Flashcards in Intracellular Bacteria and Spirochetes Deck (88):
What are the four major intracellular pathogens?
1. Chlamydia and Chlamydophila
What are the three notable spirochetes?
2. Borrelia (lyme/ relapsing fever)
Chlamydia and Chlamydophila are obligate ____________. Because of this, how must they be grown in culture?
Obligate intracellular parasites.
When growing them in culture, you must grow them on embryonated eggs or tissue cultures
What is unique about the cell wall of chlamydia?
It lacks peptidoglycan
What virulence factors is used by chlamydia?
Why is chlamydia an obligate intracellular pathogen?
Because it cannot synthesize ATP so it relies on the host
What are the three main strains of chlamydia?
1. Chlamydia pneumoniae
2. Chlamydia psittaci
3. Chlamydia trachomatis
What disease is associated with chlamydia pneumoniae?
pneumonia transmitted person-to-person
What disease is associated with chlamydia psittaci? Who is most likely to get this infection?
The pathogen is found in birds (parrots specifically) so bird owners are more likely to get this
What disease is associated with chlamydia trachomatis?
1. STD causing urethritis, cervicitis, prostatitis and PID
2. neonatal disease
3. ocular disease in developing countries
What is the most common bacterial STD in the US?
What is the leading cause of blindness worldwide?
Describe the life cycle of trachoma for spreading ocular disease in developing nations.
1. flies carrying the bacteria land on childrens eyes and feed on discharge
2. Caretakers of the children acquire the bacteria
3. Flies breed in human feces and spread the disease to other
Describe the gram staining, shape and structure of Rickettsia.
It is a small pleomorphic coccobaccilli that has the structure of a gram negative bacteria but does NOT strain with gram staining
What type of bacteria (gram neg or gram pos) has a structure similar to Rickettsia? What is the difference?
Rickettsia has peptidoglycan and LPS similar to gram negative but they do not stain with a gram stain.
Rickettsia is an obligate __________________ so when culturing it needs to be grown on ______________.
obligate intracellular pathogen so needs to be grown on egg yolks or tissue culture
What cell do Rickettsia replicate in?
they replicate in endothelial cells of blood vessels (damaging the vessels)
What is the vector for Rickettsia? How many species are there?
The vector is arthropods each with specific mammalian or avian reservoirs and specific geographical distribution
What are the two main types of Rickettsia that affect humans?
1. Rocky Mountain Spotted Fever
What is the main reservoir of Rickettsia associated with RMSF?
What area of the country has the highest prevalence?
What is the peak seasons?
It was first isolated in rocky mountains (hence the name), but it is most prevalent in the southeast.
The main reservoir is rodents and it peaks in spring/summer
How long is the incubation for RMSF and what does the person first present with?
How does the infection progress?
It incubates for a week when the person will start feeling fever, malaise, headache.
After a week they develop a rash (INVOLVING PALMS AND SOLES OF FEET)
What symptom of RMSF tells you that you are "too late"?
What is the mortality rate?
the rash involving palms and soles of feet. It is a week after the infection,
Mortality is over 10%
How is Rickettsia that causes epidemic typhus transmitted?
Via human body louse
Where would one likely see Rickettsia prowazekii? (rickettsia that causes typhus)
In areas where there is poor hygenic conditions
What is the case fatality of epidemic typhus?
Describe the shape of Erlichia and Anaplasma.
How do Erlichia and anaplasma stain of the gram stain?
They do not, but they stain with Giemsa and Wright stains
Are erlichia and anaplasma structurally more like gram postives or gram negatives?
They are more like gram negatives because they have dual membrane, but they lack peptidoglycan and LPS.
Erlichia/anaplasma and Rickettsia are both similar to gram negative bacteria, but in different ways. How is each group similar to G-?
Erlichia/Anaplasma- have dual membrane but lack peptidoglycan and LPS
Rickettsia- no peptidoglycan but have LPS
Describe the growth pattern of Erlichia and anaplasma?
They grow in morulae (clusters like mulberries)
Where do erlichia chaffeensis grow?
What does this cause?
Monocytes causing human monocytic erlichiosis
What is the vector of erlichia chaffeensis?
the dog tick and lone star tick
What three states have the highest incidence of erlichia chaffeensis?
Arkansas, OK, Missouri
What cells are infected by anaplasma?
Granulocytes causing granulocytic ehrlichiosis
What is the vector of anaplasma phagocytophilum?
Ixodes tick (same for lymes disease)
What is the major clinical presentation of Ehrlichia or Anaplasma?
They cause acute febrile syndrome with blood cell abnormalities
Coxiella burnetii is associated with what clinical presentation?
What strain of gram negative bacteria is coxiella related to?
Coxiella does not gram stain, but it has a _______ style membrane.
Coxiella burnetii undergoes ________________ based on the LPS.
Phase variation (I and 2)
What is the animal reservoir for coxiella burnetii?
cattle, sheep, goats, and are transmitted by ticks
In addition to being transmitted by ticks, how else can humans get coxiella?
Acute Q fever has a ___________ incubation time, and causes _________________.
A variable incubation time and causes pneumonia syndrome (fevers, chills, headache, fatigue, sweats, muscle aches)
How is acute Q fever treated?
It resolves on its own without treatment
Chronic Q fever is characterized by ________.
If Q fever occurs during pregnancy it results in what?
Abortions and neonatal death
Mycoplasma is associated with what pathogenesis?
It is a common cause of community acquired pneumonia (WALKING PNEUMONIA)
What pathogen causes walking pneumonia?
What are two potential causes for non-gonorrheal urethritis?
1. mycoplasma genitalium
2. Ureaplasma urealyticum
What is the onset time for mycoplasma-caused pneumonia (walking pneumonia)?
What bacterial species has still never been cultivated in vitro?
Treponoma pallidum (syphilis)
What is the shape and gram staining capabilities of spirochetes?
They are spiral in shape but are too narrow to show up on the gram stain.
Spirochetes cannot be seen with _______ microscopy because ______________. You must use ______________ microscopy.
They cannot be seen with light microscopy because they are too narrow. You must use dark field microscopy
What stain is used to identify spirochetes?
silver-based stains like Warthin-Starry and Dieterle.
Spirochetes have an inner and outer membrane but they are NOT gram negative. What are the three types of spirochetes? Which have LPS?
Treponema- no LPS
Borrelia- no LPS
What is the only kind of spirochete that has LPS?
Describe the motility of spirochetes.
They have corkscrew motility due to the periplasmic flagella
What are the major antigens of spirochetes?
Lipoproteins that signal through TLR2
How many species of treponema pallidum are there? What does each subspecies cause?
1. pallidum- syphilis
2. pertenue- yaws
3. endemicum- endemic syphilis
4. carateum - pinta
What is the only host of treponema pallidum?
What is the oxygen consumption of treponema?
You can not culture what bacteria strain in vitro?
How do you culture it?
Treponema pallidum cannot be cultured in vitro so it must be cultured through serial passage in rabbits
How many organisms of treponema pallidum are capable of causing disease?
less than 10
How many stages are there for syphilis (great pox)
3- early primary, early secondary and late
How long after infection does the primary stage of syphilis begin? What is the characteristic sign that it has begun?
Primary stage begins 3 weeks after infection and its characterized by a chancre (painless genital ulcer) that clears itself
Describe what occurs during the secondary stage of syphilis.
There is a generalized rash that resolves spontaneously and relapses
What happens before the tertiary stage of syphilis?
Latency that can last up to decades
What are the three associations of tertiary syphilis?
1. benign gummatous (skin and bone)
2. Cardiovascular (ascending aortic aneurysm)
What is the effective treatment for syphilis?
What two diseases are caused by borrelia?
1. Lyme's disease by borellia burgdorferi
2. Relapsing fever -endemic caused by hermsii, turkatae, parkeri. epidemic caused by recurrentis
What strain of borellia causes epidemic relapsing fever?
What is the vector of B. burgdorferi? What does it cause?
It is the ixode tick and it causes lyme's disease
What two bacteria are carried by the ixode tick?
Anaplasma and B. burgdorferi
What is complex about the lyme disease life cycle?
It takes two years
Spring - eggs->larva
summer- larvae infects animals
fall- the tick is a dormant nymph
winter- dormant nymph
Spring- infect animals and people
Summer infect animals and people
Fall- infect people and animals
Winter- adult tick lays eggs
What four pathological findings do you see in early stages of Lyme's disease?
1. erythema chronicum migrans (bullseye rash)
2. sore joints
3. cardiovascular conduction abnormality
4. neurological issues
What three things are characteristic of late stage lyme's disease?
What three strains of borellia cause endemic relapsing fever?
1. B. turicatae
2. B. hermsii
3. B. parkeri
What vector causes endemic relapsing fever?
Rodents are a reservoir and humans are accidental hosts
How is endemic relapsing fever diagnosed?
looking at a blood smear
Where in the country is tick-borne relapsing fever prevalent?
CA and the pacific northwest
What is the vector for epidemic relapsing fever?
human body louse associated with bad hygenic environements
What two bacteria are carried by the human body louse?
1. Rickettsia (typhus)
2. B. recurrentis (epidemic relapsing feveR)
What is the major pathogen of the leptospira bacteria?
Where does it typically cause infection geographically?
L. interrogans- tropical and subtropical areas as well as temperate urban areas
Leptospira is a zoonotic infection of dogs, cattle and rats. How is it excreted? Why is this bad?
It is excreted in urine so when these animals pee in sewers, etc, leptospira can get into the water supply
How is leptospira interrogans taken up into humans?
Absorbed through abraded skin or mucous membranes
What are the two major disease presentations of leptospira?
1. bacteremia- nonfocal fever syndrome
2. Weil's disease- bleeding, liver failure, hepatic failure
What bacteria is associated with Weil's disease?