Test 1 Flashcards
What is microbiology?
test q
study of microscopic organisms such as bacteria, viruses, archaea, fungi (yeast) and protozoa
note: all of these examples are cellular besides viruses
Who made the first microscope with magnification of 50x-300x?
Antoni Van Leeuwenhoek
Who was the first to discover the bacterial world?
Antoni Van Leeuwenhoek
Who introduced the first systemic method of vaccination and used cow pox virus (vaccinia virus) to cross immunize against human small pox virus (variola virus)?
Edward Jenner
Whats the year of vaccines?
1796 (when Edward Jenner introduced small pox vax)
Who saved the silk and wine industry in France?
Louis Pasteur
Who introduced the first vaccine for the rabies virus?
Louis Pasteur
Who introduced the first vaccine for Bacillus anthracis (the bacteria causing anthrax), a disease of cows, sheep, etc. and can be fatal to man?
Louis Pasteur
Who introduced the principles of pasteurization?
Louis Pasteur
Who was the pioneer of aseptic (no dirt= clean) in obstetrics?
Ignaz Philipp Semmelweiss
He directed his medical students to wash their hands in chlorine water before helping laboring mothers and the birth death rate greatly dropped
Who proved germ theory?
Robert Koch
who introduced postulates named after himself, which provided a way to identify a specific microorganism as causing a specific infectious disease?
Robert Koch
Who introduced agar to nutrient medium to provide it with a solid substratum?
Robert Koch
Who first isolated bacillus anthracis (bacteria that causes anthrax) in pure culture?
Robert Koch
Microbiology of air (air-bone) is that air has no ______ in and of itself. Microbes are found in the air temporarily as a result of coughing, sneezing, sweeping, etc
flora
What are some common human viruses spread by air?
-common cold (rhinovirus, adenovirus)
-measles (rubeola = true measles)
-rubella (German measles)
-Influenza (flu)
-mumps (infectious parotitis)
-small pox (Variola virus, extinct)
*for sure know Rubeola, Rubella, and Variola
What are some common bacterial infections spread by air?
-Streptococcal pharyngitis (strep throat, Streptococcus pyogenes)
-Diphtheria (Corynebacterium diphtheria)
-Pertussis or whooping cough (Bordetella pertussis)
-Tuberculosis (Mycobacterium tuberculosis)
What are the routes of transmission for microorganisms?
-air-borne
-blood borne
-food borne
-water borne (fecal-oral transmission)
-vector-borne
-STDs
What is the difference between horizontal and vertical transmission?
in horizontal transmission viruses are transmitted among individuals of the same generation, while vertical transmission occurs from mothers to their offspring
define endemic
-illness/disease within population
-relatively small scale (low number of cases)
-not usually associated with outbreaks
define epidemic
illness/disease in more than one population, an outbreak of something
define pandemic
-illness/disease in all people/populations
-larger than an epidemic/more specific
-more than 2 continents are involved
What are the 3 shape classifications of bacteria?
1) coccus (spherical, plural= cocci, means like a berry)
2) rods (cylindrical, aka bacillus)
3) helicoidal (spiral, special type of rods)
define diplococcus
spherical pairs
define streptococcus
spherical chains
define staphylococcus
spherical irregular grape-like clusters
define gaffkya
spherical arrangement in packets of 4 (tetrads)
define sarcina
spherical arrangements in packets of 8
What are the characteristics of rods/bacillus?
-straight, sausage shaped, cylindrical shaped, cigar shaped (fusiform)
-outnumber all other forms of bacteria
-coryneform bacillus can be in V or L type structures
What type of bacteria is a shape intermediate between cocci and bacilli?
coccobacillus
define vibrio
curved rod, comma shaped
define spirillum
helical shape with a thick rigid cell wall
define spirochete
thin flexible cell wall
What are bacterial cells usually measured in?
micrometers
What is flagellum?
organ of motility
ATP and cell wall are needed for flagella to function (functions in a rotary fashion)
define atrichous
-a= no/without flagella= no motility
-trichous= hair
define monotrichous
single polar flagellum (1 flagellum)
define amphitrichous
1 flagellum on each end
define lophotrichous
multiple polar flagella, tuft (threads of hair) on one or both ends
loph= tuft
define peritrichous
flagella distributed over the entire cell
What is another name for pili?
fimbria
What are pili?
protein fibers that originate from the cell membrane that are not flagella (smaller shorter and more numerous than flagella)
present on mostly gram negative bacteria
What is the function of pili?
