Bacterial CNS

Question 1

what are the types of hemolysis?

Answer 1

1. alpha
   
   1. green, aka partial hemolysis
   2. alpha hemolysin partially breaks down RBC, the culture is clear
2. beta
   
   1. culture apears clear
   2. breaks down the RBC and hemoglobuin entirely
3. gamma
   
   1. the culture just has the growth with out any color change
   2. does not contain hemolysin

Question 2

gram negative rods

nonmotile

facultative anaerobes

1. oxidase?
2. catalase?
3. required growth factors?

Answer 2

haemophilus influenzae

1. gram negative rods
2. non-motil
3. facultative anearobes
4. oxidase +
5. catalase +
6. reduce nitrates
7. require preformed growth factors
   
   1. X(hemin)
   2. V(NAD)

Question 3

invade bloodstream by breakdown in the tight junctions between epithelial cells

describe the significant subtype.

Answer 3

haemophilus influenza B

1. type b
   
   1. encapsulated strain capable os sytemic invasion
   2. HiB = vaccine against this strain

Question 4

what are the virulence factors for HiB?

Answer 4

1. virulence
   
   1. capsule
      
      1. most important factor
   2. IgA proteases
   3. fimbriae adherance
   4. LPS- via gram negative rod

Question 5

strict human pathogen

1. O2 use
2. gram
3. culture
4. important features

Answer 5

neisseria meningitidis

1. aerobic, nonmotile, non-spore forming
2. gram negative, diplococci
3. chocolate agar
4. importantt features
   
   1. catalase +
   2. capnophilic- requires CO2
   3. requires iron-possible reason for being strict human pathogen
      
      1. ​competes with human host by binding human transferrin

Question 6

what are the virulence factors for neisseria meningitidis?

Answer 6

1. pili (fimbriae)
2. capsule
3. transferin - receptor for iron
4. endotoxin - gram - LPS
5. IgA protease

Question 7

transmission from respiritory dropletts, found on mucosal surfaces of nasohparynx and oropharynx

Answer 7

neisseria meningitidis

Question 8

meningitidis in children and infants

Answer 8

HiB

Question 9

meningitidis found in every age group

Answer 9

Neisseria meningitidis

Question 10

purpura of skin and mucous membranes

petechial rash

DIC

Answer 10

these are all symptoms of meningococcemia

Question 11

meningitidis from organism that colonizes the nasopharyngeal mucosa

Answer 11

neisseria meningitidis

Question 12

neisseria meningitidis meningisums include (3)

Answer 12

meningismus

1. inflammation of the meninges or subarachnoid hemorrhaging
2. nuchal rigidity
3. kernigs sign, brudzinskis sign

altered sensorium- cannot think clearly

Question 13

Gram + diplococci

1. hemolytic
2. catalase
3. oxidase
4. urease
5. ferments

Answer 13

Question 14

list two important species taht are catalase + and -

Answer 14

Question 15

key virulence factor for invasive streptococcus pneumoniae

Answer 15

polysaccharide capsule

Question 16

most common cuase of meningitis in adults, second most common cause in children.

transmission through respiratory droplets.

1. gram
2. hemolysis
3. catalase
4. Ab sensitive test
5. urease
6. ferments

Answer 16

streptococcus pneumoniae

Question 17

What does the protease of the following target

1. HiB
2. N. meningitidis
3. S. pneumonia

Answer 17

IgA

• prblems is the potential of inhibiting beneficial effects of IgG Ab
• PCR diagnostic assay
  
  • require low number of sample to detect bacteria

Question 18

patient presents to the ER 11 days after eating some ice cream, which was later found to be recalled.

The bacteria was sampled and found to grow on blood agar.

1. bacteria
2. gram
3. O2 demand
4. Catalse
5. Oxidase
6. derived from

Answer 18

Question 19

CNS invasion of lysteria monocytogenes includes

1. BBB
2. WBC
3. oral mphage

Answer 19

1. taken up by phagocytosis and can exit the cell and enter the surrounding enviornment. This is an issue if this happens while the cell is in the brain or near.
2. CNS invasion by one of the three methods
   
   1. invasion of the endothelial cells of the BBB
   2. transportation of bacteria to the CNS within circulating leukocytes
      
      1. phagocyte facilitated
   3. bacteria inoculated into oral tissues through chewing of contaminated food
      
