Spirochetes

• Spirochetes

  Order: Spirochaetales

  Families: Spirochetaceae, Leptospiraceae
• Leptospiraceae: 1 genus of interest to humans because it causes wide infections in humans: leptospira
• Spirochetaceae: borrelia, treponema which are also the genera/genus of interest under this family
• General Morphology of Spirochetes:

  Long, slender, helically curved or helically coiled, gram (-)negative bacilli
• Different staining techniques of specimens:

  • Levaditi method/staining: Tissue specimens
  • Fontana-tribondeau: Clinical specimens made into smears
• Three unique morphologic features of spirochetes

  • Axial fibril
  • Outer sheath
  • Insertion disk/s
• • Axial Fibril - serves as locomotor organelle of spirochete organisms or the motility organelle
  • Outer Sheath - or the outer membrane/periplast
• The number of axial fibrils is directly proportional to the number of insertion disks present
• Insertion disks - point of insertion of the endoflagella that wraps or extend throughout the body of a spirochete organism. These disks are located near the terminal portion of the spirochete cell wall.
• The arrangement of wrapping around the coiled body of the spirochete will give a very unique type of motility called: corkscrew-like winding motility
• Differentiation of Genera based on these 3 factors:

  1. Number of Axial Fibrils present inside
  2. Number of Insertion Disk present inside (Number of insertion disks depends on the number of endoflagella present.)
  3. Biochemical or metabolic features
• • Treponema: Slender with tighter coils; pointed ends
  • Borrelia: Thicker with fewer and looser coils; pointed ends
  • Leptospira: Resembles borrelia (according to textbooks) but with hooked ends
• Identify the spirochete

  A) Borrelia

  B) Leptospira

  C) Treponema

  
• TREPONEMA

  •Tighter coils because its coils are numerous and slender and has pointed ends

  •Fine spiral organism

  •Spirals are regular and angular

  •They cannot grow in vitro

  •isolated outside the body because these group of organism are strictly microaerophilic, which means they needed only a small amount of oxygen for them to grow. That's why its difficult to be isolated in vitro
• TREPONEMA

  Animal Inoculation: Rabbit Testis = animal of choice for

  the T. pallidum organism

  •T. pallidum cannot be seen in light microscopy and the best type of microscopy for T. pallidum by use of dark-field microscopy or phase-contrast.

  •Only one spirochete that can be seen through light microscope: Borrelia organisms.
• TREPONEMA

  4 species that colonizes humans:

  • Treponema pallidum subspecies pallidum
  • Treponema pallidum subspecies pertenue
  • Treponema carateum
  • Treponema pallidum subspecies endemicum
• Treponema pallidum subspecies pallidum: causative agent of venereal syphilis (the sexually transmitted syphilis)


  Treponema pallidum subspecies pallidum: causative agent of venereal syphilis (the sexually transmitted syphilis)
• Treponema pallidum subspecies pertenue: causes Yaws (otherwise known as frambasia, pian, bubaor bouba) infections occurring in childhood populations inwarm, mild, tropical climates.


  Treponema pallidum subspecies pertenue: causes Yaws (otherwise known as frambasia, pian, bubaor bouba) infections occurring in childhood populations inwarm, mild, tropical climates.
• Treponema carateum: cause Pinta (other name: carate or Mal de pinto) causes discoloration in the skin of the infected individual


  Treponema carateum: cause Pinta (other name: carate or Mal de pinto) causes discoloration in the skin of the infected individual
• Treponema pallidum subspecies endemicum: causes endemic syphilis or bejel or siti or termed as dichuchwa. A type of syphilis transmitted via non-sexual body contact or by sharing and eating of drinking utensils.


  Treponema pallidum subspecies endemicum: causes endemic syphilis or bejel or siti or termed as dichuchwa. A type of syphilis transmitted via non-sexual body contact or by sharing and eating of drinking utensils.
• TREPONEMA

  Enter the host in 2 ways:

  • Penetrating the intact mucus membranes
  • Entering through breaks in the skin
• TREPONEMA

  When the organism enters the system, it has predilection to blood so it causes spirochete organisms to become systemic in terms of the infection and therefore can cause Endarteritis (inflammation of the arteries) and tissue destruction
• SYPHILIS

  •sexually transmitted disease that is the common type of infection that Treponema pallidum cause to humans is Syphilis or Venereal syphilis.

