MICRO CH18

Staphylococcus 

• Gram + or -?

• Can it synthesize catalase?

  • how does staph differ from Streptococcus?

• Does it have the tendency to be drug resistant?

  • 2 examples of drugs?

• Is it part of the normal flora?

  • where?

  • does it always cause disease?

gram positive, yes, strep doesnt synthesize catalase, yes, MRSA and VRSA, yes, nose skin gut vagina, no

Staphylococcus (cont…)

• Does salt inhibit its growth?

  • what does this make it?

• Does it cause nosocomial infections?

• Pyogenic or pyrogenic?

• Which is the most serious species of the staph?

its haloduric so it can handle salt but doesnt prefer salt, yes, pyogenic, s.aureus

S. aureus

• What areas of the body can be problematic? 

skin, gut, genital areas but not sexually related, blood

What are some examples of exoenzymes utilized by S.aureus?

• ____: to free itself from clots)

• ____: breakdown hylaurinc acid (which holds together connective tissue)

  • what does this allow the bacteria to do?

• ____: triggers clotting

• ____: breakdown penicillin + acts as cell wall inhibitor= makes antibiotics useless

  • is this common or uncommon?

• ____: breakdown fat 

staphylokinase, hyaluronidase, spread, coagulase, beta lactamase, common, lipase

S.aureus

• Are the toxins produced by S. aureus endo or exotoxin?

• ____: lyses leukocytes + macrophages via breaking their ____

• What do hemolysis destroy?

• ____: infected hair follicle/gland

  • leads to?

  • does it always stay in the follicle/gland?

  • what flora type causes this?

  •  What are the dangers of untreated boils? 

exotoxin, leukocidin, cell membrane, RBCs, folliculitis, sty, no it can grow into sty>furnuncle>carbuncle, endogenous flora, reaches the blood (aka septicemia)

S.aureus

____: highly contagious disease spread by SCRATCHING

• caused by what 2 species?

• common among what age group?

____: strain of s.aureus; causes sloughing off of skin

• what does s.aureus require to carry to cause SSSS?

• What is the name of the toxin used?

• What occurs to cause this sloughing off: ____ toxins causes skin cells to “unstick” from each other by acting on ____ (skin cell’s “glue”)

impetigo, s.aureus and s.pyogenes, kids, Needs plasmid of exfoliative toxin, staphlococcus scaled skin syndrome, plasmid of exfoliative toxin, epidermolytic toxin, epidermolytic, desmoglein

S.aureus and GI tract

• is this an infection or intoxication?

  • what is the name of the toxin? ____: acting on desmoglein (skin cell “glue” protein)

  • is this an exo or endotoxin?

  • what is the problem with ingesting – the toxin or bacteria itself?

• Is s.aureus common cause of food poisoning? 

• does the patient commonly require hospitalization? why?

intoxication, epidermolytic toxin, enterotoxin, exotoxin, ingesting the toxin, yes, no bc resolves in under 24 hours

S.aureus and Toxic shock syndrome

• is it only menstrual related cases? 

  • what else can cause this?

  • what produced INCREASES risk?

• Does this only affect females?

  • it it more common in males or females?

• whats an important sign of TSS?

no, catheders + wounds + surgical wounds + c-sections, any cotton packing, no it can affect males, males, sunburnish rash

S.aureus and systemic effect

• How are these usually spread?

• is it common in all individuals?

• know what target area each example pertains to?

  • Endocarditis = ___

  • Osteomyelitis = ___

  • Arthritis = ___

  • UTI =  ___

  • Pneumonia = ___ 

  • Meningitis = ___ 

  • Bacteremia and Septicemia = ___

skin lesions, NO bc its only gonna affect nonhealth people, heart lining, bones, joints, bladder, lungs, meninges, blood

S.aureus and systemic effect (septicemia)

• ___: small numbers of bacteria not multiplying in blooD

• ___: large numbers of microbes multiplying in blood

• Who’s more at risk systemically:

  • bed sores, extensive surgery

  • sick ppl

  • pneumonia ppl

• Signs/symptoms of septicemia?

  ***hint: “Cold Tigers Chase Fast Energetic Bunnies"****

bacteremia, septicemia

• confusion

• tachypnea and tachycardia

• chills

• fever

• edema

• blood clotting

• Types of samples are collected to isolate S. aurues? (***think liquid excretion stuff from body***):

  • Pus

  • Tissue exudates (tissue fluids)

  • Sputum (saliva+mucus coughed up), Urine, blood

• What 2 tests can be used to differentiate S. aureus strains of pathogenic potential?

MSA test and coagulase test,

Streptococcus  

• Gram + or -? Gram +

• catalase positive or negative?

• Which groups are “most” important?

  **hint: “fav pp”

  • Who grouped these?

gram positive, catalase negative

• faecillis, agalactiae, viridians group, pyogens, pneumoniae, rebecca lancefield

Streptococcus

• alpha, beta, and gamma hemolytic refers to strept’s effect on ____

• M-proteins: ____ protein that ___ phagocytosis + helps bacteria ___ to respiratory epithelium 

• What pyrogenic toxin induces fever and a red rash?

  • causes rash by ____ blood vessels near skin’s surface

• ____: breakdown DNA released from dead cells of abcesses

  • what does this do?

• ____: slows down WBC movement to infection site

blood agar, fimbriae, blocks, bind, erythrogenic toxin, dilating, deoxyribonuclease, increase spread, C5a peptidase

Which is more difficult to treat: staph or strept?

STAPH

Streptococcus pyogenes

• group A or B?

• Is it alpha, beta, or gamma hemolytic?

• what does it form?

• where does it form?

