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ORDER: SPIROHAETALES.

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4 Genera of Medical Importance.

1. SPIRILLUM
2. .2.BORRELIA
3. LEPTOSPIRA.

4. TREPONEMA..

GENERAL FATURES

• They are spiral bacteria.
• They are thin and actively motile.
• They are flexible and non-flagellated-except S. minus.
• They are unicellular
• They vary in length from 1-500u
• They are Gram-ve but stain poorly
• They stain better with Giemsa, Wright, Leishman, and silver impregnation technique.

FEATURES CONTD

• Their routine diagnosis is by Microscopy (DG) and serology.
• They are generally sensitive to Penicillin and Tetracycline.

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SPIROCHAETES.

• GENERAL CHARACTERISTICS.
• SPIRAL, THIN, ACTIVELY MOTILE, NO FLAGELLA(EXCEPT SPIRILLUM,
• VARY IN LENGTH BX 1--500U, STAIN POORLY WITH GRAM STAIN BUT GENERALY G-VE; THEY STAIN BETTER WITH GIEMSA, WRIGHT & LEISHMAN STAINS.
• THEY ARE BEST DEMONSTRATED IN TISSUE SECTIONS BY SILVER IMPREGNATION TECHNIQUE.
• THEY ARE UNICELLULAR.
• ROUTINE DIAGNOSIS IS BY DG MICROSCOPY.
• THEY ARE SENSITIVE TO PENICILLIN & TETRACYCLINE.

SPIROCHAETES.

• SPIRILLUM MINUS.
• HAS TERMINAL FLAGELA AT BOTH ENDS AND DARTING MOVEMENT.
• IT IS RELATIVELY SHORT, 2-10U IN LENGTH;
• DIAGNOSIS: DG AND BY LEISHMAN STAIN. ALSO BY ANIMAL INNOCULATION.USING G/PIGS & WHITE RATS & MICE.
• SPECIMEN SHOULD COME FROM THE LOCAL LESION, GLAND PUNCTURE OR BLOOD.

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SPIROCHAETES.

• CLINICAL FEATURES:
• CAUSES RAT-BITE FEVER (SODOKU)
• COMMON IN JAPAN AND SE COUNTRIES.
• SIMILAR ILLNESS FROM BITES BY CATS AND FERRETS.
• S/S: RELAPSING FEVER, LOCAL INFLAMMATION, REGIONAL LYMPHADENOPATHY;SIMILAR TO INFECTION BY STREPTOBACILLUS.MONILIFORMIS.(+ARTHRITIS)
• Rx:PEN & TETRACYCLINE.
• DD: BORRELIA INFECTION. NB; COMMON CAUSE OF BFP. rx.

SPIROCHAETES.

• BORRELIA.
• GENERAL FEATURES:
• G-VE BACTERIA, WITH LARGER & WIDER COILS THAN OTHER SPIROCHAETES; VARY BX 5-30U IN LENGTH BY 0.3-0.7u WIDE.
• SOME OF THEM OCCUR AS COMMENSALS IN HUMAN MUCOUS MEMBRANES.(e.g. B. refringens & B. gracillis on human genitalia).
• DIAGNOSIS: 1 MICROSCOPY. 2. CULTURE ON ARTIFICIAL MEDIA ENRICHED WITH SERUM/ASCITIC FLUID. 3. ANIMAL INOCULATION IN MICE OR YOUNG RATS. 4. INNOCULATE CHORIO-ALLANTOIC SAC OF CHICK EMBRYO. 5. CRUSSH INFECTED LICE/TICK ON SLIDE WITH A DROP OF SALINE/DW AND EXAMINE UNDER DG.

SPIROCHAETES.

• SEROLOGY
• CF Abs and Lytic Abs ARE PRODUCED BUT THESE ORGANISMS SHOW HIGH DEGREE OF MUTABILITY LIKE THE TRYPANOSOMES, THEREFORE THEY ARE OF LITTLE USE.
• SPECIES:
• 1. B vincenti. Causes Vincent’s Angina.
• 2. B. recurrentis)
• 3. B. duttoni ) organisms of relapsing fever.

SPIROCHAETES.

• Clinical: B. vincenti causes Vincent’s Angina (cheilosis, gingivo-stomatitis, ulcerative-pharyingitis & submental lymphadenopathy)
• Often in association with Fusobacterium fusiforme, both normal flora of human gum but become pathogenic under lowered immunity as in: Trauma, poor vitamins, secondary infection systemic illness, cancer, leukaemia etc.
• Diagnosis: As above. Rx: Pen & Tetracycline.

SPIROCHAETES.

• B. recurrentis: causative agent of European Relapsing Fever. It is Louce-borne. The louce vector is PEDUCULUS HUMANUS CORPORIS.
• B. duttoni: causes the African Relapsing Fever and it is Tick-borne..
• The tick is ORNITHODORUS MOUBATA. It is a zoonosis. The vector in the middle East is O. THOLOZANI.
• Relapsing fever has an interesting cycle: I.P. 3-10 days; followed by chills, fever lasting 3-10 days; followed by remission of 3-10 days and the cycle is then repeated for 3-10 cycles. The fever becomes less severe with each successive cycle.

SPIROCHAETES.

• Spirochaetes in blood during the attack of fever. They settle in large organs, liver, spleen, GIT, Kidneys with fatal necrosis, haemorrhage & jaundice. Meninges & brain may be involved.
• Infection with B. duttoni is fraut with neurological sequellae like iritis, nerve palsies,spastic paralysis. The relapses are shorter, more frequent and more numerous.
• There is BFP with STS.
• Rx. Pen & Tetracycline.

