L9- Atypical Bacteria Flashcards
define insidious
slow growing (weeks - months), often resistant to first line antibiotics
(1) and (2) are important Actinomycetes and share these two important features: (3) and (4)
1- Actinomyces
2- Nocardia
3- long, branching filaments
4- Gram+ wall
Actinomyces israelii are (aerobic/anaerobic) that are (endo/exo)-genous to to the body. They most notably result in (3- include its unique characteristics), but can also result in (4)
1- anaerobic
2- endogenous (commensal oral and GI flora)
3- opportunistic abscesses in anoxic tissue (Lumpy Jaw) with sulfur/foul smelling granules
4- slow granulomatous abscessed in any tissue
define acid-fast test and what a positive result indicates
- heat fix to slide –> de-stain with Acid Alcohol
- bacteria with Thick Lipid Mycolic Acid Wall retain the stain –> appear Red
acid-fast stain is also called….
Ziehl-Neelsen stain
what are the two types of Acid-Fast bacteria
- Nocardia, acid fast branching
- Mycobacterium species, acid fast bacilli
list features of Nocardia asteroides
- acid-fast branching filamentous
- weakly Gram+
- aerobic
- exogenous transmission: inhalation of dust
Nocardia asteroides infection is called (1) and will result in (2) in the (3) part of the body, particularly in (4) patients
1- nocardiosis
2- opportunistic abscesses (pulmonary cavitation disease)
3- lungs
4- immuno-comprimised
describe the mechanism of mycobacterium tuberculosis (TB) infection
- a facultative intracellular organism
- transmission through air droplets (via active pulmonary disease)
- organism is phagocytized, but unable to be digested due to thick lipid cell wall
- granulomas formed and host tissue damage due to inc in CKs and recruitment proteins
Mycobacterium tuberculosis takes advantage of individuals with….
low cell-mediated immunity (CD4+ Th1)
-ex. young children
Mycobacterium leprae (leprosy) is a (obligate/facultative) intracellular bacteria that replicates in (2) or (3). It is spread through (4).
1- obligate intracellular bacteria
2- macrophages
3- nerve cells
4- close contact with untreated leper over many months
what two diseases are caused by mycobacterium leprae
- both involve nerves and cause loss of sensation, difference is based on host immune response
1) Lepromatous leprosy- more severe
2) Tuberculoid Leprosy- less severe
Mycobacterium marinum are infections of the (1) from contact through (2) via (3). The first signs of infection are (4)
1- skin
2- aquariums, fish (in fresh or saltwater)
3- skin exposure (cut, scrape)
4- reddish, tan skin with granuloma
list some features of Mycoplasma ssp and include some examples of species
- no cell wall
- smallest prokaryote
- sterols in membrane
- ‘fried egg’ appearance on Histo.
Exs: Mycoplasma pneumoniae or genitalium, Ureaplasma
Mycoplasma pneumoniae is also called (1) and is transmitted via (2). They are resistance to (3) due to the lack of cell wall and usually present as (4).
1- walking or atypical pneumonia
2- air droplets
3- 1st line anti-biotics (β-lactams, cephalosporins)
4- dry persistent cough
Mycoplasma genitalium and Ureaplasma are STIs that cause (1) in females with (2) and (3) as symptoms and (4) and (5) as possible long term complications
1- PID (pelvic inflammatory disease) 2- painful intercourse 3- vaginal bleeding/discharge 4- sterility 5- ectopic pregnancy (complications due to being a long, asymptomatic infection)
Mycoplasma genitalium and Ureaplasma are STIs that cause (1) in males with (2) and (3) as symptoms and (4) as a possible long term complication
1- urethritis 2- stinging/burning during urination 3- penile discharge 4- sterility (complications due to being a long, asymptomatic infection)
what is a special feature of Ureaplasma in pregnant females
it can cross the placenta –> spontaneous abortion or pre-mature birth
Chlamydia species are (obligate/facultative) intracellular bacteria meaning they depend on (2) and (3) from the host. They are Gram(+/-). (5) is required for growth in lab.
1- obligate intracellular bacteria 2- ATP 3- NAD 4- neither, don't Gram stain well 5- tissue culture, can't grow on plate/agar
Chlamydia exists in (1) or (2) form
1- EB, elementary body / infectious form
2- RB, reticulate body / replicative form
list the Chlamydia species
- Chlamydia trachomatis (STI, trachoma)
- Chlamydia pneumoniae (pneumonia)
- Chlamydia psittaci (Psittacosi- zoonotic disease)
briefly describe the cycle of Chlamydia species
1) EB invades epithelial cell as inclusion body
2) EB –> RB w/in cell
3) RB multiplies
4) RB condense to EB form
5) EB form matures
6) EB is released to infect other cells
describe structure of Acid-Fast Mycolic Cell Wall
- Mycolic acids –> thick lipid waxy layer –> limits nutrient uptake => slow growth rate & adds additional protection (no lysosomal fusion w/in macrophage)
- Waxy coat interferes with Gram staining
- Cord Factor (glycolipid) is present –> toxic by disrupting oxidative phosphorylation
(1) is a glycolipid found on Acid-Fast Mycolic Cell Walls and is very toxic, involved in (2)
1- Cord factor
2- disrupting oxidative phosphorylation
indicate which disease each Chlamydia trachomatis serotype causes:
(1) A, B, C
(2) D - K
(3) L1-L3
1- trachoma
2- urogenital infections (STIs)
3- Lymphogranuloma Venereum (LVG- uncommon STI)
what is a trachoma
blinding ocular disease caused by Chlamydia trachomatis (serotype A, B, C), usually in developing countries
(1)% of Chlamydia trachomatis Cervicitis is asymptomatic and if left untreated can lead to the following (2- hint 4 things). The best screening is (3)
1- 80%
2- transmission to neonate, pelvic inflammatory disease, ectopic pregnancy, sterility
3- PAP smear- look for intracytoplasmic vacuoles
serotype D-K Chlamydia cause (1) or (2) in males, (3)% are asymptomatic
1- nongonoccal urethritis (if w/o gonorrhea which it is commonly transmitted with)
2- epididymitis
3- 50%
serotype D-K Chlamydia cause (1) and (2) in everyone and (3) and (4) in neonates
1- inclusion conjunctivitis
2- proctitis (rectal infection)
3- inclusion conjunctivitis
4- infant pneumonia
these two types of Chlamydia species cause atypical pneumonia, but include differences in transmission
- Chlamydia pneumonia via human to human aerosals
- Chlamydia psittaci via exposure to birds (Zoonotic / ‘Parrot fever’)
- Both have persistent cough for wks to mos, whether in teenagers or exposed zoo workers
list the three types of Rickettsia and their associated arthopod
- R. rickettsi via Ticks
- R. prowazekii via Lice
- R. typhi via Fleas
Rickettsia bacteria are (obligate/facultative) intracellular bacteria and are transmitted via (2). They usually penetrate skin or mucous membranes to infect (3)
1- obligate intracellular bacteria
2- arthropods
3- endothelial cells –> small BVs => vasculitis
describe Rocky Mountain Spotted Fever
- from tick bite infected with Rickettsia rickettsii, onset is 7-14 days afterwards
- high fever, regional lymphadenopathy
- endovasculitis => petechial rash (spotted rash) on palms/soles, encephalitic signs, gangrene of skin/tissues
