Neurology and Microbiology Quiz

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Questions and Answers

Which organism is classified as a Gram positive bacillus?

Neisseria meningitidis

Clostridium botulinum

Listeria monocytogenes (correct)

Streptococcus pneumoniae

What is the main role of cerebrospinal fluid (CSF)?

Acts as a barrier to pathogens

Provides a cushion for the brain (correct)

Transports oxygen to the spinal column

Delivers nutrients to the brain

Which of the following is NOT a layer of the meninges?

Cerebral cortex (correct)

Pia mater

Dura mater

Arachnoid mater

What do the specialized blood vessels forming the blood-brain barrier primarily do?

Deliver nutrients and oxygen to the CNS Signup and view all the answers

Which bacterium is known to affect the peripheral nervous system and can cause leprosy?

Mycobacterium leprae Signup and view all the answers

Which of the following pathogens is a Gram negative coccobacillus?

Haemophilus influenzae Signup and view all the answers

Which type of bacteria can typically penetrate the blood-brain barrier?

A small subset of pathogens Signup and view all the answers

Which organism is classified as a Gram negative cocci?

Neisseria meningitidis Signup and view all the answers

Which of the following is a valid route of infection for meningitis?

Hematogenous spread Signup and view all the answers

Which of the following conditions is NOT mentioned as being influenced by altered gut microbiota?

Heart disease Signup and view all the answers

What is the term for the inflammation of both the brain and the meninges?

Meningoencephalitis Signup and view all the answers

Which type of sampling technique is used to avoid skin flora during specimen collection for CNS infections?

Aseptic technique Signup and view all the answers

What is the purpose of collecting multiple tubes during a lumbar puncture?

To obtain various types of analyses Signup and view all the answers

In which condition is the gut-brain axis particularly noted for influencing brain function?

Parkinson’s Disease Signup and view all the answers

What happens if lumbar puncture specimens are refrigerated?

It can alter the test results Signup and view all the answers

What is considered abnormal within the CNS and PNS?

Any microbes present Signup and view all the answers

What laboratory test result is considered critical for bacterial meningitis diagnosis?

Positive bacterial culture Signup and view all the answers

Which common agents are known to cause viral meningitis?

HSV and enteroviruses Signup and view all the answers

Which lab test is specifically recommended if a fungal pathogen is suspected?

Fungal culture and smear Signup and view all the answers

What symptom is common to both viral and bacterial meningitis?

Stiff neck Signup and view all the answers

What is the typical prognosis for viral meningitis?

Good Signup and view all the answers

Which testing method is used for rapid detection of common viral causes in CSF?

NAAT testing Signup and view all the answers

What is the normal CSF cell count in a non-infected individual?

Few WBC and no RBC Signup and view all the answers

How long does it typically take to get results from a bacterial culture and smear?

2-3 days Signup and view all the answers

Study Notes

Nervous System Infections Overview

Nervous system infections often affect the brain, spinal column, and peripheral nervous system (PNS)
Meninges are the three layers of tissue surrounding the brain and spinal cord
Cerebrospinal fluid (CSF) is produced within the brain and acts as a cushion
The blood-brain barrier is a specialized system of blood vessels that deliver nutrients to the CNS. It selectively allows passage of specific nutrients and molecules, limiting many pathogens from entering the nervous system
The nervous system does not have its own resident microbiota
Any microbes present in CNS or PNS suggest infection

Bacterial Meningitis

Bacterial meningitis is inflammation of the meninges
Common causative agents include:
- Neisseria meningitidis (GNC)
 - AKA meningococcus
 - Common serotypes include A, B, C, W, X and Y, with B most common in <1 year olds
- Streptococcus pneumoniae (GPC)
 - AKA pneumococcus, potentially most common bacterial meningitis
- Haemophilus influenzae (GNCB)
Transmission typically occurs through respiratory droplets and/or close contact with carriers.
Symptoms frequently include fever, headache, stiff neck, nausea, vomiting, and potentially purpura and/or petechiae

Bacterial Infections Affecting PNS

Bacterial infections affecting the peripheral nervous system can be caused by:
- Mycobacterium leprae: Infects nerves directly, causes Hansen's disease (leprosy)
Clostridium botulinum: Produces botulinum toxin, a neurotoxin that causes flaccid paralysis.
Clostridium tetani: Produces tetanus toxin, a neurotoxin that causes spastic paralysis

Listeria Meningitis (Listeriosis)

Listeria monocytogenes (GPB) is the causative agent
Grows at low temperatures, which can present a foodborne risk
Foodborne transmission is common via dairy products, deli meats, fruits, and vegetables.
Symptoms in healthy adults may resemble a mild cold, but more serious infections may lead to neurological issues in vulnerable populations (e.g., pregnant women, neonates, immunocompromised).

Tetanus ("Lockjaw")

Caused by Clostridium tetani (GPB/anaerobe, endospore-former)
Endospores enter through deep wounds.
Production of the neurotoxin, tetanospasmin, causes spastic paralysis.
Vaccine and antitoxin are available but recurring booster doses are necessary for long-term immunity.

Botulism

Caused by Clostridium botulinum (GPB, anaerobe, endospore-former)
Toxin (botulinum) prevents muscle contraction, resulting in flaccid paralysis.
Foodborne botulism, wound botulism, and infant botulism are common types
The toxin is highly potent; small amounts (e.g., 1 ng) can be lethal.
The toxin can be used therapeutically in certain medical situations (e.g., excessive sweating, muscle spasms, etc.)

Laboratory Diagnosis and Treatment

Diagnosis frequently involves lumbar punctures to collect CSF
Appropriate lab tests include cell counts/differentials, protein/glucose levels, NAAT tests, bacterial cultures, and fungal cultures.
Treatment varies by agent, with antibiotics and supportive care used for bacterial infections.

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Description

Test your knowledge on critical topics related to neurology and microbiology. This quiz covers the classification of bacteria, the functions of cerebrospinal fluid, and the mechanisms behind CNS infections. Dive into the intricate relationship between the nervous system and microbiota.