CSF and Meningitis

1. Older Adults (>65yrs) Listeria monocytogenes Aerobic gram negative bacilli What are the typical Bacterial Meningitis Neisseria meningitidis agents? Streptococcus pneumoniae "You kids GET OFF MY 'LAwNS'" 2. Group B Strep (Streptococcus agalactiae) Escherichia coli K1 What are the typical agents of Bacterial Listeria monocytogenes Meningitis? Neonates (<1mo) Find Babies with Ultrasound GEL 3. Infants (1-23Mo) Haemophilus influenzae Escherichia coli What are the typical agents of Bacterial Neisseria meningitidis Meningitis for this age group? Streptococcus pneumoniae Streptococcus agalactiae (GBS) Mother HENSS don't want baby chickees to get bacterial meningitis 1 / 43 4. Children (>2yrs) Streptococcus pneumoniae Neisseria meningitidis What are the typical agents of Bacterial Meningitis in this age group? SNot nosed kids and their meningitis music 5. What is the typical Order of Collection for CSF fluid into tubes? Tube 1:æ Chemistry and immunological testing. [Most contaminated fluid] Tube 2:æ Microbiology Hematology, Cell Count [Usually least Tube 3:æ contaminated] Tube 4:æ Optional, Micro 6. 7. Fill in The Blank E.coli K1 ______________ and _______________ are the most common causes of neonatal meningitis Group B Streptococcus (Streptococcus agalactiae) A 3-week-old child develops fever and C) Gram-negative bacilli lethargy, has a full fontanelle, and just about one hour ago had a seizure. Cul- Among children one month of age and younger, gram-negative bacilli, mainly E. coli 2 / 43 tures of the blood and of the CSF grew and other enteric bacilli, are the most common the same organism. The most likely cause of meningitis. pathogen is: Group B streptococci and Listeria monocyA) Neisseria meningitidis togenes also cause meningitis in this age B) Streptococcus pneumoniae (pneugroup of children, but not as often as do the mococcus) gram-negative bacilli. C) Gram-negative bacilli Group B streptococci septic infections that ocD) Staphylococci cur very early do so as a result of spread of E) Haemophilus influenzae the organism to the newborn from the maternal genital tract. Neisseria meningitidis is a common cause of meningitis in children older than one month of age, and among older children, adolescents, and adults, Neisseria meningitidis and Streptococcus pneumoniaeare the two most common pathogens of meningitis. Haemophilus influenzae is a common cause of meningitis among older children and adolescents. (Levinson, 7/e, pp 114, 121.) 8. What is the normal range for CSF protein? 15-50mg/dL 9. What is the normal range for CSF glucose? 45-100mg/dL 10. 0-5cells/mm^3 3 / 43 What is the normal range for leukocytes in CSF? 11. Name the 3 ways that pathogenic bacte- Transcellularly ria can cross the blood brain barrier? Paracellularly Via the Trojan horse mechanism 12. What is KERNIG'S sign? 13. What are the typical laboratory findings -CSF turbid in Acute Bacterial meningitis? -PMN: Increased -Low Glucose -Increased protein -Increased WBC 14. What are some common etiological agents of Acute Meningitis ? When the thigh is flexed at 90 degrees, the KNEE is incapable of straightening Streptococcus pneumoniae Neisseria meningitidis Streptococcus agalactiae (GBS) Haemophilus influenzae Listeria monocytogenes 4 / 43 15. What are the typical laboratory values of -clear NORMAL CSF? -colorless Protein: (15-45mg/dL) Glucose: 40-80 mg/dL -only a few WBC present 16. 1. Elizabethkingia (Chryseobacterium) Describe the situation where one of these organisms could cause neonatal meningisepticum: in hospitals, found in water acute meningitis: system and wet surfaces. Premature babies often get this kind of meningitis 1) Elizabethkingia (Chryseobacterium) meningisepticum 2. E. coli K-1: acquired from mom during the birth process (vertical transmission) 2) E. coli K-1 3. Chronobacter (Enterobacter) sakazakii: in 3) Chronobacter (Enterobacter) sakaza- 2011 it was found in formula, causing babies kii. to get infected; highly virulent 17. A neonate acquires meningitis during A delivery. Which of the following organisms should be suspected? A) Escherichia coli and Streptococcus agalactiae B) Haemophilus influenzae and Neisseria meningitidis C) Haemophilus influenzae and Streptococcus pneumoniae D) Listeria monocytogenes and Neisseria meningitidis 5 / 43 E) Staphylococcus aureus and Staphylococcus epidermidis 18. Where is Elizabethkingia meningisepticum