Micro Test 2

Front 1

Antibiotic Selection (2 types)

Back 1

Empirical - "best guess"

Rational - culture & sensitivity, evaluate pathogen

Front 2

Mode of action for Penicillins

Back 2

competitively binds transpeptidase that generates cross-links in cell wall, causes cell death via osmotic shock

Front 3

Pen V name and used for

Back 3

phenoxymethylpenicillin

used oral because acid resistant

used for Streps

Front 4

Pen G
name?
used for?
how taken?

Back 4

benzylpenicillin
used for Gonorrhea, syphilis, etc
used IM or IV

Front 5

Amoxicillin and ampicillin
administered?
used for?

Back 5

Oral, IM, or IV
Broader range than Pen V or G

Streps, Neisseria, Haemophilus, E. coli, and others

Front 6

Isoxazolyl Penicillins
Names?
Used for?

Back 6

Methicillin and cloxacilin

Good for bugs that are resistant to other β-lactam drugs

(Staphs that produce penicillinase)

Front 7

This drug has no inherent antimicrobial activity. It contains a β-lactam core that does not bind transpeptidases. Competitively binds penicillinase.

Back 7

Clavulanic acid

Front 8

Large class of β-lactam derivatives. Usually given parenterally. Prefix "cef-" or "ceph"

Back 8

Cephalosporins

Front 9

Binds 50S subunit of ribosome where it inhibits aminoacyl translocation to shutdown protein synthesis.

Back 9

Erythromycin and Clindamycin

Front 10

Binds 50S subunit of ribosome, inhibits protein synthesis.

Acid sensitive

Good for respiratory infections

Back 10

Erythromycin

Front 11

Binds 50S subunit of ribosome to shutdown protein synthesis

Good against MRSA

Known for triggering C. difficile diarrhea

Back 11

Clindamycin

Front 12

Binds 16S rRNA to block 30S subunit of ribosome to shutdown protein synthesis. Taken orally. Good for intracellular pathogens (Chlamydia, Rickettsiae, Mycoplasma)

Stains Teeth

Back 12

Tetracyclines

Front 13

Prodrug that is converted by anaerobes into a toxic compound that binds DNA

Converting enzyme - Pyruvate-ferrodoxin oxidoreductase

Used for anaerobes (Clostridia, H. pylori, Protozoans)

Back 13

Metronidazole

Front 14

Enzyme that converts metronidazole to active form

Back 14

Pyruvate-ferrodoxin oxidoreductase

Front 15

Mechanism of sulphonamides action and their mechanism

Back 15

Interfere with folic acid biosynthesis (needed to make DNA/RNA).

Works against broad range of Gram+ and Gram-

Front 16

Mechanism of Quinolones and their use

Back 16

Inhibits DNA gyrase or topoisomerase IV (cipro, nalidixic acid)

Good against most drugs

Front 17

Mechanism and use of Vancomycin and administration

Back 17

Inhibits cell wall synthesis

Drug of last resort

IV administered

HIGH TOXICITY

Front 18

How can bacteria defeat antibiotic? (7 methods)

Back 18

Digest, alter it's target, avoid it, secrete it, natural resistance, mutation, acquired resistance

Front 19

How are staphs resistant to penicillin

Back 19

Penicillinase

Front 20

Mechanism of MRSA's resistance to β-lactam drugs

Back 20

Has a modified transpeptidase that does not bind beta lactam antibiotics

Front 21

Mechanism of tetracycline resistance

Back 21

Transported out of cell by efflux pump

Front 22

What drugs is MRSA resistant to?

Back 22

beta-lactams, tetracycline, and sulphadrugs

Rx with Vancomycin

Front 23

Parasite causing malaria

Predominant species in endemic regions

Back 23

Plasmodium

P. falciparum, P. vivax, P. ovale, P. malariae

P. falciparum predominant in edemic regions

Front 24

Transmission of malaria occurs by

Back 24

Anopheles mosquito (vector)
-Zoonotic infection

Front 25

Malaria life cycle main steps

Back 25

1. Mosquito blood meal and transmission of plasmodium to human
2. Liver stage, ruptured liver cells releasing schizont
3. Human blood stage, gametocytes form and may be passed to next mosquito

Front 26

Clinical findings of Malaria
Incubation
Symptoms
Diagnosis
Treatment

Back 26

7-30 day incubation

prodromal symtoms, involvement of spleen, kidneys, lungs, nervous system possible

Severe: (usually P. falciparum)
-cerebral malaria, severe anemia, hemoglobinuria, pulmonary edema or ARDS, reduced platelets, cardio collapse and shock

Diagnosis by microscopy

Rx: chloroquine and quinine
-blocks heme detoxification
-resistance high

Front 27

Relapses in malaria caused by

Back 27

P. vivax or P. ovale hypnozoities dormant in liver

Front 28

Giardiasis
causitive agent?
incubation?
symptoms?
diagnosis?
treatment?

