Obligate Intracellular Bacteria Flashcards
C. trachomatis host range
Humans
except for 1 biovar that causes mouse pneumonitis
C. trachomatis EB morphology
round
C. trachomatis Inclusion morphology
round, vacuolar
C. trachomatis Glycogen containing inclusions?
Yes
C. trachomatis Plasmid DNA?
yes
C. trachomatis susceptibility to sulfa meds?
yes
C. psittaci host range
birds, lower mammals, rarely humans
C. psittaci EB morphology
round
C. psittaci inclusion morphology
variable, dense
C. psittaci glycogen containing inclusions?
no
C. psittaci plasmid DNA?
yes
C. psittaci susceptibility to sulfa meds?
no
C. pneumoniae host range
humans
C. pneumoniae EB morph
pear-shaped
C. pneumoniae inclusion morph
round, dense
C. pneumoniae glycogen-containing inclusions?
no
C. pneumoniae plasmid DNA?
no
C. pneumoniae susceptibility to sulfa meds?
no
Infectious stage of Chlamydia
Elementary body
Metabolically active form of chlamydia
Reticulate body
Removal of ___ or increase of ___ will cause differentiation of chlamydia into _______
IF-gamma
Tryptophan
active EB infection
Chlamydia trachomatis associated with ___ and ___ ___ in women
infertility
ectopic pregnancy
Most common sexually transmitted bacterial pathogen in US
Chlamydia trachomatis
Ways chlamydia trachomatis survive
- can turn on/off apoptosis in infected host cells to facilitate transmission
- Inhibit cell death to sustain survival in chronic infections
Clinical syndrome of C. trachomatis serovars A, B, Ba, C
Endemic trachoma (multiple or persistent infections that ultimately lead to blindness)
C. trachomatis serovars A, B, Ba, C routes of transmission
Hand to eye from fomites, flies
C. trachomatis serovar L1, L2, L2a, L3 clinical syndrome
Lymphogranuloma venereum
C. trachomatis serovar L1, L2, L2a, L3 route of transmission
sexual
C. trachomatis serovars D-K Clinical symdrome
Urethritis, cervicitis, PID, epididymitis, infant pneumonia, conjunctivitis (does not lead to blindness)
C. trachomatis serovars D-K routes of transmission
Sexual, hand to eye by autoinoculation of genital secretions
eye to eye by infected secretions
neonatal
C. trachomatis is hyperendemic to these 5 places and has a high rate in ____ ____
Africa, Asia, Central America, South America, Middle East
Preschool children
Trachoma is chronic inflammation of the ____
conjunctiva
Major cause of preventable blindness
Trachoma acquired by…
Contact with secretions on towels, finger, or by flies
Symptoms of trachoma
mild irritation, itchy eyes, may also be discharge from infected eye
Trachoma progresses ___ with increases in these symptoms
slowly
eye pain, blurred vision, photophobia
Repeated trachoma infections result in….
scarring of the inner eyelid
May eventually turn eyelid inward (entropion)
Lymphogranuloma venereum is transmitted ____ and is more common in these 3 places
sexually
Africa, Asia, South America
Lymphogranuloma venereum is characterized by…
a brief appearance of a primary genital lesion at the initial infection site
The second stage of Lymphogranuloma venereum is ____ ____ and causes….
acute lymphadenitis
inguinal lymph nodes to become enlarged and matted together
Lymphogranuloma venereum can progress to a third stage, mostly in ___, causing….
women
rectal fistulas, genital hyperplasia, rectal stricture, draining sinuses
Oculogenital infections are caused by _____
C. trachomatis
Oculogenital infection is defined as…
acute inclusion conjunctivitis in adults and newborns
Oculogenital infections are transmitted by…
contaminated genital secretions getting into eyes via fingers or during passage of the neonate through the birth canal
Oculogenital infection autoinfection occurs ___
rarely
Symptoms of Oculogenital infections are…
swollen eyes purulent discharge (does not cause blindness)
Oculogenital infections also cause these conditions:
urethritis, cervicitis, bartholinitis, proctitis, salpingitis, epididymitis, acute urethral syndrome
Oculogenital infections are a major cause of ____ and contribute to rising rates of ____ and ___ ___
PID
infertility
ectopic pregnancies
Infants born to women infected with C. trachomatis may develop ___ or ___
inclusion conjunctivitis
pneumonia
____ is preferred anatomic site for screening women for C. trachomatis
Endocervix
Urethral C. trachomatis samples should not be collected until…
2 hours after the patient has voided
screening for c. trachomatis in homosexual men may include testing ___ or ____ specimens
rectal
pharyngeal
can urine be tested for c. trachomatis?
Yes- it’s what we do at aspirus
Mccoy, Hela, and monkey kidney cells are used to culture ____
C. trachomatis
how C. trachomatis culture is analyzed for growth
After 48-72 hours incubation, monolayers are stained with fluorescein-labeled monoclonal Ab and observed microscopically
This is how most C. trachomatis genital infections are detected:
Nucleic acid amplification
3 methods of C. trachomatis Nucleic acid amplification:
PCR
SDA (Strand displacement amp.)
TMA (Transcription-mediated amp.)
C. trachomatis PCR and SDA amplify…..
cryptic plasmid in chlamydial EB
C. trachomatis TMA amplifies…
23s RNA sequence
Why are C. trachomatis serological tests of limited use?
Most adults with chlamydial infection have had prior exposure- will be positive regardless
Direct detection methods for C. trachomatis
Cytologic exam (cell scrapings from conjunctiva, PAP smear)
Antigen detection (used conjugated monoclonal Abs to detect EB in smears)
Nucleic acid hybridization
Common drugs to treat C. trachomatis
Erythromycin (and other macrolides)
Tetracyclines
Fluoroquinolones
Ways to differentiate C. trachomatis from C. psittaci
C. psittaci is sulfa resistant
Morphology of EB and inclusion bodies differ
C. psittaci is pathogen of …..
all bird species
Reservoir for C. psittaci is…
Psittacine birds (parrots and parakeets)
C. psittaci incubation period
5-15 days
C. psittaci onset
insidious or abrupt
C. psittaci clinical findings
Diverse in symptoms and severity
headache, pneumonia, mental changes, hepatosplenomegaly
about 20% fatal
Testing for C. psittaci
Serologic for safety
C. psittaci drug of choice
tetracycline
C. psittaci prevention
treat infected birds or quarantine imported birds for a month
C. pneumoniae transmission
aerosolized droplets from respiratory tract
C. pneumoniae spectrum of disease
Associated with pneumonia, bronchitis, pharyngitis, sinusitis, flu-like illness
(5-10% of community-acquired pneumonia)
C. pneumoniae direct detection methods
NAAT to detect nucleic acid sequences in throat swabs, nasopharyngeal, BAL fluids, sputum
C. pneumoniae Cultivation specimen and detection method
swab of oropharynx
species-specific monoclonal Abs to detect in cell culture
Main test for C. pneumoniae serodiagnosis
Microimmunofluorescence using C. pneumoniae EB as antigen
Criteria for serodiagnosis of C. pneumoniae
4-fold rise in IgM or IgG
A single IgM titer of 16+ or IgG of 512+ is suggestive of recent infection
DOC for C. pneumoniae
Tetracycline, doxy, macrolides, fluoroquinolones, erythromycin
Prevention of C. pneumoniae
avoid aerosolized droplets from infected people
Rickettsia, Orentia, Anaplasma, Ehrlichia are fastidious bacteria that multiply only ____ and appear as small _____ ____ ____ bacilli
intracellularly
pleomorphic gram negative
Rickettsia, Orentia, Anaplasma, Ehrlichia transmission
insect vector or inhaling aerosols
3 groups of Rickettsia
Spotted fever
typhus
scrub typhus
Rickettsia is suspected when the triad of ___, ___, and ____ are the primary clinical manifestation in patients with _______
fever, headache, rash
exposure to an insect vector
What is HGA?
Human granulocytic anaplasmosis
A. phagocytophylum infects bone marrow cells, mainy PMNs
What is HME?