found? DIRRRTTYYYY Hospital Water 19. What is Brudzinski's neck sign? Bending of neck causes flexion of knees and hips 20. C A nurse is evaluating the status of a client who had a craniotomy 3 days ago. Which assessment finding would indicate the patient is developing meningitis as a complication of surgery? A) A Negative Kernig's sign B) Absence of nuchal rigidity C) A Positive Brudzinki's sign D) A Glasgow Coma Scale score of 15 21. E. coli K1 K1(capsular) antigen Neonatal meningitis 22. Why is GBS quick to cause infection? -acquired at birth causing ---bacteremia 6 / 43 ---pneumonia ----meningitis WITHIN FIRST WEEK 23. LEVELS to this s*** young boy (3 start- 1) Dura mater ing with most outward) 2) Subarachnoid space 3) Pia mater 24. Where do bacteria that cause meningitis The subarachnoid space replicate? 25. How many layers of meninges are in the 3: brain? Dura mater What are they? Arachnoid mater Pia mater 26. 27. What type of WBC is associated with BACTERIAL meningitis? What does normal CSF look like? 7 / 43 Neutrophils "Neuts" Clear, colorless Protein CSF: 15-45mg/dL WBCs: Few or none Glucose CSF: 40-80mg/dL 28. What is the subarachnoid space filled with? CSF (cerebrospinal fluid) 29. A CSF Specimen was sent to the laboratory for analysis. A glucose, protein, and cell count were performed. Based on the following results, what would be the probable cause? C) Purulent infection Glucose: 15mg/dL Protein: 150mg/dL Leukocytes: 1,000 cells/mm^3 neutrophils A) Normal CSF B) Viral infection C) Purulent infection D) Tuberculosis or fungal infection Purulent infection is correct. For a CSF to be considered purulent, the glucose value should be <45mg/dL, the protein value should be >100mg/dL, and the leukocyte count should average 800 cells/mm^3 (range 5020,000cells/mm^3) with polymorphonuclear cells predominating. The glucose value is low because bacterial organisms are using the glucose as an energy source for growth and the protein value is elevated due to an increase in cellular presence. Normal CSF is incorrect. To be considered normal, the glucose value must be within 45-100mg/dL, the protein must be within 15-50gmg/dL, and the leukocyte count must be within 0-5cells/mm^3 with no predominant cell line 8 / 43 Viral infection is not correct. In a viral infection, the spinal fluid will have a normal glucose value (range 45-100mg/dL), a slightly elevated protein value (range 15-50mg/dL), and an average leukocyte count of 80 cells/mm^3 (range 0-5cells/mm^3) with mononuclear cells predominating. Tuberculosis of fungi is incorrect. In this type of infection, the glucose value is low to normal, the protein value is >50mg/dL, and the leukocyte count is around 100cells/mm^3 with mononuclear cells predominating. 30. Fill in The Blank Pressure Replication in the subarachnoid space results in INCREASED ________________ in the skull, harming the brain 31. Normal CSF contains all of the following D) Fibrinogen proteins EXCEPT: Normal CSF contains protein fractions similar A) Transferrin to those found in serum such as transthyretin B) Transthyretin (prealbumin), albumin, transferrin, haptogloC) Albumin bin, ceruloplasmin, IgG, IgA, etc., but does not D) Fibrinogen contain IgM fibrinogen, or beta lipoprotein. [Strasinger 2014, p193] 32. Which CSF tube specimen # is used to diagnose and treat meningitis? 9 / 43 2 33. Fill in The Blank Decreased In bacteria meningitis, the glucose levels in CSF are _________ 34. Gram stain of? Neisseria meningitidis 35. Fill in The Blank Increased In bacterial meningitis, the protein levels in CSF are _______ 36. The appearance of normal CSF is: B) colorless and clear A) pale yellow and clear B) colorless and clear C) opalescent D) xanthochromic CSF looks like water. If it is yellow or pink it is called xanthochromic. This indicates a previous bleed into the CNS. Opalescence is a haziness, usually due to the presence of lipids. [Strasinger 2014, p183] 37. A turbid cerebrospinal fluid is most com- A) white blood cells monly caused by increased: Protein and glucose are dissolved substances A) white blood cells and don't contribute to turbidity. B) protein Bacteria and WBCs are solids that make the C) glucose CSF turbid. When bacteria are present, so are D) bacterial organisms 10 / 43 WBCs. The large WBCs contribute more to turbidity than the smaller bacteria. [Strasinger 2014, p183] 38. Physical Examination of CSF based on Color/Appearance: