Treponema Pallidum

What is Treponema Pallidum : Treponema pallidum It is a bacterial causative agent of syphilis. They are spirochetes, a term used to refer to bacteria with a conglomerate shape, similar to a spring or corkscrew.

They are extremely thin microorganisms, to the extent that they are impossible to see under a microscope. Furthermore, these bacteria are not cultivable in vitro.

Treponema Pallidum
Treponema Pallidum

Syphilis is a sexually transmitted disease distributed around the world. However, there are other subspecies of this bacterium whose mode of transmission is not sexual (for example, there may be skin contact).

They are as pathogenic to humans as diseases such as yawning. These pathogens predominate in African countries and areas of hot climate.

General Features

These spiral bacteria do not form spores.

-They have a limited temperature tolerance range and are sensitive to high temperatures.

They are anaerobic and use carbohydrates as a carbon source.

-They are chemoorganotrophic.

Its metabolic capacity is quite low, an immediate consequence of the small size of its genome. This characteristic is common in parasitic organisms, as all essential nutrients can be taken from their host.

It has a total of 113 genes used to code for transport proteins, which carry macromolecules through the medium.

-They throw a negative result for catalase and oxidase tests.


The spirochetes are characterized by an unusual morphology compared to other bacteria. They have spiral, cylindrical and flexible shapes.

The size range is 5–20 µm in length and 0.1 to 0.4 µm in diameter. There is a separation of about 1-1.5 µm between the turns. They are so thin that their visualization is not possible using a conventional optical microscope.

axillary fibers

Tea. Pallidium It is a bacterium that shows motility. One of the clinical features of croup is the presence of axillary fibrils. The axillary filaments, also known as endoflagella, help in the mobilization of bacteria.

They are similar to a flagellum and each filament adheres to a pole of the cell, causing a rotational motion. Given the small size of bacteria, the liquid represents an important obstacle to displacement.

Like a corkscrew, these bacteria are capable of moving around and the speed of this movement is variable. Similarly, there can be gentle push-ups.


Due to their small size, Gram staining is difficult to apply to these microorganisms. However, its membrane structure resembles that of Gram-negative bacteria; The membrane is thin and with a diverse composition of lipids. A large number of endoflagels are found in the membrane.

The membranes of pathogenic bacteria play an important role in immunological responses and virulence.

For this bacterium, a supposed antigen is exposed on the surface and weighs 47 kg. Although this idea is debated, this element is named as the main antigen exposed in the outer membrane.


Penis Treponema It is composed of both harmful and non-pathogenic bacteria that inhabit humans and animals. Taxonomically, they belong to the phylum Spirochaetes, Spirochaetales and the family Spirochaetaceae.

Treponema pallidum was previously known as Spirochaeta pallida . Furthermore, based on the study of DNA hybridization, T. The pallidum is genetically indistinguishable from Treponema perton , the etiological agent of the ankles.

Habitat and Transmission

The habitat of this microorganism is the human genital tract. As it is a parasitic parasite, it cannot survive outside its host.

Transmission occurs during sexual intercourse by direct contact with injuries, bodily secretions, bleeding, semen and saliva.

It is believed that transmission occurs through microscopic subcutaneous lesions caused by sexual activity. The infection can also be transmitted through kissing, biting and oral-genital sex.

Similarly, bacteria can be transferred from mother to fetus by placental transfer.

Cultivation and Identification

It is not possible to grow this bacterium in vitro . This feature of the pathogen has greatly hindered its study. Alternatively, it can be propagated in rabbit testicles.

They can be detected in the patient’s serum using immunological techniques, serological tests or visualization samples from lesions in a dark-field microscope.

Because of the impossibility of cultivating the pathogen, the development of molecular techniques for its identification is important.

biological cycle

In the 1950s, studies by Delameter and colleagues helped to elucidate and describe the complex life cycle of this bacterium. The study cultivated the bacteria in rabbit testicles.

According to these investigations, the pathogen can take two forms of vegetative reproduction: one per transversal division, most important under normal conditions, and a second dominated by the production of the gemule.

The production of gems or “buds” is reminiscent of the saprophytic forms of spirochetes, resulting in a cyst.

Preliminary work confirms that the aggregation of two or more organisms may be followed by a process involving the cyst with many spirochetes. Many organisms develop within these cysts, which emerge as a kind of “tangled ropes”.

Finally, the emerging shapes may undergo cross-section and gem formation.

symptoms and treatment

Syphilis is a complex infection that produces severe systemic diseases and can lead to death of the patient when left untreated.

The disease is characterized by a period of symptomatology and a period of latency. Different stages may be different:

  • Primary syphilis occurs three to twelve weeks after sexual contact with an infected person. It is characterized by the formation of a lesion called a chancre.
  • Secondary syphilis occurs one week to six months after initial contact. It is characterized by the formation of a maculopapular rash. A latent phase may come after this period.
  • Tertiary syphilis appears ten to twenty years after initial contact. Symptoms include cardiovascular, dermatological, skeletal and neurological problems.

The infection is treated with antibiotics, the most commonly used being penicillin. If the patient is allergic, tetracycline is an effective alternative. Similarly the use of erythromycin is suggested.

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