Intro to Micro

the following are identifiable by ____ staining techniques:

• mycobacterium

• cryptosporidium

• nocardia (partially)

acid fast

provide an example bacteria that prefers cold environments/cold enrichment.

listeria monocytogenes

provide an example bacteria that prefers room temperature environments.

yersinia enterocolitica

provide an example bacteria that prefers hotter environments (42°C).

campylobacter jejuni

provide an example bacteria that is an acidophile (can grow at acidic pH).

helicobacter pylori

which media type enhances growth of most?

non selective

which media type enhances growth of some, suppresses growth of others?

selective

which media type can allow different organisms to appear differently, generally through color?

differential

the following bacteria for respiratory specimens grow well on ____ agar plates:

• haemophilus species

• neisseria/moraxella

CHOC

the following bacteria for genital specimens grow well on ____ agar plates:

• neisseria gonorrhea

CHOC

common isolates for ____ include:

• N. meningitidis

• E. coli

• S. pneumoniae

• S. agalactiae

• S. aureus

• Listeria monocytogenes

CSF

what bacteria is group A streptococcus?

streptococcus pyogenes

groups C and G are hemolytic streps. true or false?

true

the following bacteria are considered ____ for throat cultures:

• alpha hemolytic strep viridans

• neisseria species

• corynebacterium species

• coag negative staph

normal flora

sputum and BAL (bronchs) are used to diagnose upper respiratory tract infections (pneumonia). true or false?

false

a good quality sputum/bronch sample is assessed by _____ epithelial cells per low power field (10x).

<10

a good quality sputum/bronch sample is assessed by _____ PMNs per low power field (10x).

>25

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• commonly community acquired; geriatric

streptococcus pneumoniae

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• associated nosocomial

• alcoholics

klebsiella pneumoniae

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• community acquired

• nosocomial

• generally secondary to other infection/predisposing factor

staphylococcus aureus

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• cystic fibrosis patients

pseudomonas aeruginosa

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• infants, children, immunosuppressed

• Hib vaccine has helped decrease prevalence of invasive type

haemophilus influenzae

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• middle aged adults

• required specialized media (BCYE)

legionella pneumophilia

for respiratory (sputum/bronchs) specimens, which bacteria best fits the following information

• atypical pneumoniae

• requires specialized media (and hold up to 4 weeks)

mycoplasma pneumoniae

what preservative is often used for urine culture specimen collection?

boric acid

the UA results for ____ may include:

• leukocyte esterase

• bacteria

• WBCs

• nitrite

• blood

UTI

absence of ____ is most useful in ruling out UTI in a patient with symptoms consistent with a UTI.

pyuria

the following bacteria are common pathogens isolates of ____ samples:

• salmonella

• shigella

• campylobacter

• E. coli

• Plesiomonas shigelloides

stool

the following bacteria are considered _____ normal flora:

• lactobacillus (childbearing age)

• staph and corynebacterium (later years)

vaginal

the following are common pathogens of the ____

• Neisseria gonorrheae

• Chlamydia trachomatis

• Actinomyces

genital tract

_____ is a nonspecific vaginitis that is due to overgrowth of some normal flora

• most likely Mobiluncus

• Gardnerella vaginalis can be an indicator for BV (clue cells)

• increased risk post miscarriage/D&C

bacterial vaginitis

what term is being defined: humans and microbes benefit?

mutualism

what term is being defined: microbes benefit, humans unaffected?

commensalism

what term is being defined: microbes benefits at expense of human host?

parasitism

what term is being defined: organisms that cause disease?

pathogens

what term is being defined: organisms that cause disease in compromised patients?

opportunistic pathogens

what term is being defined: means by which a microbe can harm its host?

pathogenecity

what term is being defined: degree of pathogenecity?

virulence

what term is being defined: infected/potentially infectious human, generally asymptomatic?

carrier

what term is being defined: infectious disease of animals that can be transmitted to people?

zoonosis

the preferred portal of entry of the following infection sites are _____:

• respiratory tract

• genitourinary tract

• GI tract

• conjunctiva

mucous membranes

the preferred portal of entry of the following infection sites are _____:

• hair follicles

• sweat glands

skin

what refers to surface molecules that bind specifically to surface receptors (usually sugars) on specific host tissue?

adhesions/ligands

_____ evade host defenses by:

• increasing virulence

• impairs phagocytosis with no antibodies

  • S. pneumo

  • K. pneumo

  • Y. pestis

  • H. influenzae

  • B. anthracis

capsules

_____ evade host defenses by:

• part of cell wall of S. pyogenes

• impairs phagocytosis

M protein

which enzymes destroys PMNs and macrophages (staph/strep)?

leukocidins

which enzymes lyse RBCs, streptolysins (made by strep), and possibly WBCs?

hemolysins

which enzymes coagulates fibrinogen → fibrin → protective clot around bug?

coagulases

which enzymes breaks down fibrin → dissolves clot used to isolate infection?

kinases

which enzymes breaks down hyaluronic acid found in connective tissue?

hyaluronidase

which enzymes facilitates spread of gas gangrene by breaking down collagen in connective tissue of muscles and other body organs (Clostridium species)?

collagenase

what toxin is made by bacteria and released into the host (usually by gram positive bacteria)?

exotoxins

the following listed are examples of ____:

• cytotoxin (host cells)

• enterotoxin (GI tract)

• neurotoxin (nerve cells)

exotoxins

what toxin is part of outer portion of cell wall (lipid A) of gram negative bacteria?

endotoxins

which exotoxin best fits the following:

• C. diptheriae (tox gene)

• S. pyogenes (erythrogenic toxins A, B, C)

cytotoxin

which exotoxin best fits the following:

• S. aureus (diarrhea/vomiting, TSS)

• Vibrio cholera (fluid/electrolyte loss → dehydration → death)

enterotoxin

which exotoxin best fits the following:

• Clostridium botulinum (blocks acetylcholine → muscle paralysis)

• Clostridium tetanus (blocks relaxation pathway in muscle cells: chronic contractions/”lock jaw”)

neurotoxin

the following may be involved with which toxins?

• fever

  • phagocytosis → IL-1 → hypothalamus → fever

• septic shock (decreased bp)

  • phagocytosis → TNF → damaged capillaries → fluid loss → bp drop

endotoxins

antibodies are not helpful for endotoxins. true or false?

true