Human monocytic ehrlichiosis
E. chaffeensis infects monocytes
Ehrlichia infections present with…
nonspecific symptoms like fever, headache, myalgia
rarely rash
asymptomatic to severe
Rocky mountain spotted fever spread through…
bite of infected tick
Signs, symptoms, progression of Rocky Mountain Spotted Fever
fever, headache, rash
Can rapidly progress to severe and life-threatening illness
Rash is ____ in Rocky Mountain Spotted Fever and usually occurs ___ ___ after fever
common
2-4 days
Rocky Mountain Spotted Fever Drug of choice
Doxy
Murine Typhus is also known as:
Endemic Typhus
Flea-borne typhus
Transmission of Murine Typhus
contact with infected fleas
Main animal host for fleas causing Murine Typhus
Rats
Geographic region of Murine Typhus
Tropical and subtropical
Symptoms of Murine Typhus
body aches/muscle pain, fever, chills, loss of appetite, N/V, stomach pain, cough, rash
Murine Typhus DOC
Doxy
Endemic Typhus is AKA
Louse borne typhus
Transmission of Endemic Typhus
Contact with infected body lice
symptoms of Endemic Typhus
fever, chills, muscle aches, rash, cough, N/V, confusion
Brill-Zinsser disease
relapse of Endemic Typhus due to weak immune system
Endemic Typhus DOC
Doxy
Scrub Typhus AKA
Bush Typhus
Transmission of Scrub Typhus
bites of infected chiggers
symptoms of Scrub Typhus
Usually begin within 10 days of being bitten
fever, chills, headache, body aches, eschar, mental changes, rash, enlarged lymph nodes
People with severe Scrub Typhus may develop…
organ failure and bleeding
DOC for Scrub Typhus
Doxy
HME transmission
bite of infected Lone Star Tick
HME symptoms
muscle aches, fever, headache, fatigue within 1-2 weeks of bite
Rash, nausea, confusion, red eyes possible
Serious illness can become fatal if not treated correctly
HME DOC
Doxy
HGA transmission
Ixodes scapularis and I. pacificus
mainly nymphal and adult ticks
Symptoms of HGA
fever, headache, body aches, chills within 1 to 2 weeks of bite
HGA Tx
Doxy
Sennetsu fever vector
undetermined
Sennetsu fever symtoms
sudden high fever, headache, muscle aches within a few weeks of initial infection
Preferred specimen for Spotted fever group
biopsy of skin tissue from rash
Ways to directly detect Anaplasma/Ehrlichia
Peripheral blood or CSF sample
PCR
Giemsa or Wright stain (thick and thin smears)
Rickettsiae can be cultured in ______ and in ______
embryonated eggs
tissue culture
Rickettsiae specimen for culture
blood or punch biopsy
Main tool for diagnosing ehrlichiosis and rickettsia
serodiagnosis
EIA, IFA, Western Blot
Ways to diagnose Rocky mountain spotted fever
IFA and DFA
except latex agglutination
DOC for rickettsia, anaplasma and ehrlichia
Tetracyclines, especially doxy
Cause of Mediterranean and Israeli spotted fevers
R. conorii
Cause of Indian and Kenya tick typhys
R. conorii
Vector for R. conorii
ticks
Distribution of R. conorii
Southeastern Europe, Middle East, Africa
Cause of Rocky Mountain Spotted fever
R. rickettsii
Vector for R. rickettsii
Dermacentor spp. tick
Distribution of R. rickettsii
North and south america
Cause of Endemic typhus
R. prowazekii
Vector for Endemic typhus
lice
distribution of R. prowazekii
worldwide
Cause of Brill-Zinsser disease
R. prowazekii (recrudescent disease)
Cause of Murine typhus
R. typhi
Vector for Murine typhus
fleas
distribution of R. typhii
worldwide
Cause of scrub typhus
O. tsutsugamushi
vector for scrub typhus
chiggers
distribution of O. tsutsugamushi
worldwide
Cause of HME
E. chaffeensis
vector for HME
Amblyomma americanum- Lone Star Tick
Distribution of E. chaffeensis
Southeast, South Central and mid-Atlantic US
E. ewingii vector
Amblyomma americanum- Lone Star Tick
Distribution of E. ewingii
US (Overlapping with E. chaffeensis)
Cause of HGA
Anaplasma
vector for Anaplasma
Ixodes spp. ticks
distribution of Anaplasma
US and Europe
Cause of Sennetsu fever
Neorickettsia sennetsu
vector for Sennetsu fever
ticks
distribution of Neorickettsia sennetsu
Southease Asia (Japan)