• Can it be caused from endogenous flora and exogenous flora, or both?

group A, betahemolytic, pus, throat and nasopharynx, both

Streptococcus pyogenes

____: really common in pre-school/little school kids; yellow crust, burning, itchy papules

• Nick in skin that makes contact with infected fingers or another crust/blister

____: acute febrile infection of dermis; red skin, lesions in head and face

• How is the bacterium acquired to cause this disease?

• Where it an infection?

____: causes inflamed pharynx

• how common is this?

• how is it spread?

• Is this exclusive to pyogenes?

impetigo, erysipelas, enters from broken skin, an infection of the skin, strep throat, very common, air droplets and snot, no it can be caused by other species like staph.aureus

s.pyogenes

• What toxin is produced to yield scarlet fever?

• What organ does the long term complication from GAS glomerulonephritis effect?

  • Does it cause a local or systemic infection?

• What long term complication from GAS attributes to the top cause of heart valve damage to kids?

erythrogenic toxin, kidney, systemic, rheumatic fever

s.pyogenes

___:“Flesh eating bacteria”; progressive, rapid spreading, inflammatory reaction that reaches deep fascia 

• enzyme are used?

• initial symptom: raised red area around cut, severe pain and swelling

• How: bacteria enters thru skin or insect bite > secretes ___ to destroy tissue > as necrosis continues, tissue ____ = allows for deeper invasion

necrotizing fasciitis, collagenase, collagenase, sloughs off

What is the drug of choice for streptococcus?

penicillin

S. pneumoniae 

• What is its major virulence factor

• Is this part of the normal flora?

• How many of pneumonia cases are cause by this?

• What situations/conditions increase the risk?

• What can it cause to otherwise healthy little kids?

• Its importance in contribution to cases of meningitis in the US? 

• polysacc capsule

• yes

• MAJORITY of pneumonia cases

• living in close quarters, young/elderly people, sick people, lung disease people

• middle ear infections (akaottis media)

• leading cause (of the top 3)

s.pneumoniae

• 2 vaccines?

  • what does the value associated with the vaccine name correlate to?

• Know antibiotics used?

• pneumovax and prevnar

• capsule type

• penicillin, cephalosporin, erythromycin, chloramphenicol

s.pneumoniae - viridans group

• Where is viridians group located?

• species attaches to the enamel?

• species attached to the gingival lining?

• what can it cause in teeth:

  • plaque, dental caries, gingivitis, periodontal disease

5. what infection is cause if gets into the blood?

mouth, s.mutants, s.salivarius, endocarditis

S.agalactiae 

• group A or B?

• Is it part of the normal flora?

• Under what situation can this be VERY problematic to a newborn?

group B, no, vertical transmission

S. faecalis 

• what genus is this now?

• what kind of infections can it cause?

• what does VRE stand for?  

• enterococcus

• UTI, endocarditis, bacteremia, wound infections

• vancomycin resistant enterococcus faecalis

Neisseria 

• Gram + or -?

• motile or nonmotile?

• morphology?

• aerobic or anaerobic

• What is it considered? (she’s a celebrity…)

• What structure aids facilitates attachment?

• What are the 2 pathogenic species we discussed?

  • which one is NEVER part of the normal flora?

gram negative, nonmotile, diplococcus, aerobic, fastidious, fimbriae and polysacc capsule, n.meningitis and n.gonnorrea, n.gonnorrea

N. gonorrhoeae 

• causes disease in ___ eye and genital area

• can it live a long time outside of its host?

• infects ANY mucus membranes, but the main ones are where specifically

• newborn

• no

• mucus membranes of eye, urinary tract, rectum, pharynx

N.gonnorrea

• Can males and females be asymptomatic?

  • who’s more likely to be asymptomatic?

• male symptoms?

• female symptoms?

  • are female symptoms always severe?

• Can infections disseminate?

• What more progressive disease can untreated cases lead to? 

•  YES both can be

• women

• painful urination, cloudy yellow discharge, urethritis 

• bloody urination, urethritis

• no it can be mild (which is why it goes unnoticed…)

• PID, meningitis, endocarditis, arthritis 

Neisseria

1. What 2 important diseases are caused?

2. What characteristic symptoms are seen with meningococcal septicemia?

   • What are they a result of? – think back, is this Gram + or -?

• What age group can be affected due to infected or carrier moms

• How can gonorrhea be prevented?

  • how are condoms effective

• Meningococal septicemia and mengingocal meningitis

• petechiae/purpura and big black lesions

• endotoxins

• infants

• sex with condom, no sex, loyal partner

• acts as physical barrier from spreading gonnorrea

Neisseria

• 2 important diseases are caused?

• characteristic symptoms seen with meningococcal septicemia?

  • What are they a result of?

• which specific meninges is inflamed with meningococcal meningitis?

  • symptoms: sore throat, fever, headache, stiff neck, convulsions

• m.septicemia and m.meningitis

• petechiae and big black lesions (necrosis)

• endotoxin

• CNS meninges

• How common is neisseria meningitidis in causing meningitis in the US?

• Know the vaccines for all top 3 causative agents of bacterial meningitis!!

• 2nd most common cause,

• Pneumovax or Prevnar for pneumococcal meningitis

• menomune and menactra for meningococcal meningitis

• HIB for Haemophilus influenzae

Acinetobacter

• where is it found in the environment?

• how does its ability to survived long term in the environment affect transmission?

• What species is most commonly reported?

• where can it cause infection?

• 2 situations are going to place an individual at risk for acquiring the bacterium?
  
  
  
  

• soil and water

• inanimate objects

• a.beumanni

• skin, lungs, blood, urinary tract

• healthcare associated places and solider in combat conditions