Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology 2 > upper respiratory tract > Flashcards

upper respiratory tract Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Function of the respiratory tract

A

> Perform respiration
- The exchange of oxygen and carbon dioxide
Deliver air from outside of the body to the alveoli where gas
exchange occurs
 Respiratory tract includes entire course that air must travel
 The components of the respiratory tract participate in
defending itself against infection

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

role of normal l flora

A

 Organisms normally found at specimen site
> Protect against pathogenic microorganisms
> Stimulate the immune system
- Natural antibodies
 Under normal conditions, a balance of organisms is
maintained that limits the quantity or dominance of any one
type of organism
 “Normal flora” changes with time
Ex. Moraxella catarrhalis, once considered part of normal
flora, is now associated with some infections

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

chamges in URT normal flora

A

 Changes in upper respiratory tract (URT) flora may occur
due to
> Antibiotic use
> Hospitalization
> Chronic illnesses
 It is important to distinguish between a culture positive for
an organism that is a potential pathogen colonizing the RT
and the clinical disease state caused by that pathogen

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

colonization vs infection

A 
 Interpretation
> Method and site of collection
> Presence of white blood cells (WBCs)
> Number of organisms present
> Compatible clinical syndrome present
Ex. Isolation of a few colonies of Staphylococcus aureus from a 
sputum  specimen with many epithelial cells does not suggest s. aureus 
pneumonia
 Some pathogens are always pathogenic
Ex. Mycobacterium tuberculosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

upper respiratory tract includes

A 
> Nose
> Mouth
> Throat
> Epiglottis
> Larynx
> Paranasal Sinuses
> Middle Ear
> Eyes

 Colonized by wide variety of normal flora
NOTE: Viruses not considered normal flora

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

Upper Respiratory Tract Infections

A

> Common contagious infections that are caused by a variety of bacteria and viruses
Many of the infections are viral
Viral infections may lead to other infections
Ex. - Sinusitis
- Otitis Media
- LRT Infections

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

Pharyngitis (ie. Sore throat)

A 
> Inflammation of the pharynx
> Common bacterial cause - Group A Streptococci (GAS)
> Other causes include
- C. diphtheriae
- N. gonorrhoeae
- C. albicans
- Groups B,C,F,G streptococci

> S. pneumoniae, S. aureus, H. influenzae and N. meningitidis
may be recovered from the pharynx but do not cause pharyngitis

> Common Viral cause
- Common cold or early influenza

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

pharyngitis ( GAS symptoms)

A

> Exudate in the pharynx (pus)
Painful adenopathy (glands)
Lack of cough

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

Pharyngitis Epidemiology

A

> Winter to early spring
Favors person-to-person transmission
- Droplet Inhalation
- Hand Contamination/URT Inoculation

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

PHARYNGITIS Clinical Manifestations

A

> Bacterial and viral distinction is difficult
Viral infections tend to present with rhinorrhea (runny nose)

> Bacterial infections
- Pain with difficulty swallowing
- Fever is more common
- Thick exudate covering the tonsils
Streptococcus pyogenes is the most common bacterial cause
Corynebacterium diphtheriae can lead to a potentially fatal form, diphtheria
- Now rare due to DPT vaccination
Other causes include N. gonorrhoeae, Arcanobacterium haemolyticum and
Fusobacterium necrophorum

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

PHARYNGITIS Pathogenesis

A

> Primarily due to inflammatory effects of a variety of

extracellular bacterial products - cause cellular destruction

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

Pharyngitis Complications

A 
> Sinusitis, otitis media, pneumonia
> Soft tissue abscess
> Acute rheumatic fever (damage to heart valves) - Rare in developed areas
> Acute glomerulonephritis
> Streptococcal TSS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Pharyngitis Laboratory Diagnosis

A

> Primary goal
- Differentiate between viral and bacterial

> Secondary goal
- Detect uncommon causes of bacterial pharyngitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Pharyngitis specimen collection

A

Oropharynx (Throat Swab)

> A throat swab is collected by swabbing the posterior pharynx and tonsils

> Most often, swabs are transported to the lab in a transport media (commercially available)

> Most labs will investigate for Group A hemolytic streptococci

> Rapid antigen test (GAS) may be preformed first;

