M1: Intro To Microbiology Flashcards
38-41%
Bacteria
Study of MO, a large and diverse group of microscopic organisms that exist as single cells or cell clusters; it also includes viruses, which are microscopic but not cellular.
Microbiology
14-15%
Viruses
22-23%
Fungi
4-5%
Protozoa
Formulated about spontaneous generation, equivocal generation, germ & cell theory and abiogenesis.
Aristotle
Life from inanimate object. Early belief that some forms of life could arise from vital forces present in nonliving or decomposition matter.
Spontaneous Generation
Is an obsolete theory regarding the origin from inanimate matter, which held that this process was a commonplace and everyday occurrence, as distinguished from univocal generation, or reproduction from parent.
Equivocal generation
Generally accepted to have been ultimately disproven in the 19th century by the experiments of Louis Pasteur, expanding upon the experiments of other scientists before him (such as Francesco Redi) who had performed similar experiments was succeeded by
Cell theory & Germ theory
Refers to both the supposed process by which life would systematically emerge from sources other than seeds,eggs or parents and to the theories which explained the apparent phenomenon. Life emerges from nonliving matter.
Abiogenesis
One form of life emerges from a different form
Heterogenesis/Xenogenesis
First to observe living microbes. His single-lens magnified up to 300x. Father of Microbiology and considered to be first microbiologist. Known for his work on microscope. Observed single celled organisms.
Antoine Van Leeuwenhoek
Single celled organisms
Animalcules
Extended Antoine’s studies, organized bacteria into general & specifies according to taxonomic classification of microbes
Otto Muller
Proved that micro-organisms were responsible for causing human disease. “Germ theory”
Friedrich Henle
Cell described as the basic unit of life. Known for Law of Elasticity.
Robert Hooke
Describes his microscopic & telescopic observations, and some original work in biology.
Microphagia
Developed aseptic techniques. Developed rabies vaccine.
Louis Pasteur
Identified cause of anthrax & TB. Koch’s Postulate. Inoculation of MO.
Heinrich Hermann Robert Koch
Noted syphilis, gonorrhea transmission. Specimen: prostitute’s vaginal discharge inoculate in penis.
John Hunter
Principle of vaccination. Milder form of small pox.
Edward Jenner
Patient transmission of cholera (H20 transmission) Disprove the miasma theory of cholera transmission. Father of Epidemiology.
John Snow
Era of chemotherapy began when he discovered first antibacterial agent, a compound effective against the spirochetes that causes syphilis.
Paul Ehrlich
Discovered penicillin
Alexander Fleming
Discovered sulfanilamide
Gerhard Domagk’s
Discovered streptomycin
Selman Waksman
First to cultivate virus in cell cultures which led to vaccine development
John Enders
Microbes can be isolated in a disease. Isolate microorganisms, culture. If inoculate to healthy individual develop disease similar to the 1st perform. Can isolate it again same with the 1st person.
Koch’s Postulate
Obligate intracellular. 18-600nm (mostly 200mn) Requires host cells for replication and enclosed in a protein shell with or without a lipid membrane coat.
Viruses
Viral like particles which do not contain nucleic acids
Prions
Contains both RNA & DNA
Mimivirus
Example of Obligate intracellular microbes
Chlamydia & Rickettsia
Most complex, eukaryotic, unicellular and multicellular. 1-2um(protozoa) in diameter up to 10 meters(tapeworms) in length or arthropods.
Parasites
More complex cellular structure, eukaryotic organisms that contain a well-defined nucleus, mitochondria, golgi bodies and ER. Unicellular & Filamentous form. Dimorphic.
Fungi
Unicellular form & asexual
Yeast
Filamentous form. Asexual & Sexual.m
Molds
Replicate within the host, multiply to produce very large number of progeny, thereby causing an overwhelming infection.
Microparasites
Examples of microparasites
Viruses, Bacteria, Protozoa & Fungi
One infectious stage matures into one reproducing stage and in most cases, the resulting progeny leave the host to continue the cycle. Infection is determined by the numbers of organisms that enter the body.
Macroparasites
Examples of Macroparasites
Worms & Arthropods
Prokaryotic-simple unicellular organisms with no nuclear membrane, mitochondria, golgi bodies or ER. Asexual reproduction. Complex cell wall: gram positive & negative.
Bacteria
Protect the wall against the immune system and chemotherapeutic agents and stimulates pathogenic responses
Peptidoglycan
Thin peptidoglycan
Gram negative
Thick peptidoglycan
Gram positive
Is the only prokaryotes, the rest is eukaryote.
