Spirochaetales Flashcards
Spirochaetales
Morphology
Culture
Spiral shaped very long and thin 0.1-0.2 uM by 10-30 uM long
can’t be seen by light microscopy, so it is non-staining
Must use darkfield illumination, immunofluoresence, or silver-impregnation
Live spirochaetales can be seen rotating and bending by dark feild microscopy, using their endoflagellae.
reproduce by transverse binary fission.
Cultivation:
can’t grow in cell-free media
needs rabbit epithelial cells or to be cultured in live rabbit testis.
Spirochaetalis species
what are they?
clinical diseases?
There are 2 families of the order Spirochaetales:
Spirochetaceae, and Leptospiraceae,
Spirochetaceae
Treponema
-Treponema pallidum pallidum - syphilis
-Treponema pallidum endemicum - bejel
-Treponema pallidum pertenue - Yaws
-Treponema carateum - Pinta
Borrelia
-Borrelia burgdoferi - Lymes disease, borreliosis
-Borrelia recurrentis - Epidemic relapsing fever
-Many other borrelia species - Endemic relapsing fever
Leptospiraceae
-Leptospira interrogans - Leptospirosis, Weil’s Disease
Treponema
Habitat
transmission
Humans are the only host
Transmitted by direct contact or sexual contact.
Treponema pallidum pallidum
Clinical disease in adults
Treatment
Causes Syphilis, which has 3 phases.
Primary phase, 10 days - 3 months after exposure
Hard Chancre Sores (ulcus durum) form on the infection site: Genitals, and rarely in the oral or peri-anal regions.
Bacteria replicates locally within the sores.
spontaneous recovery occurs in 2-6 weeks 50% of cases
Secondary phase, 2-24 weeks after primary infection develops
Bacteria disseminates disease becomes disseminated rash anywhere on the skin or mucous membranes. mucionous sores in mouth vagina, anus, and condylomata lata (warts) in the armpits, thighs, aka the intertrigenous areas.
All lesions are highly infectious
Spontaneous remission usually occurs and so may spontaneous relapse of symptoms. Patient is still always infected and disease is progressing towards late phase.
Late phase, 3-30 years
all tissues are involved
Granulomatous lesions in bones, vessels, skin
Neurosyphillis: ataxia, progressive paralysis, dementia, incontenence, Tabes dorsalis (demyelination of the dorsal spinal tracts)
Cardiovascular syphillis: Aortitis, Aortic aneurysm.
All stages of the disease can be eradicated by Penicillin. BUT it also causes a huge death of the bacteria and thus high antigen release, so FEVER must be controlled by Steroid anti-inflammatories
Spirochaetalis Treponema pallidum pallidum
Clinical disease in neonates
Prevention
Congenital syphilis, transplacental infection
~50% are stillborn or aborted
Early congenital syphilis:
Mucocutaneous lesions, osteochondritis (cracks in the cartilaginous lining of joints and inflammation), anemia, hepatosplenomegaly
Late congenital syphilis:
Hutchinson’s triat: Cornea inflammation and blindness, Tooth deformation, and CN8 nerve deafness, vestibulocochlear.
Neurosyphilis
Rhagades
Cardiovascular lesions
Cluttons joints
Bone deformations of the legs, nasal cavity, and palate.
Prevention: Treat mother with Penicillin while she is pregnant
Trepanoma pallidum pallidum
Diagnosis
Exuadates from the skin lesions: Dark field microscopy, IF-antibody labeling, Silver impregnation
Serology:
Non-specific treponemal serology tests: circulating antibodies (produced during treponema infection, but also produced in some other conditions).
VDRL (Venereal Disease Research Laboratory)
RPR (Rapid Plasma Reagin)
Cardiolipin conjugated to latex beads is used as the antigen to detect these circulating antibodies against a dilution of patients sera.
Wasserman reaction, complement fixation test: Patient serum dilutions mixed with cardiolipin, then mixed with complement, then mixed with sheep RBCs, then mixed with antibodies against sheep RBCs. If there are antibodies against cardiolipin in patients sera the complement will be sequestered and won’t lyse the sheep RBCs.
Specific treponemal serology tests:
FTA-ABS: Fluorescent Treponemal Antibody-absorption. Lab grown and killed Treponema are fixed onto a slide, then mixed with patients serum, then probed with anti-human IgG and IgM fluroscent secondary ABs.
TPI: Treponema pallidum immobilisation test. Live lab grown Treponema are mixed with heat inactivated serum from the patient, and mixed with complement system protein from guinea pigs. If patients sera contains antibodies against the treponema, it will become immobilized by the Abs and complement. this is the most specific test.