  • Positive samples reported
  • Negative samples cultured for confirmation

> Gram stain smears are not diagnostic and therefore not typically done
- many normal flora present that resemble the potential pathogens

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

Pharyngitis Throat Swabs ( container, time & temp )

A

> Rejection Time - 48 hours
Specimen holding temperature - 4°C
Container - Swab in transport media

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

Pharyngitis culture

A

> Sheep Blood Agar (SBA) is commonly used - BAP

> May use antibiotics to reduce normal flora

> Selective Strep Agar (SSA) - Used in some labs

> N. gonorrhoeae - GC Selective media (Ex. Modified Thayer Martin) - CO2

> C. diphtheriae - BAP and/or other selective and differential media (ex. Tellurite media, Loeffler media)

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

Pharyngitis Selective Strep Agar (SSA)

A

> Modified sheep blood agar designed to inhibit gram-negative bacilli and staphylococci species

> Allows for the isolation, sub-culturing and identification of pathogenic streptococci (ex. beta-hemolytic streptococci and S. pneumoniae)

> Tryptic Soy Agar is the basal medium for Selective Strep Agar

> Commonly used within Eastern Health

> Ingredients include

  • Ribonucleic Acid and Maltose which enhance hemolysis
  • Neomycin and Polymyxin B (selective agents) which supress the normal floraq
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Pharyngitis ( other methods of ID)

A
  • Latex agglutination (Lancefield Grouping)

- Rapid Antigen Detection Tests (RADTs)

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

Bacterial Pharyngitis Treatment

A
  • reduce symptoms & transmission

> Antibiotic Therapy

  • Drugs of choice - Penicillin or amoxicillin
  • Alternates for patients who are allergic to penicillinMacrolides, clindamycin, first-generation cephalosporins

> Antibiotics have been shown to shorten duration and in some cases the severity of symptoms.
Effect is usually modest

 Bacterial pharyngitis caused by GAS
> Most cases are self-limiting with resolution in 3 to 4 days, even without antimicrobial therapy
> Some patients are asymptomatically colonized with GAS - don’t often develop symptoms

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

Pharyngitis viral infections

A 
> Most common cause of pharyngitis
> Common viruses
- Rhinovirus
- Coronavirus
- Adenovirus
- Parainfluenza virus
- Epstein-Barr virus (EBV)
- Influenza virus
- HIV may manifest into a sore throat in acute phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

treatment of viral Pharyngitis

A
  • supportive care
    > Exception - influenza
  • Specific antiviral agents are available
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

sinusitis

A

common inflammatory reaction of the nose & paranasal sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

acute sinusitis

A

usually a bacterial infection that follows a viral infection of URT

  • Common causes - S. pneumoniae, H. influenzae and anaerobes in patients with dental disease
  • Other causes - M. catarrhalis, GAS, S. aureus, anaerobes, Gram negative rods
    (ex. K. pneumoniae, E. coli)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Chronic Sinusitis

A

Anaerobic bacteria and S. aureus are common in adult infections
- S. pneumoniae, S. aureus and viridans streptococci are common in child infections

25
Q

acute sinusitis Epidemiology

A

Predominately occur in winter and spring months

26
Q

Acute sinusitis Causes

A

> Common Viral Agents
- Rhinovirus, coronavirus, parainfluenza, adenovirus and influenza
Common Bacterial Agents
- Streptococcus pneumoniae, H. influenzae (most common)
- Streptococcus pyogenes, M. catarrhalis, Staphylococcus aureus
Fungal sinusitis is uncommon
- More likely in immunocompromised

27
Q

Acute sinusitis Pathogenesis

A

> Under normal conditions
- Sinuses undergo continuous cleansing process through the action of
ciliated epithelial cells
- Bacteria are ultimately cleared from the nasopharynx
In Acute Rhinosinusitis
- Mucosal swelling can partially or completely obstruct the sinus ostia
interrupting normal processes
- Creates environment for bacterial overgrowth
- Viral infection and bacterial toxins can alter the normal cleansing function
of the ciliated epithelial cells
Noninfectious obstructions can also cause similar disruption of normal
operations

28
Q

Acute sinusitis Clinical Manifestations

A

> Purulent nasal discharge and pain in the face
Headache with referred pain from upper teeth
Possible drainage obstructions
Cough, low-grade fever

