Exam 3 Study Deck Flashcards
generally, how do viruses cause upper respiratory infections
viruses disrupt the stratified squamous epithelial cells that line the oral/nasopharynx
this disruption allows normal bacteria in the area to produce infections
what are four factors that can predispose you to an infection
1.) overuse of antibiotics or immunosuppressive therapy (steroids/radiation)
2.) inadequate hydration
3.) malnutrition/old age
4.) immunosuppressive diseases (cancer/HIV)
describe some features of laryngitis
-usually caused by a virus
-symptoms: hoarseness/lowering of voice
if laryngitis is bacterial, what are the two main suspects?
1.) streptococcus pyogenes
2.) diphtheria
what are 6 types of viruses that can cause laryngitis
1.) influenzae
2.) rhinoviruses
3.) coronoviruses
4.) parainfluenzae
5.) adenoviruses
6.) human metapneumonviruses
what are the four main symptoms of laryngotracheobronchitits or “croup”
1.) fever
2.) difficulty breathing (stridor)
3.) hoarseness
4.) barking cough
what are 6 types of viruses that can cause laryngotracheobronchitis (croup)
1.) parainfluenzae
2.) influenzae
3.) rhinoviruses
4.) respiratory syncytial virus
5.) adenovirus
6.) mycoplasma
what is the most common virus to cause laryngotracheobronchitis or “croup”
parainfluenzae
who are most affected by laryngotracheobronchitis or “croup”
young children under 3 years of age
who are most affected by epiglottitis
children between 2 and 6
what are the four symptoms of epiglottitis
1.) fever
2.) painful swallowing
3.) drooling
4.) respiratory obstruction
what is the most common bacteria to cause epiglottitis
haemophilus influenzae type b
which 2 types of bacteria can cause epiglottitis
staph and streps (strep. pneumo.)
young children with epiglottitis are prone to what
developing bacteremia
what are the three features of a pharyngitis or tonsillitis infection caused by arcanobacterium haemolyticum
1.) gram positive, diphtheroid rod
2.) beta-hemolytic on blood agar
3.) invades pharyngeal mucosa
what are the four features of a pharyngitis or tonsillitis infection caused by streptococcus pyogenes
1.) gram positive cocci in chains
2.) catalase negative and beta-hemolytic on blood agar
3.) invades pharyngeal mucosa
4.) produces toxins and virulence factors
what are the three features of a pharyngitis or tonsillitis infection caused by corynebacterium diphtheriae
1.) gram positive rod (Chinese letters)
2.) pseudomembrane produced by diphtheria toxin
3.) obstruction by pseudomembrane
which two mediums should be used to isolate corynebacterium diphtheriae in the case of pharyngitis and tonsillitis
1.) cystine-tellurite blood agar
2.) tinsdale medium
what is the most common bacterial cause of pharyngitis or tonsillitis
streptococcus pyogenes
which antibiotic is most commonly used to treat bacterial pharyngitis and tonsillitis caused by streptococcus pyogenes
penicillin
what are the two main consequences of untreated, strep. pyogenes pharyngitis or tonsillitis
post streptococcal sequelae -acute rheumatic fever and glomerulonephritis
what are the four main symptoms of rheumatic fever
1.) fever
2.) carditis
3.) subcutaneous nodules
4.) polyarthritis
what are the four main symptoms of acute glomerulonephritis
1.) edema
2.) hematuria
3.) hypertension
4.) proteinuria
what are the four main virulence factors of bacterial pharyngitis caused by strep. pyogenes
1.) protein F
2.) M protein
3.) enzymes
4.) exotoxins
what role does protein F play in bacterial pharyngitis
mediates epithelial cell attachment
what role does M protein play in bacterial pharyngitis
antiphagocytic
what role do enzymes play in bacterial pharyngitis
invade and destroy
what are 5 enzymes involved in bacterial pharyngitis
1.) streptolysin O
2.) streptolysin S
3.) streptokinase
4.) DNase
5.) hyaluronidase
what role do exotoxins play in bacterial pharyngitis
mediate production of rash or multi system effects that can cause death
what are 6 complications of pharyngitis and tonsillitis
1.) necrotizing fasciitis
2.) impetigo
3.) bacteremia
4.) pneumonia
5.) toxic shock syndrome
6.) scarlet fever
what are three symptoms are scarlet fever
1.) white exudate on tonsils
2.) rash
3.) cherry-red tongue
what is Vincent’s Angina (necrotizing ulcerative gingivitis) or (trench mouth)
bacterial infection of the gingival edge
can develop into septic jugular thrombophlebitis, bacteremia, and metastatic infection
what are the two main bacterial organisms to cause Vincent’s Angina
1.) fusobacterium necrophorum
2.) spirochetes
what is a common organism to cause a peritonsillar abscess
bactericides fragilis
