Spirochetes

order spirochahaetes family Spirocheatacae

treponema

borrelia

order spirochaetes leptospiraceae family

leptospira

order nitrospmonadales family spirillaceae

spirillum

spirochetes common characteristics

long, gram negative, helically coiled, .1-3um in width, 5-120 um in length

endo-flagella → corkscrew shaped appearance/ motility

T. pallidium ssp. pallidum

Stages: primary, secondary, early latent, tertiary

venereal syphilis- STI, vertical transmission, blood transfusion

Common worldwide

can cause congenital syphilis in newborns

primary/ early syphilis

<1 year

21 day average incubation

painless, chancre (3-6 weeks, resolves without treatments, extremely contagious)

regional lymphadenopathy

transmission: exposure to infected lesions/ body fluid

Secondary Syphilis traits

6wks - 6 months post initial infection

30% asymptomatic

rash- skin/mucous membranes + palms of hands and soles of feet (rough red-brown, painless)

Symptoms: lymphadenopathy, fever, nonspecific symptoms, hair loss, condylomata lata

highly infectious, resolves without treatments

can infect others via body fluids/ sexual activity

Condylomata lata

smooth, papillated, benign, 10-40%who progress will have lesions

appears in secondary syphilis

early latent syphilis traits

asymptomatic

tertiary syphilis/ late latent traits

10-30 years after exposure

~30% of untreated patients progress to this stage

neurosyphilis, ocular syphilis, aortic aneurysm

harder to determine the cause

gummatous lesions on bones/ body

neurosyphilis

paralysis, numbness in extremities, dementia

tertiary syphilis

ocular syphilis

vision changes/ blindness

tertiary syphilis

aortic aneurysm in tertiary syphilis

occurs in 10% of patients that progress to tertiary syphilis

congenital syphilis

Syphilis crossing the placenta and infecting fetus regardless of stage of pregnancy mother is in.

Causes fetal death, low birth weight, decreased survival, deformed bones, anemia, enlarged spleen and liver

Must be treated upon delivery

~30% of mothers have syphilis

diagnosis of congenital syphilis

Rapid plasma reagin, examined thoroughly for evidence of congenital syphilis (lesions, body fluids, tissues, examined by darkfield microscopy, PCR testing, special stains)

Rapid plasma reagin

nontreponemal test performed on serum of patients, testing for antibodies against products released from cells damaged by organism

in infants- increasing titer in first few months of life, searching for nonspecific antibodies.

IgM and IgG antibodies to lipoidal material released from damaged host cells and to lipoprotein like material released from organism.

Confirmatory test (primary- 70-80% sensitivity; secondary- 95% sensitivity)

Titer can indicate response to therapy

Assays can determine reinfection

False positives caused by lupus, pregnancy, malaria, TB, infectious mononucleosis, hepatitis, HIV

T. pallidum subsp. pertenue (Yaws)

most common non-venereal infection

children <15 years old

transmission- contact from open skin lesions (skin picking/ bites)

Dermal and bone involvement

Primary, secondary, tertiary stages

Affects people in Africa, South America, Caribbean

Transmission: direct skin contact

Yaws- primary stage

2-4 weeks post inoculation, lesion

Lesions are pruritic, non-tender, common in lower extremities

Yaws- Secondary stage

Weeks to months after primary infection

Lesions near mouth/ nose that spread and develop into ulcers

Contagious/ shedding organism when lesions are open/active

Yaws- tertiary stage

10% of patients (5-10 years after primary infection)

Skin infection- deforming, subcutaneous gummatous nodules with large necrotic skin ulcers; bone infections resulting in exostosis

Hard for patients to remember when/where they were first exposed

open lesions = contagious

T. pallidum subsp. carateum (pinta)

Least severe of non-venereal infections

Mainly infects children <15 years old

Affects people in central/south america

Lesions develop 1-8 weeks post inoculation

Symptoms: Ulcerative/ papulosquamous skin lesions that are depigmented;

sentinel lesion in the lower limbs are loaded with organisms

Skin rash develops 3-5 years post-infection

6-15 years post initial infection, pigment of lesions changes and bony prominences occur

Spirochetes are found in skin biopsy of late stages, but not contagious

Transmission: direct skin contact

Pentids (pinta syphilis)

diffuse, scattered lesions similar to primary lesions

2-4 years of rashes that change color forming large lesions and pigment changes

develops 3-5 years post inoculation of Pinta

T. pallidum subspecies Endemicum (Bejel)

non venereal, endemic syphilis

geographically in dry arid climates (Africa, Middle East, South East Asia)

primarily infects children 2-15 years old

27% of children in region are serology positive

Can take years-decades to develop

Transmission: sharing cups/ utensils (mucous membrane introduction)

Primary stage: painless ulcerations (oral/nasopharyngeal regions)

Secondary stage: no ulcerations, visible/diffuse skin rash, lesions at the same areas

Nasopharyngeal ulceration progresses to bone involvement (bone loss)

Gummas of mouth, palate, nose come at later stages

T. denticola (necrotizing gingivitis)

found worldwideand associated with periodontal disease. It is a spirochete that can cause severe gum infections and tissue destruction.