29
Q

acute sinusitis ( 4 criteria for diagnosis of bacteria sinusitis)

A
  • according to infectious disease Society of America

> Persistent symptoms without improvement for more than 10 days
Severe symptoms present for 3 to 4 days at the beginning of the illness
High fever, purulent discharge, facial pain
Initial improvement followed by a subsequent worsening

30
Q

Acute sinusitis complications

A

> Orbital Cellulitis
- Protrusion of the eye (proptosis) or limitation of ocular movements possible

> Osteomyelitis
- Of frontal bone with abscess

> Meningitis

> Brain Abscess

> Cavernous Sinus Thrombosis - Blood Clot

31
Q

Acute sinusitis Laboratory Diagnosis

A
  • diagnosed clinically or through an x-ray
  • sirect sinus puncture & aspiration
    • gold standard
    • transported in anaerobic media

> Nasal and routine nasopharyngeal specimens are not typically
helpful due to the fact that many of the normal flora present also cause
the infections

32
Q

Acute sinusitis culture

A

cultures of these specimens will not distinguish between normal colonizers and pathogens
> Aspirate specimens should be set up for both aerobic and anaerobic cultures

> Common medias of choice include

  • BAP
  • CHOC
  • MAC
  • EMB
  • Enrichment broth
  • anaBAP

> Aerobic cultures are incubated at 350C in increased CO2

33
Q

Acute sinusitis treatment

A 
> Viral Sinusitis
- Antibiotic therapy not required or appropriate
> Bacterial Sinusitis
- Varies based on causative agent 
- Dependant on antimicrobial resistance
34
Q

ACUTE OTITIS MEDIA

A

 Acute Otitis Media (AOM)
> Infection of the middle ear

> Most common bacterial infection in children between 3 and 24 months of age

> Most children have had at least one episode by the age of 3

> Risk factors
- Prior history of AOM, exposure to passive tobacco smoke, nasopharyngeal colonization with otopathogens (causative agents of ear infections) and presence of anatomic nasopharyngeal disorders

35
Q

Causes of Viral & bacterial AOM

A

 Causes of Viral AOM
> Adenoviruses, rhinoviruses, coronaviruses, respiratory syncytial virus
(RSV), influenza, human bocaviruses, others

 Causes of Bacterial AOM
> Streptococcus pneumonia accounts for a significant proportion of
isolates
> Haemophilus influenzae, Moraxella catarrhalis
> Streptococcus pyogenes, Staphylococcus aureus (Less common)

36
Q

Cute otitis media Pathogenesis

A

> Similar to that of acute bacterial sinusitis in that
- Viral URT infection generally precedes or occurs concurrently with most cases of AOM

> Infection is established when there is subsequent impairment of the normal host defense and drainage mechanisms

37
Q

ACUTE OTITIS MEDIA

Clinical Manifestations

A

> In young children
- Fever, irritability, ear pain, drainage of purulent secretions
- Red bulging tympanic membrane
In older children
- Tugging at the involved ear may be noticed during or at the end
of the course of an URT infection
Changes in hearing and later drainage of purulent secretions
from the ear canal
-Possible perforation of the tympanic membrane

38
Q

ACUTE OTITIS MEDIA Complications

A

> Damage to the tympanic membrane resulting in
perforation
Chronic middle ear effusions (build up of fluid)
- In younger children - subsequent hearing loss can
affect speech development and education (Less of a
consequence in adults)
Severe suppurative complications of AOM are rare

39
Q

ACUTE OTITIS MEDIA

 Laboratory Diagnosis

A

> Rarely required

  • Invasiveness
  • Predominant pathogens
40
Q

ACUTE OTITIS MEDIA  Antibiotic treatment

A

> Important in children older than 6 months with severe otitis media
- Fever greater than or equal to 39° C
- Moderate or severe pain for at least 48 hours
- Otorrhea (drainage)
Important in children 6 to 23 months with bilateral non-severe AOM
Drug of choice - Amoxicillin

41
Q

EPIGLOTTITIS

A

 Epiglottis - A cartilaginous structure positioned at the anterior aspect of the opening of the trachea
- Function is to protect the airway from aspiration of secretions and food during swallowing

