infectious disease 2 Flashcards
bacteria definition
Single-celled microorganisms with well-defined cell walls that
can grow independently on artificial media without the need for other cells.
bacteria shapes
cocci
bacilli
spirilla
cocci - spherical bacteria
bacilli - rod-shaped
spirilla - spiral shaped
bacteria classification
➢ Response to staining (gram-positive, gram-negative, or acid-fast)
➢ Motility (motile or nonmotile)
➢ Tendency toward capsulation (encapsulated or nonencapsulated)
➢ Capacity to form spores (sporulating or nonsporulating)
➢ Aerobic: oxygen is needed to replicate and develop
➢ Anaerobic: they can sustain life in an oxygen-poor (anaerobic)
bacterial structure and function
- unicellular organisms
- rigid cell wall that surrounds bacterial cell
- require nourishing medium
bacteria may cause…
an immune response that will ultimately damage human tissues along with the invading bacteria.
CDIFF
diarrhea, GI system, fecal-route
staphylococcal infections
who: chronic skin lesions, surgical and burn patients
how: bacteria arthritis, surgical wounds, food poisoning
what system level: integumentary
streptococcal infection
strep throat
organ level: group A
- Group B: neonatal pneumonia, meningitis, and sepsis
clostridial myonecrosis
gangrene: death of body tissue. associated with loss of vascular supply and bacterial invasion.
- anaerobic conditions affecting integumentary system level
pseudomonas
- most common hospital and nursing home @ Integumentary, Circulatory, Respiratory system levels
bactericidal
Drugs that typically kill or destroy bacteria
bacteriostatic
Drugs that do not actually kill bacteria but limit their growth and
proliferation
basic mechanisms of antibacterial drugs
- inhibition of bacterial cell wall synthesis and function
- inhibition of protein synthesis
- inhibition of DNA/RNA synthesis and function
how do antibacterial walls damage cell wall synthesis and function
drugs can cause inadequate production of peptidoglycans * within the cell wall
- can punch holes in cell membrane
-* drugs can act as detergents that break down phospholipid layer to create gaps
how do drugs inhibit bacterial protein synthesis
drug binds to ribosomes to block protein synthesis and misread the RNA code
how to drugs inhibit bacterial DNA /RNA synthesis and function
drugs inhibit bacteria DNA/RNA to stop folic acid production, which is responsible for bacterial nucleic acid synthesis
bacterial resistance
certain bacteria have an acquired defense mechanism against drugs, which can cause bacteria to survive against drug and produce resistant strains
antibiotic stewardship
Antibacterial drugs should be used carefully and not overused
Virus
- smallest known organisms made up of only RNA/DNA.
- dependent on host cells, only contain genetic code to replicate
- not * susceptible to antibiotics
exocytosis
lysis
exocytosis: process by which virus is released
lysis: host cell may simply be destroyed, may stimulate the production of inflammatory mediator
list the bloodborne viral pathogens
- hepatitis B
- hepatitis C
hepatitis B
- HBV can be transmitted to HCWs via percutaneous injuries or by direct contact with blood
- vaccine highly recommended
hepatitis C
accidental percutaneous injuries (NEEDLE INJURIES) are the highest vehicle risk for transmission to HCW
how long is the incubation period for HCV
6 to 7 weeks
what is the percentage of all ppl that develop chronic hepatitis?
(for people with hep C)
75%
how is HSV2 (herpes 2) mainly transmitted
mostly acquired through sexual contact, causes vesicles to form in genitourinary tract
how does primary infection occur through for HSV1
Primary infection occurs through a break in the mucous membranes of the mouth, throat, eye, or genitals or via minor abrasions in the skin.
what med is used for herpes simplex virus
acyclovir
what type of herpes is varicella zoster virus
herpes virus type 3
infectious mononucleosis
- acute infectious disease, primarily affects younger adults and children
- herpes virus type 4, aka Epstein Barr virus
- transmitted through oral secretions or transplanted organs
-contagious before symptoms develop until the fever subsides
RESPIRATORY SYNCYTIAL VIRUS
causes annual outbreaks of pneumonia, bronchiolitis, and
tracheobronchitis in infants and very young children and is the main cause of hospitalization for a respiratory illness in this group
influenza
- caused by influenza viruses A or B and occurs in epidemics between late fall and early spring.
- the mode of transmission is from person to person by inhalation of aerosolized virus or direct contact
covid 19
A viral disorder generally characterized by high FEVER; COUGH; DYSPNEA;CHILLS; PERSISTENT TREMOR; MUSCLE PAIN; HEADACHE; SORE THROAT; a new loss of taste and/or smell (see AGEUSIA and ANOSMIA) and other symptoms of a VIRAL PNEUMONIA
viral resistance
Viruses can mutate and alter their structural or functional
characteristics so that previously effective drugs will be unable
to control specific viral infections adequately
interferons
endogenous substances that exert nonspecific antiviral activity
herpes viruses percentages
HSV1
HSV2
HSV1 - 70%
HSV2 - 20%
varicella period of communicability
1-2 days before onset of the rash
4-5 days or until all lesions form crusts
