microbiology chapter 1

microbio ch 1 powerpoint terms

microbiology

study of microorganisms or microbes, often invisible to naked eye

bacteria, archaea, fungi, protists, helminths, viruses, and prions

microbe encompasses what kind of microorganisms and cellular entities

prokaryotic cells

earliest life forms, unicellular bacteria and archaea

eukaryotic cells

all multicellular organisms and a number of unicellular microorganisms

endosymbiotic theory

eukaryotic cells evolved from prokaryotic cells

pathogens

microbes that cause disease

true pathogens

which pathogens always cause disease

opportunistic pathogens

pathogens that cause disease only in a weakend host

1850-1920

golden age of microbiology

robert hooke

first to publish descriptions of cells

antonie van leeuwenhoek

refined earlier versions of the microscope, and first to see bacteria

spontaneous generation

life comes from nonliving items

biogenesis

life emerges from existing life

rotting meat rise to maggots

“proof” of spontaneous generation

francesco redi

meat in uncovered jar resulted in maggots on meat, meat in jar with gauze covered top resulted in no maggots on the meat

louis pasteur

showed that biogenesis is responsible for the propagation of life, pasteurization killed off yeast and prevented stored wine from turning bitter, developed first vaccine against anthrax and rabies

pasteur

investigated the hypothesis that air contained contaminating microbes by performing an experiment with a specialized s-neck flask

germ theory of disease

microbes cause infectious diseases

Robert Koch

developed technique to determine the specific etiological agent of an infectious disease (cause of disease)

Koch

developed staining techniques and media for isolation and cultivation of bacteria

koch postulate 1

same organism must be present in every case of the disease

koch postulate 2

organism must be isolated from the diseased host and grown as pure culture

koch postulate 3

isolated organism should case the same disease when inoculated into a susceptible host

koch postulate 4

organism must be re-isolated from the inoculated, diseased animal

Ignaz Semmelweis

developed first aseptic techniques in the hospital setting

Semmelweis and Holmes

initiated a mandatory hand washing policy for medical students and physicians

Joseph Lister

investigated processes for aseptic techniques, first to utilize hand washing and misting operating rooms with antiseptic chemicals

Florence Nightingale

established aseptic techniques in nursing

healthcare-acquired infections/HAIs

aseptic processes prevent

question that can be investigated

scientific method begins with a

proposed hypothesis

second step of scientific method

collect and analyze observations, use them to form conclusion

third step of scientific method

supports or contradicts

a conclusion states whether the data _____ or _____ the hypothesis

observation

any data collected using our senses and instrumentation

conclusion

interprets observations

scientific law

precise statement, or mathematical formula, that predicts a specific occurrence

scientific theory

hypothesis that has been accepted through many studies with consistent, supporting conclusions

taxonomy

study of how organisms can be grouped by shared features

morphology

classification of bacteria by the physical features

Cal Linnaeus

father of taxonomy. established the binomial system for classifying organisms

domain, kingdom, phylum, class, order, family, genus, species

taxonomic hierarchies by broad to specific

bacteria, archaea, eukarya

the three domains

animalia, plantae, fungi, protista, archea, and bacteria

6 kingdom classification

eukaryotic species

group of similar organisms that can sexually reproduce together

prokaryotic species

cells that share physical characteristics and have at least 70% DNA similarity; further divided into strains, serovears, etc. at least 97% identical 16S rRNA sequence similarity

strain

is used to recognize genetic variants of the same species

mutations and gene transfer

what often leads to new strains

symbiotic relationship

when two or more organisms are closely connected

parasitism

hurt the host

mutualism

beneficial to both involved organisms

commensalism

no perceived benefit or cost to the host

parasite

describes helminths and protozoans NOT pathogens

human microbiome project

aims to characterize all of the microbes in and on our bodies

normal microbiota

bacteria, archaea, and eukaryotic microbes

location of microbe

what makes a microbiota normal

utero, delivery, early interactions

babies are colonized by microbes in which three ways

transient microbiota

temporary passengers that do not persist as stable residents of our bodies. can be removed through hygiene

malaria

mosquito-borne, typical disease caused by Plasmodium sp.

planktonic

single bacteria that are free-floating

biofilms

sticky communities made up of a single/diverse microbial species. DIFFER from planktonic communities, live on surfaces + tissues

free-growing planktonic cells

microbes inside of biofilms release what kind of cells periodically

bioremediation

harnesses the power of microbes to help clean up toxic waste

growth media

mixtures of nutrients that support growth in an artificial setting

Julius Richard Petri

developed petri dish

broth, plate, slants, deeps

media that comes in a variety of consistencies and formulations

defined (synthetic) media

media whose exact chemical compositions are known. may contain pure organic or inorganic compounds that do not vary from one source to another. have a molecular content defined by means of an exact formula. useful in research.

complex media

MOST media used in clinical applications. contains at least one component that is not chemically definable. extracts of animals, plants, or yeasts.

grow as broad a spectrum of microbes as possible

general purpose of using media

enriched media

contains complex organic substances that fastidious bacteria require for growth

selective media

contains one or more agents that inhibit the growth of certain microbes. encourage a select microbe type to grow. important in primary isolation of a certain type of microorganism from a mixed sample.

differential media

allow multiple types of microorganisms to grow, but display visible differences between colonies (color, size, etc)

hemolysins

enzymes that lyse red blood cells to release iron-rich hemoglobin

beta hemolysis

complete lysis of red blood cells

alpha hemolysis

incomplete lysis of red blood cells

gamma hemolysis

no hemolysis

pure culture

specific type of microbe isolated from a diverse sample

aseptic culturing techniques

conditions maintained to limit contaminants

biological safety cabinet

enclosed cabinet that minimizes the chances of contaminating the culture and protects the researcher

streak plate technique

helps to isolate colonies of a specific microbe for study

colony

grouping of cells that developed from a single parent cell

mixed cultures

>1 characteristically different colonies; most biological specimens are mixed cultures

stains

increase contrast so the sample is easier to see

smear, expose to heat, stain

steps of staining

basic dyes

most commonly used stains

positive, negative

basic dye has what charge and is attracted to which other charge

acidic dyes

used in negative staining

negative, negative

acid dyes have what charge and are repelled from a surface with what charge

mordants

chemicals that may be required in certain staining procedures to interact with a dye and fix, or trap, it on or inside a treated specimen

simple staining

staining technique that uses one dye and determines the size, shape, and/or cellular arrangement

flagella staining

type of structural staining where mordants are added to coat the thin flagella and then a basic dye applied

capsule staining

type of structural staining where both basic dye and acidic dye are used to show a capsule as a clear halo

bacterial endospore staining

type of structural staining where a specimen is heated to drive the dye into the spores, nonsporulating cells are stained with safranin

differential staining

highlights differences in bacterial cell walls in order to discriminate between classes of cells

gram stain

classifies bacteria as either gram-positive or gram-negative

purple

gram positive appears as what color

pink

gram-negative cells will appear pink

crystal violet/primary stain

what is added to a heat-fixed bacterial smear during gram staining

iodine/mordant

what is added that forms an insoluble crystal violet-iodine complex

acetone-alcohol/decolorizing step

used to rinse out sample in a gram-stain

safranin/counterstain

added to the gram-stain sample