Microbiology π¦ Flashcards
what is Meningitis?
- inflammation of meninges covering brain and spinal cord
Signs & Symptoms of Meningitis
- Headache
- Photophobia
- Malaise
- Neck stiffness
- Coma
Types of meningitis
- Epidemic cerebrospinal meningitis (bacterial)
- Tuberculous meningitis
- Acute aseptic meningitis
Causative organisms of Epidemic cerebrospinal meningitis (bacterial)
- Neisseria meningitides.
- Streptococcus pyogenes
- Streptococcus pneumoniae
- Staphylococcus aureus
- Haemophilus influenza
- pseudomonas aeruginosa
what are types of Acute aseptic meningitis?
Viral infection:
- Primary: poliomylitis, Coxsackieβs, ECHO and arboviruses.
- Secondary :to mumps, chicken pox, and measles.
Spirochaetal infection:
- Leptospira causing swineherd disease.
Causes of Neonatal meningitis
- E.coli.
- Citrobacter.
- Group B streptococci.
- Klebsiella,Enterobacter.
- Listeriamonocytogenes.
Lab diagnosis of meningitis
- Sample
- Direct film
- PCR
- Serological method
Sample for diagnosis of meningitis
CSF
Collection of CSF
- Lumbar puncture
- Aseptic conditions
- between 4th and 5th lumbar vertebrae.
- screw-capped bottles
- Sent to the laboratory at once
General rule for specimen collection
- Wash your hands before and after sample collection
- Samples must be: Before the start of antimicrobial therapy.
- CSF specimens are best taken at the bedside where suitable media are directly inoculated.
- Viral transport media for transporting swabs for viral cultures.
Significance of PCR in diagnosis of meningitis
PCR is a great diagnostic tool in all types of meningitis.
Serolofical methods in diagnosis of meningitis
- using commercially available bacterial antigen kit to detect the presence of common bacterial pathogens. These tests are considered one of the rapid diagnostic methods.
what does Neisseria meningitides cause?
acute cereprospinal meningitis
Morphology & Characters of Neisseria meningitides
- Gram-negative, kidney shape, diplococci, pilliated & capsulated
- intracellular
Laboratory diagnosis of acute cerebrospinal meningitis.
- Samples
- Direct film
- Culture
- Identification
- Definitive Identification
- Rapid diagnosis
Sample in Diagnosis of a case of N.meningitidis
- CSF, blood and in the nasopharynx early in the disease.
- C.S.F is obtained by lumbar puncture under complete aseptic precautions.
Morphology of CSF in a case of N.meningitidis
- C.S.F is turbid and under tension due to presence of pus cells.
Direct film in Diagnosis of a case of N.meningitidis
- Detection of intracellular Gram Negative diplococci is diagnostic