Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NBDE Part 1 > Microbiology General, Mycology and Parasitology > Flashcards

Microbiology General, Mycology and Parasitology Flashcards

1
Q

Prokaryote vs. Eukaryote

A

Ribosome Size: Pro: 70S Euk: 80S

Nucleic Acid Location: Pro: Nucleoid (cytoplasm)

Euk: Nucleus

DNA Type: Pro: Circular Euk: Linerar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacteria, Virus, Fungi, Parasites

A

Bacteria: Prokaryote (Outer surf: cell wall of peptidoglycan) RNA and DNA. Rep: binary fission

Virus: Noncellular (outer surf: Protein capsid and lipoprotein env.) RNA or DNA. Rep: assembly within host cell

Fungi: Eukaryote (Outer surf: cell wall of chitin) RNA and DNA. Rep: budding (yeast) Mitosis (molds)

Parasite: Eukaryote (outer surf: cell membrane) RNA and DNA. Rep: Mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Endemic

A

infection occurs at minimal levels within a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Epidemic

A

infection occurs more frequently than normal within a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pandemic

A

infection occurs worldwide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Infectious States

A

Acute: Short-term active infection with symptoms

Chronic: long-term active infection with symptoms

Subclinical: Infection is detectable only by serological tests

Latent: No active growth of microorganisms but potential for reactivation

Carrier: Active growth of microorganisms with or without symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Symbiotic Association

A

Symbiosis: The essential association between two different organisms that live close to each other with or without mutual benefit

  • Mutualism: Both organisms derive benefit from each other
  • Commensalism: One organism benefits, whereas the other is neither harmed nor helped
  • Parasitism: One organism benefits, whereas the other is harmed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Infectious Swellings

A

Abscess: An acute inflammatory lesion consisting of a localized collection of pus surrounded by a cellular wall

Granuloma: A chronic inflammatory lesion consisting of granulation tissue: fibrosis (fibroblasts), angiogenesis (new capillaries) and inflammatory cells (macrophages, lymphocytes, plasma cells, epithelioid cells, and multinucleated giant cells

Cyst: An epithelial-lined sac filled with fluid or air

Cellulitis: An acute, diffuse swelling along fascial planes that separate muscle bundles

  • Pus: is a creamy substance that contains dead neutrophils, necrotic cells and exudate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sterilization, disinfection, antiseptics, pasteuration, sanitization

  • Common sterilization techniques, disinfectants, and antiseptics
A
  • Sterilization: The killing of all microorganisms, including bacterial spores.
    • Heat sterilization (moist heat and dry heat) is the most reliable (spore test).
      • Normal cycle: 121 C for 15-20 min
      • Heat sensitive: glutaraldehyde
    • Spore tests (with Bacillus stearothermophilus) are recommended on a weekly basis
  • Disinfection: Killing of many but not all microorganisms (inanimate objects)
    • Phenols (rare), Quarternary ammonium compounds (antiseptic), Chlorine (most common form = sodium hypochlorite = bleach)
  • Antiseptics: Chemicals that kill microorganisms on the surface of skin and mucous membranes
    • Many antiseptics can also be used as disinfectants
    • Iodophors (most effective skin antiseptic), Ethanol and isopropyl alcohol (most widely used skin antiseptic), Hydrogen peroxide (only effective against catalase negative organisms), chlorhexidine gluconate (handwash/mouth rinse), Triclosan (handwash/toothpaste)
  • Pasteurization: A method of heat-killing milk-borne pathogens such as mycobacterium tuberculosis, salmonella, streptococcus, listeria and brucella. Heats milk to 62 C for 30 min., then rapid cooling
  • Sanitization: method of treating public water supplies to reduce microbial load
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Infection control Regulations vs. recommendations

A

Center for disease control and Prevention (CDC) = major agency responsible for infectious disease epidemiology, surveillance, and prevention. It provides recommendations and guidelines for infection control procedures used by healthcare workers

Occupational Safety and Health Administration (OSHA), a division of US Department of Labor, is responsible for composing and enforcing infection control laws and regulations that MUST be followed by healthcare workers. OSHA may use CDC recommendations and guidelines in drafting its mandates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Universal vs. standard precautions

A

Universal Precautions: All human blood (and other body fluids that contain viable blood) are treated as infectious. Emphasizes prevention of bloodborne diseases (HIV, HBV, etc)

Standard precautions: Any body fluid (excretion or secretion) except sweat, regardless of the presence of blood, is treated as infectious. Emphasizes prevention of bloodborne, as well as airborne, droplet, and contact-transmitted diseases.

  • The greatest risk for bloodborne infection among healthcare workers is HBV
  • Handwashing is the most important infection control practice for reducing nosocomial infections and must be performed after removal of PPE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are Fungi? describe details

A

Fungi

  • Gram (+), eukaryotic microorganisms
  • All are either obligate (the majority) or facultative aerobes
  • Cell membranes: lipid bilayer contains ergosterol
  • Cell walls: carbohydrate and protein (chitin)
  • Capsule (if present): Polysaccharide coating
  • Laboratory diagnosis by KOH preparation

Most fungal spores and conidia are killed at temperature > 80C for 30 min.