rhinitis is most commonly cause by a virus or bacteria
virus
what are 5 symptoms of rhinitis
1.) fever
2.) increased mucous
3.) sneezing
4.) itchy watery eyes
5.) inflammation of nasal mucosa
what are the three miscellaneous bacteria that cause pharyngitis
1.) corynebacterium diphtheriae
2.) bordetella pertussis
3.) klebsiella species
how long is the incubation period for corynebacterium diphtheriae
2 to 4 days
what are some complications of end stage infection of corynebacterium diphtheriae
nervous system damage which leads to seizures, coma, or blindness
what would you see on a positive tellurite plate for corynebacterium diphtheriae
dark colonies with black halos due to reduction of tellurite to metallic tellurium
what is the differential media used to grow corynebacterium diphtheriae
tellurite
what is most common medium used to isolate corynebacterium diphtheriae
Loffler’s medium
what are the two main causative agents of pertussis or whooping cough
1.) bordetella pertussis
2.) bordetella papartussis
what are the three symptomatic phases of pertussis
1.) catarrhal stage
2.) paroxysmal stage
3.) convalescent stage
explain the catarrhal stage of pertussis
first stage
development of respiratory symptom after the 7 to 13 day incubation period
explain the paroxysmal stage of pertussis
second stage
spells of paroxysmal coughing and lymphocytosis that develop after 2 weeks
explain the convalescent stage of pertussis
third stage
disease begins to get better after four weeks
what are the three main virulence factors of bordetella pertussis/parapertussis
1.) adhesion
2.) toxicity
3.) overcoming of host defenses
when are bordetella pertussis/parapertussis most detectable in the lab
before 2 weeks
after 2 weeks, they are undetectable
where should one obtain samples for bordetella pertussis/parapertussis
areas with ciliated epithelial cells
which stain should be used for bordetella pertussis/parapertussis specimens
DFA stain with polyclonal antibodies
which test can commonly be used to test for bordetella pertussis/parapertussis
PCR tests that are sensitive to culture.DFA combo
what does the gram stain for bordetella pertussis/parapertussis look like
faintly staining minute coccobacilli in single or pairs
which two agents cause chronic granulomatous infection of the nasal passages, sinuses, and pharynx/larynx
klebsiella rhinoscleromatis or klebiella ozaenae
what is ozena
production of a foul smelling mucopurolent discharge due to a klebsiella ozaenae infection
what is stomatitis
disease of the mucous membranes of the oral cavity most commonly caused by the herpes simplex virus
what are the 7 host factors to prevent lower respiratory tract infections
1.) nasal hairs
2.) convoluted passages
3.) mucous linings
4.) cilia
5.) IgA secretions
6.) reflexes like coughing
7.) host flora
what are four microorganism factors that allow organisms to cause lower respiratory tract infections
1.) adherence
2.) toxin production
3.) growth in host tissue
4.) evasion of host response
define colonization
survival and growth on the host tissue
how does strep. pneumo adhere to tissue
production of a lipoteichoic acid adherence complexes
how do gram negative bacteria adhere to tissue
fimbriae
how do viruses adhere to tissue
production of hemagglutinin
staph. aureus produces which toxin
extracellular enzyme like coagulase
streptococci produces which toxin
hyaluronidase
how does growth in host tissue allow an organism to cause disease
growth causes interference with tissue cell function
what are the two ways organisms can evade host response
1.) thick polysaccharide capsule
2.) ability to multiply in host cells
which organism is a good example of avoidance of host response
mycobacterium tuberculosis
gets phagocytosed and then multiplies once it gets into lymph nodes
eventually spills out of lymph nodes and spread
what most commonly causes bronchitis and when does it most commonly occur
most bronchitis infections occurs secondary to the flu or common cold in the winter months
what are the three main symptoms of acute bronchitis
1.) cough (croup - barking cough)
2.) fever
3.) sputum production
which organism, bacterial or viral, most commonly causes bronchitis
viral
which specimen is most commonly obtained to rule out bronchitis
nasopharyngeal specimens
what are the three clinical characteristics of chronic bronchitis
1.) excessive mucous production
2.) 3 consecutive months
3.) acute flare ups
who is most affected by bronchiolitis
those under two years old
what are the 6 main symptoms of bronchiolitis
1.) acute presentation
2.) wheezing
3.) cough
4.) rhinorrhea
5.) tachypnea
6.) respiratory distress
