Respiratory Micro Flashcards
What are the 6 defenses of the respiratory system against microbes?
1 mucociliary lining 2 change in direction of airway 3 mucociliary elevator 4 normal flora 5 alveolar macrophages 6 IgA mucosal secretion
What are the pathogenic “requirements” to colonize the respiratory system?
1 sufficient dose
2 airborne
3 viable in air
4 tissue susceptible to infection
What are the #1 and #2 causes of the common cold and describe their genomes?
1 rhinovirus: ss + RNA
2 coronavirus: ss + RNA
What are the #1 and #2 causes of sinusitis?
#1 haemophilus influenza #2 strep pneumo
Describe the clinical course of sinusitus
viral cause lasts 5-7 days of sneezing, runny nose, nasal congestion, post-nasal drip, facial pressure, aural fullness, sore throat, fever; bacterial cause greater than 5-7 days with facial swelling and tooth pain
How should you treat sinusitus?
viral - supportive
bacterial- amoxicillin, azithromycin
In which age group is group A strep the most likely cause of pharyngitis and what complications would you need to look out for?
kids 5-15 yrs, treat w/in 9 days w/ penecillin/azithromycin to prevent glomerulonephritis and/or rheumatic fever
What is the cause of diptheria and how do you treat it?
Corynebacterium diptheriae (gram + rods), antitoxin, antibiotic, vaccine
What are the three causes of croup/laryngitis?
parainfluenza
influenza
RSV
What is the most common age group for croup and what are the hallmark symptoms?
kids 6 mo - 3 years, inspiratory stridor, barking cough, accessory muscle breathing
What is the most important virulence factor at work in Rhinovirus colonization and what does it do?
I-CAM 1 : adhesion, upregulated by host inflammatory factors
Which respiratory pathogen’s genomes encode for the F viral fusion protein and what illnesses do they cause?
Parainfluenza (ss - RNA)- croup, common cold
Respiratory syncytial virus (ss - RNA) - pneumonia, bronchiolytis, common cold, croup
How do you diagnose Corynebacterium diptheriae?
gram stain: gram + rod
KTeO3 agar culture –> black Te (+)
pseudomembrane with gray fibrinous exudate in pharnyx
How does the diptheria toxin work?
it’s an A-B toxin that inhibits E2-F activity, preventing protein translation
What are the 2 respiratory pathogens which have a fecal to oral transmission route and what illnesses do they cause?
Coxsackie A/B - common cold/Hand-Foot-Mouth/Myocarditis/pericarditis
Adenovirus- common cold/hemorrhagic cystitis/conjunctivitis/gastroenteritis
How do you treat a Moraxella catarrhalis pneumonia or sinusitis?
amoxicillin-clavulanate, second or third gen. cephalosporins, TMP-SMX
What are Moraxella’s most notable virulence factors and how would you diagnose an infection?
VF: pili, antigenic variation, endotoxin, capsule
Dx: gram stain (-), tributyrine hydrolysis, DNAse, nitrate reduction, no lactose reduction
Name the 3 single stranded RNA viruses that cause the common cold
Rhinovirus, Coronovirus, Coxsackie A and B
Top 5 causes of pneumonia in kids?
Strep pneumo (amox, cephalsporin) mycoplasma pneumo (Erythro, Tetra) chlamdia pneumo (Doxy) Influenza RSV
What are the common causes of bronchitis?
Rhinovirus, Parainfluenza, Influenza, CoxSackie, Adenovirus, RSV, Mycoplasma, Chlamydia. Bacterial after 14 days
What are the causes of pharyngitis?
in Kids - GAS
Adults - Viral- rhino, corona, para, influenza, adeno, RSV, EBV
How do you treat nocardia asteroides?
TMP-SMX + drain abcesses
How do you treat an HIV positive patient for Pneumonia?
TMP-SMX and pentamidine
Name the respiratory pathogens which have hemagglutinin and explain how it works
Influenza, parainfluenza, adenovirus, bordatella pertussis, mycoplasma pneumo (cold hemagglutinin)
Name the respiratory pathogens with IgA protease
Strep pneumo, Hib
If you find inclusion bodies in a gram negative sample from a 15 year old with pneumonia, how would you treat them?
Doxy
