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Questions and Answers
What is the primary motility mechanism of spirochetes?
What is the primary motility mechanism of spirochetes?
- Periplasmic flagella (correct)
- Cilia
- Flagella
- Pseudopodia
Which of the following Treponema subspecies is responsible for syphilis?
Which of the following Treponema subspecies is responsible for syphilis?
- T.pallidum ssp.pallidum (correct)
- T.carateum
- T.pallidum ssp.pertenue
- T.pallidum ssp.bejel endemicum
Which method is NOT effective for directly observing Treponema under a microscope?
Which method is NOT effective for directly observing Treponema under a microscope?
- Fluorescent microscopy
- Darkfield microscopy
- Light microscopy with Giemsa stain (correct)
- Light microscopy with Gram stain (correct)
What is a primary virulence factor of T.pallidum that aids in its disease-causing ability?
What is a primary virulence factor of T.pallidum that aids in its disease-causing ability?
What is the role of hyaluronidase in the virulence of T.pallidum?
What is the role of hyaluronidase in the virulence of T.pallidum?
What is the correct characteristic of Leptospira interrogans?
What is the correct characteristic of Leptospira interrogans?
Which treatment is appropriate for Lyme disease?
Which treatment is appropriate for Lyme disease?
What mainly contributes to tissue destruction and lesions in leptospirosis?
What mainly contributes to tissue destruction and lesions in leptospirosis?
Which of the following is a transmission method for leptospirosis?
Which of the following is a transmission method for leptospirosis?
What percentage of patients with neurological or cardiac involvement may progress to the subsequent stage of Lyme disease?
What percentage of patients with neurological or cardiac involvement may progress to the subsequent stage of Lyme disease?
Which of the following symptoms is NOT typically associated with atypical (walking) pneumonia?
Which of the following symptoms is NOT typically associated with atypical (walking) pneumonia?
What is the primary reason cell wall synthesis inhibitors cannot be used to treat M. pneumoniae infections?
What is the primary reason cell wall synthesis inhibitors cannot be used to treat M. pneumoniae infections?
Which of the following is a secondary complication that can arise from M. pneumoniae infection?
Which of the following is a secondary complication that can arise from M. pneumoniae infection?
Which organism is known to cause postpartum fever and is resistant to erythromycin and tetracycline?
Which organism is known to cause postpartum fever and is resistant to erythromycin and tetracycline?
What preventive measure is recommended to reduce the risk of M. pneumoniae infection?
What preventive measure is recommended to reduce the risk of M. pneumoniae infection?
What is the primary cause of congenital syphilis?
What is the primary cause of congenital syphilis?
Which treatment protocol is recommended for early-stage syphilis?
Which treatment protocol is recommended for early-stage syphilis?
What is Bejel primarily caused by?
What is Bejel primarily caused by?
What is a common late-stage symptom of congenital syphilis?
What is a common late-stage symptom of congenital syphilis?
Pinta is primarily associated with which type of symptoms?
Pinta is primarily associated with which type of symptoms?
Which method is NOT recommended for the prevention of syphilis?
Which method is NOT recommended for the prevention of syphilis?
Which type of syphilis is transmitted through contaminated eating utensils?
Which type of syphilis is transmitted through contaminated eating utensils?
What is a primary characteristic of icteric leptospirosis?
What is a primary characteristic of icteric leptospirosis?
What organ is primarily affected in icteric leptospirosis leading to jaundice?
What organ is primarily affected in icteric leptospirosis leading to jaundice?
What type of lesions are associated with Treponema pallidum subsp. pertenue in its early stages?
What type of lesions are associated with Treponema pallidum subsp. pertenue in its early stages?
Which of the following antibiotics is not effective against Mycoplasmataceae due to their lack of a cell wall?
Which of the following antibiotics is not effective against Mycoplasmataceae due to their lack of a cell wall?
What is the typical incubation period for icteric leptospirosis?
What is the typical incubation period for icteric leptospirosis?
Which species of Mycoplasma is strictly aerobic?
Which species of Mycoplasma is strictly aerobic?
What is the primary method through which leptospires infect the body?
What is the primary method through which leptospires infect the body?
What type of colonies are characteristic of Mycoplasma species?
What type of colonies are characteristic of Mycoplasma species?
Which of the following treatments is effective for icteric leptospirosis?
Which of the following treatments is effective for icteric leptospirosis?
What primarily contributes to the disease caused by gram-negative spirochetes?
What primarily contributes to the disease caused by gram-negative spirochetes?
Which organism is responsible for epidemic relapsing fever?
Which organism is responsible for epidemic relapsing fever?
What is a characteristic feature of Lyme disease?
What is a characteristic feature of Lyme disease?
How is epidemic relapsing fever primarily transmitted?
