Bacteria Flashcards
Describe cell morphology, virulence factors and lab ID of Mycobacterium tuberculosis
Morphology: peptidoglycogen layer plus arabinogalactan (mycolic acid and waxy lipids)
Virulence: waxes, mycosides, cord factor-all are some sort of lipid
ID: bacilli acid fast, slow growing that requires special media
How is Mycobacterium tuberculosis transmitted, where in the US do most cases occur, and in what population
Transmitted: Aerosol
USA cases: Cali, Texas, NY and DC
Population: crowded populations (prisons), homeless people, and AIDS pts
True or False TB is the worlds leading infectious dz
True
Describe primary TB symptoms and progression
Symptoms: asymptomatic to mild flu like
Progression: Bacteria go to alveoli and are ingested by macrophages-> TB multiplies in macrophages-> T cells encounter TB macrophages in the lymph nodes and cell mediated starts->bacteria are contained in tubercles and cell mediated response slows growth of bacteria -> tubercles can then be calcified
What virulence factor of TB is the partial causative agent of the tubercles
Cord factor
Describe the tuberculin skin test
Purified protein derivative (PPD) from the bacterial wall is injected into the skin and if the person has been exposed to TB then the injection site becomes inflamed and hardened
BCG vaccinated people will produce a false positive
Describe the latent phase of TB
No clinical signs, no bacterial shedding, (+) PPD, chest X-ray + or -
Describe secondary TB
Cell mediated immunity fails-> tubercles become necrotic and ghon complex forms-> macrophages become more active and release IL-1 and TNF-> Tubercle/Ghon complex rupture (material is coughed up) and infection spreads to other organs.
Describe miliary TB
Rapid failure of cell mediated immunity causes rapid progression of TB, miliary lesions develop, TB is disseminated to other organs leading to death.
What is the name for the TB vaccine and where is it derived
Bacillus Calmette-Guerin vaccine derived from attenuated bovine TB
What is MDR-TB
resistant to 2 or more TB drugs
What is XDR-TB
resistant to 2 or more TB drugs plus fluoroquinolones, and 1 second line TB drug
Name abx used to treat TB
isoniazid, rifampin, ethambutol, streptomycin
Describe M. avium-intracellular
MAC
mycobacterium that may cause chronic pulmonary lesions and lymphadenitis
can be highly resistant to many traditional antituberculosis drugs
Describe Treponema pallidum in terms of cell morphology, the disease it causes, transmission and how to ID the bug
Morphology: non staining spirochete
Causes: syphilis
ID: immunologic test (use when lesion is absent) and immunofluorescence microscopy of lesion (only if lesion is present..duh)
Describe primary, secondary and tertiary syphilis
1: Chancre (painless lesion) last 3-6 wks then “heals”
2: Rash over a wide area 1-6 months after infection
3: Multiorgan systemic infection
Describe Borrelia burgdorferi in terms of cell morphology, the disease it causes, symptoms, transmission, how to ID the bug, and treatment
Morphology: non staining spirochete
Causes: Lyme dz
Symptoms: skin rash w/ bulls eye target, fever, headache, fatigue, swollen lymph nodes
-Non specific if rash is not present
Transmission: tick with prolonged association
ID: Antigenic tests after several weeks, non culturable
Treatment: requires treatment for months or years
Describe Leptospira interrogans in terms of cell morphology, the disease it causes, symptoms, transmission, and how to ID the bug
Morphology: non staining spirochete
Causes: leptospirosis
Symptoms: asymptomatic or non-specific for 1-2 wks, then nonspecific which progresses to renal and liver failure
Transmission: skin contact w/ urine of infected urine especially via contaminated water (rarely human to human)
ID: rising Ab titer, PCR , non culturable
Describe Burkholderia mallei in terms of cell morphology, the disease it causes, symptoms, and transmission
Morphology: Gram negative bacilli
Causes: Glanders dz: horses, causes nasal mucus discharge
Symptoms: septicemia, cutaneous lesions, lung, liver, spleen involvement 95% mortality in untreated, 50% mortality if treated
Transmission: body fluids from infected animals
ID: Antigenic tests after several weeks, non culturable
Describe Burkholderia pseudomallei in terms of cell morphology, the disease it causes, symptoms, virulence factors, transmission, and where it is found
Morphology: gram negative bacilli
Causes: melioidosis
Symptoms: pulmonary infection, with ulceration, septicemia
Virulence: capsule, cytotoxic lethal factor, filamentous hemagglutin (causes abscess)
Transmission: transmitted by direct contact w/ contaminated soil water
Where: Endemic Southeast Asia, N Australia, S Pacific
What is important about Burkholderia cepacia
Infrequent pathogen that causes PNA in immunocompromised or cystic fibrosis pts
Found in soil and water
Abx resistance and very hard to control if it is in a hospital
Describe Peptostreptococcus in terms of cell morphology, the disease it causes
Morphology: anaerobic gram positive cocci in chains
Causes: normal microbiota of vagina GI, and skin, can cause necrotizing soft tissue infections and PID
Transmission: transmitted by direct contact w/ contaminated soil water
Describe Fusobacterium in terms of cell morphology, the disease it causes
Morphology: anaerobic gram negative bacilli
Causes: periodontal infections and skin ulcers
Describe Faecalibacteium in terms of cell morphology, and why we care about the bug
Morphology: anaerobic gram positive bacillus
Why we care: abundant gut microbiota that may boost immune system
Describe Bifidobacterium in terms of cell morphology, and why we care about the bug
Morphology: anaerobic gram positive bacillus
Why we care:
- Microbiota of gut, vagina, mouth.
- Probiotic component
Describe Lactobacillus in terms of cell morphology, and why we care about the bug
Morphology: anaerobic to microaerophilic gram positive bacillus
Why we care:
- Microbiota of GI and genital tract
- Probiotic component
Describe Propionbacterium acnes in terms of cell morphology, the disease it causes
Morphology: anaerobic gram-positive bacillus/pleomorphic/diptheriod
Causes: acne (dermal inflammation)
