Infectious Disease 2 Flashcards

1
Q

Bacteria characteristics

A

single celled

well defined walls

no true nuclear membrane

grow independently but require nourishing medium to maintain fxn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacteria classification

A

shape
- spherical = cocci
- rod = bacilli
- spiral = spirilla or spirochetes

response to staining
motility
capsulation
capacity to form spores
aerobic or anaerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pathogenic effects of Bacteria (how do they harm?)

A

bacteria multiply and compete with host cells for essential nutrients

may directly harm human cells by releasing toxic substances

may cause an immune response that will damage human tissues along with the bacteria

not all bacteria is harmful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bacterial infections examples

A

Enterobacteriaceae

C diff

staph

strep

clostridial myonecrosis

pseudomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Clostridiomes (clostridium) Difficle (CDI) or C. Diff

A

diarrhea after antibiotic consumption

GI system

transmission of C. diff is through fecal-oral route (poopy hands to another person who then eats)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Staphylococcal infections

A

People with chronic skin lesions and surgical and burn patients

Infections of burns, surgical wounds, bacterial arthritis, food positioning

Integumentary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Streptococcal infections

A

strep throat

multiple versions target different organ systems
- Groups A; respiratory droplets
- Group B (GBS) - neonatal pneumonia, meningitis, and sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Clostridial Myonecrosis (GAS Gangrene)

Types

A

Gangrene is death of body tissue usually associated with loss of vascular supply abd then bacterial invasion and putrefaction

3 types; dry, moist and gas

anaerobic conditions

integumentary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes dry, moist and gas gangrene

A

dry and moist - loss of blood circulation due to various causes

gas - occurs in wounds infected by anaerobic bacteria, leading to gas production and tissue breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pseudomonas

A

most common in hospital and nursing home - acquired pathogens

integumentary, circulatory and respiratory systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you select an antibacterial drug?

A

broad-spectrum (when pathogen is unknown) vs specific agents

other factors such as patient tolerance, bacterial resistance, and doctor preference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Bactericidal vs Bacteriostatic activity

A

Bactericidal - drugs that kill or destroy bacteria

Bacteriostatic - drugs that do not kill but limit the growth and proliferation of bacteria

classification may depend on drug dosage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the basic mechanisms of antibacterial drugs

A
  1. inhibition of bacterial cell wall synthesis and function
  2. inhibition of bacterial protein synthesis
  3. inhibition of bacterial DNA/RNA synthesis and function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do antibacterial drugs cause inhibition of bacteria cell wall synthesis?

A

Bacteria have a rigid and firm cell wall made of peptidoglycans

Antibacterial drugs can cause inadequate production of peptidoglycans or other structural components of the wall

some drugs punch holes in the cell membrane, destroying selective permeability

some drugs act as DETERGENTS that break apart phospholipid bilayer, creating gaps and leakage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Antibacterial drugs inhibiting bacterial protein synthesis

A

antibacterial drugs enter and bind to ribosomal subunits of bacteria

binding blocks protein synthesis or causes mis reading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Antibacterial inhibition of RNA/DNA synthesis

A

FOLIC acid serves as an enzymatic cofactor in several reactions, including the synthesis of bacterial nucleic acids and certain essential amino acids

drugs inhibit bacterial nucleic acid synthesis by inhabiting the production of folic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does resistance to antibacterial drugs occur?

A

certain bacterial strains have a natural or acquired defense mechanism against specific anti-bacterial drugs, which enables the strain to survive the effects of the drug and continue to grow and reproduce similar resistant strains, representing a gene etic selection process in which only the resistant strain survives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do we control the problem of bacterial resistance?

A

antibiotic stewardship (used carefully and not overused)

identify specific pathogenic bacteria and administer selective agents over broad agents to kill resistant strains more effectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Common side effects of antibacterial drugs

A

hypersensitivty reactions (skin rashes, itching, wheezing)

GI problems

can interrupt therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Virus characteristics

A

subcellular organisms made up of only an RNA or DNA nucleus covered with proteins

smallest known organisms

completely dependent on host cells to replicate

not susceptible to antibiotics

antiviral meds can moderate the course of the viral illness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hep A virus family

A

Picornavirdae

22
Q

Heb B virus family

A

Hep B

23
Q

Hep C virus family

A

Flaviviridae

24
Q

Chicken pox virus family

A

Herpesviridae

25
Q

Herpes virus family

A

herpesviridae

26
Q

Influenza virus family

A

Orthomyxoviridae

27
Q

Corona virus family

A

cornaviridae

28
Q

What happens during viral replication

A

virus often incapacitates the infected cell so that the infected cell cannot carry out its normal physiological activities

antiviral drugs can interrupt the process of viral replication

29
Q

What happens after viral replication?

