Microbiology 220 Exam 1

COMPOUND LIGHT MICROSCOPE (TWO MAIN OBJECTIVES):

1) Magnification - enlargement of an image 2) Resolution - the ability to see fine detail. THESE ARE INDIRECTLY RELATED: AS MAGNIFICATION INCREASES; RESOLUTION DECREASES

THERE ARE TWO LENS SYSTEMS IN A COMPOUND LIGHT MICROSCOPE

1) OCULAR LENS (EYEPIECES) standard is 10x; may be changed to 15x or 20x 2) OBJECTIVE LENS 4x scanning - 40x; 10x low power - 100x; 40x high power; - 400x 100x oil immersion - 1000x

Plasmodium (four species cause malaria)

1) Plasmodium falciparum 2) Plasmodium Vivax 3) Plasmodium Ovale 4) Plasmodium Malariae

The specific type host a virus infects is determined by 2 factors:

1) The virus's requirements for a specific attachment to the host cell. 2) The host must have the factors the virus need to multiply. Sometime viruses can cause cancer.

gram stain positive

thick cell wall of peptidoglycan, stains purple or violet

gram stain negative

thin cell wall of peptidoglycan and has a outer membrane made of phospholipid, lipoprotein, lipopolysaccharides. Stains pink or red

two types of eletron microscopes

transmission - magnifies up to 10,000 times scanning - magnifies up to 10,000 times.

Pneumocystis carinii

ubiquitous systemic opportunistic pathogen pneumonia in HIV patients

Rhizopus, Mucor, Aspergillus

ubiquitous, systemic, opportunistic pathogen. Rhizopus nigricans (common black bread mold)

Characteristics of Protozoa

unicellular eukaryotes heterotroph sasexual or sexual by conjugation classified by locomotion lack cell walls Some protozoa produce a protective capsule called a cyst. pseudopods (false feet)

Heterotrophs

which get their nutrition from other source: dead/nonliving

Edward Jenner

Vaccination

Robert Koch

microbes cause particular diseases that may be contagious (doesn't have to be direct contact)

Plasmodium requires two hosts for its life cycle.

1) Anopholes mosquito definitive host because it harbors the sexual reproductive stage 2) Human the asexual reproductive stage of Plasmodium

2 reasons smear must be fixed

1) Kills the bacteria 2) secure specimen to the slide

two general method of arthropod vector transmission are

1) mechanical- passive transport of pathogens by the insect's feet or other body parts (houseflies can carry microbes from feces to food on their feet) 2) biological- active transport from arthropod bites whereby the disease is transmitted from person to person

how do you prepare a smear?

1) place a drop of water on a clean slide (use a very small drop of water) 2) using a sterile loop place a small amount of bacteria in the drop of water and make a smear approximately the size of a quarter. 3) allow the smear to air dry

Alexander Fleming

1st antibiotic, Penicillin

Paul Ehrlich

1st synthetic drug, Salvarsan to treat Syphilis

Anton van Leeuwenhoek

1st to view microbes using a microscope

Subcutaneous mycoses

Acquired through direct implantation of spores into a puncture wound in the skin. Caused by saprophytic fungi that live in soil and on vegetation.

Systemic mycoses

Acquired through inhalation of spore. Infection begins in the lungs and spread to other body tissues and organs Not contagious animal to human or human to human

How to fix a smear on a slide?

After the smear is completely dried, pass it back and forth through a flame twice.

Cutaneous mycoses

Also called Dermatomycoses Fungi which cause them are dermatophytes. Transmitted human to human and animal to human by direct contact or by contact with infected hairs and epidermal cells (as with barber clippers or shower room floors)

Vectors

Animals that carry microbes from person to person

Joseph Lister

Antiseptic surgery techniques

Gram staining involves the application of 4 different solutions

CRYSTAL VIOLET-primary stain (basic dye) GRAM IODINE-mordant (not dye) DECOLORIZER -alcohol/acetone; ethyl alcohol SAFRANIN -COUNTERSTAIN (basic dye) (washing occurs after each application)

Eukaryotes

Cells that have a nucleus

Prokaryotes

Cells without a nucleus

What is the general shape of bacteria?

Coccus (sphere), Bacillus (rod), Spirillum (curved) and Spirochete (spiral)

neterotroph

Consumes other organism

Viruses have a simple structure

Contain DNA or RNA (not both) Capsid made of protein The capsid may or may not be surrounded by an outer covering called the Envelope. Envelope are made with proteins, carbohydrates and lipids. It modified the host's cell membrane Envelope may or may not be spiked.

What are some examples of bacteria?

Escherichia Coli (E. Coli) Streptococcus Staphylococcus Bacillus anthracis

Toxoplasma gondii

Ingestion of cat feces. lives in the gut of a healthy adult cats Asymptomatic in normal healthy adults congenital neurological damage to fetus if Toxoplasma is acquired by pregnant woman

Linnaeus's System of classification

Kingdom Phylum Class Order Family Genus Species

Parts of a compound microscope(from the light to the eye)

Light Source CONDENSER STAGE (SPECIMEN ON SLIDE) OBJECTIVE LENS PRISM OCULAR LENS

Saprophytes

Living (parasites)

Flagella

Long hair like structures

Arthropods

Most important group of vectors.