Bacteria
A distinct nucleus is absent. DNA is in the form a single circular chromosome, additional extrachromosomal DNA is carried in __________. Transcription & translation can be carried out simultaneously.
Prokaryotes. Plasmids.
DNA is carried on several chromosomes within a nucleus bound by a nuclear membrane. Transcription requires formation of mRNA and movement of mRNA out of the nucleus into the cytoplasm.
Eukaryotes
Translation takes place on
Ribosomes
Is rich in membrane-bound organelles (mitochondria, ER, golgi apparatus & lysosomes) which are absent in prokaryotes.
Cytoplasm in Eukaryotes
To limit list of consideration of microbes, must know the
Normal flora
0.1% present in the intestine
E.coli
Location: Staphylococcus, corynebacterium, streptococcus & moxarella
Eye
Location: Lactobacillus spp & candida albicans
Urogenital tract
Location: streptococcus mutans, S.pneumoniae, s.aeureus & corynebacterium
Mouth & Nose
Location: bacteroides fragilis, enterococcus & e.coli
GIT
Location: staphylococcus aureus, s.epidermidis, streptococcus spp & propionibacterium acnes
Skin
Medtechs use E.coli for testing H20. If seen in H20, means
Fecal contamination
Protects you from the other microbes that can cause diarrhea
GI normal flora
GI normal flora disturbance. Limited to bacteria in the skin normal flora.
Irritable Bowel Syndrome (IBS)
Should be left at room temperature or in an incubator at 5°C
Blood
Transport at room temperature
CSF
Transport rapidly to the laboratory
Neisseria species
Probability that a test will be positive in the presence of a pathogen (all infected patients are detected)
Sensitivity
Probability that a test will be negative if the pathogen is not present (all positive patients are infected)
Specificity
Cheapest. For initial detection of microbes.
Microscopy
Most common. Cannot be used for all bacteria (acid fast bacteria, endospore) Differentiate bacterial species into two large group (gram + & -) based on the chemical properties of their cell walls.
Gram Stain
Two types of bacteria with similar clinical symptoms
Streptococcus pneumoniae & Klebsiella pneumoniae
Need these to completely or definitely classify bacteria (Gram Stain)
Gram variable & Gram indeterminant
Means they may stain either negative or positive. Some organisms are not susceptible to either stain used by the Gram technique
Gram variable
Have a thinner layer (10% of cell wall), which stains red. Outer membrane contains lipids, and is separated from the cell wall by the _____________.
Gram negative bacteria. Periplasmic space.
Thick mesh-like cell wall made of peptidoglycan (50-90% of cell wall) which stains purple.
Gram positive
Steps in Gram Stain: 1. ________ bacterial smear. To adhere to the slide.
Heat fix
Steps in Gram Stain: 2. Apply the __________. (+) peptidoglycan (-) outer membrane.
Crystal violet
Steps in Gram Stain: 3. Apply Gram’s _________. Mordant. Fixes the crystal violet to the bacterial cell wall.
Iodine
Steps in Gram Stain: 4. Rapid decolorization with ____________. (+) purple (+) colorless.
Alcohol/Acetone
Steps in Gram Stain: 5. Counterstain with __________. (+) purple (-) red
Safranin
Physical property of some bacteria referring to their resistance to decolorization by acids during staining procedures. Uncommon characteristics shared by Mycobacterium & Nocardia. Difficult to characterize using standard microbiological techniques.
Acid Fast Bacteria
Cover with tissue paper. Flood slide with carbofuschin, the primary stain, for 2 minutes while heating with steam or heating on hot plate. Remove paper cover, decolorize slide with mixture of HCL acid & ethanol. Counterstain with __________.
Ziehl-Neelsen Stain. Methylene Blue.
Isolate endospores. Stain endospores green and any other bacterial bodies red. The green stain is ___________. Counter stain is _________ which dyes any other bacterial bodies red.
Schaeffer-Fulton Stain. Malachite green. Safranin.
Dormant, tough & non reproductive structure procedure by certain bacteria from _________ phylum. (Bacillus & Clostridium) suggestive of the bacterium changing internally to a spore or seedlike form. Important when the bacterium is experiencing an environment that is deleterious to the usual vegetative state of the bacterium.
Endospores. Firmicute.
Allow the endospore to show up as red, while the rest of the cell stains blue.