      1. followed by macrophage phagocytosis which in turn can invade cranial nerves

Question 20

fifth most common cause of meningitis

1. risk groups

Answer 20

Question 21

bacitracin resistant

catalase negative

1. gram
2. hemolysis
3. virulence factors-3

Answer 21

streptococcus agalactiae

1. gram +
2. beta hemolysis
3. virulence
   
   1. capsule
   2. pore forming bet heolysin/cytolysin

Question 22

affects neonates, infants and older than 60.

gram +

bacitracin resistant

catalase negative

Answer 22

streptococcus agalactiae

Question 23

how many samples are collected and for who on a CSF analysis

Answer 23

1. 4 samples
   
   1. chemistry/serology
   2. microbiology
   3. hematology
      
      1. differential
   4. immunological test/protein electrophersis

Question 24

How does glucose level in CSF analysis affect the following and what does it indicate? -3

Answer 24

1. increase WBC + neutrophils a +decreased CSF glucose
   
   1. bacterial meningitis
2. increased WBC + lymphcytes + decreased CSF glucose
   
   1. tubercular meningitis
3. increased WBC + lymphocytes + normal CSF glucose
   
   1. viral meningitis

Question 25

patient CSF presents with 1. increased WBC 2. neutrophils 3. decreased glucose

Answer 25

bacterial mengitis

Question 26

csf sample presents with the following 1. increased WBC 2. lymphoctes 3. decreased glucose

Answer 26

tubercular meningitis

Question 27

csf sample show the following 1. increased WBC 2. lymphocytes 3. normal glucose

Answer 27

viral meningitis

Question 28

harsh acidic enviornment leads to 1. what type of colonization 2. where do microbes colonize?

Answer 28

1. harsh acid environment leads to low colonization 2. mucosal lining ofthe stomach is less acidic and acts as a more moderate location for colonization 1. microbes survive the stomach and colonize the lining

Question 29

lactobacilli are most likely to found

Answer 29

duodenum and small intestine

Question 30

what do the species that inhabit the duodenum need to survive? what are very sensitive to bile salts?

Answer 30

bile salt hydrolase gram positive are sensitive to bile salts, due to lack of an outer membrane

Question 31

what may cause malnutrtition?

Answer 31

increase in proximal intestine bacteria lead to bacteria consuming more nutrients (faster uptake) than host-\> malnutrtion

Question 32

what location of the gut has tthe highest diversity of microbes?

Answer 32

large intestines

Question 33

describe the bacteria in the large intestine 1. diversity 2. O2 in enviornment 3. carbohydrate source

Answer 33

1. highest diversity 2. anaerobic enviornment 1. few facultative 2. mostly anerobic 3. most intestinal bacetria need a fermentable car ohydrate source 1. large intestine has digestted food and host mucus 4. food competition is fiercest here

Question 34

what type of bacteria becomes a problem when it translocates?

Answer 34

commensals are fine where they are, when they translocate there can be problems 1. accidental pentration into a sterile host area can have serious complications

Question 35

microbes that don't normally cause disease but can if they enter other regions

Answer 35

opportunistic infections

Question 36

describe diseased mirobiota vs normal(healthy) microbiota

Answer 36

1. diseased individuals have less diversity in their microbiota than healthy controls

Question 37

inflammation states, regarless of disease increase \_\_\_\_- and decrease \_\_\_\_\_

Answer 37

inflammation states, regarless of disease are often associated with an increase inenterobacteriaceae and decreases in lachnopiraceae

Question 38

who has a better/mature microbiota?

Answer 38

germ free- no microbes or microbiota = poor immune systems, low cardiac output, thin intestinal walls, susceptible to pathogens gnotobiotic - all microbes in the microbiota are known

Question 39

describe a method of energy increase between twins one obese and the othe lean

Answer 39

certain microbes may incease energy harvesting efficiency leading to increased host energy uptake leading to increased fat storage 1. H2 build up from bacteria fermentation normally feedb-inhibition fermentation 1. fatty acids are cleaved into acetate and butyrate 2. H2 is oxidized by ***_methanogens_*** counteracting the H2 buildup and allowing fermentation to continue 3. fermentation end products ***_acetate and butyrate_*** are readily utilized by human cells ,resulting in weight gain

Question 40

a disease that is acquired when a person looses immunity.

Answer 40

opportunistic infecttion. differentiate from commensal organisms, which only cause infection when the bacteria translocates. When a commensal organism causes infection it is considered a pathobiont