Cloudy/Turbid = WBCs, Increased protein or Lipid Milky = WBCs, Increased protein or Lipid Xanthochromic = Pink to orange color, RBC degradation, increase bilirubin, carotene, increased protein, melanoma pigment Hemolyzed = Inter-cranial hemorrhage or traumatic tap 39. The normal concentration of proteins A) <1mg/dL in cerebrospinal fluid, relative to serum Consider that a normal serum protein is approtein, is: proximately 7g/dL, and a normal CSF protein is A) <1mg/dL 15mg/dL. B) 5-10mg/dL The units are different by 3 orders of magniC) 25-35mg/dL tude. D) 50-60mg/dL This indicates that the CSF protein is <1% of serum protein. [Strasinger 2014, p193] 40. Haemophilus growth requirements 11 / 43 41. 42. What percent of the US population is colonized by H. influenzae? 85% of adults Haemophilus etymology haemo, "blood" ; hilos, "lover" 60% of daycare children ("blood lover"; requires blood for growth on media) 43. Name that Haemophilus Species! H. influenzae Beta Hemolysis on Horse BAP: No Requires X Factor (Hemin): Yes Requires V Factor (NAD): Yes 44. Name that Haemophilus Species! H. haemolyticus Beta Hemolysis on Horse BAP: Yes Requires X Factor (Hemin): Yes Requires V Factor (NAD): Yes 45. Name that Haemophilus Species! Beta Hemolysis on Horse BAP: No Requires X Factor (Hemin): No Requires V Factor (NAD): Yes 12 / 43 H. parainfluenzae 46. Haemophilus influenzae Fill in the Blank ________________ colonies on a CHOC 47. What is the best medium for growth of blood agar plate (BAP), which is a trypticase soy S. pneumoniae ? agar (TSA) plate containing 5% sheep blood. Human blood is NOT an acceptable substitute for the blood in the agar because the antibodies contained in human blood may inhibit bacterial growth 48. presumptive ID of Streptococcus pneu- Bile Solubility: Soluble moniae Catalase: NEG GPDC ----lancet shaped 49. Streptococcus pneumoniae picture w/ WBCs 50. Fill in The Blank S. pneumoniae Patients with Sickle Cell Anemia, splenectomy or asplenia, malignancy, malnutrition, and chronic renal or liver disease are more likely to develop serious __________________ infection 51. S. pneumoniae colonies have a flattened and depressed center after 24-48 13 / 43 hours of growth on a BAP, whereas the viridans streptococci retain a raised center 52. GBS and pneumococcal disease overview. Streptococcus pneumoniae is aspirated from the normal orophyaryngeal flora to the lung where it produces pneumonia. Bacteremic spread can infect other sites particularly the brain where meningitis is produced. GBS vaginal colonization during pregnancy leads to infection of the fetus either in the uterus or during childbirth. 53. Pneumococcal capsule. In this test, live Streptococcus pneumoniae have been mixed with antibody specific to the capsular polysaccharide. The opsonizing antibody defines the capsule, which appears "swollen" when compared with preparations without antibody. (Reproduced with permission from Wil14 / 43 ley JM: Prescott, Harley, & Klein's Microbiology, 7th edition. McGraw-Hill, 2008.) 54. Gonococcus and meningococcus, cellular view. Neisseria gonorrhoeae and Neisseria meningitidis differ in that N meningitidis has a capsule. (Left) Both attach to microvillus cells by outer membrane proteins (OMP) and pili. They are endocytosed in vacuoles. (Middle) Both multiply freely in the cytoplasm. (Right) Both escape to the submucosa, but the gonococcus is actively phagocytosed and remains localized. The meningococcal capsule allows it to evade phagocytosis and it enters the bloodstream. 55. Neisseria meningitidis Cell wall is shown shedding multiple "blebs" (arrows) containing lipopolysaccharide-endotoxin. Note the typical trilamellar gram-negative cell wall structure in the wall and the blebs. 15 / 43 (Reprinted with permission from Devoe IW, Gilcrist JE. J Exp Med. 1973;138:1160.) 56. What is Waterhouse-Friderichsen syndrome? Particular form of disseminated meningococcus with death resulting from adrenal insufficiency due to hemorrhage into the adrenal glands when bacteria attacks adrenal glands mortality is 30% 57. An autopsy performed on an 8-year-old B child revealed Waterhouse-Friderichsen syndrome. Blood and throat cultures taken just prior to death were positive for which organism? A) Neisseria gonorrhoeae B) Neisseria meningitidis C) Haemophilus influenzae D) Klebsiella pneumoniae 58. Meningococcemia. Small and large coalesced petechiae are shown in the skin of a patient with meningococci circulating in the blood. (Reproduced with permission from Nester EW: Microbiology: A Human Perspective, 6th edition. 