

Gram-positive cell envelope
-Only two layers
-Relatively thick cell wall that is easily penetrated
Term
Penicillinases
Definition
-Beta-lactamases (cleave beta-lactam ring)
-Enzymes that render penicillin inactive
-Bacteria can produce a large variety of these enzymes specific for penicillins (and other beta-lactam antibiotics)
Term
Classification of Penicillins (4)
Definition
1. Narrow-spectrum penicillins
-Pencillinase-sensitive
2. Narrow-spectrum penicillins
-Pencillinase-resistant
3. Broad-spectrum penicillins
4. Extended-spectrum penicillins
Term
Assess for penicillin allergy in each patient who will be receiving penicillin
Definition
If history of mild reaction – consider cephalosporin

If history of anaphylaxis – avoid administration of penicillin or cephalosporins
Term
3 Types of penicillin allergy
Definition
Immediate (reaction in 2 to 30 minutes)
Accelerated (reaction in 1 to 72 hours)
Late (reaction takes days or weeks to develop)
Term
Penicillin Allergy Treatment
Definition
-Epinephrine
-Respiratory support
-Prevention – skin testing
Term
Penicillinase-Resistant Penicillins
Definition
-Nafcillin
-Oxacillin
-Dicloxacillin
-Narrow spectrum-used against penicillinase-producing staphylococcus.
Term
Broad-spectrum penicillins (aminopenicillins)
Definition
Ampicillin (Principen)
Amoxicillin (Amoxil, DisperMox, Moxatag, Trimox)-very common drug


Adverse effects
-Rash
-Diarrhea
Term
Beta-lactamase inhibitors
Definition
Clavulanic acid, tazobactam, sulbactam


Extends antimicrobial spectrum when combined with penicillinase-sensitive antibiotics
Term
Examples of penicillin/beta-lactamase inhibitors
Definition
Ampicillin/sulbactam (Unasyn)
Amoxicillin/clavulanic acid (Augmentin)
Ticarcillin/clavulanic acid (Timentin)
Piperacillin/tazobactam (Zosyn)
Term
Third generation cephalosporins
Definition
Preferred therapy for several infections
Highly active against gram-negative organisms
Able to penetrate to CSF
Term
Vancomycin (Vancocin, Vancoled)
Definition
Drug of last resort. No longer working.

MRSA, MRSE, C.diff
Supporting users have an ad free experience!