TOPIC 23: SPIROCHETE AND SPIRILLUM

Spirochete and spirillum

• Long, slender, helically curved, gram-negative bacilli

• Axial filaments (axial fibrils/endo flagella) facilitate the motility of the organisms

• Motility is by rapid rotation around its long axis, like a drill

Treponema, borrelia, Leptospira

Pathogenic spirochete

6-10

Treponema axial filaments

30-40

Borrelia axial filaments

2

Leptospira axial filaments

1

Treponema insertion disks

2

Borrelia insertion disks

3-5

Leptospira insertion disks

Genus Treponema

tightly coiled with a corkscrew appearance

Genus Leptospira

less tightly coiled with sharp hook-like bends at the end of the cell

Genus Borrelia

much less tightly coiled forms which have the appearance of an extremely long undulating bacillary form

Treponoma pallidum subsp. pallidum

• Sexual contact or congenital

• Worldwide

• Venereal syphilis

• Group All ages

Treponoma pallidum subsp. pertenue

• Traumatized skin comes in contact with an infected lesion (person-to-person contact)

• Humid. Warm climates: Africa, South and Central America, Pacific Islands

• Yaws

• Skin-papules, nodules, ulcers Primary lesions (mother yaw), disseminated lesions (frambesia)

• Children

Treponoma pallidum subsp. endemicum

• Mouth-to-mouth by utensils (person-to-person contact)

• Arid, warm climates: North Africa, Southeast Asia, Middle East

• Endemic (Nonvenereal syphilis)

• Skin/mucous membrane patches, papules, macules, ulcers, scars; May progress to disseminated oropharyngeal with generalized lymphadenopathy; May demonstrate a latent stage, and late syphilis destructive to skin, bone, and cartilage

• Children or adults; rarely congenital

Treponoma carateum

• Traumatized skin comes in contact with an infected lesion (person-to-person contact)

• Semiarid, warm climates: Central and South America, Mexico

• Pinta

• Skin papules, macules, and Hyperkeratotic pigments may lead to disseminated skin lesions and lymphadenopathy; a late stage may result in pigmentary changes in the skin (hyper- or hyperpigmentation)

• All ages but primarily children and adolescents

Venereal syphilis

contracted during sexual intercourse

Treponema pallidum subsp. pallidum

When we say “Treponema pallidum” without any subspecies after, we are referring to

Primary Syphilis

• First clinical sign of syphilis: hard chancre (a painless ulcer) which develops at the site of inoculation

• Extremely infectious because the lesion contains a large number of organisms

• Bubo formation – appears 1 week after the appearance of hard chancre

• 10% of patients may have extragenital lesions – face, lips, tongue, tonsils, breast, fingers

• Dissemination of the organism occurs during this primary stage. Once the organism has reached a sufficient number, usually within 2-24 weeks then the clinical manifestation of secondary syphilis becomes apparent

Secondary Syphilis

• 2 to 10 weeks after primary syphilis

• Fever, weight loss, malaise, loss of appetite, sore throat, headache (influenza-like symptoms)

• Skin is the organ most commonly – rash on the face, scalp, palms of hands, and soles of the feet

• Condylomata lata – white mucous patches around moist areas like the anus and vagina (if the patient has this clinical manifestation it is most likely to be syphilis)

• Highly infectious state

• This is the time when the patient usually seeks medical attention because in the 1st stage, it is only a painless ulcer

Latent Stage

• Disease becomes asymptomatic but not necessarily inactive

• If you do not receive treatment, you can continue to have syphilis in your body for years without any signs or symptoms

Tertiary syphilis

• Appears 3-25 years after the initial infection in up to 35% of untreated px

• Gumma formation (definitive characteristic) – granuloma-like lesions that are soft, painless, and noninfectious and found on the skin or in the bones or visceral organs

• Central nervous system disease (neurosyphilis), cardiovascular abnormalities, eye disease

Bulldog

Appearance of a deformed maxilla due to mother not seeking treatment or being tested

Saber shin

Bowing of the tibia

Hutchinson’s triad

Deafness, blindness, notched and peg-shaped teeth

Borrelia recurrentis and Borrelia burgdorferi

Causes borreliosis (relapsing fever)

borreliosis

transmission thru the bite of infected body louse or ticks

Borrelia recurrents

• Causes Louse-born or epidemic relapsing fever

• Humans are the only reservoir (host)

• 2-15 days before Sx appear

• Symptoms:

  • Fever

  • Headache

  • Myalgia

  • Petechiae

  • Diffuse abdominal tenderness

  • Conjunctival effusion

Borrelia burgdorferi

• Causes Lyme disease (tick-borne)

• Most common vector-borne disease in North America and Europe and is an emerging problem in northern Asia

Leptospira

spiral-shaped, right-handed helices with hooked ends

Leptospira interrogans

• Can infect most mammals, reptiles, amphibians, fish, birds, and invertebrates

• Causes Leptospirosis

• Contact with infected animals or water contaminated with urine or blood of infected animals

• 2-20 days before Sx appear

• Transmission: Enters the human host through breaks in the skin, mucous membranes, or conjunctivae

Anicteric leptospirosis

• The most common clinical infection of leptospira

• Self-limiting

• High fever and severe headache that lasts 3-7 days

• “Anicteric” = not affected by jaundice

Weil’s disease/icteric leptospirosis

• The most severe illness of leptospira

• Liver, kidney, or vascular dysfunction with lethal pulmonary hemorrhage

• Death can occur in up to 10% of cases

• “Icteric” = affected by jaundice; refer to the serum of px with jaundice

Spirillum minus

• Gram (-) thick, spirillum w/ tapering ends

• Normal flora of rat’s URT

• Causes rat bite fever (Sodoku = Japanese; So = rat; Doku = poison)

• Transmission: Bites / scratches from infected rodents

• Remedy: pest extermination or cover food to avoid deadly rodent contamination