 Epiglottitis (known as supraglottitis in adults)
> Can be rapidly progressive infection of the epiglottis and adjacent soft tissues in the upper airway
> Can result in airway obstruction and respiratory failure, a life- threatening emergency

42
Q

EPIGLOTTITIS Epidemiology

A

> Historically primarily a disease of children aged 2 to 7
The emergence of the vaccine for H. influenzae type B (Hib) has
resulted in a decline of child incidence
Now, most cases are in adults

43
Q

Epiglottitis causes

A 
> Hib
> Group A streptococcus
> Streptococcus pneumonia
> Staphylococci aureus (including MRSA)
> Hemophilus parainfluenzae
> Klebsiella spp
44
Q

Epiglottitis Pathogenesis

A

> Soft tissues accumulate fluid, leading to edema
- Usually H. influenzae
Adults usually have involvement of other structures in the
supraglottic region

45
Q

Epiglottitis Clinical Manifestations

A

> Severe pharyngitis, sore throat and severe pain on swallowing
Treatment should begin immediately

46
Q

Epiglottitis complications

A

> Most important complication
- Respiratory compromise progressing to respiratory failure
- Airway obstruction from edema of the supraglottic structures
Other complications
- Development of epiglottic abscess, necrotizing epiglottitis,
pneumonia
- In patients who are bacteremic - Meningitis and septic shock

47
Q

Epiglottitis laboratory diagnosis

A

> Direct swab cultures and blood cultures on suspected
patients
Direct Smear
- WBCs, pleomorphic, gram-negative bacilli (H.
influenzae)
Culture on CHOC agar at 5% -10% CO2

48
Q

Epiglottitis treatment

A

> IV antibiotics should be administered
- third-generation cephalosporins
- ampicillin-sulbactam
Coverage for methicillin-resistant S. aureus (MRSA)
should be added when risk factors exist
Patients should be monitored closely if immediate air
securement is not required at the time of initial evaluation
- Additional measures taken as appropriate

49
Q

Pertussis

A

> Commonly called whooping cough
Highly communicable respiratory illness in susceptible
patient populations
Transmitted from person to person via aerosolized droplets
or direct contact with secretions

50
Q

Pertussis Epidemiology

A

> More common in infants and young children
- Serious complications are seen more in this age group
Pertussis vaccine introduced in the 1940s
- Significant declined by the 1970s
Recently, incidence has again begun to increase
- large outbreaks in areas with notable infant mortality
- Increased incidence in adults/adolescents due to waning
immunity

51
Q

Pertussis causes

A

> Bordetella pertussis, Bordetella parapertussis, Bordetella
bronchiseptica, Bordetella holmesii and adenoviruses
(serotypes 1, 2, 3, and 5)

52
Q

Pertussis Pathogeneisis

A

> Not completely understood
Studies suggest a significant role for pertussis toxins (PTs)
- Damages tracheal epithelial cells, impairs immunity

53
Q

Pertussis Key clinical manifestations

A

> Exhausting paroxysms of coughing

> Whooping sound by inspiration through a narrowed airway

54
Q

Pertussis complications

A

> Pneumonia in young children
Alveolar rupture and other tissues as a result of forceful coughing
Example of complications as a result of severe and forceful
coughing episodes
- Pneumothorax, hemorrhages, nosebleeds, others

55
Q

Pertussis laboratory diagnosis

A

> CBC may show lymphocytosis - reaction to PT
Nasopharyngeal swabs using calcium alginate
- Plate on Bordet-Gengou or Regan-Lowe (RL)
- Direct fluorescent antibody (DFA) staining
- Labs now favor polymerase chain reaction (PCR)

56
Q

Pertussis treatment

A

> Vaccination - Prevent disease
Antibiotics
- Erythromycin, clarithromycin and azithromycin
- Only helps patient early on and as prophylaxis for contacts (reduce the spread)

57
Q

Otitis Externa

A
  • Superficial infection of the external ear canal (Swimmer’s
    ear)
    > Common cause - P. aeruginosa
    > Other causes - Enterobacteriaceae, S. aureus
58
Q

Thrush

A
  • Fungal infection of the oral cavity (mouth, oropharynx and
    tongue)
    > Common Cause - Candida albicans
    > C. albicans is part of the normal flora in small numbers
    > Infections are common in immunocompromised patients and those on
    antimicrobial therapy

Microbiology 2 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions