03 - Special Culture or Exam Required - Microbes 31 through 36 Flashcards
Name all of the Microbe Genera that require a special culture or exam?
Also think of the special exam or culture
Some have been described in further detail earlier…
Mycobacterium (Acid-fas stain, PCR, special culture)
Chlamydia (ELISA, PCR)
Mycoplasma (ELISA / EIA or special culture)
Legionella (immunodiagnostic)
Rickettsia (immunodiagnostic)
Coxiella (ELISA, PCR)
Borrelia
Treponema (immunodiagnostics, IF immu-fluoroescence microscopy (DARKFIELD)) (NOT COVERED IN MICROBES PDF)
Leptospira (NOT COVERED IN MICROBES PDF)
Trichomonoas (protozoa, wet prep, microscopy) **(NOT COVERED IN MICROBES PDF)
a. Very small, unusual, atypical gram-negative bacteria (not realistic to observe via Gram stain); obligate intracellular
b. Obligate intracellular parasite
(1) Elementary Bodies (EB) – infectious form; metabolically inactive; moderately resistant to harsh environment; convert into RB
(2) Reticulate Bodies (RB) – noninfectious; metabolically active;
Chlamydia trachomatis
c. Cell structures
(1) Lipopolysaccharide – only weak endotoxin activity
(2) Major Outer Membrane Protein (MOMP) – the important structural component of cell wall
d. Reproduction:
(1) EB enters host cell
(2) EB converts to RB (inclusions)
(3) RB replicates bacterial cells and produce EB
Chlamydia trachomatis
Leading cause of STD’s
Chlamydia trachomatis
STD - leading cause (50% of cases) – may be referred to as “non-gonococcal urethritis”
Chlamydia trachomatis
“non-gonococcal urethritis”
Chlamydia trachomatis
(1) Sexually Transmitted Disease
(2) Trachoma - Inclusion conjunctivitis disease – a leading cause of blindness
(3) Lymphogranuloma venereum – involvement of inguinal lymph nodes
Chlamydia trachomatis
Trachoma - Inclusion conjunctivitis disease – a leading cause of blindness
Chlamydia trachomatis
Typical treatment of Chlamydia trachomatis
(e.g. doxycycline, tetracycline, or erythromycin) intended to cover gonorrhea also
Lab Dx of Chlamydia trachomatis
Laboratory diagnosis (1) Obligate intracellular parasite -- requires a living host cell for culture
(2) Clinical diagnosis may be based on the failure to demonstrate Neisseria gonorrhoeae by smear or culture
(3) Special culture materials required – collection kit includes cell culture vial
(4) Identify by using nucleic acid probe or ELISA
a. Agent of pneumonias, bronchitis, sinusitis – usually asymptomatic or mild with persistent cough
b. Probable agent of atherosclerosis – inflammation of endothelium of blood vessels which then leads to plaque buildup
Chlamydia pneumoniae
a. Atypical bacterium – no cell wall, small, poorly staining
b. Etiological agent of “primary atypical pneumonia” (walking pneumonia)
Mycoplasma pneumoniae
walking pneumonia
Mycoplasma pneumoniae
(1) Symptoms (after 1-3 weeks incubation): headache, malaise, cough (often paroxysmal), and less often chest discomfort
(2) Sputum production may be scant; infiltration of lungs may be more extensive than clinical findings suggest
(3) Pneumonia may progress from one lobe to another and may be bilateral (“walking pneumonia”)
(4) Duration of illness: often more than a month
(5) Epidemiology – occurs primarily in school age children and young adults, especially military (up to 50/1,000/year)
(6) Treatment: Erythromycin or tetracycline
Etiological agent of “primary atypical pneumonia” (walking pneumonia) WHICH IS
Mycoplasma pneumoniae
Pneumonia may progress from one lobe to another and may be bilateral
walking pneumonia found in Mycoplasma pneumoniae
Laboratory diagnosis – Requires special request and special culture media and complex tests – procedures are generally not available except in the most sophisticated of labs
For this type of pnemonia Lab Dx described above
Mycoplasma pneumoniae
a. “Atypical” bacteria – small, coccobacilli, obligate intracellular parasites
b. Various species cause spotted fever or typhus
(1) Spotted Fever
(a) Rocky Mountain Spotted Fever – Tick (R. rickettsii)
(2) Typhus
(a) Epidemic typhus (classical typhus fever) – Louse (R. prowazekii)
(b) Murine typhus – Flea (R. typhi)
(c) Scrub typhus – Mite (Orientia tsutsugamushi)
Rickettsia and Orientia species
when you hear TICK think….
Rickettsia and Orientia species
Spotted Fever &/or Typhus think…
Rickettsia and Orientia species
Rocky Mountain Spotted Fever – Tick
(R. rickettsii)
Epidemic typhus (classical typhus fever) – Louse
(R. prowazekii)
Murine typhus – Flea
(R. typhi)
Scrub typhus – Mite
(Orientia tsutsugamushi)
what are generally effective antimicrobics for
Tetracyclines and chloramphenicol