bronchiolitis is most commonly caused by which virus
respiratory syncytial virus
when are you most likely to get bronchiolitis
winter to early spring
how is bronchiolitis diagnosed
through nasal washes
what are the two categories of pneumonia
1.) community acquired
2.) health care-associated
what is the etiology of pneumonia in both adults and children
adults - bacterial
children - viral
how are children tested for pneumonia
nasal washes
which three bacterial organisms most commonly cause pneumonia in children 2 months to 5 years old
1.) haemophilus influenza
2.) strep. pneumo
3.) staph. aureus
which two organisms most commonly cause pneumonia in neonates
1.) chlamydia trachomatis
2.) pneumocystis jiroveci
which two organisms most commonly cause pneumonia in children 5 to 14 years old
1.) mycoplasma pneumoniae
2.) chlamydia pneumoniae
what is the most common cause of pneumonia in your adults under the age of 30
mycoplasma
what is the most common cause of bacterial pneumonia in adults over the age of 30
strep. pneumo
what is the most well known bacteria to cause chronic infections of the lower respiratory tract
mycobacterium tuberculosis
what is the main cause of cystic fibrosis
mutation in the cystic fibrosis transmembrane conductance regulator
which organism is most commonly isolated in cystic fibrosis cases
pseudomonas
what three things can cystic fibrosis predispose you to
1.) pancreas involvement
2.) sinus infections
3.) abscess formation
how does mycobacterium tuberculosis cause lower respiratory tract infections
breakdown cell-mediated immune mechanisms of host (macrophages and masking foreign antigens)
this allows microbes to grow in the host without causing a large immune reaction
what is the most common specimen submitted in the laboratory
sputum
what are the two main types of sputum specimens sent to the lab
1.) expectorated sputum
2.) induced sputum
what is expectorated sputum
sputum that is coughed out
not a good specimen cause it’s often contaminated
what is induced sputum
sputum is stained through hitting the chest and draining the sputum
what is a gastric aspirate submitted for
isolation of acid-fast bacilli
done for those like children who can’t produce sputum
how are endotracheal or tracheostomy suction sputum specimens collected
using Luken’s trap method
transtracheal aspirates are used to isolate what
actinomyces and anaerobes
what do epithelial cells in a specimen indicate
oral contamination
what does a gram stain provide the physician with
1.) quality of specimen
2.) possible cause of infection
how are exogenous genital tract infections acquired
via sexual activity
how are endogenous genital tract infections acquired
from organisms in the normal flora
which organism most commonly causes vaginitis
candida albicans
how is vaginitis caused by candida albicans treated
anti fungal
how is vaginitis caused by Candida albicans detected
culture or molecular testing
how is vaginitis caused by bacterial vaginosis detected
gram stain for clue cells
what are two common symptoms of vaginitis caused by a trichomonas vaginalis infection
1.) frothy, green vaginal discharge with musty smell
2.) strawberry cervix
how is vaginitis caused by trichomonas vaginalis detected
direct wet mounts of vaginal washings or molecular methods
which three organisms commonly cause urethritis/cervicitis
1.) neisseria gonorrhoeae
2.) chlamydia trachomatis
3.) herpes simplex virus
how is urethritis/cervicitis caused by chlamydia detected
EIA, fluorescent AB staining or PCR
how is urethritis/cervicitis caused by neisseria gonorrhoeae detected
culture on selective medias (Thayer Martin)
PCR
how is urethritis/cervicitis caused by neisseria gonorrhoeae detected in men specifically
gram stain - shows gram negative diplococci
how is herpes diagnosed
PCR or viral cultures
which two organisms most commonly cause proctitis
1.) neisseria gonorrhoeae
2.) chlamydia trachomatis
which two organisms can cause bartholinitis
1.) neisseria gonorrhoeae
2.) chlamydia trachomatis
or those from normal flora
which two organisms most commonly cause epididymitis
1.) neisseria gonorrhoeae
2.) chlamydia trachomatis
which organism most commonly causes prostatitis
E. coli
which organism most commonly causes orchitis
mumps
what are some features of neisseria gonorrhoeae
1.) gram negative
2.) diplococci
3.) oxidase and glucose positive
4.) negative for sucrose-maltose-lactose
5.) needs 5% CO2
6.) doesn’t grow on maconkey
7.) colonies are sticky
what are some features of gardenerella vaginalis
1.) gram variable
2.) rods
3.) pinpoint colonies
4.) hippurate positive
how is gardenerella vaginalis detected
