Ch. 12 mechanisms of infectious disease

Question 1

host

Answer 1

any orginism capable of supporting the nutritional and physical growth requirements of another organism

Question 2

infectious disease

Answer 2

the disease state brought about by the interaction with another organism

Question 3

colonization

Answer 3

the presence and multiplication of a living organism on or within the host

Question 4

microflora

Answer 4

bacteria inhabiting exposed surfaces of the body

Question 5

virulence

Answer 5

the disease-inducing potential

Question 6

pathogens

Answer 6

microorganism so virulent that they are rarely found in the absence of disease

Question 7

saprophytes

Answer 7

free-living organisms obtaining their growth from dead or decaying organic material from the environment

Question 8

mutualism

Answer 8

an interactino in which the microorganism and the host both derive benefits from the interaction

Question 9

commensalism

Answer 9

an interaction in which colonizing bacteria acquire nutritional needs and shelter but the host body not affected

Question 10

parastatic relationship

Answer 10

only the infecting organism benefits from the relationship

Question 11

Agents of infectious disease

Answer 11

• Prions
• viruses
• bacteria
• rickettsiaceae
• chlamydiaceae
• fungi (eukaryotes)
• parasites

Question 12

prions

Answer 12

• protein particles with no nucleic acid or genome

- produces transmissible neurodegeneratice diseases such as creutzfeldt-jacob Disease

Question 13

Virus

Answer 13

• small pathogens
• no organized cellular structure
• consists of protein coat surrounding a nucleic acid core of DNA or RNA
• they are incapable of replication outside a living cell
• they use other cells to hide within or replicate

Question 14

Microorganisms

Answer 14

-eukaryotes (fungi)
+membrane-bound nucleus

-Prokaryotes (bacteria)
+the nucleus is not seperated

Question 15

classification of bacteria

Answer 15

-microscopic: rod, round
-stating of the cell:
+gram-positive organisms: purple by crystal violet
+gram-negative: counter stained by safranin

Question 16

parasites

Answer 16

-types: protozoa, helminths, arthropods

-method of infecting:
+ infect and cause dissease on other animal
+animals then transmit it to the humans

Question 17

Rickettsiaceae, anaplasmataceae, chlamydiaceae, coxiella

Answer 17

• organisms that combine the chracteristis of viral and bacterial agents to produce disease in humans
• like virus’, they are dependent on host cells

-has rigid peptidoglycan cell wall like bacteria
+they produce asexually by cellular division
+they contain RNA and DNA similar to the bacteria

Question 18

classification of infectious disease

Answer 18

• incidence
• portal of entry
• source
• symptoms
• disease course
• site of infection
• virulence factors

Question 19

epidemiology:

Answer 19

the study of factors, event, and circumstances that influence the transmission of infectious disease among humans

Question 20

incidence

Answer 20

the number of new cases of an infectious disease that occur within a defines population

Question 21

prevalence

Answer 21

number of active cases at any given time

Question 22

incidence of disease

Answer 22

• endemic disease: found in a particular geoprapphic region
• epidemic: abrupt and unexpected increase in the incidence of disease over endemic rates
• pandemic: spread of disease beyond continental boundaries

Question 23

portals of entry

Answer 23

• penetration
• direct contact
• ingestion
• inhalation

Question 24

source of an infectious disease

Answer 24

-location:
+nosocomial: developed in hospitalized pts.
+community acquired: acquired outside of health care facilities

-host: an object substamced from which the infectious agent was acquired (may be endogenous or exogenous)

Question 25

symptomatology

Answer 25

- specific: reflects the site of infection (diarrhea, rash, convulsion, hemorrhagempneumonia) - nonspecific: can be shared by a number of diverse infectious disease (symptoms such as fever, myalgia, headache) - obvious: predictable patters (chickenpox, measles) - covert: may require laboratory testing to detect (hepatits or increase white blood cell count)

Question 26

disease course in infection

Answer 26

- incubation period - prodormal stage - acute stage - convalescent stage - resolution stage

Question 27

factors influencing the site of an infectious disease

Answer 27

- type of pathogen - portal of entry - competence of the host's immunologic defense system

Question 28

type of antimicrobial agents

Answer 28

- antibacterial agents - antiviral agents - antifungal agents - antiparasitic agents

Question 29

drug resistance

Answer 29

``` -bacterial resistance mechanisms: +inactivate antibiotics +genetically alter antibiotic binding sites +bypass antibiotic activity +changes in the bacterial cell wall ``` -antiviral resistance mechanisms +nuceoloside analogs +protease inhibitors

Question 30

intravenous immunoglobulin and cytokine therapy

Answer 30

- supplementing or stimulating the host's immune response so that the spread of a pathogen is limited or reversed - pathogen-specific antibodies given to the patient as an infusion to facilitate neutralization, phagocytosis, and clearance of infectious agents above and beyond the capabilities of the diseased host

Question 31

criteria for diagnosis of an infectious disease

Answer 31

+the recovery of a probably pathogen or evidence of its presence from the infected sites of a disease host +accurate documentation of clinical signs an symptoms compatible with an infectious process

Question 32

technique for laboratory diagnosis of an infectious agent

Answer 32

- culture - serology or detection of characteristic antigens - genomic sequences or metabolites produced by the pathogen

Question 33

categories of virulence factors

Answer 33

- toxins - adhesion factors - evasive factors - invasive factors

Question 34

nonpharmacological intervention

Answer 34

-surgical interventions +providing access to an infected site by antimicrobial agents (drainage of an abscess) +cleaning of the sire (debridement) +removing infected organs or tissie (appendectomy)

Question 35

antibiotic mechanisms

Answer 35

- interference with a specific step in bacterial cell wall synthesis - inhibition of bacterial protein synthesis - interruption of bacterial nucleic acid synthesis - interference with normal bacterial metabolism

Question 36

classification of antibiotic action

Answer 36

- bactericidal: if it causes irreversible and lethal damage to the bacterial pathogen - bacteriostatic: if its inhibitory effects on bacterial growth are reversed are reversed when the agent is eliminated

Question 37

classification and target site of antibacterial agents

Answer 37

- penicillins= cell wall - cephalosprins=cell wall - monobactams=cellwall - aminoglycosides= ribosomes - tetracyclines=ribosomes - macroslides=ribosomes - sulfonamides=folic acis synthesis - glycopeptides=ribosomes - quinolones=DNA synthesis

Question 38

weapons of bioterrorism

Answer 38

-category A agents: +plague, tularemia, smallpox, hemorrhagic fever viruses ``` -category B agents: +agenst of food-borne and water-borne diseases +agents of zoonotic infections +ciral encephalitides +toxins from castor bean ``` ``` -category C agents +myobacterium tuberculosis +nipah virus and hantavirus +tick-borne and yellow fever viruses +cryptosporidium parvum ```