A team of researchers affiliated with multiple institutions in France has found that a class of antipsychotic drugs known as phenothiazines was successful in treating a form of meningitis in mice when used with antibacterial agents. In their paper published in the journal Nature Microbiology, the group describes experiments they conducted with meningitis mouse models and what they found.
Meningitis is not a disease, but a condition caused by viral, bacterial or fungal infections. The condition occurs when infections result in swelling of the meninges (membranes that cover the brain and spinal column). Different types of infectious agents can result in different degrees of danger to a patient. One agent, a kind of bacteria called Neisseria meningitidis, is well known for the severity of its infections—typically, 10 percent of people die from it. In this new effort, the researchers report on experiments they conducted with a class of antipsychotic medicines that allowed antibacterial agents to perform better against Neisseria meningitidis.
Neisseria meningitidis is notoriously difficult to treat because of the way it behaves inside blood vessels. Each bacterium is covered with sticky, hair-like appendages called type IV pili. The pili allow the bacteria to group together into a clump and adhere to the walls of blood vessels. The clumps prevent antibacterial agents from killing most of the bacteria, allowing the infection to continue. In this new effort, the researchers found that phenothiazines work against the stickiness of the pili, preventing the bacteria from clumping. This allows antibacterial agents to do their job.
The researchers tested the combination of drugs in test mice with meningitis. They report that the combination resulted in a reduction of existing clumps, a reduction in the development of new clumps and increased survival rates.
It is not yet known if it would be safe to treat humans with the same drugs because they have not been tested in patients with a severe inflammatory infection. The researchers describe their work as proof of concept and suggest much more work will need to be done to find out if phenothiazines can be used to treat meningitis patients. They note that other pathogens also use Type IV pili as a defense mechanism, which suggests that if phenothiazines pan out as a human treatment, they might be useful for more than just combating Neisseria meningitidis.
What are meningitis and septicaemia?
Meningitis is inflammation of the lining around the brain and spinal cord – the meninges. Septicaemia is blood poisoning caused by the same germs and is the more life threatening form of the disease. Septicaemia can occur with or without meningitis.
Meningitis is an inflammation (swelling) of the protective membranes covering the brain and spinal cord. A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling. However, injuries, cancer, certain drugs, and other types of infections also can cause meningitis.
Bacteria called Neisseria meningitidis cause meningococcal disease. About 1 in 10 people have these bacteria in the back of their nose and throat with no signs or symptoms of disease; this is called being ‘a carrier’. But sometimes the bacteria invade the body and cause certain illnesses, which are known as meningococcal disease.
There are five serogroups (types) of Neisseria meningitidis — A, B, C, W, and Y — that cause most disease worldwide. Three of these serogroups (B, C, and Y) cause most of the illness seen in the United States.
People spread meningococcal bacteria to other people by sharing respiratory and throat secretions (saliva or spit). Generally, it takes close (for example, coughing or kissing) or lengthy contact to spread these bacteria. Fortunately, they are not as contagious as germs that cause the common cold or the flu. People do not catch them through casual contact or by breathing air where someone with meningococcal disease has been.
Sometimes the bacteria spread to people who have had close or lengthy contact with a patient with meningococcal disease. Those at increased risk of getting sick include:
- People who live with the patient
- Anyone with direct contact with the patient’s oral secretions, such as a boyfriend or girlfriend
Close contacts of someone with meningococcal disease should receive antibiotics to help prevent them from getting the disease. This is known as prophylaxis (pro-fuh-lak-sis). Health departments investigate each case of meningococcal disease to identify all close contacts and make sure they receive prophylaxis. This does not mean that the contacts have the disease; it is to prevent it. People who are not a close contact of a patient with meningococcal disease do not need prophylaxis.
One of a group of tranquilizing drugs with antipsychotic actions thought to act by blocking dopaminergic transmission (messages sent using the substance dopamine) within the brain.
Examples of phenothiazines include: chlorpromazine (brand name: Thorazine), fluphenazine (Duraclon), mesoridazine (Serentil), perphenazine (Etrafon and Trilafon), prochlorperazine (Compazine), promazine (Robinul and Anectine), thioridazine (Mellaril), trifluoperazine (Stelazine) and triflupromazine (Robinul).