Bacteria: Gram Indeterminate Bacteria Flashcards
List the gram indeterminate bacteria
- Chlamydia trachomatis
- Chlamydia pneumonaie
- Chlamydia Psittaci
- Coxiella burnetti
- Gardnerella Vaginalis
- Mycoplasma Pnuemoniae
- Rickettsia Prowazekii
- Rickettsia Rickettsii
Chlamydia spp. bacteria are
obligate intracellular ogranisms
Chlamydia spp. bacteria take up
Gram stain poorly (Chlamydia spp. are weakly gram-negative)
the cell wall of Chlamydia spp. bacteria
lacks muramic acid (a component of peptidoglycan)
elementary bodies
elementary bodies (the extracellular, infectious form of Chlamydia) are formed in the first of two developmental stages of Chlamydia and do not replicate
reticulate bodies
(the intracellular, replicating form of Chlamydia) are formed in the second of two developmental stages of Chlamydia
after division, Chlamydia reticulate bodies
after division, Chlamydia reticulate bodies transform back to elementary bodies (the nonreplicating infectious form) and are released from the host cell
intracytoplasmic reticulate bodies of Chlamydia can be seen as
intracellular inclusion bodies on microscopy
Giemsa stain can be used to visualize
Chlamydia intracytoplasmic inclusion bodies
a nucleic acid amplification test (NAAT) is the preferred method to detect the presence of
Chlamydia bacteria
Chlamydia trachomatis serovars D-K and L1-L3 cause
sexually transmitted infections (STIs)
Chlamydia trachomatis serovars D-K are
sexually transmitted, and infection often presents with watery vaginal or urethral discharge
STIs caused by Chlamydia trachomatis serovars D-K may lead to
pelvic inflammatory disease (PID) if left untreated
STIs caused by Chlamydia trachomatis serovars D-K may be transmitted from
mother to child during delivery and often cause conjunctivitis or pneumonia
Chlamydia trachomatis serovars L1-L3 can cause
lymphogranuloma venereum (LGV), which is characterized by painful inguinal lymphadenopathy
Chlamydia trachomatis serovars A-C can cause
infection of the eye known as trachoma (the leading cause of preventable blindness in the world)
hand-to-eye contact is the most common mode of transmission of
trachoma (caused by Chlamydia trachomatis serovars A-C); trachoma can also be transmitted via fomites
reactive arthritis (or Reiter’s syndrome) is a
complication that can develop in response to infections caused by certain bacteria, such as Chlamydia trachomatis
the classic triad of symptoms seen in Reiter’s syndrome (caused by multiple pathogens, including Chlamydia spp.) includes