Moeller stain
Enable the survival of a bacterium through periods of environmental stress. When the environment returns to favorable, this can reactive itself to the vegetative state. Consists of bacterium’s DNA & part of its cytoplasm. It can survive without nutrients. Resistant to ultraviolet radiation, desiccation, high temperature & chemical disinfectants. Are commonly found in soil & water.
Endospore
Detects fungi. Dissolves human cells. Only fungal cells remain to be seen under the microscope. It denatures the proteins in the human cells. Athlete’s foot, fungal vaginitis and many other fungal infections.
Potassium Hydroxide Test (KOH)
Method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Importance are for diagnostic purposes & prognosis of disease. Uses Agar solid & Broth liquid. Shapes of bacterium.
Microbe cultivation
Just to grow bacteria in general
Enriched Non-Selective Media
Some will grow some will not
Selective Media & Differential media
Specific for micro organisms
Specialized media
Single celled prokaryotes form a long circular DNA molecule but not contained within a defined nucleus. Many are motile. Reproduced by binary fission, both aerobic & anaerobic. Classification uses both phenotypic & genotypic data.
Bacteria
For motility
Flagella
Smallest bacteria around 0.1-0.2um in diameter
Chlamydia & Ricketssia
Bacterial Structure: genetic info is carried in a long __________ circular molecule of DNA.
Double stranded
Bacterial Structure: No _______ is present and the DNA is tightly coiled into the nucleoid.
Nuclear membrane
Bacterial Structure: Genetic info is extrachromosomal, present as small circular self-replicating DNA molecules termed _______.
Plasmids
Bacterial Structure: _______ contains no organelles other than ribosomes for protein synthesis.
Cytoplasm
Bacterial Structure: Uses a smaller ribosome, the ______ ribosome. Target of antimicrobials (alino glycosides)
70s
For transport of nutrients
Protein
All bacteria are surrounded by a complex cell wall except
Mycoplasma
Are the principal molecules of the outer membrane. Hydrophilic (through porins) & Hydrophobic.
Lipopolysaccharides & Lipoprotein
Lipopolysaccharides: _______ from CHO chains
O antigens
Lipopolysaccharides: _______ from lipid A component
Endotoxin
Disrupt peptidoglycan synthesis
Beta lactam & Glycopeptide antibiotics
Can digest peptidoglycan
Lysozymes (body secretion)
For protection from phagocytosis. Polysaccharide. Stain: india ink, quelung (use antibody, serologic identification & (+) swelling)
Capsules
Protection against phagocytosis by host cells and important in determining virulence
Capsules of anthrax bacilli
Cause a fatal infection
Capsulated streptococcus pneumonia
Cell wall have lipoechoic acid. The stain gets trapped in a thick, cross linked, meshlike structure, the peptidoglycan layer, which surrounds the cell. 20-80nm thick of peptidoglycan, hydrophilic.
Gram positive
Thin peptidoglycan layer does not retain the crystal violet stain. Cells must be counterstained with _______ and turned red. 5-10nm thick of peptidoglycan. Serves as antigenic determinant but varies.
Gram negative bacteria
Once Gram (-) is lyse, this is released; cause fever.
Lipid A
Serves as antigenic determinant but varies
Lipopolysaccharides
Shape and identification of bacteria. For protection and contains proteins.
Cell wall
Long helical filaments extending from the cell surface. For motility.
Flagella
Bacteria flagella is independent of
ATP
Protein & strongly antigenic
Flagellins
Flagella: singly
Polar
Flagella: cluster/clump
Iophotrichous
Flagella: distributed over the general surface of the cell
Peritrichous
For attachment to other bacteria (sex pili) or to host cells (common pili)
Pili/Fimbrae
All gram (-) has lipid A and only 1 gram (+)
Listeria Gram (+)
2 cocci
Streptococcus & Staphylococcus
2 spore forming
Bacillus anthracis & Clostridium tetani
No spore
Corynebacterium & Listeria
Can destroy bond of the bacteria
Man’s lysosome
L isomer of LAA
Eukaryotes
D LAA
Prokaryotes
Microbial genetics: know that it is bacteria
Get D-AA
Destroyed by penicillin
Transpeptidase
Single enzyme test for Staphylococcus
Catalase test
Single enzyme test for Streptococcus pneumoniae
Oxidase test
Single enzyme test for Helicobacter pylori (rapid test)
Urease test
Single enzyme test for S. Aureus (confirmatory test)
Coagulase test
Oxidative metabolism takes place at the
Membrane-cytoplasm interface
Equalize the intra and extracellular concentrations
Facilitated diffusion
Increase intracellular concentrations of a substrate.
