Unit 1; Chlamydia, Ricketsia, Spirochetes Flashcards
What Chlamydia species can cause human infections?
C. trachomatis, C. psittaci, C. pneumoniae
C. pneumoniae is least pathogenic due to lack of plasmid
What Chlamydia species can cause infections in animals?
C. abortus, C. pecorum
How is Chlamydia similar to viruses?
Chlamydia requires host resources for their metabolism
because chlamydia is gram-negative, the LPS has little __________ activity.
endotoxic
????
small amount of peptidoglycan?
Chlamydia:
Major outer membrane protein (MOMP)-very diverse, but very conserved in _____________.
C. pneumoniae
Plasmid DNA is present in what species of chlamydia? but not in which one?
C. trachomatis and C. psittaci,
not in C. pneumoniae
Glycogen-containing inclusions only in C.__________
trachomatis
Susceptibility to sulfonamides: C.__________
trachomatis
What are the two components of chlamydia life cycle?
Intracellular: reticulate body (RB)-replicative
Extracellular: elementary body (EB)-infective
What is the most common sexually transmitted bacteria in the US?
Chlamydia Trachomatis
What is the most common sexually transmitted bacteria in the US?
Chlamydia Trachomatis
What is the most common sexually transmitted bacteria in the US?
Chlamydia Trachomatis
C. Trachomatis:
_____ serovars (outer membrane proteins) based on MOMP antigenic differences
18
What complications can C. Trachomatis cause?
PID, ectopic pregnancy and infertility
GTI in females ages of 15 and 24 yr
Lymphogranuloma venereum (LGV): acute and chronic (e.g. rectal fistulas, rectal stricture etc.)
How common is Ocular trachoma?
Blindness?
84 million worldwide
7 to 9 million worldwide
Prevalent areas of chlamydia?
Africa, Asia, Central and South America
What is the major transmitsion for C. Trachomatis?
direct contact (human to human)
Vertical transmission: neonatal pneumonia or inclusion conjunctivitis
In US: C. Trachomatis causes ____% NGU
60
What are the oculogenital infections caused by chlamydia?
acute inclusion conjunctivitis in adults and newborns, GTI (urethritis, cervicitis, bartholinitis, salpingitis, proctitis, epididymitis and acute urethral syndrome in females, NGU
Is chlamydia always easily recognized?
no, Many asymptomatic and not easily recognized
What are the usual symptoms of chlamydia?
unusual discharge and pain, symptoms similar to gonorrhea
How is chlamydia diagnosed in the lab?
Preferred for screening: endocervix sample.
Others: Urogenital swab and fresh urine sample.
*Bacteria is labile, so keep sample cold and transport ASAP.
plasmid DNA is responsible for causing ________.
disease
Whare are the basic steps of chlamydia life-cycle?
- specific host cell receptor binding
- endocytosed into cell
- EB recognized into large reticular body
- multiplication by binary fission —-> produces an inclusion
- condensation into EB forms
What can chlamydia sometimes be mistaken for by doctors?
benign tumors
What is a major way the immune system can stop the spread of chlamydia?
stop the production of the receptor needed for chlamydia to be taken into the cell.
Why are cultures not usually done for chlamydia?
because it is intracellular. But if done, must use cell lines.
Why are cultures done for chlamydia only 70-90% sensitive?
some cells in the culture may not have the receptor needed to become infected.
What is the transport media used for chlamydia?
2SP, 0.2M sucrose-phosphate transport medium with antibiotics (prevents other bacteria from contaminating it)
What culture media is sometimes used for chlamydia but less frequently?
McCoy, HeLa and monkey kidney
48-72 hr culture, stained with fluorescent labeled monoclonal antibody
cell lines
Chlamydia cultures are _____% specificity and _____% sensitivity.
100, 70-90
this method is preferred for legal implications
What are the three direct detection methods for chlamydia?
- Inclusion bodies: round, vacuolar (by DFA staining)
- Antigen detection: EIA
- NA hybridization: Digene hybrid capture II assay (uses RNA probe to detect DNA in a sample)
chlamydia inclusions can be stained by use of _________.
iodine
-100% specificity with the presence of inclusion bodies
C. Psittaci is ______________ resistant.
Sulfonamide
type of chlamydia that is more common in birds and domestic animals
C. Psittaci
What are the symptoms of C. Psittaci?
Birds: diarrhea or no symptoms
Bird to human: aerosols, IP: 5-15 days
Pnumonia, severe headache, mental status changes, hepatospenomegaly
Should use BSL___ for C. Psittaci.
3
How is C. Psittaci diagnosed?
almost always by serology
IgM titer: 1:32 or greater for diagnosis
PCR: rRNA sequences followed by RFLP
What are the symptoms of C. pneumoniae?
Pnumonia, brochitis, pharyngitis, sinusitis and flulike illness
May be the causative agent of atherosclerosis.
C. peneumoniae is more common in…
how is it spread?
More common in human, no birds or animals
Person to person: aerosolized droplets
How can C. pneumonia be diagnosed?