2009.) 16 / 43 59. Listeriosis overview. Listeria monocytogenes is ingested in dairy and meat products. It invades through the intestinal mucosa producing a bacteremia. The organisms may seed elsewhere particularly the brain (meningitis) or the fetus in pregnancy. 60. Listeriosis, cellular-view. (Left) Listeria monocytogenes internalin mediates attachment to an enterocyte and enters in an endocytotic vacuole. Listerolysin O (LLO) lyses the vacuole and the organism escapes to the cytoplasm. (Middle) The cytoskeleton is modified and the organisms move along fibers by polymerizing actin (comet tail) invading adjacent cells. (Right) Listeria has entered another cell now in a double vacuole, which LLO again lyses. The process continues with escape to the submucosa and bloodstream invasion. 61. Haemophilus disease overview. 17 / 43 (Left) Invasive disease is caused by encapsulated strains, mostly type b (Hib). From a nasopharyngeal colonization site, the organisms invade locally to produce cellulitis or epiglottitis. Invasion of the blood occurs in all Hib forms and most frequently leads to meningitis. (Right) Localized disease is produced when nonencapsulated strains from the nasopharynx are trapped in the middle ear, paranasal sinuses or compromised bronchi. 62. Haemophilus influenzae disease, cellular view. Organisms attach to epithelial cells using pili and outer membrane proteins (OMPs). Invasion takes place between cells by disruption of cell-cell adhesion molecules. In the submucosa, the capsule allows the bacteria to evade phagocytosis and enter the bloodstream. PMNs, polymorphonuclear neutrophils 63. A small, gram-negative coccobacillus re- B covered from CSF of a 2-year old child gave the following results: Indole:POS X requirement: POS Urease: POS 18 / 43 Sucrose: NEG Glucose : POS (acid) V requirement: POS Lactose : NEG Hemolysis: NEG What is the most likely identification? A) H. parainfluenzae B) H. influenzae C) H. ducreyi D) H. aphrophilus 64. Which of the following plates should be B used in order to ID H. haemolyticus and H. parahaemolyticus? A) Sheep blood agar and chocolate agar B) Horse blood agar and Mueller-Hinton agar with X and V strips C) Brain-heart infusion agar with sheep red cells added D) Chocolate agar and Mueller-Hinton agar with X factor added 65. Haemophilus influenzae which requires A X and V factors for growth, can be differentiated from H. aegypticus by which two tests? 19 / 43 A) Indole and Xylose B) Glucose and Urease C) Oxidase and Catalase D) Indole and Oxidase 66. What deficiency helps to facilitate infec- Complement C5-9 deficiency tion via N. meningitidis? OR Properdin deficiency 67. What are the virulence factors of S. pneumoniae? Capsule Autolysin Hyaluronidase IgA protease 68. What is a normal Glucose CSF range? 45-100mg/dL 69. What locations in the body are generally Blood sterile? CSF Deep Tissue 70. Listeria monocytogenes has specific re- Monocytes ceptors for what cell? 71. Fill in The Blank Neisseria meningitidis Individuals who are deficient in terminal components of complement (C5-C9) are at higher risk for _____________________ infection 72. How does neonatal GBS acquisition usu- Vertical transmission from mother to infant ally occur? 73. Listeria monocytogenes 20 / 43 Fill in The Blank Infection caused by ___________ ____________________ is more commonly seen in neonates, older patients, alcoholics, and immunosuppressed individuals 74. Pathogenic steps leading to pneumococcal meningitis. The pneumococcus adheres to and colonizes the nasopharynx. IgA1 protease protects the pneumococcus from host antibody (A). Once in the bloodstream, the bacterial capsule helps the pneumococcus to evade opsonization (B). The pneumococcus accesses the cerebrospinal fluid through receptors on the endothelial surface of the blood-brain barrier (C). (Redrawn, with permission, from Koedel U et al. Pathogenesis and pathophysiology of pneumococcal meningitis. Lancet Infect Dis. 2002;2:731.) 75. Complement reaction sequence and infections associated with deficiency states. 21 / 43 (Redrawn, with permission, from Detrick B. Immunology. In: Carroll KC et al, eds. Jawetz, Melnick, and Adelberg's Medical Microbiology, 27th ed. McGraw-Hill, 2015.) 