Viruses are classified by their host

Most viruses are able to infect specific types of cells of only one host species. Viruses that infect bacteria are called Bacteriophages.

Balantidium coli

Movement - by cilia only parasitic ciliate of humans. Acquired through ingestion of drinking water contaminated with feces.

Entamoeba histolytica

Movement: pseudopods (cytoplasmic extensions); also used for feeding Causes: Amoebic Dysentery- bloody, mucus filled stool acquired through ingestion of drinking water contaminated with feces

How is Yeast described?

Non filamentous, Unicellular. Typically spherical or oval; Larger than bacteria.

Apicomplexans

Not motile Obligate Intracellular Inside the host cells

General characteristics of Algae

Protista unicellular eukaryotes various shapes photoautotrophs important in "balance of nature" and food chain mostly aquatic Cell walls contain cellulose sexual and asexual reproductive organs rarely associated with human disease; usually it occurs from ingestion of fish and animals which contain toxins produced by algae (dinoflagellates and diatoms)

Paul Berg- Recombinant DNA

Recombinant DNA

Microscopy

The most important tools in microbiology

ASEXUAL PORTION OF THE PLASMODIUM LIFE CYCLE

Sporozoites or infective stage of Plasmodium enters human with bite of infected mosquito Sporozoites are carried by the blood to the liver In the liver, they undergo schizogony and produce thousands of progeny called merozoites Merozoites re-enter bloodstream and infect RBCs In the RBCs, they mature to trophozoites and appear as a ring (called ring stage) Ring stage enlarges, divides repeatedly, causing the RBC to eventually burst and release more merozoites Bursting of the RBCs and release of the merozoite waste products is responsible for the chills and fever associated with malaria Most of these merozoites infect new RBCs and the process repeats itself. Some are picked up by feeding mosquitos in which they undergo the sexual portion and infect other humans

The genus-species of any organism is the scientific name of the organism.

Staphylococcus aureus Staphylococcus epidermis Escherchia coli Clostridium tetani Clostridium botulinii Clostridium perfringens

When writing taxonomic names what do we capitalized?

The genus is always Capitalized

Taxonomy

The science of classification

What do we write in lowercase (taxonomic names)

The species is lowercase

Some bacteria are autotrophs

Which manufacture their nutrients through photosynthesis.

A Fungal infection is called a mycosis groups

a) systemic - deep in the body b) subcutaneous - Below the skin c) cutaneous - affect hair, skin, and nails (on the skin)

How does bacteria reproduce?

binary fission

Louis Pasteur

biogenesis and pasteurization

What do we italicize/underline when typing/writing a taxonomic name?

both the genus and species when typed, when written underline it.

How does Yeast reproduce?

by budding

How does bacteria move?

by flagella

Trichophyton, Microsporum, Epidermophyton

cause ringworm (Latin: tinea) dermatophytes habitat is soil and animals tinea capitis-ringworm of the scalp; tinea cruris-ringworm of the groin; tinea pedis-ringworm of the foot; tinea unguium-ringworm of the nail

How is mold described?

composed of long filaments if cells joined together called hyphae (hypha) the hyphae that absorbs nutrients is called the vegetative hyphae. reproductive or aerial hyphae extends from the surface and bear reproductive structures called spores. Hyphae grow together and intertwine, forming visible masses or mats called mycelia.

How is fungi described?

eukaryotes unicellular (yeast) or multicellular (molds) cell walls are present; contain chitin reproduce sexually or asexually by spores.

pseudohyphae

forming a short chain of cells

Candida albicans

human normal microbiota cutaneous, systemic, mucocutaneous opportunistic pathogen thrush, vaginitis

Pfiesteria

is an example of a dinoflagellate associated with human illness

2000x magnification

is the highest magnification possible in a compound microscope.

Trichomonas vaginalis

movement by flagella has no encysting stage (does not form cysts) causes urethritis (males) and vaginitis (females) acquired through contact with vaginal-urethral discharge,usually by sexual transmission but possibly from toilet seats and clothing

Trypanosoma

movement by flagella several different diseases caused by different species: Chagas disease: carried by Triatoma fly (kissing bug) African trypanosomiasis (African sleeping sickness): carried by tsetse fly

Giardia lamblia

movement is by flagella (8) has two nuclei causes Giardial enteritis acquired through ingestion of drinking water contaminated with feces

TO CALCULATE THE TOTAL MAGNIFICATION:

multiply Ocular strength X Objective strength

Viruses

obligate intracellular parasites require living host cell to reproduce We refer them as infectious particles that are active or inactive. Viruses lack the protein-synthesizing

What is the purpose of oil immersion?

oil oozes up and comes into contact with the oil immersion lens and this creates a closed system which prevents light rays from escaping.

Multicellular

organisms made of more than one cell

Cilia

short hair like structures

dimprphism

some fungi can grow as either mold or yeast exhibiting 2 forms of growth.

Carolus Linnaeus

swedish biologist, devised the system of binomial nomenclature

Cryptococcus neoformans

systemic mycosis associated with bird feces (actually carried by birds); transmitted by the inhalation of dried pigeon droppings most often occurs in immunosuppressed individuals may cause chronic fungal meningitis

Histoplasma capsulatum

systemic, found in soil, often associated with birds because it uses bird droppings for nutrients. It is not carried by birds can be fatal in the brain