- uveitis
- urethriris
- arthritis
Chlamydophila pneumoniae can cause
atypical pneumonia
Chlamydophila psittaci is transmitted via
bird droppings and can cause atypical pneumonia
_____ are effective against Chlamydia spp.
- macrolides (particularly azithromycin)
2. tetracyclines (particularly doxycycline)
the standard treatment for suspected chlamydial infection
the standard treatment for suspected chlamydial infection presumes a Neisseria gonorrhoeae and Chlamydia trachomatis co-infection; ceftriaxone should be administered in addition to azithromycin or doxycycline (effective against Neisseria gonorrhoeae and Chlamydia trachomatis, respectively)
Coxiella burnetti bacteria are
- gram negative
2. obligate intracellular ogranisms
Coxiella burnetii infection does not present with
rash
Coxiella burnetii is the cause of
Q fever (a typically mild disease that causes flu-like symptoms)
Coxiella burnetii forms
spore-like structures that enable the bacteria to survive in the digestive tract and feces of the host
Coxiella burnetii is spread via
aerosol transmission
common symptoms of Q fever include
headache and dry cough
Q fever can present with
fever
farm animals are a major reservoir for
Coxiella burnetii
Q fever can cause
granulomatous hepatitis
Gardnerella vaginalis bacteria are
gram variable
if the normal vaginal flora (consisting primarily of acid producing Lactobacillus spp.) is disrupted
if the normal vaginal flora (consisting primarily of acid producing Lactobacillus spp.) is disrupted, the pH of the vagina increases, creating a suitable environment for growth of Gardnerella vaginalis
Gardnerella vaginalis infections may present with
a thin, grey-white, “fishy” smelling vaginal discharge
the vaginal discharge from bacterial vaginosis (i.e. Gardnerella vaginalis) has a pH of
> 4.5 (usually between 5.0-6.5)
the whiff test
the whiff test involves the addition of 10% KOH solution to vaginal discharge in suspected bacterial vaginosis caused by Gardnerella vaginalis; the production of a pungent, fishy odor indicates a positive result
wet mount preparation of discharge seen in bacterial vaginosis caused by Gardnerella vaginalis shows
characteristic clue cells (vaginal epithelial cells diffusely covered in Gardnerella vaginalis bacteria)
__________ is effective against Gardnerella vaginalis
metronidazole
Mycoplasma pneumoniae bacteria
lack a cell wall and thus cannot be visualized with use of Gram stain
the cell membrane of Mycoplasma pneumoniae contains
cholesterol
chest X-ray of patients with Mycoplasma pneumoniaee infection shows
chest X-ray of patients with Mycoplasma pneumoniaee infection shows a reticulonodular or “patchy” infiltrate, which often appears much more severe than the patient’s clinical symptoms
Mycoplasma pneumoniae causes
“walking pneumonia,” which refers to the mild severity of pulmonary infection
Mycoplasma pneumoniae infection is common in
military recruits living in close quarters
Mycoplasma pneumoniae infection commonly occurs in
adults under 30 years of age
Mycoplasma pneumoniae infection may result in
development of IgM cold agglutinins (immunoglobulins that cause the agglutination of RBCs at low temperatures), which can lead to hemolysis
________ ________ is designed to grow Mycoplasma pneumoniae
Eaton’s agar
________ are effective against Mycoplasma pneumoniae
macrolides
Rickettsia spp. bacteria are
- obligate intracellular organisms
2. weakly gram-negative coccobacilli
Rickettsia spp. bacteria take up
Gram stain poorly (Rickettsia spp. are weakly gram-negative)
host eukaryotic cells provide Rickettsia spp. bacteria with a source of
- CoA (which is essential for bacterial growth and reproduction); Rickettsia bacteria cannot produce CoA on their own
- NAD+ (which is essential for bacterial growth and reproduction); Rickettsia bacteria cannot produce NAD+ on their own
the Weil-Felix test is
an agglutination test that aids in diagnosis of rickettsial infections
headache and fever are common symptoms of
early rickettsial infections
rickettsial infections commonly result in
a small-vessel vasculitis
rickettsial infections commonly cause
vasculitis, resulting in a petechial or maculopapular rash
________ is the drug of choice for treatment of Rickettsia spp. infection
doxycycline
the rash seen in Rickettsia prowazekii infection
- develops centrally on the trunk and spreads outward to the extremities
- typically spares the face, palms, and soles
military camp recruits and prisoners of war are at a higher risk for
Rickettsia prowazekii infection
Rickettsia prowazekii is transmitted via
the feces of lice and is introduced into the bloodstream when a patient scratches the feeding/defecation sites
the disease caused by Rickettsia prowazekii is called
epidemic typhus
________ and ________ are common symptoms of Rickettsia prowazekii infection
myalgias and arthralgias
Rickettsia prowazekii infection can lead to
pnuemonia
Rickettsia prowazekii infection can cause
encephalitis, which may present with fever, dizziness, and confusion
Rickettsia rickettsii causes
Rocky Mountain spotted fever
the Dermacentor tick is the vector of
Rickettsia rickettsii bacteria
the rash of Rocky Mountain spotted fever develops
- after a 2-14 day incubation period
2. peripherally on the wrists and ankles and spreads centrally to the trunk
symptoms of Rickettsia rickettsii infection include
headache, fever, myalgias, and rash
