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
What is the reservoir and transmission for Coxiella burnetii?
- Infects mammals, birds, and ticks
- Mammals infected by aerosols and may shed Coxiella in feces, urine, milk, and birth products
- Survives in environment and can be spread by the wind
What happens after an acute Coxiella burnetii infection? What patients have a higher risk?
- Incompletely eliminated after acute infection
- Will continue to multiply in immunocompromised patients and endocarditis patients despite high antibody levels
What is the popular name for the infection caused by Coxiella Burnetii?
Q fever
When do major outbreaks of Coxiella burnetti happen?
•Major outbreaks have been related to sheep and goats and associated during lambing season (whenever that is)
What are the clinical manifestations of Q fever?
- 60% seroconvert without disease
- 38% self limited disease
- 2% require diagnostic evaluation
- Prolonged fever
- Pneumonia
- Hepatitis
- Rash
- Meningitis, encephalitis, meningoencephalitis, peripheral neuropathy
- Pericarditis, myocarditis
How can Coxiella burnetii cause spontaneous abortions?
•Chronic uterine infection may develop in half of patients infected during pregnancy, and may later experience multiple spontaneous abortions
What is a serious sequelae related to Q fever?
- Q-fever endocarditis
- Intermittent fever
- Vegetations frequently absent
- Cerebral emboli, renal insufficiency, splenomegaly, hepatomegaly & hepatitis
How do you diagnose a Coxiella burnetii infection?
serology
What is the Tx for Coxiella burnetii infections?
- Doxycycline x 2 weeks in acute cases
- Doxycycline + hydroxychloroquine(increases phagosomal pH) for 18-36 months for endocarditis - sometimes has to be continued for life
What kind of bacteria is Francisella tularensis?
•Small aerobic pleomorphic gram-negative bacillus
What is the reservoir for Francisella tularensis?
- Tularemia is an infectious zoonosis
- Many animals harbor infection including rabbits, squirrels, and muskrats
What is the transmission for Francisella tularensis?
•Humans acquire the infection through direct contact with infected animal tissues, ingestion of contaminated water or meat, the bite of an infected tick or deer fly, or breathing an aerosol of bacteria – not communicated person to person
When sending a suspected Francisella tularensis sample to the lab, what should you do?
Warn them - this pathogen poses an extreme risk to lab personnel
What are the clinical manifestations of Francisella tularensis infection?
- Ulceroglandular
- Glandular
- Oculoglandular
- Typhoidal
- Oropharyngeal
- Pneumonic
What are the signs and Sxs of the ulceroglandular manifestation of Francisella tularensis?
- Fever and constitutional symptoms
- Swollen lymph nodes that drain an inoculation site
- Ulcer formation
- Sore throat
- Patchy infiltrates on chest x-ray
What are the signs and Sxs of the glandular manifestation of Francisella tularensis?
- Fever
- Constitutional symptoms
- Lymphadenopathy
What are the signs and Sxs of the typhoidal manifestation of Francisella tularensis?
Fever of unknown cause
What are the signs and Sxs of the oropharyngeal disease manifestation of Francisella tularensis?
- Uncommon in the United States
- Mucous membranes of the mouth and pharynx are the portal of entry
- Contaminated water or food such as inadequately cooked game meat is the source
- Painful exudative pharyngitis and tonsillitis
- Pharyngeal ulcers
- Swollen retropharyngeal and cervical lymph nodes
What are the signs and Sxs of the pneumonic disease manifestation of Francisella tularensis?
- Inhalation exposure
- Fever, malaise, dry cough, substernal discomfort, pleural effusion, dyspnea, and sore throat
- Chest x-ray with peribronchial infiltrates to bronchopneumonia with effusion
- Hilar adenopathy
What is the Dx for Francisella tularensis?
Serology
What is the Tx for Francisella tularensis infection?
- Gentamcin or streptomycin
- Doxycycline
- Ciprofloxacin
What is the prognosis for a Francisella tularensis infection?
•When appropriately treated mortality is 1% or less
What kind of a germ is Bacillus anthracis? What does it need for culture?
- Spore forming gram-positive non motile rod that is aerobic or facultatively anaerobic, catalase positive, hemolysis negative
- Grows on sheep agar
- Soil contaminated with spores
What are the reservoirs for Bacillus anthracis? What are the spores present in?
- Zoonotic infection from goats, sheep, cattle, antelope, kudu, pigs, horses, zebu, and other animals.
- Animal related products include meat, wool, hides, bones, and hair
What are the clinical manifestations of inhalation anthrax infection?
- Clinical Manifestations
- Inhalation
- Mediastinal adenopathy
- Mediastinal widening
- Pleural effusion
- Rapidly fatal if not treated with multiple antibiotics and pleural drainage
What form of Bacillus anthracis infection is most common?
- Cutaneous
- Most common
What are the other types of anthrax infection, in addition to cutaneous and inhalation?
GI - oropharyngeal and intestinal
meningeal - nearly always fatal, can occur as complication of inhalation, cutaneous , or gastrointestinal disease
How is anthrax infection Dx’ed?
Blood culture
What is the Tx for Bacillus anthracis infection?
- Multi-drug regimen
- Pleural drainage
What is the prevention for anthrax infections?
- Prevention
- Vaccination for possible exposure
- Post-exposure antibiotics
What is the prognosis for an anthrax infection?
- 45% mortality of inhalation in 2001 attacks
- 20% mortality in untreated cutaneous disease
What kind of germ is Yersinia pestis? Reservoir?
