Listeria monocytogenes
The test designed for Listeria monocytogenes DNA detection in human biological material by realtime PCR.
Category «Other infections»
Listeria monocytogenes
Listeria monocytogenes is a gram-positive facultative anaerobic microorganism. This pathogen causes listeriosis – an infectious disease characterized by polymorphism of clinical manifestations and high lethality. The risk group includes pregnant women, children under three years of age, elderly people, patients with immunodeficiencies (including HIV), oncological diseases, sugar diabetes, and patients after organ transplantation.
The main source and natural reservoir of L. monocytogenes is environment, primarily soil. Bacteria can also be extracted from plants, silos, dust, reservoirs, and waste water. Other sources of L. monocytogenes include livestock, pets, rodents, and some tick species.
Listeria monocytogenes has several routes of transition:
- Foodborne route: through consumption of infected food products (dairy products, meat, seafood, unwashed vegetables).
- Airborne route: through inhaling dust contaminated with listeria (during processing of hides, wool, feathers, down).
- Vertical route: infection transition from mother to fetus during pregnancy or delivery.
- Contact route: through damaged skin or mucous membranes of eyes and oropharynx, care for infected animals.
- Transmissive route: through insect vector bite.
The main Listeria monocytogenes pathogenicity factors include:
- Internalin proteins (InlA and InlB): invasion factors that enable listeria to enter cells (InlA targets epithelial cells, InlB targets hepatocytes).
- Membranolytic enzymes: listeriolysin O and specific phospholipases C cause lysis of phagosomes, allowing free division of listeria in the cytoplasm and the development of incomplete phagocytosis.
- Surface protein ActA: induces actin polymerization, enabling active bacterial movement within the cell and intercellular spread.
Diagnostics
Incubation period for listeriosis is on average 2–4 weeks. Chronic disease development and carrier state formation are possible, which requires prescription of long-term antibiotic therapy.
The most frequent primary localized infection form is gastrointestinal infection. The symptoms include high body temperature, cramping abdominal pain, stool disorders (diarrhea-type), myalgia. Invasive listeriosis can cause sepsis (primary generalized form) and nervous system damage with development of meningoencephalitis and brain abscess (secondary generalized form). Development of endocarditis, pneumonia, pyelonephritis, peritonitis, osteomyelitis, liver and spleen abscesses is possible. In oncology patients, listeria persistence in tumor cells occurs.
Listeria monocytogenes is of particular danger to pregnant women. In most cases of infection, acute respiratory disease symptoms or gastrointestinal form may be observed. In clinically manifest listeriosis and carrier state formation, there is a higher risk of prenatal infection, which may lead to pregnancy complications and fetal pathology. Early pathogen identification allows for timely antibiotic therapy and, thus, better prospects both for the mother and the baby.
Bacteriological and serological methods, PCR, and immunochromatography (listeria antigen detection) are used for listeriosis laboratory diagnostics. PCR is characterized by high sensitivity and specificity and allows for listeria DNA detection in blood, swabs from mucous membranes, liquor, amniotic fluid, biopsy samples, feces and meconium.
Indications
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Symptoms of respiratory disease during pregnancy -
Suspected neonatal listeriosis -
Acute intestinal infection of unknown origin -
Meningoencephalitis of unknown origin -
Sepsis -
Immunodeficiencies -
Differential diagnostics of prenatal infections -
Liver and spleen abscess of unknown origin
Listeria monocytogenes
The Listeria monocytogenes test is designed for detection of Listeria monocytogenes DNA in human biological material by real-time PCR.
The reagent kit can be used in clinical diagnostic laboratories of medical institutions and in research practice.
Biomaterial: epithelial cells swabs, cerebrospinal fluid, amniotic fluid, biopsy samples and punctate, feces, meconium, whole peripheral blood.
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Please note that the specialists of the DNA Technology company provide consultations exclusively to medical specialists on the application and research features. Requests related to the appointment, delivery, or interpretation of tests are not considered. For relevant information, we recommend contacting the laboratory directly.