NEURO INFECTIONS

Acute Bacterial Meningitis

What infection is defined as inflammation of the subarachnoid space and meninges?

Subarachnoid space and meninges

Which anatomical areas are inflamed in acute bacterial meningitis?

Classic triad

What term is used for the clinical presentation of fever, headache, and nuchal rigidity in meningitis?

Fever, headache, and nuchal rigidity

What are the three components of the classic triad of acute bacterial meningitis?

Encephalitis

What is the term for inflammation of the brain parenchyma?

Brain parenchyma

What specific anatomical structure is inflamed in encephalitis?

Altered consciousness, behavioral disorders, and focal neurologic signs

What are three clinical presentations of encephalitis?

Meningoencephalitis

What term describes inflammation involving both the meninges and the brain parenchyma?

Mumps or HSV

Which two specific pathogens are mentioned as causes of meningoencephalitis?

Encephalomyelitis

What is the term for inflammation of the spinal cord?

Spinal cord

What anatomical structure is inflamed in encephalomyelitis?

Encephalomyeloradiculitis

What term is used when encephalomyelitis involves the nerve roots?

Nerve roots

What structures are involved in encephalomyeloradiculitis in addition to the spinal cord?

Streptococcus pneumoniae

Which microbe is described as a Gram positive lancet-shaped diplococcus?

Gram positive lancet-shaped diplococci

What is the morphology and Gram stain of Streptococcus pneumoniae?

Alpha-hemolytic

What is the hemolytic pattern of Streptococcus pneumoniae?

Optochin sensitive

Is Streptococcus pneumoniae optochin sensitive or resistant?

Streptococcus pneumoniae

What is the most common cause of acute bacterial meningitis in adults?

Pneumonia and head trauma

With what two conditions is Streptococcus pneumoniae meningitis frequently associated?

Neisseria meningitidis

Which microbe is described as a Gram negative kidney-shaped diplococcus?

Gram negative kidney-shaped diplococci

What is the morphology and Gram stain of Neisseria meningitidis?

Oxidase positive

What is the oxidase test result for Neisseria meningitidis?

13

How many serogroups of Neisseria meningitidis exist?

Neisseria meningitidis

Which bacteria is the only one known to generate epidemics of meningitis?

Petechial or purpuric rash

What specific skin finding is a clinical clue for Neisseria meningitidis?

Haemophilus influenzae

Which microbe is described as a Gram negative coccoid bacilli?

Gram negative coccoid bacilli

What is the morphology and Gram stain of Haemophilus influenzae?

Satellite phenomenon

What laboratory phenomenon does Haemophilus influenzae exhibit with S. aureus?

S. aureus

With which bacteria does Haemophilus influenzae exhibit the satellite phenomenon?

Factors X and V

What two specific factors does Haemophilus influenzae require for growth?

Hib vaccine

The incidence of Haemophilus influenzae meningitis declined due to what intervention?

Group B Streptococcus

Which microbe is a Gram positive cocci that is Beta-hemolytic and Bacitracin-resistant?

Gram positive cocci

What is the morphology and Gram stain of Group B Streptococcus?

Beta-hemolytic

What is the hemolytic pattern of Group B Streptococcus?

Bacitracin-resistant

Is Group B Streptococcus bacitracin-sensitive or resistant?

Group B Streptococcus

What is the predominant cause of meningitis in neonates?

Normal vaginal flora

Where is Group B Streptococcus typically found as part of normal human flora?

Listeria monocytogenes

Which microbe is a Gram positive bacilli with tumbling motility?

Gram positive bacilli

What is the morphology and Gram stain of Listeria monocytogenes?

Tumbling motility

What specific type of movement does Listeria monocytogenes exhibit?

22-28C

At what temperature range does Listeria monocytogenes exhibit tumbling motility?

4C and high salt

Listeria monocytogenes is notable for surviving in what two harsh conditions?

GI route

How does Listeria monocytogenes typically enter the body?

Deli meats and cheese

What two food types are mentioned as sources of Listeria monocytogenes?

The Philippines

In what specific geographic location is Listeria monocytogenes rarely seen?

Increased

What is the typical opening pressure in acute bacterial meningitis?