76. Pathophysiological alterations leading to neuronal injury during bacterial meningitis. (Redrawn, with permission, from Koedel U et al. Pathogenesis and pathophysiology of pneumococcal meningitis. Lancet Infect Dis. 2002;2:731.) 77. What are the expected findings consis- CSF: Turbid, Cloudy tent with Bacterial meningitis? Protein CSF: Elevated (>45mg/dL) WBC: elevated NEUTROPHILS: Elevated Glucose CSF: very low(<40% of serum glucose concentration") 78. Haemophilus influenzae satelliting around Staphylococcus aureus 79. 22 / 43 Cerebrospinal fluid culture positive for Haemophilus influenzae, type b (Gram stain). 80. Hemolytic activity comparison 81. CAMP Test 82. Hippurate POS 83. Routes for bacterial invasion of the meninges. 84. Schematic depiction of the subgaleal, epidural, subdural, and subarachnoid spaces in the central nervous system. 85. N. meningitidis etymology GBS meningis, "the covering of the brain"; itis, "inflammation" 23 / 43 (inflammation of the meninges as in meningitis) 86. All of the following substances are T-in- D dependent antigens EXCEPT: A) endotoxin B) lipopolysaccharide C) polymerized flagellin D) phytohemagluttinin E) Epstein-Barr virus 87. A 15-month old child living in a relic gious community that does not vaccinate their children develops meningitis. A gram-negative rod is seen in the CSF. What is the most likely causative agent? a. An enterovirus b. Escherichia coli c. Haemophilus influenzae d. Neisseria meningitidis e. Streptococcus agalactiae 88. Haemophilus influenzae—Gram stain. Arrows point to two small "coccobacillary" gram-negative rods. (Used with permission from Professor Shirley Lowe, University of California, San Francisco School of Medicine.) 24 / 43 89. Haemophilus influenzae Gram stain. The gram-negative bacilli are small and so short that some appear almost round. This is the basis of the term coccobacilli. The morphology of Bordetella pertussis is the same. (Reproduced with permission from Connor DH, Chandler FW, Schwartz DQ, et al: Pathology of Infectious Diseases. Stamford CT: Appleton & Lange, 1997.) 90. What is the first event in a patient who d ultimately develops Neisseria meningitidis meningitis? a. Crossing the blood-brain barrier b. Meningococcemia c. Skin lesions d. Upper respiratory colonization e. Waterhouse-Frederichsen syndrome f.Traumatic implantation directly into the brain 91. Repeated Neisseria meningitidis sep- A ticemias in an individual should raise physician awareness of what underlying condition? (A) C5 to C8 deficiencies (B) Chronic hepatitis B infection (C) Ketosis-prone diabetes 25 / 43 (D) Multiple myeloma (E) Severe neutropenia" 92. A baby born at 32 weeks, gestation with B Apgar scores of 2 and 7 was placed in the neonatal intensive care unit. She developed a fever and leukocytosis; lumbar puncture revealed pleocytosis with increased protein, decreased glucose, and Gram POSitive Rods. Which of the following organisms was most likely isolated from the CSF? A) Escherichia coli B) Listeria monocytogenes C) Neisseria meningitidis D) Streptococcus agalactiae E) Streptococcus pneumoniae 93. What are Listeria virulence factors? -Cell attachment factors (internalins) -hemolysins(listeriolysin O, two phospholipase Cs) -Protein that mediates actin-directed intracellular motility (ActA) Ability to grow at 4C can lead to high concentrations in foods 94. A false positive CAMP test for the presumptive ID of GBS may occur if the 26 / 43 A plate is incubated in a: A) Candle jar or CO2 incubator B) Ambient air incubator C) 35C incubator D) 37C incubator 95. Blood cultures (two) on a newborn grew B beta-hemolytic streptococci with the following reactions: CAMP test: POS Bile Solubilitiy:NEG PYR: NEG Bacitracin: RESistant Hippurate hydrolysis: POS 6.5% Salt: POS (growth) Bile Esculin hydrolysis: NEG SXT: RESistant Which is the most likely ID? A) Group A streptococci B) Group B streptococci C) Group D streptococci D) none of the above 96. All of the following statements about Listeria monocytogenes infection are correct EXCEPT: A) abscess and granulomas occur in many different tissues 27 / 43 E B) laboratory isolation involves cold enrichment media C) neonatal infections have a poor prognosis D) bacteria parasitize neutrophils and monocytes E) neonatal infections occur ONLY during passage through the infected birth canal 97. Which of the following organisms caus- C) Group B streptococci es neonatal