​Infectious Diseases and Microbiology - Meningitis ( Listeria monocytogenes)

​Infectious Diseases and Microbiology - Meningitis ( Listeria monocytogenes) 
Symptoms of Listeriosis are caused by Listeria monocytogenes.

The gram-positive rod, tumbling motility, and growth at low temperatures are the characteristics of this organism.
Both the use of infected foods and the transfer of the disease from person to person are modes of transmission. The capacity of the bacterium to grow at temperatures that are lower than those found in refrigerators makes food contamination more likely. Infectious foods such as infected meats, cheese, milk, poultry, and shellfish are among the sources of illness. The transmission of the disease from one individual to another can take place through in utero infections, colonization of the birth canal, and nosocomial transmission by nursing staff in hospitals.

Listeria can be broken down into three distinct categories. Perinatal listeriosis can present itself in a variety of ways, including meningitis, pneumonia, or septicemia. Severe cases of the disease can lead to stillbirths, spontaneous abortions, or granulomatosis infantiseptica, which is a life-threatening condition. It is possible for immune-competent persons, including pregnant women, to experience infections that are asymptomatic. Adult bacterial meningitis caused by Listeria is uncommon in adults who are otherwise healthy, but it is common in people who are immunocompromised as a result of cancer chemotherapy, transplants, or HIV infection.

Invasion of host cells is the primary mechanism that causes pathogenic symptoms. Internalin and listeriolysin O are two virulence factors that contribute to the facilitation of this process. After binding to host cells, internalin stimulates the process of endocytosis. Listeriolysin O is a poreforming toxin that enables organisms to break out from the confines of the final membrane. It is possible for L monocytogenes to circumvent the humoral immune response because it replicates in the cytoplasm and spreads to neighboring cells and cells. In a pregnant woman who is asymptomatic, the invasion of placental endothelial cells from a bacteremia is the mechanism that facilitates the propagation of the infection across the placenta. The majority of immune responses are cell-mediated.

A wide range of antibiotics, such as aminoglycosides, trimethoprim-Prevention sulfamethoxazole, ampicillin, and others, are effective in treating infections caused by Listeria. The eradication of animal reservoirs, the use of precautions when handling neonates, and the prompt diagnosis and treatment of pregnant women who are infected are all components of infection control.