Normal to slightly elevated

What is the typical opening pressure in viral meningitis?

High

What is the typical opening pressure in TB and fungal meningitis?

Neutrophils

Which white blood cells predominate in acute bacterial meningitis?

Lymphocytes

Which white blood cells predominate in viral meningitis?

Lymphocytes

Which white blood cells predominate in TB and fungal meningitis?

Decreased

What happens to CSF glucose levels in acute bacterial meningitis?

Normal

What happens to CSF glucose levels in viral meningitis?

Low

What happens to CSF glucose levels in TB and fungal meningitis?

Increased

What happens to CSF protein levels in acute bacterial meningitis?

Normal to slightly elevated

What happens to CSF protein levels in viral meningitis?

Increased

What happens to CSF protein levels in TB and fungal meningitis?

Positive in more than 60 percent

How often is the Gram stain positive in acute bacterial meningitis?

Negative

What is the typical Gram stain result in viral meningitis?

Negative

What is the typical Gram stain result for TB and fungal meningitis?

AFB or India Ink

What two specific stains are required if the Gram stain is negative for TB or fungal pathogens?

Clostridium tetani

Which pathogen has a tennis racket appearance due to a large terminal spore?

Tennis racket

What is the characteristic appearance of Clostridium tetani?

Large terminal spore

What specific structure gives Clostridium tetani its tennis racket appearance?

Degrades synaptobrevin

What is the mechanism of the Clostridium tetani toxin?

GABA and Glycine

The tetanus toxin blocks the release of which two inhibitory neurotransmitters?

Inhibitory neurotransmitters

What type of neurotransmitters are GABA and Glycine?

Rabies Virus

Which virus is described as bullet-shaped?

Bullet-shaped

What is the characteristic shape of the Rabies Virus?

Negri bodies

What are the eosinophilic cytoplasmic inclusions found in Rabies called?

Eosinophilic cytoplasmic inclusions

What is the microscopic description of Negri bodies?

Retrograde axonal transport

How does the Rabies Virus travel from a bite to the CNS?

Poliovirus

Which virus enters via the mouth and binds to the CD155 receptor?

Central chromatolysis

What term describes the dissolution of the Nissl body caused by Poliovirus?

Dissolution of Nissl body

What is central chromatolysis?

CD155 receptor

To which receptor does the Poliovirus bind?

LMN flaccid paralysis

What type of paralysis is caused by Poliovirus?

M. tuberculosis

Which pathogen is identified as acid-fast bacilli?

Acid-fast bacilli

What is the diagnostic hallmark of M. tuberculosis?

Tubercles

What structures seed the parenchyma in M. tuberculosis infection?

Inhalation of droplets

How is M. tuberculosis typically transmitted?

Thick basal exudates

What does M. tuberculosis form in the subarachnoid space?

Subarachnoid space

Where are the thick basal exudates of M. tuberculosis located?

Treponema pallidum

Which pathogen is described as slender spirals with endoflagella?

Slender spirals

What is the morphology of Treponema pallidum?

Endoflagella

What structure in Treponema pallidum contains hyaluronidase?

Hyaluronidase

What enzyme is contained in the endoflagella of Treponema pallidum?

Cardiolipin

What is the important antigen used in testing for Treponema pallidum?

FTA-ABS

What test is used to confirm a Treponema pallidum infection?

Cryptococcus neoformans

Which pathogen is an encapsulated yeast seen with India Ink?

Encapsulated yeast

What is the morphology of Cryptococcus neoformans?

India Ink

Which stain is used to visualize the capsule of Cryptococcus neoformans?

Pigeon droppings

With what environmental source is Cryptococcus neoformans associated?

Immunocompromised

In which patient population is Cryptococcus neoformans typically opportunistic?

Early Cerebritis

What is the first stage of a brain abscess occurring on days 1-3?

Days 1-3

What is the timing for the early cerebritis stage?

Coagulative necrosis

What type of necrosis is surrounded by inflammatory cells in early cerebritis?

Perivascular inflammatory cells and marked edema

What two morphologic features besides necrosis characterize early cerebritis?

Late Cerebritis

What is the second stage of a brain abscess occurring on days 4-9?

Days 4-9

What is the timing for the late cerebritis stage?