culture
DNA probes (AFFIRM)
PCR
what are some features of candida albicans
1.) yeast
2.) doesn’t grow on maconkey
3.) colonies are white with feet
4.) gram positive with budding
how is candida albicans detected
culture
DNA probe (AFFIRM)
what are some features of trichomonas vaginalis
1.) parasite
2.) sexually transmitted
how is trichomonas vaginalis detected
washes
DNA probe (AFFIRM)
PCR
what is chancroid
sexually transmitted disease characterized by genital ulcerations and inflammatory inguinal adenopathy
which organism causes chancroid
haemophilus ducreyi
which two things can help diagnose chancroid
1.) negative for treponema pallidum infection
2.) ulcers that don’t look like HSV
what are the four stages of syphilis
1.) primary
2.) secondary
3.) early latent
4.) tertiary or neurosyphilis
explain the primary stage of syphilis
first stage
one or more ulcerative lesions
spirochetes detected on dark field microscopy
which organism causes syphilis
treponema pallidum
explain the secondary stage of syphilis
second stage
diffuse lesions with lymphadenopathy
spirochetes detected on dark field microscopy
positive serology test
explain the early latent stage of syphilis
third stage
persistence of infection without symptoms in the last 12 months
explain the late latent stage of syphilis
fourth stage
persistence of infection without symptoms in the last 12 months
what is seen on tzanck smears for HSV-2
giant multinucleated cells
what is granuloma inguinale
ulcerative disease of skin and lymphatics of general area
which organism causes granuloma inguinale
calymmatobacterium (klebsiella) granulomatis
how is granuloma inguinale diagnosed
through Donovan bodies in giemsa or wright stained smears
Donovan bodies are seen in which condition
granuloma inguinale
what is lymphogranuloma venereum
infection of chlamydia trachomatis that causes genital lesions and lymphadenopathy
how is lymphogranuloma venereum diagnosed
through inclusion bodies within leukocytes seen in IF
what are two things needed for a mucopurulent cervicitis diagnosis
1.) mucopurulent secretion
2.) induced endocervical bleeding
what is pthirus pubis
organism known as crab lice that affects adults
what are the three characteristics of a bioweapon
1.) the biological agent or toxin
2.) method of retaining the variability of the bacteria-virus-toxin
3.) a delivery system that disperses the agent or toxin
what are 5 ideal qualities for a biologic terrorist agent
1.) high attack rate
2.) high case fatality rate
3.) easily transmitted between persons
4.) no effective treatment available
5.) difficult to diagnose
what is category A of bioterrorism agents
high priority organisms or toxins that pose the highest risk to the public and national security
what are two examples of category A of bioterrorism agents
1.) bacillus anthracis
2.) yersinia pestis (plague)
what is category B of bioterrorism agents
agents that are the second highest priority
what are two examples of category B bioterrorism agents
1.) brucella
2.) salmonella
what is category C of bioterrorism agents
emerging pathogens that could be engineered for mass spread in the future - third highest priority
what are two examples of category C bioterrorism agents
1.) SARS coronavirus
2.) multi-resistant mycobacterium tuberculosis
what are 5 epidemiological clues we look for that make us suspect a bioterrorism event
1.) large outbreak with a high infection and death rate
2.) single case of uncommon disease
3.) unusual symptoms
4.) infection in an abnormal geographical location
5.) unusual seasonal distribution
what are some phenotypic features of anthrax
1.) gram positive rods in long chains - non-motile
2.) spore forming
3.) grows on AP but not maconkey
4.) ground glass appearance
5.) catalase positive, non-hemolytic
which organism causes the primary disease of herbivores which are infected by ingesting spores in soil
anthrax
how is anthrax transmitted
naturally through human contact with infection animals
what are the three forms of anthrax
1.) cutaneous
2.) inhalation
3.) gastrointestinal
how is smallpox spread
via respiratory droplets or aerosols expelled from the oropharynx
what are some phenotypic characteristics of yersinia pestis (plague)
1.) gram negative rod - non-motile
2.) gray-white and translucent colonies on BAP and chocolate agar
3.) stains bi-polar on Giemsa
4.) catalase positive, oxidase-urea-indole negative
5.) grows in a stalactite matter in broth
how is yersinia pestis (plague) transmitted
flea bites or handling infected animals like Prairie dogs
what are the three types of the plague
1.) bubonic
2.) septicemic
3.) pneumonic