SPIROCHAETES.

• LEPTOSPIRA.
• The genus has several saprophytic and pathogenic strains classified into two subgroups:
• The saprophytic group= BIFLEXA
• The pathogenic group=INTERROGANS.
• They contain several antigenic variations-hence serotypes; and those with common antigens are grouped as serogroups.

SPIROCHAETES.

• Pathogenic strains include:
• 1. L. icterohaemorrhagiae
• 2. L. canicola.
• DIAGNOSIS: 1. Microscopy -DG, silver impregnation, IFT.
• 2. Culture: in liquid & semi-solid media enriched with serum, peptone or tissue, such like Ellinghausen & McCulloch medium, Fletcher’s, Stuart’s medium. They also grow well on chorio-allantoic membrane of chick embryo. 3. Animal inoculation –(g/pigs & hamsters)
• Serology-Agglutination, CFT, Indirect IFT.

SPIROCHAETES.

• Epidemiology of Leptospirosis. It is a zoonosis. Certain persons are more at risk of infection, Viz:Farmers, Veterinarians, Livestock handlers, Abbatoir attendants, swimmers etc.
• Leptospires are normally carried in the kidneys of rodents (rats,mice,etc), from where man is infected directly or indirectly through some domestic animals.
• CLINICAL: L.icterrohaemorrhaegiae produces jaundice & haemorrhages Principally, the liver, kidneys, brain & meninges,lungs are affected.(WEIL’s DISEASE). Other serotypes cause mild illnesses.(flue-like).
• Preventio: 1. Avoid contact with infected animals.2. vaccinate certain groups. NB: Diagnosis should be considered in certain difficult cases of PUO. Rx: Pen & Tetracycline.

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SPIROCHAETES.

• GENUS TREPONEMA.
• 3 species of medical importance. They are morphologically indistinguishable, but separated on clinical and epidemiological basis only.
• Org. T. pallidum T. pertenue T. carateum
• Disease. Venereal syphilis Yaws Pinta.
• Geog dist Universal&urban Trop & rural Trop & rural
• Age Adults mainly children Adolescents
• Transm. Ven & cong. Contag(flies) Contag(biting insects)

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SPIROCHAETES.

• GENUS TREPONEMA.
• T. pallidum T. pertenue T. carateum
• Clin. Course. All systems. Skin, lymp, bone. Skin ,lymp.
• Serology. Pos in 3-4wks pos in 3—4 wks pos in 3-12mts
• Host range. Humans, monkeys & rabbits. Humans,chimp.

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• T. pallidum. Does not grow in artificial medium, multiplies by binary fission every 30-33 hours. Moves by angulation,buckling,undulation,looping, comp & expansion.

SPIROCHAETES.

• T. PALLIDUM.
• Causative agent of Syphilis.
• Materials for diagnosis. 1. Ulcer scrapping. 2. Serum. 3. Lymph node aspirate. 4. Tissue extract.
• Serological Tests.
• Screening tests: (They are non-specific tests). 1. Veneral disease research laboratory (VDRL) test,
• 2. Wasserman compl. Fixation test, 3. Kolmer/Eagle/Hinton test.
• 4. Kahn/Kline test.5. Rapid plasma regain (RPR) test. (The antigen for these tests is a cardiac extract called CARDIOLIPIN, which is diphosphotidyl glycerol.)

SPIROCHAETES.

• T. PALLIDUM.
• Specific (Confirmatory) tests for syphilis.
• 1. Treponema pallidum immobilization (TPI) test.
• 2. Treponema pallidum haemagglutination (TPHA) test.
• 3. Treponema pallidum immunofluorescent test (FTA-abs).
• 4. PCR

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• When syphilis test is positive in absence of the disease, it is known as Biological false positive (BFP). This is seen only with the screening tests. BFP may be acute (up to 6months) or chronic (more than 6months).

SPIROCHAETES.

• T. PALLIDUM.
• Syphilis is conveniently classified into 2 types: Acquired and congenital.
• Each of these is further subclassified into 3 groups, viz:
• Acquired: 1. primary. 2. secondary. 3. tertiary.
• Congenital: 1. Early congenital.
• 2. Late congenital.
• 3. Stigmata.

SYPHILIS: CLINICAL CLASSIFICATION

• CONGENITAL SYPHILIS. Acquired Syphilis.
• Early Congenital Syphilis. Primary Syphilis
• Late Congenital Syphilis. Secondary Syphilis
• Stigmata. Tertiary Syphilis

SPIROCHAETES.

• T. PALLIDUM
• DIAGNOSIS OF SYPHILIS.(The organism does not grow in artificial media).
• 1. Patient’s history.
• 2. Physical examination.
• 3.Microscopy( DG, silver staining, fluorescent staining.)
• 4. Serology. Non-specific tests; specific tests.
• 5. Animal inoculation.
• 6. CSF examination.(Antibodies, protein level,cell content & types).
• 7.Ancillary tests.(Xray, tissue biopsy, etc).

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SPIROCHAETES.

• T. PALLIDUM.
• Treatment of Syphilis.
• The best drug for treating syphilis is Penicillin. However, the organism is sensitive to a large number of antibiotics. (See my book).
• Control of Syphilis.
• As for any STDs.
• GOLDEN RULE.
• All genital ulcers must be assumed to be syphilitic until proved otherwise.

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