Active transport
Grown in media with glucose and inorganic salts
E.coli
Needs many organic compounds for growth
Streptococci
Aerobic metabolism, number of ATP produce
38
Utilizing an inorganic final hydrogen acceptor(fermentation) is much less efficient and produces only 2 molecules of ATP
Anaerobic metabolism
Period of adjustment
Lag Phase
Cell division with the population doubling at a constant rate
Generation time
Cell growth slows to a stop
Stationary phase
Phase of decline
Death
Cell division (chained, paired & clustered) segregation of the replicated genomes. Division of a cell to give a separate daughter cells.
Septation
Formed by an invagination of the cytoplasmic membrane and ingrowth of the peptidoglycan cell wall
Septum
Target the processes involved in bacterial growth and division
Antimocrobials
Inhibit synthesis of peptidoglycan cell wall
Glycopeptides (vamcomycin)
Inhibit the unwinding of DNA by DNA Gyrase during DNA replication
Quinolones (ciprofloxacin,levofloxacin)
Highly resistant spores. Dipicolinic acid and high calcium content. Abundant in soils. Clostridium & Bacillus. Survival under adverse conditions.
Endospores
The process involved in decoding the genetic info contained within a gene to produce a functional protein or RNA molecule
Gene Expression
Carries the info that defines the properties and processes of a cell
DNA
Total genetic information; comprise of one parental strand and one newly synthesized DNA strand
Genome
Origin of replication
OriC
Initiate unwinding & separation of the two DNA strands (each separated DNA strands (each separated DNA strands serve as a template for DNA polymerase)
Helicase & Topoisomerase
Capable of proofreading newly incorporated deoxyribonucleotides and excising those that are incorrect.
DNA Polymerase
Translate into proteins. Most genes.
mRNA
Scaffold for assembling ribosomal subunits
rRNA
Participate in decoding mRNA into functional proteins
tRNA
A component of RNA polymerase that is important in promoter recognition region. Control the expression of genes.
Sigma factor a
Nucleotide sequences in DNA that can bind the RNA
Promoters
Transcription terminal protein
Rho
Encodes the protein required for the uptake and metabolism of lactose
Lac operon
Cholera toxin from
Vibrio cholera
________ of uropathogenic E.coli which mediate colonization.
Fimbriae
Start codon
AUG
Stop codons
UAA, UGA & UAG
Regions of DNA to which regulatory proteins bind
Operator site
Increase the rate of transcription initiation. Positive regulation.
Activators
Inhibit transcription. Negative regulation.
Repressors
A global regulatory protein that controls the expression of multiple gene
Camp-dependent catabolite activator protein (CAP)
Example of Camp-dependent catabolite activator protein (CAP) bacteria
Corynebacterium Diphtheriae
Regulator component: detect environmental changes
Sensor
Regulator component: activate or repress transcription
DNA-binding protein
Inhibit RNA Polymerase
Rifampicin
Control of virulence gene expression in Vibrio Cholera
ToxR
Activates the transcription of other virulence genes such as toxin-co-regulated pili (colonization)
ToxT
Primary reservoir of genetic information within the cell
Bacterial chromosome
Independent self replicating & circular units of dsDNA
Plasmids
Different codons specify the same AA
Silent mutations
AA substitution may or may not alter its stability or functional properties
Missense mutations
Formation of stop codon causing premature termination and production of truncated protein
Nonsense mutation
Both bacteria inoculated. Take antibiotic but only affected to 1 bacterium. Bacteria has antibiotic resistance and implanted to the gene.
Transformation
Like transformation but uses bacteriophage
Transduction
Sex pilus used. Donor bacteria may transfer antibiotic resistance gene to another.
Conjugation
Transposon. Mobile genetic material that incorporate to recipient bacteria, these transposon may trigger mutation, triggering antibiotic resistance.
Transposition
Encodes CHON
mRNA
Encodes AA
tRNA
Gene expression transcription
DNA dependent Polymerase
Detect, identify and quantity antigen and antibody response
Serologic Diagnosis
Capsular swelling. Slide agglutination test.
Antigen test
Immunoprecipitation techniques, elisa, western blot, compliment fixation, latex agglutinations & RIA
Antibody test
For capsule
Quelung
Acts on linkage to NAM
Cyclosporine