Venereal disease research lab (syphilis diagnosis)

only for diagnosis of tertiary neurosyphilis on CSF specimens

antigen detection (cardiolipin, lecithin, cholesterol)

antigen precipitates when combines with lipoidal antibodies in serum or csf from syphilis patients (positive result)

Treponemal tests for syphilis diagnosis

screening tool for all stages (high sensitivity, positive test for life)

fluorescent treponemal antibody absorption (FTA-ABS)

Treponema pallidum particle agglutination assay (TP-PA)

Treponemal Enzyme immuno-assay (EIA)

Western Blot (INNO-LIA)

PCR

Darkfield microscopy

Fluorescent treponemal antibody absorption syphilis diagnosis test (FTA-ABS)

antigen is whole organism, patient serum absorbed with non-pathogenic treponemes to remove non-specific antibody (looking to see specific ABS)

Treponema pallidum particle agglutination assay (TPPA)

gelatin particles contain organism antigens, if patient serum contains antibodies clumping appears

treponemal enzyme immuno-assay (EIA)

many assays available that can detect either patient IgM or IgG serum antibodies

better than FTA-ABS or TPPA

Western blot for syphilis diagnosis

innogenetics NV multi-parameter line assay (INNO-LIA)

confirmatory test- measures antibody against 3 antigens and 1 peptide

most accurate testing available

PCR for syphilis diagnosis

detects as few as 10 organisms/ specimen

specific and sensitive

darkfield microscopy for syphilis diagnosis

needs active lesion

confirmatory tests for syphilis diagnosis

EIA screening

RPR- confirms EIA, establishes base line titer to monitor treatment success (should decrease as pt is treated)

INNO-LIA Western blot- confirmatory test for new positive diagnosis

Borrelia species

North America: B. burgdorferi, B. bissettiae, B. mayonii

Eurasia: B. burgdorferi, B. garinii, B. afzelii, B. bavariensis, B. spielmanii, B. bessettiae, B. valaisiana

Relapsing fever

RF borrelia group

>20 species in group

B. hermsii, turicatae, parkeri (north america, tick borne, endemic)

B. recurrentis (worldwide, louse-borne, epidemic)

characteristics of borrelia sp.

helical, 0.2-0.3 um in diameter, 3.18um in length

periplasmic endoflagella that provide corkscrew motility

microaerophilic

unique- linear chromosomes, linear and circular plasmids

Lyme borreliosis

Ixodus ricinus tick transmission with rodent reservoir

chronic lyme borreliosis is not supported by extensive culture studies.

symptoms of lyme borreliosis

Erythema migrans- early infection, expanding bullseye rash, possible nonspecific symptoms that differ as patients age

Disseminated infection if untreated/ late disease- hematogenous spread leading to infection at other sites (other skin sites of infection, cardiac involvement, neurologic, meningitis, palsies)

• in europe: borrelial lymphocytoma- 5-10% neurological involvement; neuroborreliosis- >6months of CSF inflammation markers

• In U.S.: mono or oligoarthritis

chronic lyme borreliosis

not supported by extensive culture studies

persistence of organism despite appropriate antimicrobial therapy

nonspecific symptoms, concentration problems in previously infected individuals, atrophy in skin/ tissue with malignancies

long term affects with no organism present- autoimmune

lyme borreliosis diagnosis

difficult to effectively grow in culture due to low numbers in clinical samples

methods: stains, culture, NAAT, serology

Stains for lyme borreliosis diagnosis

EM biopsies using silver stain (low positivity rate)

possible peripheral blood smears using Wright’s Stain- very organism loaded in blood

cultures for lyme borreliosis diagnosis

infection stage/ sample dependent (2-3 weeks for growth)

blood culture medium with added plasma (~70% of patients with EM had positive culture).