How is epidemic relapsing fever primarily transmitted?
Which vectors are responsible for tick-borne borreliosis?
Which vectors are responsible for tick-borne borreliosis?
What is the typical incubation period for an acute infection of relapsing fever?
What is the typical incubation period for an acute infection of relapsing fever?
What is a common reservoir for Lyme borreliosis?
What is a common reservoir for Lyme borreliosis?
Which of the following is NOT associated with relapsing fever?
Which of the following is NOT associated with relapsing fever?
Flashcards
Spirochete
Spirochete
A type of bacteria that is spiral-shaped and has a thin, flexible structure.
Treponema
Treponema
Treponema are a type of bacteria in the Spirochaetales order causing various diseases such as syphilis, yaws, and pinta.
How do Spirochetes move?
How do Spirochetes move?
They use specialized structures called periplasmic flagella, also known as axial fibrils or endoflagella, to move.
Treponema pallidum subspecies
Treponema pallidum subspecies
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Why is it difficult to grow Treponema?
Why is it difficult to grow Treponema?
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Leptospirosis
Leptospirosis
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Leptospira interrogans
Leptospira interrogans
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Leptospira virulence factors
Leptospira virulence factors
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Epidemiology of Leptospirosis
Epidemiology of Leptospirosis
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Anicteric Leptospirosis
Anicteric Leptospirosis
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Mycoplasma pneumoniae Infection
Mycoplasma pneumoniae Infection
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Symptoms of M. pneumoniae
Symptoms of M. pneumoniae
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M. pneumoniae Treatment
M. pneumoniae Treatment
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Complications of M. pneumoniae
Complications of M. pneumoniae
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Preventing M. pneumoniae Spread
Preventing M. pneumoniae Spread
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Relapsing Fever - Pathogenesis
Relapsing Fever - Pathogenesis
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Lyme Disease - Stages
Lyme Disease - Stages
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Relapsing fever - Cause
Relapsing fever - Cause
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Lyme Disease - Discovery and Transmission
Lyme Disease - Discovery and Transmission
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Relapsing Fever - Epidemiology
Relapsing Fever - Epidemiology
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Lyme Disease - Reservoirs
Lyme Disease - Reservoirs
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Relapsing Fever - Louse-borne Transmission
Relapsing Fever - Louse-borne Transmission
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Relapsing Fever - Tick-borne Transmission
Relapsing Fever - Tick-borne Transmission
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What is Icteric Leptospirosis?
What is Icteric Leptospirosis?
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What is Leptospiremia?
What is Leptospiremia?
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How are Leptospires spread?
How are Leptospires spread?
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Describe Mycoplasmas.
Describe Mycoplasmas.
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What are Mycoplasmataceae?
What are Mycoplasmataceae?
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What is unique about Ureaplasma spp.?
What is unique about Ureaplasma spp.?
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What is M. pneumoniae?
What is M. pneumoniae?
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What is the role of the P1 pili in M.pneumoniae?
What is the role of the P1 pili in M.pneumoniae?
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What is syphilis?
What is syphilis?
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What is congenital syphilis?
What is congenital syphilis?
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How is syphilis treated?
How is syphilis treated?
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What is Bejel?
What is Bejel?
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What is Yaws?
What is Yaws?
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What is Pinta?
What is Pinta?
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What is Lyme Disease?
What is Lyme Disease?
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What are Borrelia bacteria known for?
What are Borrelia bacteria known for?
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Study Notes
Spirochaetales
- Gram-negative spirochetes
- Spirochete comes from Greek for "coiled hair"
- Extremely thin and can be very long
- Motile by periplasmic flagella (axial fibrils or endoflagella)
Taxonomy
- Order: Spirochaetales
- Family: Spirochaetaceae
- Genus: Treponema, Borrelia
- Family: Leptospiraceae
- Genus: Leptospira
Treponema
- Too thin to be seen with light microscopy in specimens stained with Gram or Giemsa stain
- Motile spirochetes can be seen with darkfield microscopy
- Staining with anti-treponemal antibodies labeled with fluorescent dyes
- Intracellular pathogen
- Three periplasmic flagella at each end
- Does not survive well outside of host and cannot be grown in cell-free cultures in vitro
Treponema and Human Disease
Microorganism | Disease |
---|---|
T. pallidum ssp. pallidum | Syphilis |
T. pallidum ssp. endemicum | Bejel |
T. pallidum ssp. pertenue | Yaws |
T. carateum | Pinta |
Virulence Factors of T. pallidum
- Outer membrane proteins promote adherence
- Hyaluronidase may facilitate perivascular infiltration
- Antiphagocytic coating of fibronectin
- Tissue destruction and lesions are primarily a consequence of the host's immune response
T. pallidum (Syphilis)
- Transmitted through direct sexual contact or from mother to fetus
- Not highly contagious (~30% chance of acquiring the disease after single exposure to infected partner)
- Transmission rate is dependent on the stage of the disease
- Long incubation period, where the host is non-infectious
Syphilis
- Tissue destruction and lesions are primarily a consequence of the patient's immune response
- Syphilis is a disease of blood vessels and the perivascular areas
- Despite the host immune response, organisms can persist for decades
- In early stages, there is inhibition of cell-mediated immunity
- Inhibition of CMI reduces in late stages, hence late lesions tend to be localized
Primary Syphilis
- The primary disease process involves invasion of mucous membranes, rapid multiplication, and wide dissemination through perivascular lymphatic and systemic circulation.