Most antifungal drugs target the ergosterol component of fungal cell membranes, altering their permeability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain Fungal Reproduction

A

Fungal Reproduction:

  • Sexual: Mating and formation of spores
    • Zygospores: single, large spores with thick walls
    • Ascospores: Formed in a sac (ascus)
    • Basidiospores: Formed on the tip of a pedestal (basidium)
  • Asexual: Budding and formation of conidia (asexual spores)
    • Arthrospores: Formed by fragmentation of the ends of hyphae
    • Chlamydospores: Rounded, thick-walled, and highly resistant
    • Blastospores: formed by budding process
    • Sporangiospores: Formed on a stalk within a sac (sporangium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain the pathogenesis of fungal/Mycology infections

A

Pathogenesis:

  • Fungal infection: Leads to a largely cell-mediated immune response (Type IV Hypersensitivity reaction) and Granuloma formation
  • Mycotoxicosis: Induced by ingestion of fungal toxin
  • Allergic response: Type I hypersensitivity reactions to inhalation of fungal spores
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are Aflatoxins

A

Aflatoxins are hepatocarcinogenic toxins produced by Aspergillus flavus, generally found on contaminated grains and peanuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the classifications of fungi?

Morphology

Reproduction

A

Yeasts

  • Morphology: Single Cells
  • Reproduction: Asexual budding

Molds

  • Morphology: Hyphae (long filaments) which form a mat-like structure (mycelium)
  • Reproduction: Cell division

Some fungi are dimophic - they exist as molds at ambient temperatures but as yeasts at warmer (body) temperature

17
Q

What are Major systemic fungal infections that are medically relevant

A
  • Blastomyces dermatitidis
  • Coccidioides immitis
    • Desert valley fever, San Joaquin fever
  • Histoplasma capsulatum
18
Q

What are Blastomyces dermatitidis Fungi

  • Disease
    • Type
    • Characteristics
    • Treatment
A

What are Blastomyces dermatitidis Fungi

systemic infection

  • Blastomycosis
    • Type: Dimorphic
    • Endemic in eastern US and central america
    • Inhalation of microconidia produces granulomatous nodules in lungs and respiratory infection
    • Treatment: Itraconazole, Amphotericin B
19
Q

What are Coccidioides immitis Fungi

  • Disease
    • Type
    • Characteristics
    • Treatment
A

What are Coccidioides immitis Fungi

systemic infection

  • Coccidioidomycosis (desert valley fever, San Joaquin fever)
    • Type: Dimorphic
    • Endemic in southwest US and latin America
    • Inhalation of arthrospores produces respiratory infection
    • Treatment: Amphotericin B, Itraconazole, Ketoconazole, Fluconazole
20
Q

What are Histoplasma capsulatum Fungi

  • Disease
    • Type
    • Characteristics
    • Treatment
A

What are Histoplasma capsulatum Fungi

systemic infection

  • Histoplasmosis
    • Type: Dimorphic
    • Endemic in ohio and mississippi river valleys
    • Found in soil often contaminated by bird/bat droppings
    • Inhalation of microconidia produces respiratory infection
    • Yeast cells located within host macrophages
    • Treatment: Amphotericin B, Itraconazole, Fluconazole
21
Q

What are the major cutaneous fungal infections

A
  • Disease: Dermatophytosis
    • Trichophyton sp
    • Epidermophyton sp
    • Microsporum sp
22
Q

What are the funguses that cause Dermatophytosis

What is the type of fungi

characteristics

Treatment

A

Dermatophytosis

Major cutaneous Fungal infections

  • Fungus:
    • Trichophyton sp.
    • Epidermophyton sp.
    • Microsporum sp.
  • Type: Molds
  • Characteristics:
    • Tinea corporus (ringworm)
    • Tinea capitis (scalp itch)
    • Tinea cruris (jock itch)
    • Tinea pedis (athlete’s foot)
    • Tinea unguium (nail fungus)
  • Treatment:
    • Griseofulvin
    • Miconazole
    • Clotrimazole
    • Tolnaftate
23
Q

What are the major opportunistic fungal infections

A
  • Aspergillus fumigatus
  • Candida albicans
  • Cryptococcus neoformans
  • Mucor sp.
  • Rizopus sp.
  • Absidia sp.
24
Q

What are Aspergillus fumigatus fungi?

  • Disease
    • Type
    • Characteristics
    • Susceptibility
A

What are Aspergillus fumigatus fungi?

Major opportunistic Fungal infection

  • Aspergillosis
    • Type: Mold
    • Inhalation of conidia causes respiratory infection and aspergilloma (fungus ball) formation in lungs
    • Susceptibility: AIDS, Organ transplantation
      • Produce aflatoxins
25
Q

What are Candida albicans fungi?

