Micro B Flashcards
What is the most common CNS infection?
Blood-Borne Invasion - ex Polioviruses or Neisseria meningitidis
What is the other route for CNS infections?
Invasion via peripheral nerves; less common (e.g. herpes simplex, varicella-zoster, rabies)
Fill in the blanks. “ -Blood-borne invasion takes place across: blood-brain barrier ex ___________ OR blood-cerebrospinal fluid (CSF) barrier ex ___________. “
Blood brain barrier ex Encephalitis
Blood - Cerebrospinal fluid (CSF) ex Meningitis
What are the Early symptoms of Meningitis?
Self-limiting conditions
(flu and colds).
What is Meningitis?
Inflammation of the meninges associated with an abnormal number of cells in the cerebrospinal fluid.
What are the predominant cells found in Mononuclear Pleocytosis?
Mononuclear cells
( its in the name lol)
What is Aseptic Meningitis?
A syndrome characterised by acute onset of meningeal symptoms and fever, with pleocytosis of the cerebrospinal fluid and no growth on routine bacterial culture.
What is Encephalitis?
Encephalitis is an inflammation of the brain parenchyma.
What are the infectious agents that can cause Meningitis?
Bacteria
Viruses
Fungi
Protozoa
Fill in the blanks. “ Septic meningitis is caused by ________ while Aspetic meningitis is caused by __________.”
Septic - Bacterial infection s
Aseptic- Viral infections
True or False? Septic Meningitis usually resolve without treatment.
FALSE!! ASEPTIC Meningitis usually resolve without treatment .
What are the most common general agents for Bacterial meningitis?
- Haemophilus influenzae
- Streptococcus pneumoniae
- Neisseria meningitidis –not common in Ja.
What are the most common agents for Bacterial meningitis in Neonates?
- E.coli
- Group B streptococcus
- Enterococcus
- Listeria monocytogenes
- Other enteric Gram negative bacilli
What are the most common agents for Bacterial meningitis in Adults?
- Streptococcus pneumoniae
- Staphylococcus aureus
- Listeria monocytogenes
What are the most common agents for Bacterial meningitis in Children?
- Haemophilus influenzae
- Streptococcus pneumoniae
- Neisseria meningitidis (not common in Ja.)
What are the most common agents for Viral meningitis?
Enteroviruses (Coxsackie and Echovirus)
What is the incubation period for Enteroviruses?
3-6 days
What is the Incubation period for Aboviruses?
2-15 day s
What is the causative organism of Epidemic cerebrospinal meningitis ?
Meningococcus- Neisseria Meningitis
What is the gram- stain for Neisseria Meningitis?
Aerobic gram-negative diplococci
What is the transmission for Meningococcal meningitis?
Respiratory droplets
What are the clinical findings of Meningococcal Meningitis?
- Fever
- Vomiting
- Headache
- Stiff neck
- Hypotension, and rash
What is the treatment for Nessiera Meningitidis ?
- Penicillin G
- Chloramphenicol and cephalosporins for:
- persons allergic to penicillin or
- strain is resistant to penicillin
What is the cell count of lymphocyte / mononuclear cells in Normal CSF?
Ccount 0-5 lymphocyte/mononuclear cells per ml
What are the examples of Chronic meningitis?
Mycobacterium tuberculosis meningitis
Cryptococcal meningitis
True or False? CSF should NEVER be refrigerated.
TRUE!!
What is the culture media used to diagnose Meningitis?
- Blood agar CO2
- Blood agar ANO2
- Chocolate agar CO2
- MacConkey’s agar (If indicated)
What is the appearance of Streptococcus pneumoniae?
Pus cells and Gram positive cocci in lancet pairs
What is the appearance of Neisseria meningitis?
Pus cells and Gram negative cocci in bean shaped pairs
What is the appearance of Haemophilus influenzae?
Pus cells and Gram negative pleomorphic bacilli.
Which organism is Catalase negative , alpha haemolytic , Bile solubility Positive?
Streptococcus pneumoniae
Which organism is Optochin susceptible ,Inulin fermentation positive, Mouse pathogenicity positive & Neufeld’s capsular swelling: positive
(Quellung’s reaction)?
Streptococcus pneumoniae
What is the appearance of Neisseria meningitidis?
Gram negative diplococci (bean shaped pair)
Which organism is
Oxidase - positive, Dextrose positive & Maltose positive BUT Sucrose NEGATIVE?
Neisseria meningitidis
Which Serotypes causes the most invasive disease?
A, B, C, Y & W135
Whici organism has satellitism” on blood agar
(X and V factors needed for growth)?
Haemophilus influenzae
Which organism is Gram negative with Pleomorphic bacilli?
Haemophilus influenzae
Which serotype of Haemophilus influenzae causes almost ALL invasive diseases?
Type B
Which organism is Gram - negative cocci in chains?
Streptococcus agalactiae (Group B)
True or False? Streptococcus agalactiae (Group B) is Catalase positive and Camp test Negative.
FALSE!! It is Catalase NEGATIVE and CAMP test POSITIVE
True or False? Streptococcus agalactiae (Group B) is Beta-Haemolytic.
TRUE!!
What is the Gram reaction for E.coli?
Gram negative Bacilli
True or False? Ecoli is Oxidase Positive , Indole Negative and Urea positive.
FALSE!! Oxidase: Negative
Kligler’s: Acid/Acid gas
Urea: Negative
Citrate: Negative
Motility: Motile
Indole: POSITIVE
Lysine: Variable
Which organism is Oxidase negative, Urea positive , Citrate positive , Indole negative and Lysine Positive?
Klebsiella Pneumoniae
What is the Gram reaction for Kelbsiella Pneumoniae?
Gram - negative bacilli
Which organism is a Gram negative bacilli and is Oxidase Positive ?
Pseudomonas aeruginosa
What is the Gram reaction for Listeria monocytogenes?
Small beta haemolytic colonies
Which organism is a Small gram positive bacilli which is
Catalase : Positive & Bile aesculin: Positive?
Listeria monocytogenes
Which staining is used to identify Mycobacterium Tuberculosis ?
Ziehl Neelsen stain done
What is the culture of Mycobacterium Tuberculosis ?
Lowenstein Jensen (LJ) medium
Middlebrook 7H10, 7H11 or 7H12
Fill in the blanks. “ The culture for Mycobacterium Tuberculosis is inoculated at ___________.”
Incubated at 35 degrees C for 3-6 weeks in 5-10% CO2
Fill in the blanks.” Cryptococcus neoformans is susceptible __________.”
Cycloheximide
What is the Gram reaction for Cryptococcus neoformans ?
Gram positive oval bodies .
Urea Positive
What are the different characteristics of Staphylococcus ?
- Gram reaction: Gram positive cocci
- Catalase: positive
- Coagulase positive
- Novobiocin Susceptible