- Occurs prior to development of the primary lesion.
- Usually 3-4 weeks after initial contact, the host mounts an inflammatory response at the site of inoculation, forming a chancre (usually painless).
- Chancre develops into a hardened ulcer with profuse shedding of spirochetes.
- Swelling of capillary walls and regional lymph nodes occurs.
- Lesion heals spontaneously via fibrotic walling-off within two months.
Secondary Syphilis
- Secondary disease occurs 2–10 weeks after the primary lesion.
- Characterized by a widely disseminated mucocutaneous rash
- Secondary lesions of skin and mucous membranes are highly contagious.
- A generalized immunological response follows.
Latent Stage Syphilis
- Following secondary disease, the host enters a latent period
- First 4 years = early latent
- Subsequent period = late latent
- About 40% of late latent patients progress to late tertiary syphilitic disease
Tertiary Syphilis
- Tertiary syphilis is characterized by localized granulomatous dermal lesions (gummas), with few organisms present
- Granulomas reflect containment by the host's immunologic reaction to chronic infection
- Late neurosyphilis develops typically more than 5 years after initial infection.
- Central nervous system and spinal cord involvement can manifest as dementia, seizures, wasting, etc.
- Cardiovascular involvement appears 10-40 years after initial infection, resulting in myocardial insufficiency and death.
Famous People Affected by Syphilis
- Friedrich Nietzsche
- Schubert
- Goya
- Van Gogh
- Peter I and Catherine of Russia
- Al Capone
- Mussolini
Congenital Syphilis
- Congenital syphilis results from transplacental infection.
- T. pallidum septicemia occurs in the developing fetus.
- Widespread dissemination frequently leads to
- Abortion, neonatal mortality, and late mental or physical problems following scarring.
Prevention and Treatment of Syphilis
- Penicillin remains the drug of choice.
- WHO monitors treatment recommendations
- 7-10 days continuously for early stage
- At least 21 days continuously beyond the early stage
- Prevention with barrier methods
- Prophylactic treatment of contacts identified through epidemiological tracing
Treponema pallidum subsp. endemicum
- Causes bejel (endemic syphilis)
- Initial lesions: oral
- Secondary lesions: oral papules and mucosal patches
- Late lesions: gummas of skin, bones, and nasopharynx
- Transmitted person-to-person through contaminated eating utensils.
- Primitive tropical/subtropical areas (Africa, Asia, and Australia).
Treponema pallidum subsp. pertenue
- Causes yaws
- Early: skin lesions
- Late: destructive lesions of skin, lymph nodes, and bones (painless nodules)
- Widely distributed over the body with abundant contagious spirochetes.
- Transmitted by direct contact with lesions containing abundant spirochetes.
- Primitive tropical areas (South America, Central Africa, Southeast Asia)
Treponema carateum
- Causes pinta
- Primarily restricted to skin
- 1-3 week incubation period
- Initial lesions: small pruritic papules
- Secondary: enlarged plaques persist for months to years
- Late: disseminated, recurrent hypopigmentation or depigmentation of skin lesions
- Scarring and disfigurement frequently occur.
- Transmitted through direct contact with skin lesions
- Primitive tropical areas (Mexico, Central and South America)
Borrelia spp.
- Gram-negative spirochetes
- Giemsa stain of blood or phase contrast microscopy can be used
- Antigenic shift and immune reactions are responsible for the disease.
Borrelia and Human Disease
Microorganism | Reservoir | Vector | Disease |
---|---|---|---|
B. recurrentis | Humans | Body lice | Relapsing fever |
B. spp. | Rodents, ticks | Soft-shelled ticks | Relapsing fever |
B. burgdorferi | Rodents, ticks | Hard-shelled tick | Lyme disease |
other animals |
Relapsing Fever
- Associated with poverty, crowding, and warfare
- Arthropod vectors
- Louse-borne borreliosis = Epidemic Relapsing Fever
- Transmitted person-to-person by human body lice (vectors)
- Infects host when louse is injured
- Lice leave the host and seek a new normal-temperature host
- Tick-borne borreliosis = Endemic Relapsing Fever
- Sporadic cases
- Transmitted by soft-body ticks
- Small mammals are the reservoir
- Ticks can multiply and infect new human hosts
- Pathogenesis of relapsing fever includes acute infection (2-14 days incubation), recurring febrile episodes, and constant and worsening spirochaetemia during febrile stages.