Darkfield microscopy may be able to see spirochetes within 4 days

Liquid media- Barbour-Stoenner-Kelly (BSK), modified Kelly-Penttenkofer (MKP) or other media using microaerophilic conditions (30-34*C)- requires skin biopsy

Nucleic Acid Amplification Test (NAAT) for lyme borreliosis diagnosis

Significant variability in positivity associated with clinical infection stage, sample type, organism load, and NAAT methodology

Best success: testing in EM biopsy

Only recommended if first-line case on synovial fluid

Serology for lyme borreliosis diagnosis

Immunodominant antigenic epitopes- OspC (flagellin), VlsE (outer membrane in mammalian), BmpA (porin-like adhesion)

ELISA (immunoblot assay)

test of choice (gold standard)

Borrelia recurrentis (relapsing fever)

Organisms able to vary outer membrane surface antigens causing repeated exposure to “new” organism by immune system causing organism in blood and repeated fever (sepsis)

Louse-borne or Tick-borne

Louse borne relapsing fever (LBRF)

Scratching kills louse which releases organism and inoculating the host skin/mucous membrane (louse lysis)

Associated with poverty/ crowded living conditions, poor sanitation (Africa, Middle East, Asia, Ethiopia).

Louse infection from blood meal from infected human (no louse-to-louse spreading).

Tick borne relapsing fever (TBRF)

worldwide distribution, endemic to western US

Transmission: tick bites, IV drug use, lab accidents, blood products

Organism can be passed tick-to-tick

Borrelia recurrentis Relapsing fever signs/ symptoms

incubation period: 4-18 days

sudden onset of high fever (104C), chills, delirium, muscle/bone/joint pain.

Lasts 3-5 days, relapse average time 7 (TBRF) - 9 (LBRF) days

Reoccurrence is less severe, but patient still is not well between episodes

Borrelia recurrentis Relapsing fever diagnosis

visually identify spirochetes in hematology differential smear (70% sensitivity during febrile illness)

Culture using Kelly’s medium for Borrelia- needs examination up to 6 weeks- smear looking for spirochetes

Serology- acute vs convalescence and 4x increase in titer

Leptospira sp. Leptospira interrogans

subtropical/ tropical

increase incident of infection associated with rainy season- common outbreaks

100-150 cases/ year, most commonly from hawaii and peurto rico

risk groups: farmers, exposure to sewerage, swimming in stagnate pond water associated with rain-water run-off

Organism is harbored in kidneys- urinating sheds organism- rain runoff into stagnant ponds leading to human infection.

can survive for months in the environment

Characteristics of Leptospira sp.

zoonotic infection for humans and animals

obligate aerobes

gram-negative, thin, helically coiled, spirochetes

motile

Leptospira sp. spread by infected animals

human exposure contaminated environment (urine, water, soil)

carried by cattle, pigs, horses, dogs, rodents, wild animals

many animals have no symptoms of disease

signs/symptoms leptospira leptospirosis

Organism entry via skin, mucous membranes, drinking contaminated water

incubation period 5-14 days

90% present with nonspecific illness (high fever, headache, delirium, muscle/bone/joint pain)

biphasic presentation that increases in severity (5-15%)

severe presentation: liver involvement/ jaundice, renal hemorrhage,meninitis, pulmonary insufficiency (mortality up to 50%)

pregnancy- fetal complications leading to death

leptospira leptospirosis diagnosis

serology- acute vs convalescence and 4x increase in titer

PCR/ molecular testing: negative testing, whole blood specimen (1* phase/ 1st week), urine after first week of illness (PCR); CNS, kidney/liver tissue for NAAT

Culture using Kelly’s medium for Borrelia- needs examination up to 6 weeks (smear looking for spirochetes)

Organism is shed in urine

First week of Leptospira Leptospirosis diagnosis

can visually ID spirochetes in Wright/Giemsa stain

Culture- Fletcher’s or Stuart’s medium (29-30C up to 4 months incubation), liquid medium is bed option. PCR testing.

Spirillum minus

Rat bite fever (Sudoku)- infection in Asia

RBF (Streptobacillus moniliformis)- infection in US

Spirochete characteristics: 0.2-0.5 um width, 1.7-5mm length; bipolar flagella

Rodent exposure (urine/bite)

Rat Bite Fever (Sudoku) signs/symptoms

1-4 week incubation after bite

systemic illness (chills, headache, vomiting, fever)

At Bite Site: chancre-lesion, lymphadenopathy, macropapular rash on palms and sores

Rare polyarthritis

Relapsing fever every 2-3 days that can last years

Complications: endocarditis, myocarditis, meningitis

cannot culture (only sampling infected area)

organisms can cause false positive syphilis tests (serology not helpful)