Listeria meningitis
Introduction
Introduction to Listeria meningitis Listeria meningitis is a meningitis caused by Listeria monocytogenes (Listeria monocytogenes), which is more common in infants, the elderly and adult patients with impaired immune function. In addition to meningitis, it can also cause pregnancy infection, neonatal septic granuloma, sepsis and focal infections. Such as skin abscess, suppurative conjunctivitis, lymphadenitis, endocarditis (more left heart damage), osteomyelitis, etc., Listeria is Gram-positive Brevibacterium, the size is (1 ~ 2) m × 0.5 Mm, usually arranged in double, does not produce spores, generally does not form a capsule, can form a mucopolysaccharide capsule in serum-containing glucose protein sputum water, flagella can be seen in flagellar hair, the bacteria are aerobic or facultative anaerobic, for nutrition High, can grow on ordinary medium, can grow at 3 ~ 45 °C, but the optimum temperature is 30 ~ 37%, on the blood agar plate at 35 ° C for 18 ~ 24h, the colony is grayish white, diameter 1-2mm , can produce a narrow -hemolytic ring. Culture on a nutrient agar plate at 35 ° C for 18 ~ 24h, can form a round, smooth, transparent, 1 ~ 2mm size colonies, with a hemolytic ring. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: brain abscess endocarditis abortion
Cause
Listeria meningitis etiology
(1) Causes of the disease
Listeria monocytogenes is Gram-positive bacillus, facultative anaerobic, no spores, 1 to 3 m long, flagellate and motility, growing in a variety of media, alkali-resistant and acid-resistant, most suitable The culture temperature is 35-37 ° C, the growth is less than 4 ° C, can ferment a variety of sugars, acid production does not produce gas, catalase-positive, methyl red and VP reaction positive, in serum-containing glucose protein water It can form a mucopolysaccharide capsule, which can produce a hemolytic ring on blood agar plates, arranged in pairs in cerebrospinal fluid specimens, shaped like cocci, which can be mistaken for pneumococcal bacteria. When Gram staining is excessively decolorized, its shape is like influenza bacillus, sometimes with Diphtheria-like bacilli are also highly confusing, and they need to be identified according to their biochemical characteristics.
(two) pathogenesis
The pathogenesis of this disease is not yet clear, but it is obviously related to the host immune status. In the early stage of infection, non-immune macrophages lack the viability to kill the cells, but can limit its proliferation in the lymphatic network, after 2 to 3 days of infection. Under the activation of T cells, more macrophages are attracted to the site of inflammation, leading to inflammation clearance, and humoral immunity has no protective effect on the infection of the bacteria, so in patients with low cellular immunity and immunosuppressive agents, the disease The incidence rate is relatively high.
Prevention
Listeria meningitis prevention
People with immune dysfunction should avoid contact with patients with listeriosis, high-risk susceptible people should avoid drinking raw milk, pay attention to food hygiene, and not eat raw vegetables and uncooked meat.
Complication
Listeria meningitis complications Complications, brain abscess, endocarditis, abortion
Concurrent brain abscess, endocarditis and miscarriage.
Symptom
Listeria meningitis symptoms common symptoms consciousness disorder nausea dysphagia convulsions vertigo stagnation
Similar to other bacterial meningitis, the onset is generally acute. The first symptom of 90% of cases is fever, mostly above 39 °C. There are severe headaches, dizziness, nausea, vomiting, meningeal irritation, and often accompanied by disturbance of consciousness. Such as stupor, sputum, etc., can also occur convulsions, severe cases can be coma within 24 ~ 48h, a small number of onset slow, long course and repeated, such as lesions involving the brain parenchyma may have encephalitis and brain abscess performance, Individual brain stem inflammation occurred in diplopia, pronunciation and difficulty in swallowing, facial nerve spasm and hemiplegia.
Examine
Examination of Listeria meningitis
The total number of white blood cells and neutrophils in the peripheral blood increased, monocytes did not increase, and the routine white blood cell count of cerebrospinal fluid increased to hundreds or thousands. The majority of the monocytes were multinucleated cells, and the number of mononuclear cells increased, protein increased, and sugar decreased. Cerebrospinal fluid smears can be found in small Gram-positive bacilli, and blood and cerebrospinal fluid cultures are positive.
In patients with complicated brain abscess, EEG can be abnormal.
Diagnosis
Diagnosis and identification of Listeria meningitis
diagnosis
Peripheral blood in the patient's total number of white blood cells and neutrophils increased, monocytes did not increase, cerebrospinal fluid routine white blood cell count increased to hundreds or thousands, mainly multinucleated cells, a few mononuclear cells increased, protein increased, sugar reduction Cerebrospinal fluid smear can be found in small Gram-positive bacilli, blood and cerebrospinal fluid culture positive can be diagnosed, serological examination, double serum antibody titer can help diagnose, but the bacteria antigen and Staphylococcus, Streptococcus, pneumococcus have The common antigen can cross-react, so its diagnostic value is limited. PCR detection of this bacteria in cerebrospinal fluid can help diagnose.
Differential diagnosis
The disease should be differentiated from other purulent meningitis. The cerebrospinal fluid cells are classified as mononuclear. It should be distinguished from tuberculous meningitis or fungal meningitis. The condition is mild, and the number of cerebrospinal fluid cells should not be too much. Inflammation identification.