  •Characterized by 3 different stages and each stage has a prominent feature or manifestation that needs to be understood in order for a patient manifesting that particular sign be suspected right away of venereal syphilis and so investigation can immediately start and hopefully arrive at correct diagnosis so proper treatment can be initiated.
• STAGES OF SYPHILIS

  • Primary stage
  • Secondary stage
  • Tertiary stage
• Syphilis: Primary stage

  • Characterized by chancre formation
  • Chancre- small, painless ulcer or lesion that grows in the genital area of the infected individual and does not bother them
  • Chancre formation of venereal syphilis should be differentiated from the chancre of Haemophilus ducreyi
• Chancre formation of ducreyi - soft and non-indurated
• Syphilis: Secondary stage

  • Manifested by different vague signs and symptoms and the patient goes to see the doctor for medical consult.
  • Signs and symptoms can also be seen in other infections like fever, sore throat, lymphadenopathy(enlargement of lymph nodes), weight loss and rash
  • What unique amongst these symptoms alerting the physician is the appearance of the rash.
• Syphilis: Secondary stage

  Apart from rash on soles of feet and palms, the other prominent features of patients in the secondary stage of syphilis is:

  • Alopecia (baldness)
  • Condylomata lata, also a unique manifestation in the secondary stage of syphilis because its actually the appearance of a lesion and the lesion usually appears on the moist areas of the body;
• Syphilis: Tertiary stage

  • Involvement Central Nervous System and Cardiovascular system which is already late and might be lethal to the patient
  • Manifested by gumma formation
• Gumma formation (there is generalized lymphadenopathy - lymph nodes are really swollen, big and large); actually, a pronounced immunologic reaction of the patient
• Syphilis Treatment

  • Drug of Choice: Penicillin; in fact, the MIC of penicillin to Syphilis is as low as 0.004 U of Penicillin
• CONGENITAL SYPHILIS

  Transmitted to the baby from the infected mother; baby is delivered from an infected birth canal and that means baby will get the organism and will manifest congenital syphilis
• Congenital Syphilis

  If it’s been there throughout the pregnancy of the mother, it might cause:

  • intrauterine death: or infection to be pronounced inside the uterus of the mother and might cause the fetus to die in utero.
  • congenital abnormalities: If the baby is delivered then the baby will get congenital syphilis and manifest.
• Dark-field microscopic examination-appropriate microscope to be used in detecting Treponema pallidum subspecies pallidum
• Primary/Secondary Stage (Venereal syphilis)

  Manifested: Lesions

  Primary: Chancre

  Secondary: Condylomato lata lesion.

  These lesions can be a sample for direct detection of the organism, the antigen detection – Darkfield microscopy.
• Treponema pallidum subspecies pallidum is not routinely demonstrated in a light microscope because of very thin cell wall.
• NEUROSYPHILIS- Affect central nervous system and usually already on the tertiary stage of the infection
• Serologic Methods for Syphilis

  1. Nontreponemal Tests- meaning it will detect non-specific antibodies to treponema and detects nontreponemal antibodies
  2. Treponemal tests - detects specific Ab against treponema organisms
• Nontreponemal tests

  1. VDRL (Venereal Disease Research laboratory) - most common; detects the non-specific Ab Reagin
  2. RPR (Rapid Plasma Reagin)- detects the Reagin Ab; Reagin reacts to different types of lipid as antigen
  3. Hinton Test
• Treponemal tests

  • FTA-ABS (Fluorescent Treponemal Antibody Staining/Fluorescent Treponemal Absorption Test)-Serum of px is treated or absorbed with nonpathogenic treponemes to remove any nonspecific Ab in patient serum.
  • MHA-TP (Microhemagglutination Treponema pallidum)- This makes use of RBC from turkey coated with Treponemal antigen
  • TPI test (Treponema Pallidum immobilization test)- Principle is not widely studied