9-30 Microbiology Review Flashcards
What are the clinical manifestations of Bordetella pertussis?
- Clinical Manifestations
- Onset of symptoms 1-3 weeks after exposure
- Catarrhal Phase
- Rhinorrhea, lacrimation, conjunctival injection, low grade fever – lasts days to a week
- Paroxysmal phase
- Uncontrollable expirations, followed by gasping inhalation – whooping cough
- Cough Associated with post cough cyanosis, gagging, and vomiting
- Lasts up to 4 weeks
- Convalescent Phase
- Reduction in frequency and severity of cough can last from weeks to months
What are the complications of Bordetella pertussis?
pneumonia
Dx for Bordetella pertussis?
nasal swab for culture or PCR
Tx for Bordetella pertussis?
- Treatment
- Supportive
- Azithromycin
- Chemoprophylaxis to control outbreaks
What is the popular name for a Bordetella pertussis infection?
whooping cough
How is Bordetella pertussis spread?
- Spread by large droplets
- Humans are only known reservoir
What kind of germ is Bordetella pertussis?
•Gram negative aerobic coccobacillus capsulate
How is Bordetella pertussis infection prevented?
•acellular pertussis vaccine
What kind of germ is Klebsiella pneumonia?
- Gram negative, non-motile, capsulate rods
- Facultative anaerobes
What kinds of infections does Klebsiella pneumonia cause?
- UTI, soft tissue infections, endocarditis, central nervous system infections, and severe bronchopneumonia.
- Community and hospital acquired pneumonias
- Cavitary lung lesions
What is pathognomic for Klebsiella pneumonia infection?
CURRANT JELLY SPUTUM!!!!
What kinds of infections does Moraxella catarrhalis cause?
- Pneumonia, especially in the elderly
- Otitis media in young children
What kind of germ is Moraxella catarrhalis? What does it need for culturing?
- Gram negative bacteria that grows well on blood or chocolate agar
- diplococci
- Catalase positive
- Oxidase positive
What kind of germ is Neisseria meningitidis? What does it need for culture?
- Aerobic gram negative kidney shaped diplococci, capsule
- Oxidase positive,
ferments maltose and glucose
Grows on Thayer-Martin media, chocolate agar
What is the reservoir for Neisseria meningitidis? Transmission?
- Commensal of the human upper respiratory tract
- Transmitted through close contact via larger respiratory droplets.
Name the clinical manifestations of Neisseria meningitidis.
- Meningitis
- Septicemia
- Pneumonia
- Septic arthritis, pericarditis, chronic bactermia, or conjunctivitis
What do you use to Dx a Neisseria meningitidis infection?
- Gram stain from CSF
- CSF PCR
- CSF culture, blood culture, or skin culture
How do you treat a Neisseria meningitidis infection?
PCN
3rd gen cephalosporin
How do you prevent Neisseria meningitidis infections?
- Chemoprophylaxis with rifampin in close contacts
- Meningococcal polysaccharide-protein conjugate vaccines
What is the prognosis for a Neisseria meningitidis infection?
- Untreated systemic disease with 70-90% mortality
- 10% mortality with treatment
What is the morbidity for a Neisseria meningitidis infection?
•Limb loss, hearing loss, long-term neurologic disability
What kind of germ is Pseudomonas aeruginosa? What does it look like in culture?
- Aerobic gram-negative rod
- Produces pyocyanin on laboratory medium – blue/green pigment
What is the pattern of transmission for Pseudomonas aeruginosa?
- Primarily nosocomial pathogen
- In hospital can colonize moist surfaces of the axilla, ear, and perineum
- Isolated from water in sinks, drains, toilets, and showers
- Even isolated from flowers in patients rooms
What kinds of infections can Pseudomonas aeruginosa cause?
- Hospital acquired pneumonia, Ventilator Associated Pneumonia
- Community acquired infections related to hot tubs, whirlpools, swimming pools, and extended contact lenses
- Otitis externa
- Puncture wounds through tennis shoes
- Endopthalmitis – complication of eye surgery
- Endocarditis, from sharing contaminated needles
- UTI
- Skin Infections, burns, ecthyma gangrenosum
What increases the susceptibility of a Pseudomonas aeruginosa infection?
neutropenia
What kinds of bacterial factors does Pseudomonas aeruginosa secrete?
•exotoxins, endotoxins, type III secreted toxins, pili, flagella, proteases, phospholipases, iron-binding proteins, exopolysaccharides, the ability to form biofilms, and elaboration of toxic small molecules such as pyocyanin
What is the Tx for Pseudomonas aeruginosa infection? Rationale?
- Extended spectrum penicillin and aminoglycoside combination
- Always treat with 2 antibiotics - reduces risk for AB resistance
- treatment with 1 AB will result in resistant infection
What kind of bacteria is Chlamydophila psittaci?
•Gram negative obligate intracellular bacteria
Since Chlamydophila psittaci is an obligate intracell. bact., what cells does it primarily reside in?
Macrophages - principal host cell
What kinds of diseases does Chlamydophila psittaci cause?
- Psittacosis - AKA Bird Fancier’s Disease
- Atypical pneumonia
- Febrile illness
What is the transmission for Chlamydophila psittaci ?
•Aerosolized bird secretions, dust
How is Chlamydophila psittaci infection Dx’ed?
serology
CXR will reveal just a generalized interstitial pattern
What is the Tx for Chlamydophila psitacci?
•tetracyclines, macrolides, fluoroquinolones
How are Chlamydophila psittaci infections prevented?
•30 day quarantine for all imported psittacine birds and their treatment with feed containing chlortetracycline
How many adults are seropositive for Chlamydophila pneumoniae infection? Children?
- 80% of adults are seropositive
- Common infection in children under 5 years old
What are the Sx of the atypical pneumonia caused by Chlamydophila pneumoniae?
- Incubation several weeks
- Non productive cough
- Preceded by nasal congestion, sore throat, and hoarseness
- Headaches in ½ of patients
What are the signs, tests, and labs consistent with Chlamydophila pneumoniae infection?
- Examination
- Crackles, rhonchi
- Chest x-ray
- Pneumonitis - diffuse interstitial pattern
- Labs
- Normal white count
- Diagnosis
- Serology
- Direct detection of organism in respiratory specimens
What kinds of WBC counts are typical for atypical pneumonias? Typical pneumonias?
atypical pneumonia = normal WBC count
typical pneumonia = high WBC count
What is the Tx for Chlamydophila pneumoniae?
- Tetracyclines
- Macrolides
- Fluoroquinolones
What kind of bacteria is Coxiella burnetii? What kind of cell does it infect?
•Gram negative that infects hosts monocytes