Finals - Microbial Diseases of the Nervous System-2nd - Sheet1 Flashcards
The nervous system has two main parts:
central nervous system
peripheral nervous system
is made up of the brain and spinal cord
central nervous system
is made up of nerves that branch off from the spinal cord and extend to all parts of the body
peripheral nervous system
protect brain and spinal cord
Meninges
Layers of the meninges
Dura mater
Arachnoid mater
Pia mater
Outermost layer of the meninges
Dura mater:
Middle layer of the meninges
Subarachnoid space contains cerebrospinal fluid (CSF)
Arachnoid mater:
Innermost layer of the meninges
Pia mater:
highly selective semipermeable border that separates the circulating blood from the brain and extracellular fluid in the central nervous system (CNS)
Blood–brain barrier-
Inflammation of meninges
Meningitis:
Inflammation of the brain
Encephalitis:
Inflammation of both the meninges and the brain
Meningoencephalitis:
Initial symptoms of fever, headache, and stiff neck
Followed by nausea and vomiting
May progress to convulsions and coma
Diagnosis by Gram stain and latex agglutination of CSF
Treatment: Cephalosporins, vancomycin
Bacterial Meningitis
Spinal needle is inserted, usually between the third and fourth lumbar vertebrae
Spinal Tap (Lumbar Puncture)
Occurs mostly in children (6 months to 4 years)
Gram-negative aerobic bacteria, normal throat microbiota
Capsule antigen type B
Symptoms: fever, nausea, sensitivity to light, headaches, stiff neck, anorexia, and seizures.
Prevented by Hib vaccine
Haemophilus influenzae Meningitis
Also called meningococcal meningitis
Caused by N. meningitidis
Gram-negative, aerobic cocci with a capsule
Person-to-person through droplets of respiratory or throat secretions from carriers
10% of people are healthy nasopharyngeal carriers
Begins as throat infection, rash
Neisseria Meningitis
Serotypes B, C, Y, W-135 can be found in
U.S.
Serotype B is found in
Europe
Serotype A is found in
Africa, China, and Middle East
Treatment for Nesseriria Meningitis:
Ceftriaxone or Cefotaxime( third generation cephalosporin)
Also called pneumococcal meningitis
Caused by S. pneumoniae (a gram-positive diplococcus)
Droplet thru sneezing or coughing
70% of people are healthy nasopharyngeal carriers
Most common in children (1 month to 4 years)
Mortality: 30% in children, 80% in elderly
Streptococcus pneumoniae Meningitis
Treatment for Streptococcus pneumoniae Meningitis
Penicillin or Erythromycin
Caused by Listeria monocytogenes
Gram-negative aerobic rod
Usually foodborne; it can be transmitted to fetus
Reproduce in phagocytes
Listeriosis
Listeriosis is caused by
Listeria monocytogenes
Treatment for Listeria monocytogenes
Gentamycin IV if septicemia occurs
Foods at high risk of carrying listeria include:
foods at ready-to-eat salad bars, sandwich bars and delicatessens
ready-to-eat meals
soft and semi-soft cheeses
unwashed raw vegetables
soft-serve ice cream
raw shellfish and seafood
unpasteurized dairy products
cold cured or prepared meats
NA
Caused by Clostridium tetani
Gram-positive, endospore-forming, obligate anaerobe
Grows in deep wounds
Tetanospasmin released from dead cells blocks relaxation pathway in muscles
Prevention by vaccination with tetanus toxoid (DTP) and booster (dT)
Treatment with tetanus immune globulin
Tetanus( Lockjaw)
Tetanus( Lockjaw) is caused by
Clostridium tetani
Caused by Clostridium botulinum
Gram-positive, endospore-forming, obligate anaerobe
Intoxication comes from ingesting botulinal toxin
Botulism
results from C. botulinum growing in intestines
Infant botulism
results from growth of Clostridium botulinum in wounds
Wound botulism
Botulinal Types
60–70% fatality
Found in CA, WA, CO, OR, NM
Type A toxin
Botulinal Types
25% fatality
Europe and eastern United States
Type B toxin
Botulinal Types
25% fatality
Found in marine and lake sediments
Pacific Northwest, Alaska, Great Lakes area
Type E toxin
Also called Hansen’s disease
Caused by Mycobacterium leprae
Acid-fast rod that grows best at 30°C.
Grows in peripheral nerves and skin cells
Transmission requires prolonged contact with an infected person by nasal secretions or droplets.
Leprosy
Form of leprosy with Loss of sensation in skin areas; positive lepromin test
Tuberculoid (neural) form:
Form of Leprosy with Disfiguring nodules over body; negative lepromin test
Lepromatous (progressive) form:
Treatment for leprosy:
Dapsone with Rifampicin, and Clofazimine
is a disabling and life-threatening disease caused by the poliovirus
Transmitted by ingestion
Initial symptoms: Sore throat and nausea
Viremia may occur; if persistent, virus can enter the CNS
Destruction of motor cells and paralysis occurs in <1% of cases
Poliomyelitis (Polio)
Caused by the rabies virus
Transmitted by animal bite
Rabies
type of rabies where Animals are restless then highly excitable
Furious rabies:
type of rabies Animals seem unaware of surroundings
Paralytic rabies:
- Transmission from saliva of the rabid animal
Zoonosis
Injection of human diploid cells vaccine (HDCV)
Preexposure prophylaxis:
Vaccine plus rabies immune globulin (RIG)
Postexposure treatment:
Inflammation of the brain (encephalitis) caused by infection with an arbovirus
Arboviral encephalitis:
Arthropod-borne viruses that belong to several families
Arboviral encephalitis:
is an infection usually affecting children under 5 years old
Virus causing infection usually
infects the meninges, which are the
protective tissue coverings of the
brain and spinal cord
Viral Meningitis
Soil fungus associated with pigeon and chicken droppings
Transmitted by the respiratory route; spreads through blood to the CNS
Cryptococcus neoformans Meningitis
also known as African sleeping sickness, is an insect-borne parasitic disease of humans and other animals.
African Trypanosomiasis
this causes Chronic African Trypanosomiasis (2 to 4 years)
Trypanosoma brucei gambiense
this causes Acute African Trypanosomiasis (few months)
T. b. rhodesiense infection
this is how African Trypanosomiasis is transmitted
tsetse fly
Protozoan that infects the nasal mucosa from swimming water
Naegleria fowleri
(commonly referred to as the “brain-eating amoeba” or “brain-eating ameba”), is a free-living microscopic ameba*, (single-celled living organism).
It can cause a rare** and devastating infection of the brain called primary amebic meningoencephalitis (PAM).
Naegleria fowleri
Naegleria invades brain and meninges via nasal mucosa; exposure through swimming in contaminated pools, stagnant ponds, freshwater lakes, thermal springs, hot tubs and spas; infection by inhalation of cysts in dust or soil particles
NA
are a group of neurodegenerative diseases caused by prions, which are “proteinaceous infectious particles.”
Prion diseases
Typical Prion diseases
Sheep scrapie
Creutzfeldt-Jakob disease
Kuru
Bovine spongiform encephalopathy
NA
Also called myalgic encephalomyelitis (ME)
Chronic Fatigue Syndrome
Unexplained fatigue that lasts at least 6 months + 4 of these symptoms:
Chronic Fatigue Syndrome
