Atypical Bacteria Flashcards
What are the three species of the genus Chlamydia?
C. psittaci, C. pneumoniae, C. trachomatis
These species are significant in the context of atypical bacterial infections.
What type of parasites are Chlamydia species?
Obligate intracellular parasites
They lack independent energy-producing metabolic pathways.
What is the first step in the reproductive cycle of Chlamydia?
Uptake into host cell by energy requiring phagocytosis
Involves small elementary bodies (EB).
What is the most common sexually transmitted bacterial pathogen in the US?
C. trachomatis
Responsible for 4-10 million new cases per year.
What are common infections caused by C. trachomatis in males?
Non-gonococcal urethritis, epididymitis, prostatitis
These conditions are part of the spectrum of STDs.
What are common infections caused by C. trachomatis in females?
Urethritis, follicular cervicitis, endometritis, proctitis, salpingitis, PID
These infections can lead to serious reproductive health issues.
How can newborns become infected with Chlamydia?
By passage through an infected birth canal
Can lead to conjunctivitis, nasopharyngeal infections, and pneumonia.
What is the most commonly used method for direct microscopic examination of Chlamydia?
Direct fluorescent antibody testing
Used for detection in endocervical scrapings.
What cell lines are used for culturing Chlamydia?
McCoy, HeLa 229, BHK-21, Buffalo Green Monkey kidney cells
These cultures help in laboratory diagnosis.
What is the technique most commonly used for rapid detection of C. trachomatis antigen?
Enzyme Immunoassay
Positive results should be verified due to potential false positives.
What is a common clinical manifestation of C. pneumoniae infection?
Pneumonia, pharyngitis, and acute respiratory disease
Associated with a biphasic clinical course.
What is psittacosis and what causes it?
A pneumonia-type respiratory infection caused by C. psittaci
Typically associated with exposure to psittacine birds.
How is psittacosis diagnosed?
Based on history of exposure to psittacine birds and a fourfold rise in antibody to chlamydial group LPS antigen
Diagnosis often requires serological testing.
What type of bacteria are Rickettsia spp.?
Obligate intracellular bacteria
What are the primary vectors for Rickettsia spp. infections?
- Ticks
- Mites
- Fleas
- Lice
- Chiggers
What is the generation time for Rickettsia spp. inside eukaryotic cells?
8-10 hours
Can Rickettsia spp. be grown on artificial laboratory media?
No
What is the most important and common rickettsiosis in the US?
Rocky Mountain Spotted Fever
Which organism causes Rocky Mountain Spotted Fever?
Rickettsia rickettsii
How are R. rickettsii transmitted to humans?
Via a tick bite
What conditions are associated with epidemic typhus?
- Low socioeconomic conditions
- Poverty
- Crowding
- Unsanitary conditions
What causes murine typhus (endemic typhus)?
Rickettsia typhi
What are the transmission methods for Q fever?
Via aerosols
What antibiotics are used to treat rickettsial infections?
- Doxycycline
- Tetracycline
- Chloramphenicol
- Fluoroquinolones
What are the general characteristics of Mycoplasma?
Pleomorphic, no cell wall, slow growing, highly fastidious, facultative anaerobes
M. pneumoniae and M. hominis are strictly aerobic exceptions
What respiratory disease is caused by Mycoplasma pneumoniae?
Primary atypical pneumonia (walking pneumonia)
Causes 20% of pneumonia cases in school-age children and young adults
What diseases can Mycoplasma hominis cause?
Infections of the upper genitourinary tract, including salpingitis, pyelonephritis, PID, and postpartum fevers
Can also be part of normal flora in some individuals
What is the primary laboratory diagnosis method for Mycoplasma pneumoniae?
Serology
A fourfold rise in acute and convalescent serum is used as diagnostic criteria
What is the common morphology of Mycoplasma colonies?
Fried egg appearance
Typical for M. hominis colonies
True or False: Mycoplasma pneumoniae is part of the normal flora.
False
M. pneumoniae is not part of the normal flora
What specimens can be collected for Mycoplasma diagnosis?
Body fluids such as blood, synovial fluid, CSF, wound aspirates, and respiratory secretions
Tissue samples may also be submitted
Fill in the blank: Mycoplasma hominis and Ureaplasma urealyticum can be transmitted to the fetus at delivery causing _______.
Meningitis and disseminated disease
What is a common laboratory challenge in diagnosing Mycoplasma?
Culture is rarely attempted due to technical difficulties
Mycoplasmas are hard to grow in laboratory settings
What is the significance of U9B medium in Ureaplasma identification?
Used to test urease activity directly on solid medium
Urease positive colonies appear dark golden brown
What type of microscopy is required to view Ureaplasma colonies?
Stereoscopic microscope
Ureaplasma colonies are extremely small
What techniques are now available for the detection of serum antibodies for M. pneumoniae?
Enzyme immunoassay and microimmunofluorescence
These techniques can detect both IgM and IgG antibodies.