- Gram negative coccobacillus, microaerophilic, nonmotile, and non spore forming
- Transmission cycles involve rodents and fleas, which act as vectors.
- Prairie dogs are a common host
What are the clinical manifestations of Plague?
Bubonic
Septicemic
Pneumonic
What are the signs and Sx’s of Bubonic Plague?
- Swollen, tender lymph nodes (buboes) closest to site of initial infection
- Fevers, chills, myalgia, arthralgia, headache, malaise, and prostration
- Untreated patients have continued fever, tachycardia, agitation, confusion, delirium, and convulsions
What are the signs and symptoms of septicemic plague?
- Nausea, vomiting, diarrhea, and abdominal pain
- Disseminated intravascular coagulation
- Hypotension, renal failure, and obtundation
- ARDS
What are the signs and Sx’s of pneumonic plague?
- Fever, cough, chest discomfort, tachycardia, dyspnea, bacteria laden sputum, chills, headache, myalgias, weakness, and dizziness
- Respiratory distress, hemoptysis, cardiopulmonary insufficiency, and circulatory collapse
- Death within 24 hours of symptoms
What are the TX’s for Plague?
- Streptomycin for pneumonic plague
- Tetracyclines for bubonic plague
- Chloramphenicol for meningitis
What kind of germ is Leptospirosis? How is it identified?
- Spirochete with terminal hook
- Identified on dark field microscopy or silver staining
- Obligate aerobe
What are the clinical manifestations of Leptospirosis?
- Weil’s Disease:
- Pulmonary Hemorrhage Syndrome
What is the reservoir for Leptospirosis?
- Persistent renal carriage from rodents, dogs, pigs, cattle, and sheep
- Colonizes renal tubules, excreted in urine, and survives for weeks to months in the environment
What is the transmission for Leptospirosis?
•Penetrates the skin or mucous membranes during contact with contaminated water, soil, or vegetation
What are the clinical manifestations for the early phase of Leptospirosis? How long is this time period?
- First 3-7 days
- Fever, myalgia, and headache
- Nausea, vomiting, abdominal pain, diarrhea, cough, and photophobia
- Muscle tenderness
- Rash
- Conjunctival suffusion
What is the late phase of Leptospirosis called? What signs and Sx’s characterize it?
- Late Phase: Weil’s Disease
- Jaundice
- Renal Failure
- Acute hemorrhage
- Severe thrombocytopenia
- GI bleeding
- Pulmonary Hemorrhage
- Myocarditis
- Aseptic meningitis
What is the Dx for Leptospirosis?
Agglutination test
What is the Tx for Leptospirosis?
- Doxycycline
- Penicillin
What is the prevention for Leptospirosis infection?
•Doxycycline post-exposure
What kind of germ is Haemophilus influenzae? What does it need for culture?
- Encapsulated gram negative pleomorphic rod
- Aerobic or facultative anaerobic
- Grows on chocolate agar
- X(hemin) Factor and V(NAD) Factor
What is the reservoir and transmission of Haemophilus influenzae?
- Nasopharynx of adults and children
- Transmission: respiratory droplets
What used to be the most common cause of meningitis in young children?
•H influenza type b was most common cause of meningitis in young children prior to effective vaccines
What are the clinical manifestations of Haemophilus influenzae infection?
- Meningitis - Type B strains
- Children under 5 years old and in adults with skull trauma or CSF leaks
- Epiglottitis
- Life threatening infection in children that usually occurs in children younger than 5.
- Symptoms include fever, drooling, dysphagia, and respiratory distress with stridor
- Course is rapid over a couple of hours
- Lateral neck film used for diagnosis
- Pneumonia:
- Fever, cough, and lobar consolidation
- Parapneumonic effusion and empyema
- Diagnosed by blood culture or culture from pleural fluid
- Smoking – risk factor
- Bronchitis
- Risk factor is chronic lung disease ( COPD)
- Acute Sinusitis
- Otitis Media
How is Haemophilus influenzae infection dx’ed?
•Diagnosis made by detecting PRP capsular antigens in CSF
What is the Tx for Haemophilus influenzae infection?
•3rd generation cephalosporin for meningitis
How is infection by Haemophilus influenzae prevented?
- Conjugate capsular polysaccharide-protein vaccine effective for type b disease
- Antibiotic prophylaxis in nonimmunized household or daycare contacts of patients with H influenza type b
- Rifampin
What is the thumb sign on CXR?
swollen epiglottis, sign of epiglottitis due to H. influenzae
What kind of a germ is Corynebacterium diptheriae?
- Gram-positive bacillus – club shaped
- Non-spore forming
- Aerobic
What is the reservoir for Corynebacterium diptheriae?
throat and pharynx
What is the transmission route for Corynebacterium diptheriae?
•Bacterium or phage via respiratory droplets
What are the clinical manifestations of respiratory diptheria?
- Incubation of 1-7 days
- Sore throat, malaise, and fever
- Pharyngeal erythema followed by tonsillar exudate
- Exudate changes into a grayish membrane that is tightly adherent and bleeds on attempted removal
- Cervical adenopathy – Bull Neck
- Stridor
What are some serious complications of respiratory diptheria?
- Extension of membrane can lead to airway obstruction
- Myocariditis, recurrent laryngeal nerve palsy, and peripheral neuritis
What is the Tx of Corynebacterium diphtheriae?
- Erythromycin
- Antitoxin
How is respiratory diptheria prevented?
•Vaccination with toxoid vaccine