Direct methods: NAAT (RCR and real-time PCR)
Cultivation: oropharynx swab, cold in TM, culture in McCoy cell lines- multiple blind passages
Use monoclonal antibody to detect organism
Serodiagnosis: CFT, 4 fold rise in IgG or IgM
Drugs for C. trachomatis?
Tetracyclines, azithromycin, doxycycline, erythromycin,fluoroquinolones and other macrolide antibiotics
-similar for C. trachomatis?
What is the drug of choice for treating C. psittaci?
Tetracycline
-Obligate intracellular and fastidious organism
-Can survive briefly outside of host
-Small (1-2 micron), pleomorphic and gram –ve
-Human: accidental host in most cases
-Multiply intracellularly, but not intracellular development
-Damage endothelial cells, cause cell injury and death
Rickettsia
What are the three groups of Rickettsia based on arthropod mode of transmission?
- spotted fever group, 2. the typhus group, 3. the scrub typhus group
What is the vector for R. conorii, R. rickettsia, and R. parkeri?
Tick
causes Indian or kenya tick typhus, & Mediterranean or Israeli spotted fevers
R. conorii
cause Rocky Mountains spotted fever
R. rickettsia
causes mild illness with no reported fatalities
R. parkeri
Lice is the vector for…
R. prowazekii: epidemic typhus and Brill-Zinsser diseases
Fleas are the vector for…
R. typhi: Murine typhus
How is Rickettsia diagnosed?
And specimen
common PCR or RFLP, others: EIA, IFA and DFA (useful for R. rickettsii, Ab produced 2 wks after infections in others)
Specimen: biopsy from the rash (preferred)
Three bacteria that…
-cannot survive outside the host cell
-very little is known
-Ehrlichia sp.
-Anaplasmam phagocytophilium,
-Neorickettsia sennetsu
E. chaffeensis infects ___________.
What is the vector?
monocytes
ticks
A. phagocytophilium infects…
bone marrow, primarily neutrophils.
A. phagocytophilium causes…
What is the vector?
Anaplasmosis (fever, chills, headache, muscle ache.
Vector: ticks (black legged)
What symptoms does Neorickettsia sennetsu cause?
Vector?
Sennetsu fever: in SE asia, high fever, muscle aches
vector unknown (maybe raw fish??)
How are these bacteria diagnosed in the lab?
-Ehrlichia sp.
-Anaplasmam phagocytophilium,
-Neorickettsia sennetsu
-Giemsa stain of WBC (because parasite present in monocytes)
-Serodiagnosis: EIA, IFA, DFA
-PCR
What is Q fever and what is the causative agent?
an acute systemic infection of the lungs
Coxiella burnettii
Can Coxiella burnettii survive outside the host cells?
yes, but can only be grown in lung cells
Is Coxiella burnettii resistant?
More resistant to various chemical and physical agents
What are the two Coxiella burnettii antigenic states in life cycle?
- Large-cell varient form: highly infectious
- small-cell variant form: spore like, not infectious, can survive extracellular, seen in cultured cell lines
Coxiella is mostly found in…
domestic animals (cattle, sheep, and goats)
What is the difference between Q-fever and Coxiellosis?
Q-fever- acute
Coxiellosis- chronic
How prevalent is Q-fever?
endemic worldwide except in New Zealand
What are the symptoms associated with Coxiella infections?
*No rash developed (because the infection is in the lungs)
-Atypical pneumonia, granulomatous hepatitis, endocarditis, neurological manifestations, osteomyelitis
*only causes internal infections
How is Coxiella diagnosed?
-Diagnosis: must use BSL3
-Culture: 6-14 days at 370C in *CO2 environment – direct IFA
-NAAT, PCR, serology tests: EIA, IFA
What drug is used for both acute and chronic Q fever?
Tetracycline
How does chronic coxiellosis usually manifest?
1 to 20 years later as endocarditis
-Others: chronic hepatitis, osteomyelitis, septic arthritis, lung diseases
Coxiella infections can occur even with treatment, and mortality can be as high as _____%.
60
characteristics of Bartonella
intracellular, fastidious, facultative anaerobic, zoonotic.
causes similar symptoms to Rickettsia, associated with trench fever
What is the vector?
Bartonella quintana
lice
Is bacteria causes acute hemolytic bacteremia (Oroya fever), chronic vasoproliferative diseases, mortality 40-90%
Bartnonella bacilliformis
Bacteria associated with cat scratch disease?
Bartonella henselae
How is Bartonella diagnosed?
What is the treatment?
Diagnosis: Culture, PCR, serology
Treatment: Similar to C. trachomatis
What bacteria is associated with Whipple’s disease?
Tropheryma whippelii
What is Whipple’s diseases?
(arthralgia, diarrhea, weight loss, lymphadenopathy, hyperpigmentation)- in middle-aged men
Leads to malabsorption
How is Tropheryma whippelii diagnosed?
-Can not culture
-Diagnosis: NAAT, PCR and other techniques
What is the treatment for Tropheryma whippelii?
Trimethoprim/sulfamethoxazole
Macrolides
Aminoglycosides
Tetracycline
Penicillin