sepsis? A) Enterococcus faecalis B) Streptococcus pneumoniae C) Group B streptococci D) Viridans streptococci GBS cause neonatal sepsis in two forms: an early onset form, occurring in infants from birth to 4 days old, and a late onset form, occurring in infants from 7 days to 4 months old 98. Streptococcus agalactiae Characteristics -Group B -can be part of normal vaginal and oral flora -Capsule -Inhibits complement 99. Streptococcus agalactiae Diseases Neonatal sepsis (early and late onset) Meningitis 100. Haemophilus influenzae Diseases 28 / 43 -Genitourinary infections -Meningitis(to 6 years old) -Epiglottitis 101. Listeria monocytogenes Diseases Granulomas Abscesses Meningitis (newborns) 102. E. coli diseases Genitourinary tract infections Gastroenteritis Septic shock Neonatal meningitis 103. Neisseria meningitidis diseases meningitis, meningococcemia WaterHouse-Fridericksen Syndrome 104. A neonate develops meningitis at 7 days E) Streptococcus agalactiae (GBS) of age. Her mother is 16 years of age, is single, has had multiple sexual partners without barrier protection, and lives in Streptococcus agalactiae is the most common the U.S. The baby was born 23 hours afcause of neonatal meningitis. ter the mother's amniotic sac ruptured. What is the most likely causative agent? A) Escherichia coli B) Haemophilus influenzae C) Listeria monocytogenes D) Neisseria meningitidis E) Streptococcus agalactiae (GBS) 105. 29 / 43 It is most prevalent in young women with multiple partners and is most likely to infect the baby during a protracted delivery. What is the most common method by By invading the mucous layer through a break which bacteria enter the body to cause or crack (common in the winter) meningitis? 106. Define Trojan horse migration Migration facilitated by phagocytosis via a MP and then release from the cell after crossing the cell barrier "Timeo Danaos et dona ferentes" Beware of Greeks bearing gifts" 107. What is known as Brudzinski's neck sign? Bending of neck causes flexion of knees and hips 108. What is known as KERNIG'S sign? When the thigh is flexed at 90 degrees, the KNEE is incapable of straightening 109. What are the symptoms of meningitis with N. meningitidis? Chills Myalgia (muscle pain) 30 / 43 Arthralgia (joint pain) Confusion 50% of cases have nuchal rigidity 110. What are the symptoms of meningitis with L. monocytogenes? Fever Headache Nuchal rigidity Flu-like symptoms Babies will have a bulging fontanelle 111. T/F False Anaerobic cultures are often recommended for CSF cultures 112. What type of WBC in CSF is associated with bacterial meningitis? Neutrophils 113. What are the symptoms of meningitis with S. pneumoniae? Fever Headache Stiff neck Sore back 114. What are the symptoms of meningitis with H. influenzae? Fever Malaise Emesis(Vomiting) Nuchal rigidity and seizures are absent =NO seizures =Neck is A OK 115. What is the reservoir for S. agalactiae? Humans, in the vagina and GI tract of women and the urethra and GI tract of men 31 / 43 116. Why are newborns and infants at a high- Underdeveloped Immune System er risk of developing meningitis than adults? 117. What is the most common method of transmission for bacteria that cause meningitis? Aerosol Droplet Transmission 118. What are the 3 ways that pathogenic Transcellularly bacteria can cross the blood brain bar- Paracellularly rier? Via the Trojan horse mechanism 119. IgA protease is necessary for some bac- IgA is a secreted antibody that predominates teria to survive the oropharynx. Why is the area. this? 120. Explain how to test for Brudzinski's sign. Lying flat on the back, the head is lifted from the dorsal side upward until the chin is nearly touching the chest. If the knees reflexively bend toward the chest, the sign is positive. 121. Purpura fulminans, a maculopapular N. meningitidis eruption, is a unique symptom of what agent of meningitis? 122. Nuchal rigidity is NOT seen in infection Haemophilus influenzae type B from what organism? 123. Why is Neisseria meningitidis effective They possess phase variation, antigenic variat resisting immune clearance? ation, sIgA protease, LOS sialylation to resist complement, and are heavily encapsulated. 