Specific Treponema tests:
TPHA: T. Pallidum HAemagglutination test: bird RBCs coated with Treponema antigens mixed with dilution range of patients sera, will agglutinate if positive
TPPA: Same, but with gelatin particles instead of RBCs.
TP-ELISA: Recombinant antigens probed with patient sera
Western blot: probing a specific sample of just a few specific Treponema recombinant proteins with patients sera.
Nonvenereal Treponemal diseases
What are they and what bacteria causes them?
Diagnosis?
called Treponematosis
Treponema pallidum endemicum:
causes Bejel. -Endemic syphilis. Oral and skin lesions spread between people by contaminated eating utensils.
Treponema pallidum pertenue:
causes Yaws. -large granulomatous skin lesions, spread by contact
Treponema carateum:
causes Pinta. - skin lesions, spread by contact
Treponema vincentii:
is found in the oral cavity. In conjunction with Fusobacterium, it causes Fusospirochaetal infections and Vincent’s Angina, an ulcerative necrosis of the tonsils.
Diagnosed by the non-specific Treponema tests. VDLR, RPR
Borrelia species
What are they and what diseases?
What is their reservoir and how are they transmitted?
Borrelia recurentis:
Epidemic Relapsing fever. Fever is relapsing because the bacteria undergoes antigenic variation resulting in waves of bacterail growth and lysis by the immune system, followed by the change and then time lag while the immune system adapts to the new antigen.
Human reservoir, spread by lice (thus spread endemically).
Borrelia burgdorferi:
Lyme disease.
Deer and rodents are the reservoir. Spread by ticks.
Borrelia other species:
Endemic relapsing fever.
Borrelia genus
Morphology
Culture
Spirochete. 4-18uM long (shorter than Treponema)
Up to 20 periplasmic flagella originate at each pole and connect at the center, but are extracellular (not endoflagellated)
Giemsa staining - stains DNA phosphates.
or indirect immunofluoresence staining
Culture:
Microaerophilic, slow growing, requires complex nutrient mix. Difficult to culture successfully.
Borellia Burgdorferi
Clinical disease
Diagnosis
Treatment
Lyme disease
1) Localized Erythema Chronicum Migrans red bullseye skin rash around the bite, dissapears in a few weeks.
2) Early disseminated stage
Headache, fever
Joint and muscle pain
Heart failure due to Transduction blocks and myopericarditis
Meningitis, encephalitis
3) late manifestation
Acrodermatitis Chronica Atrophicans: Blue/Purple inflammation, fibrous deposition in the hands or feet.
Arthritis, knee and elbow swelling.
Cutaneous lymphoid hyperplasia: a benign accumulation of lympocytes, macrophages, and dendritic cells in a lymphadoma in the superficial skin.
Diagnosis:
Giemsa stain of the mucocutaneous lesions,
PCR amplification of burgdorfri DNA from lesions
mostly by Serology: Immunofluorescence assay, ELISA, or Western blot of serum against recombinant bacterial protein sample.
Treatment:
Early stage: Penicillin, Tetracylcine (polyketide class)
Late stage: High dose IV penicillin or Ceftriaxone.
Leptospira genus
Morphology
Culture
Thin, coiled spirochete, 20uM. Distinctively, both ends are hooked.
have Periplasmic flagella, located within the Periplasm in between their inner and outer cell membranes
Culture:
Korthof Liquid Culture: growth forms smoke like culture. Media contains 10% rabbit serum, slow growing, will grow at 30C.
Leptospira
Which species is pathogenic to humans?
What is the clinical disease?
Leptospira interrogans species causes Leptospirosis
It causes an asymptomatic infection of many animal renal systems. A zoonotic infection from contacted infected animal urine in animal workers.
Different subspecies with specific serovariants exist in different animals.
Biphasic disease
1) Acute phase: Flu like syptoms, fever and muscle pain.
2) Immune Leptospiruric Phase: Sudden onset myalgia, headache, abdominal pain, and conjunctivitis and conjuncival bleeding
Vascular collapse, Thrombocytopenia
Renal failure
Hepatic failure
Aseptic meningitis (non-pus forming meningitis)
Weil’s disease, aka Icteric leptospirosis - (icteric = jaundice) the severe form of leptospirosis with about 15-20% fatalitiy due to progressive hepatic and renal failure.
Leptospira
Diagnosis
Treatment
Prevention
Diagnosis
Silver impregnation, direct IF stain, culture in Korthof culture media.
Microscopic Agglutination Test, viewed by Dark Field microscopy: patients sera dilutions mixed with a live lab grown sample of Leptospira and observed for agglutination.
ELISA of patients sera on recombinant leptospira antigens.
Treatment:
Doxycycline.
Prevention
Prophylactic Doxycycline.