  • Disease
    • Type
    • Characteristics
    • Susceptibility
A

What are Candida albicans fungi?

Major opportunistic Fungal Infections

  • Candidiasis
    • Vaginitis
    • Angular cheilitis
    • Median rhomboid
    • Glossitis
      • Type: Yeast
      • Part of normal human flora of mouth, vagina, GI tract, and skin
      • Appears as budding yeasts or pseudohyphae
      • Susceptibility: AIDS, Prolonged use of antibiotics
26
Q

What are Cryptococcus neoformans fungi?

  • Disease
    • Type
    • Characteristics
    • Susceptibility
A

What are Cryptococcus neoformans fungi?

Major opportunistic infections

  • Cryptococcosis
    • Type: Yeast
    • Heavily encapsulated.
    • Inhalation of spores causes respiratory infection, meningitis, and pneumonia
    • Susceptibility: AIDS
27
Q

What are Mucor sp., Rhizopus sp., Absidia sp. fungi?

  • Disease
    • Type
    • Characteristics
    • Susceptibility
A

What are Mucor sp., Rhizopus sp., Absidia sp. fungi?

Major opportunistic fungal infections

  • Mucormycosis
    • Type: Molds
    • Inhalation of conidia causes respiratory, skin, paranasal sinus, and brain infections
    • Susceptibility: Diabetes (ketoacidosis), leukemia, burns
28
Q

What are common antifungal drugs to treat candidiasis

A
  • Nystatin
    • Mechanism: Binds to ergosterol
    • Forms: Topical, Oral
  • Amphotericin B
    • Mechanism: Binds to ergosterol
    • Forms: topical, oral, intravenous
  • Clotrimazole
    • Mechanism: Inhibits ergosterol synthesis
    • Forms: Troche
  • Ketoconazole
    • Mechanism: Inhibits ergosterol synthesis and blocks fungal cytochrome P450
    • Forms: Tablet
  • Fluconazole
    • Mechanism: Inhibits ergosterol synthesis and blocks fungal cytochrome P450
    • Forms: Tablet
29
Q

What are the two classifications of a Parasite?

A
  • Protozoa
    • Unicellular, eukaryotic microorganism that lack a cell wall and largely infect blood cells, intestinal and urogenital tissue, and meninges
  • Metazoa (helminths)
    • Multicellular worms that often infect the intestines, brain, liver and other tissues
30
Q

What type of immune response does parasitic infections elicit

A

Parasitic infections generally elicit an IgE-mediated host immune response accompanied by marked eosinophilia

31
Q

What are common Protozoa associated with Human Infection

A
  • Entamoeba histolytica
    • Amebiasis: Dysentery, Liver abscess
      • Contaminated water with fecal
      • Motile Trophozoite (intestinal), Nonmotile cyst (water)
  • Giardia lamblia
    • Giardiasis: Diarrhea, Flatulence
      • Contaminated water with fecal
      • Motile Trophozoite (intestinal), Nonmotile cyst (water)
  • Cryptosporidium parvum
    • Cryptosporidiosis: Diarrhea
      • Associated with AIDS
  • Trichomonas vaginalis
    • Trichomoniasis (Vaginitis, Urethritis)
      • STD
      • Motile Trophozoite
  • Plasmodium vivax, ovale, malariae, falciparum (fatal)
    • Malaria (influenza-like onset), fever, headache, anemia, splenomegaly
      • Female mosphitoes (anopheles)
      • Sporozoite, Merozoite (liver), Hypnozoite (latent), causes lysis of erythrocytes
  • Toxoplasma gondii
    • Toxoplasmosis: CNS infection, encephalitis, seizure, associated with AIDS
      • Fecal-oral. Transplacental
      • Motile Trophozoite (intesitinal), nonmotile cysts (uncooked meat and cat feces)
  • Pneumocystis jiroveci (formerly P. carinii)
    • Pneumonia
      • Inhalation
      • Fungus (originally classified as protozoan)
      • Associated with AIDS
      • Found in oral cavity, but not pathologic
32
Q

What are the common Metazoa (Helminths) associated with human infection

A
  • Taenia solium
    • Taeniasis (tapeworm)
      • Ingestion of undercooked pork
      • Cysticercosis (muscle cysts)
      • Neurocysticercosis (brain cysts)
  • Taenia saginata
    • Taeniasis (tapeworm)
      • Ingestion of undercooked beef
      • Does not cause cysticecosis
  • Enterobius vermicularis
    • Enterobiasis (pinworm)
      • Ingestion of worm eggs
      • Most common worm in US
      • Associated with perianal pruritis
  • Trichinella spiralis
    • Trichinosis (roundworm)
      • Ingestion of undercooked meat (pork, wild game)
      • Larvae only grow in striated muscle
      • Associated with muscle pain, periorbital edema, fever

NBDE Part 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions