Diplococci – Infection, Transmission & Diseases


Diplococci are bacteria that appear under the microscope as paired spheres. They belong to the streptococci family and can cause various diseases in humans.

What are diplococci?

Diplococci are a form of the cocci . Cocci, on the other hand, are spherical bacteria that can be completely round or egg-shaped. In medical terminology, cocci can be recognized by the “coccus” suffix. For example, there are the bacteria Enterococcus , Streptococcus or Staphylococcus .

If cocci do not separate after a cell division, different organizational patterns can arise. This allows a distinction to be made between packet cocci, streptococci, chain cocci, staphylococci and diplococci. While streptococci are stored in chains, diplococci lie together in pairs. Depending on the classification, diplococci are also counted among the streptococci. This is explained by the fact that the paired diplococci are a chain with two links.

The diplococci include, for example , pneumococci , meningococci and the bacteria Neisseria gonorrhoeae and Neiserria meningitidis (meningococci). These pathogens can affect humansdiseasescause. However, there are also so-called apathogenic diplococci. Apathogenic bacteria have no pathological value for humans.

The individual cocci can be distinguished based on their coloring behavior in the Gram stain. There are both gram-positive and gram-negative diplococci. While the pathogen Streptococcus pneumoniae (pneumococci) belongs to the gram-positive diplococci, Neisseria are gram-negative diplococci.

Occurrence, Distribution & Properties

The various diplococci have different distributions. Humans are the pathogen reservoir for the bacterium Neisseria gonorrhoeae. The pathogen is transmitted through sexual intercourse or during childbirth . Neisseria meningitidis live intracellularly and preferentially colonize the pharynx – nose area in humans . The pathogen is found in this area in around 10 percent of the European population. The bacteria can be transmitted from person to person by droplet infection . One possible source of infection is therefore kissing.

Meningococci have small extensions, also called pili, with which they can attach themselves to the mucous membrane of the nasopharynx for weeks or months. When the immune system is weakened, they multiply, invade the mucous membranes and thus enter the blood . Pneumococci also feel comfortable in the mucous membranes of the nose and throat. Although they can be passed from person to person by droplet infection, infections are usually caused endogenously. That means getting infectionswith pneumococci usually develop from the bacteria that are already present in the body. Carriers and transmitters of pneumococci are primarily children aged one or two years. While adults are hardly carriers of the bacteria, colonization increases again with age. In people over the age of 65 there are again quite a lot of pneumococci in the body.

Diseases & Ailments

Colonization with pneumococci is usually asymptomatic. The infestation may manifest itself as a mild infection. However, the pathogens weaken the immune system, increasing the likelihood of additional viral infections . However, especially in old age and with a weak immune system, the bacteria can spread in the body. The consequences are inflammation of the middle ear, the paranasal sinuses , the lungs or the meninges .

Penumococci are classic pathogens of lobar pneumonia. This is accompanied by fever , pain and difficulty breathing . Ulcus serpens corneae, an ulcer of the cornea in the eye, can also be caused by the pathogen. If the bacterium spreads in the blood, life-threatening sepsis develops .

The bacterium Neisseria meningitidis is the causative agent of bacterial meningitis (inflammation of the meninges). This develops preferentially in children, adolescents, the elderly and immunocompromised patients. The main symptom of meningitis is a very severe headache . These are often accompanied by neck stiffness . Neck stiffness is also known as meningism in medical jargon. Other symptoms of diplococcal meningitis include photophobia and sensitivity to noise. The classic triad of meningeal inflammation consists of meningism, high fever, and impaired consciousness. However, this characteristic triad only occurs in 45 percent of patients.

The bacterium Neisseria gonorrhoeae causes the disease gonorrhea . Colloquially, this infectious disease is also known as gonorrhea. In men, infection with gonococci can lead to inflammation of the prostate . This prostatitis manifests itself as pain when urinating , frequent urination with little urine, blood in the urine , painful bowel movements , pain when ejaculating and a feeling of tension in the perineum area. Depending on the severity of the inflammation, acute urinary retention can occur, in which the patient can no longer urinate. In addition to the prostate, there are often the epididymisaffected by the inflammation. Inflammation of the epididymis is called epididymitis . It causes severe and painful enlargement of the epididymis.

When infected with Neisseria gonorrhoeae, women develop inflammation of the pelvis and fallopian tubes . Inflammation of the fallopian tubes, also known as salpingitis , is manifested by abdominal pain. These increase both during urination and ovulation . Depending on the severity of the inflammation, fever and vaginal discharge can also occur.

Purulent inflammation of the conjunctiva can occur in newborns who become infected during childbirth. This is also known as ophthalmia neonatorum . To prevent this unpleasant disease, which can lead to blindness , mothers with a gonococcal infection are given prophylactic medication to protect the child during childbirth.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.