Epidemiology of Lyme Borreliosis
- Lyme disease was recognized in 1975 in Lyme, Connecticut.
- Associated to Borrelia burgdorferi.
- Transmitted by hard-body ticks (Ixodes spp.).
- Common reservoirs include white-footed deer mice, other rodents, deer, domesticated pets, and hard-shelled ticks.
Lyme Disease
- Characterized by 3 stages:
- Unique skin lesion (erythema migrans, or bullseye rash) with general malaise. EM not seen in all infected hosts
- Lesions periodically reoccur
- Subsequent stage: seen in 5-15% of patients, with neurological or cardiac involvement.
- Third stage: migrating episodes of non-destructive, but painful arthritis.
Leptospira
- Gram-negative spirochete
- Characteristic hooked ends, like a question mark
- Two periplasmic flagella
Leptospira interrogans
- Tissue destruction and lesions are primarily a consequence of host's immune response
Virulence Factors
- Able to directly invade and replicate in tissues, inducing inflammatory response
Epidemiology of Leptospirosis
- Mainly a zoonotic disease
- Transmitted to humans from a variety of wild and domesticated animals (rats, dogs, farm and wild animals).
- Transmitted through breaks in the skin or intact mucus membranes.
- Indirect contact (soil, water, feed) with infected urine from an animal with leptospiruria.
- Occupational disease of animal handling
Clinical Disease: Leptospirosis
1. Mild virus-like syndrome 2. Anicteric leptospirosis: systemic with aseptic meningitis 3. Icteric leptospirosis or Weil's disease: overwhelming disease with vascular collapse, thrombocytopenia, hemorrhage, hepatic, and renal dysfunction
- Icteric refers to jaundice (yellowing of skin and mucus membranes) and liver involvement
Pathogenesis of Icteric Leptospirosis
- Direct invasion and replication in tissues
- Characterized by an acute febrile jaundice and glomerulonephritis
- Incubation period usually 10-12 days.
- Leptospiremia develops rapidly after infection
- Infects the kidneys, organisms shed in the urine (leptospiruria) and renal failure, or death.
- Hepatic injury and meningeal irritation are common.
Treatment
- Treatment: penicillin or doxycycline
- Control of reservoirs and vaccination of animals
Mycoplasma
- Smallest (0.1-0.3 µm) bacteria
- Grow slowly and require sterols and glucose
- Ureaplasma spp. require urea
- Facultative anaerobes (except M. pneumoniae, which is strict aerobe)
- Lack a cell wall
- Resistant to penicillin, cephalosporins, vancomycin, but sensitive to tetracycline, erythromycin
- Small, fried-egg-like colonies (except M. pneumoniae)
Mycoplasmataceae and Human Disease
Microorganism | Human Disease |
---|---|
Mycoplasma genitalium | Non-gonococcal urethritis, pelvic inflammatory disease |
Mycoplasma hominis | Pelvic inflammatory disease, postpartum fever, systemic infections (in immunocompromised) |
Ureaplasma urealyticum | Non-gonococcal urethritis, pyelonephritis, spontaneous abortion, premature birth |
M. pneumoniae
- Mostly asymptomatic carriage
- Acute pharyngitis: low-grade fever, malaise, headache, dry/non-productive cough
- Tracheobronchitis with lymphocyte and plasma cell infiltration
- Atypical (walking) pneumonia
- Secondary complications: hemolytic anemia, arthritis, myocarditis, pericarditis, neurological abnormalities (meningooencephalitis).
Atypical (walking) Pneumonia
- Chronic onset and recovery
- Flu-like symptoms (generalized aches, discomfort, headache, chills, low-grade fever)
- Persistent non-productive cough
(Typical bacterial pneumonia)
- Abrupt, rigorous onset
- Productive cough, purulent sputum
- High fever, chest pain, stiffness in the neck
Treatment and Prevention M. pneumoniae
- Treatment: Tetracycline or erythromycin or newer fluoroquinolones
- Cannot use cell wall synthesis inhibitors
- Prevention: Avoid close contact, no vaccine
Other Mycoplasmataceae
- List of additional Mycoplasmataceae species and the associated human diseases (can vary by species)
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Description
Test your knowledge on the microbiology of spirochetes and leptospira, focusing on their motility mechanisms, virulence factors, and treatment options. This quiz covers key aspects of Treponema and Leptospira, including their diseases, characteristics, and transmission methods.