Back 28

Giardia intestinalis
Incubation 1 to 14 days
Self limiting infection typically 1 to 3 weeks

Diarrhea, abdominal pain, bloating, nausea, vomiting

Diagnosed by microscopy (cysts or trophozoites in feces)

Rx: metronidazole or tinidazole

Front 29

Toxocariasis
causitive agent?
clinical findings?
diagnosis?
Rx?

Back 29

Toxocara canis or T. cati

Visceral larval migrans (VLM)
-mostly preschool children
-larva invade liver, heart, lungs, brain, muscle
-fever, anorexia, weight loss, cough, wheezing, rashes, hepatosplenomegaly, hypereosinophilia
-death (rare) due to heart/lung/CNS involvement

Ocular larval migrans
-lesions/damage to eye
-risk of misdiagnosis as Rb

Diagnosis by hx, symptoms, Ab

Rx: albendazole (targets microtubules) and anti-inflammatories

Front 30

Ascariasis
causitive agent?
symptoms?
diagnosis?

Back 30

Ascaris lumbricoides
Usually no acute symptoms

High body burden can cause abdominal pain due to obstruction

Can develop pulmonary symptoms during larval migration (Loeffler's syndrome)

Diagnosis by stool microscopy

Effective drug treatment (albendazole)

Front 31

Most common helminthic infection

Back 31

Ascariasis

Front 32

Pediculosis (Head Lice)
causitive agent?
symptoms?
Rx?

Back 32

Pediculus humanus capitis

"tickling feeling of something moving in hair", itching, irritability"

possibility of secondary bacterial infection

Transmission via fomites possible

Treated with pyrethrin and its derivatives, malathion, lidane (neurotoxins)

Front 33

Cell wall of fungi composed of

Back 33

Glucans or Chitin

Front 34

Fungi membranes contain? Our analog is cholesterol

Back 34

Ergosterol and zymosterol

Front 35

Exogenous yeasts

Back 35

Aspergillus, Cryptococcus neoformans

Front 36

Endogenous yeasts

Back 36

candida

Front 37

Vulvovaginal candidiasis (VVC)

Back 37

"yeast infection"
overgrowth in response to hormonal changes, pH, normal flora change

itching/burning sensation

readily dx w/ microscopy

Front 38

Invasive candidiasis
population occurs in?
symptoms?
treatment?

Back 38

candidemia and disseminated infection

occurs in neonates, surgical patients, immunosuppressed

fever/chills, unresponseive to antibiotics

invloves kidney, liver, bone, muscle, joints, spleen or eyes

death due to organ failure in 50% of untreated cases

dx by microscopy

Front 39

Oropharyngeal candidiasis (OPC)

Back 39

proliferation triggering inflammation

white pseudomembrane on buccal mucosa

"thrush"

easily wiped off revealing raw, inflamed tissue underneath

Front 40

Polyenes
Used for?
Names of some drugs?
Mechanism of action?

Back 40

Used to treat candidiasis
Nystatin, Amphotericin B

Binds ergosterols in membrane causing leakage

Front 41

Azoles
Used for?
Names of drugs?
Mechanism?

Back 41

Rx of candidiasis

Fluconazole, Miconazole

Inhibits ergosterol synthesis

RESISTANCE HIGH IN C. GLABRATA

Front 42

Echinocandin B
mechanism?
rx for?

Back 42

interferes with glucan synthesis

rx for candidiasis

Front 43

Cryptococcosis
causative agent?
Symptoms?
Rx?

Back 43

Cryptococcus neoformans
-normal flora in birds
-transmitted by inhalation

Symptoms simliar to pneumonia
-can lead to fungaemia, meningoencephalitis

High mortality (12% in US, 75-90% in Africa)

Rx: Fluconazole and Amphotericin

Front 44

Aspergillosis
causitive agent?
3 pathologies?
Rx?

Back 44

Aspergillus (A. fumigatus, A. flavus, etc)

Allergic bronchopulmonary aspergillosis (ABPA)
-wheezing/coughing

Aspergilloma (fungus ball) in lung or other organs

Invasive aspergillosis
-fever, chest pain, cough, shortness of breath
-dissemination throughout organs, including brain

Rx: voriconazole (cytochrome target)

Front 45

Dermatophytes (Tinea or ringworm)
causative agent?
symptoms?
Spread?
Diagnosis?
Rx?

Back 45

Caused by many species of fungi (Trichophyton rubrum, T. tonsurans, Microsporum canus, M. jardininium)

Appears as infections on skin hair, nails

Spread by contact

Symptoms:
-4-14 day incubation
-itchy, red, raised, scaly patches that may blister and ooze
-sharply-defined edges, often redder than adjacent tissue, may be "ring-like"
-balding patches on hair
-thick, discolored, crumbly nails

Dx: KOH test, biopsy, culture

Rx: topicals (miconazole, clotrimazole, etc) or systemically (ketoconazole)