A

Virus can leave via exocytosis, leaving host cell intact (but still infected with the original virus)

OR it can destroy (lysis) the host cell, releasing viral offspring (which may result in inflammatory mediators and hypersensitivity response)

30
Q

Examples of viral infections

A

bloodborne (HBV, HCV HIV)

Herpes viruses

Viral respiratory infections (flu and covid)

31
Q

Bloodborne viral infections implications for therapists

A

Hep B transmitted to HCW via percutaneous injuries or by direct or indirect contact with blood, pre-exposure vaccine is recommended

Hep C - accidental percutaneous injuries (needle sticks) are highest risk vehicle for transmission

32
Q

Incubation period for Hep C (HVC)

A

6-7 weeks, nearly all who have acute infection will develop chronic (75% of people)

no vaccine so handwashing to prevent transmission is critical

33
Q

How many types of herpes are there

A

8

34
Q

herpes incidence

A

approx 70% over 12 have herpes 1

20% over 12 have 2

if mom has genital herpes the baby can get it during delivery

35
Q

Pathogenesis of herpes

A

primary infection occurs through a break in the mucos membranes of mouth, throat, eye, genitals or via minor abrasions on the skin

local multiplication iccurs followed by viremia and systemic infection with a subsequent latent infection and periodic reactivation of the virus (like via stress)

36
Q

Clinical manifestations of herpes

A

HSV 1 typically occurs around mouth and oral cavity causing vesicles in the mouth, throat and around lips

primary HSV 2 - vesicles form in the genitourinary tract

primary symptoms can be asymptomatic

systemic symptoms - headache, malaise, myalgias and fever

37
Q

How is HSV 2 acquired

A

sexual contact

38
Q

What type of herpes is very contagious?

A

Type 3 Varicella zoster

period of communicability extends from 1-2 days before the onset of the rash through the first 4-5 days or until all lesions have formed crusts

39
Q

What is Herpes virus type 3 known as

A

chicken pox or shingles

older adults above 50 who are immunocompromised are at higher risk

40
Q

Herpes type 4

A

Epstein-Barr virus

primarily affects young adults and children

transmitted through oral secretions, blood or transplanted organs with the virus

common in US with 95% of people between n35-40 having been infected

when infected with EBV, 35-50% chance it will become mononucleosis

41
Q

Herpes type 4 Monocucleosis implications

A

probably contagious before symptoms develop

person infected should avoid excessive activity and contact sports for at least 1 month

42
Q

RSV

A

causes annual breakouts of pneumonia, brohncitis, tracheoobroncitis in infants and young children, main cause of hospitilization

43
Q

How long do people shed RSV?

A

3-8 days, infants may shed up to 3-4 weeks

44
Q

How is RSV diagnosed

A

rapid diagnosis via viral antigen idenification of nasal washings using ELISA or IFA

45
Q

Treatment of RSV

A

hydration, humidification of inspired air, ventilatory support as needed

46
Q

Flu season an transmission

A

late fall to early spring

person to person by inhalation of aerosolized virus or direct contact

47
Q

Flu onset and fever duration

A

onset is abrupt, higher fever and chills, malaise, muscular aching, headache, sore throat and nasal congestion and nonproductive cough

fever lasts 1-7 days (usually 3-5)

48
Q

How can the flu virus progress

A

can progress rapidly in first few days causing pneumonia and respiratory failure particularly in high risk groups

secondary bacterial pneumonia may also develop in 5-10 days after the onset in the older adult

49
Q

Viral resistance

A

viruses can mutate and alter their structural or functional characteristics so that previously effective drugs will be unable to control specific viral infections adequately

limit inappropriate use of antiviral drugs

50
Q

Interferons

A

endogenous substances that exert nonspecific antiviral activity

proteins that are made by the infected cell in response to viral infection

enable healthy cells to resist infection from a wide array of viruses

51
Q

types of interferons

A

type 1 - alpha and beta
type 2 - gamma
type 3 - lambda