32 / 43 124. Secretions and droplets are the primary H. influenzae type B means of transmission for what menin- N. meningitidis gitis agents? S. pneumoniae 125. What are Opportunistic pathogens? normal flora or non-pathogenic organisms that can cause disease under the appropriate circumstances (not all normal flora can cause disease) 126. IgA proteases Who got it? Neisseria Haemophilus Streptococcus pneumoniae 127. All capsules Streptococcus pneumoniae Klebsiella pneumoniae Haemophilus influenzae Pseudomonas aeruginosa Neisseria meningitidis Cryptococcus neoformans mnemonic: "Some killers have pretty nice capsules" 128. HaEMOPhilus influenzae causes Epiglottitis ("cherry red" in children) Meningitis Otitis media Pneumonia "when a child has 'flu', mom goes to five (V) and dime (X) store to buy some CHOCOLATE" 129. MeninGococci ferment Maltose and Glucose 33 / 43 130. Gonococci ferments Glucose 131. N. meningitidis Trigger words Chocolate agar endotoxin Gram-negative diplococci in CSF Lipooligosaccharide meningitis oxidase POS petechiae purpura septic shock Thayer-Martin Agar Waterhouse Friderichsen syndrome 132. Transmission of N. meningitidis Inhalation of aerosol droplets (often from asymptomatic posterior nasopharyngeal carriers) 133. Patients with meningitis caused by Lis- Lymphocytes teria have low CSF leukocyte counts with a predominance of ________________ 134. Bacterial Meningitis CSF Cell Count (WBCs/uL) 100-100,000 Neutrophils predominate 135. Streptococcus pneumoniae and ViriA) Optochin disk test, 5ug/ml or less dans streptococci can be differentiated by: A) Optochin disk test, 5ug/ml or less B) Bacitracin disk test, 0.04 units 34 / 43 Optochin at a concentration of 5ug/ml or less will inhibit the growth of S. pneumoniae, but NOT viridans streptococci. C) CAMP test D) Bile Esculin Test However, optochin at a concentration in excess of 5ug/ml will inhibit other viridans strep as well. A zone of inhibition of 14mm or more around the 6mm disk is considered a presumptive identification of S. pneumoniae. A questionable zone size should be confirmed by performing a bile solubility test 136. Streptococcus spp. exhibit which of the b. Facultative anaerobe, oxidase NEG, catalase following properties? NEG a. Aerobic, oxidase, and catalase POS b. Facultative anaerobe, oxidase NEG, catalase NEG c. Facultative anaerobe, beta-hemolytic, catalase POS d. May be alpha, beta, or gamma hemolytic, catalase POS Streptococcus spp. are facultative anaerobes that grow aerobically as well, and are oxidase and catalase NEG. In order to demonstrate streptolysin O on blood agar, it is best to stab the agar to create anaerobiosis remembering that streptolysin O is oxygen labile 137. Haemophilus spp. that require the V fac- c tor (NAD) are easily recovered on which agar plate? a. Blood agar made with sheep RBCs b.Blood agar made with horse RBCs c. Chocolate agar d. Xylose agar 138. The optochin (ethylhydrocupreine hy- C drochloride) disk is used for the identi35 / 43 fication of: A) Haemophilus influenzae B) group A beta-hemolytic streptococci C) Streptococcus pneumoniae D) alpha-hemolytic streptococci 139. CSF Cell Count Equations: [# of cells counted x (1/volume)] Volume = [area x 0.1] 140. The presence of Lymphocytes in CSF is Viral Meningitis associated with: 141. Reference Range of CSF glucose levels: 60% - 70% of plasma concentration Should always be accompanied by a blood glucose test. 142. Why is there a decrease in CSF glucose Defective Glucose Transport levels in patients with bacterial meningitis? 143. What cells produce CSF? Choroid Plexus Cells 144. CSF fluid is located in the space between: Between the Arachnoid mater and the Pia mater 145. Describe the Porphyrin Test for Haemophilus flu: Porphyrin tests for the requirement of X Factor [Heme] - A negative prophyrin test will happen when the organism requires heme- A positive will happen if the organism already produces 36 / 43 Heme - Since H flu requires X and V factors to grow, it will be a negative porphyrin test. Meaning no color is produced under the lamp because of the lack of X factor 146. Reservoir of all bacteria causing menin- H. influenzae- Oropharynx and nasopharynx of gitis. humans N. meningitidis- humans are only natural host S. pneumoniae- humans, transient flora of Upper respiratory tract L. monocytogenes- GI tract S. agalactiae- vagina and GI tract in women; urethra and GI tract in men 147. Identification protocol for H. Influenzae Gram stain: Pale, GNR, coccobacillary at times Presumptive: Catalase and Oxidase positive Definitive: Quad plate AND Beta-lactamase 148. Identification protocol for Listeria Monocytogenes Gram stain: GPR Presumptive: Catalase positive and oxidase negative Definitive: Motility, Esculin (positive), Hippurate (positive) 37 / 43 149. Explain why normal flora are located at 1.Tissue preference or predilection for colparticular anatomic sites. onization- Tissue tropism (Staphylococcus saprophyticus & uropathogenic Escherichia coli) - Nutritional needs or growth factors 2. Organisms can only colonize specific tissues due to the need for matching receptors- Listeria monocytogenes has specific receptors for components of the monocyte cell wall 3.Ability to create biofilms 4.Influenced by Nutritional & environmental factors- Moist vs. dry areas- Staphylococcus aureus can tolerate drying Neisseria gonorrhoeae can't tolerate dryingCutibacterium colonize ducts of hair folliclespH (yeasts in the GI and urogenital tracts)areas with low red-ox potential harbor more anaerobes (gingival crevices) 5.Human factorsGeneticsAbsence of receptors can prevent attachment of pathogens to the appropriate tissueGender (men do not have Lactobacillus)Diet (gut flora of breast fed infants differs from that of bottle fed infants)Age: the vaginal flora of prepubescent girls differs after puberty 150. 38 / 43 Identification of Neisseria meningitidis Non-spore forming & Non-motile tests Oxidase and catalase positive. 151. Identification of GBS colony Beta hemolytic Large colony, small zone of hemolysis CAMP test: POSitive Hippurate: POSitive Bacitracin: RESISTANT PYR: NEGative 152. Identification of Listeria tests Esculin POS Ferments glucose H2S NEG in TSI Hippurate POS CAMP Test positive, but looks different than GBS Motility:Tumbling Motility in hanging drop preps Umbrella appearance in semi-solid media 39 / 43 153. Identification of GBS testing Beta lysin producing Staph aureus vs. test organism at right angles Arrowhead zone of hemolysis Presumptive for Group B Strep 154. Identification of Group B Strep Direct exam Streptococcus agalactiae Gram positive cocci Pair or short chains 155. Identification of S. pneumoniae direct exam Gram positive, lancet shaped diplococci Often encapsulated 40 / 43 156. A 25-year-old man was in a motorcycle C accident 3 days ago, in which he sustained severe head trauma. He has had spinal fluid leaking from his nose since the accident and now develops a severe headache. His temperature is 39°C, and on examination, you find nuchal rigidity. You do a lumbar puncture and find that the spinal fluid is cloudy and contains 5000 WBC/mL, 90% of which are polys. Of the following, which one is the MOST likely result observed in the laboratory analysis of the spinal fluid? A) Gram-negative rods that grew only on Thayer-Martin medium B) A motile spirochete that formed beta-hemolytic colonies on blood agar C) Gram-positive cocci that formed alpha-hemolytic colonies on blood agar D) Gram-positive rods that grew only on chocolate agar supplemented with X and V factors E) No organism was seen using Gram stain, but tissue stains revealed cytoplasmic inclusion bodies 41 / 43 157. Which of the following is the most com- A) Asymptomatic nasopharyngeal colonization mon clinical manifestation of N meninN meningitidis is an effective colonizer of the gitidis infection? human nasopharynx, with asymptomatic infecA) Asymptomatic nasopharyngeal colo- tion rates of >25% described in some series nization of adolescents and young adults and among B) Chronic meningitis residents of crowded communities. C) Meningitis Despite the high rates of carriage among adoD) Petechial or purpuric rash lescents and young adults, only 10% of adults E) Septicemia carry meningococci, and colonization is very rare in early childhood. Colonization should be considered the normal state of meningococcal infection. Meningeal pharyngitis rarely occurs. Meningococcal disease occurs when a virulent form of the organism invades a susceptible host. The most important bacterial virulence factor relates to the presence of the capsule. Unencapsulated forms of N meningitides rarely cause disease. A nonblanching petechial or purpuric rash occurs in >80% of cases of meningococcal disease. Of patients with meningococcal disease, 30%-50% present with meningitis, approxi42 / 43 mately 40% with meningitis plus septicemia, and 20% with septicemia alone. Patients with complement deficiency, who are at highest risk of developing meningococcal disease, may develop chronic meningitis. (Chap. 180) 43 / 43