-serve as attachment sites to viruses and cells of body
-some bacteria contain a specialized “F pilus” which serves as a conjugation tube for transfer of DNA (F stands for fertility, but remember that bacteria is asexual)
-pili act as virulence factor (enhance attachment to host cells)
What are the 3 major modes of genetic exchange between bacteria ?
1) conjugation
2) transduction
3) transformation
What is conjugation?
genetic exchange between bacteria, involves cell-to-cell contact
What is transduction?
foreign DNA is introduced into a cell by a virus or viral vector
define transformation
genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s)
What is another name for the capsule of bacterial cells?
glycocalyx or slime layer
The capsule of a bacterial cell is a gelatinous, sticky substance that surrounds the outside of the cell. It is usually _________________ in nature. The layer can be thick and covalently bound to cell and is referred to as a “capsule.” A thinner, loosely attached layer is referred to as a “slime layer”
polysaccharide
What does the capsule of a bacterial cell protect the cell from?
-from desiccation and other environmental factors
-against phagocytosis by macrophages and phagocytic WBCs
What are the SHiNE SKiS encapsulated organisms (bacteria w/ capsule)?
-strep pneumonia (S)
-haemophilus influenza (h i)
-Neisseria meningitis (N)
-E. coli (E)
-Strep algalacticae (Group B strep) (S)
-Klebsiella (K)
-Salmonella (S)
What does Quellung reaction positive mean?
when microorganisms are mixed with specific anti-microbial serum, the capsule swells
Bacterial cell walls help maintain shape and protect the cell membrane from rupture. What differentiates gram positive bacteria from gram negative bacteria?
test q
the amount of peptidoglycan in the cell wall
What is endotoxin?
potentially fatal toxin released from the lipopolysaccharide layer of the dead and dying gram-negative bacteria
LPS (endotoxin) of gram negative bacteria are the bacterial cell outer membrane components
What is exotoxin?
a bacterial posion composed of protein that may be excreted by a microorganism or released upon lysis
acts on a tissue site
categorized by tissues they affect
many gram positive and gram negative organisms produce exotoxins
-enterotoxin
-neurotoxin
What bacteria has the cell wall with a thicker layer of peptidoglycan?
test q
gram positive
What bacteria has the cell wall with a thinner layer of peptidoglycan?
test q
gram negative
What is found in the LPS of gram negative bacteria that is responsible for fever toxicity?
test q
Lipid A
on cell death, lipid A is released and is related to endotoxins!!!!
How many layers does gram positive bacteria have?
test q
3 layers
How many layers does gram negative bacteria have?
test q
5 layers
T/F: most bacteria are haploid because they have only one chromosome that contains the cell’s essential genetic info
true
What is the nucleoid?
-localized region of the cytoplasm which contains double stranded, circular DNA molecule
-NOT membrane bound
What are plasmids?
-present in some but not all bacteria (nonessential genetic info, comprised of 1-2% of total cell DNA)
-small circular double stranded DNA
-codes like nucleus, for cell products like enzymes
What part of the bacterial cell is responsible for antibiotic resistance?
plasmids
What are the vehicles for genetic engineering?
plasmids
What are ribosomes?
-spherical structures made up of protein and ribosomal RNA
-involved in protein synthesis
-built from RNA and protein and are composed of a large subunit (50S) and a small subunit (30S)
-for proteins to be synthesized, the 2 subunits come together and form a 70S functional ribosome (50S + 30S= 70S)
-their relative size is measured in Svedburg units by how fast they settle when spun in a centrifuge
What is the function of ribosomes?
translate RNA and make protein
What are inclusions (volutin/metachromatic granules)?
nutrient storage granules that stain red with methylene blue and are composed of polyphosphate used for energy like ATP
What are endospores?
-organelles for survival
-produced when nutrients are limited
-extremely resistant dormant cell produced by some gram positive bacterial species (some may live 60+ years)
-main reason for sterilization in canning process is to kill endospores (especially those of clostridium botulinum)
-under ideal conditions, they germinate into vegetative cells
What 2 genera of bacteria produce spores (endospores)?
1) clostridium (terminal spores, anaerobic- air is toxic)
2) bacillus (central spores, aerobic- need air to grow)
What is the difference between eukaryotic and prokaryotic cells?
What is the bright-field/compound light microscope? What are its characteristics?
-possess 2 lens system: objective lens near the specimen and the ocular lens near your eye
-objective lens produces a magnified image of the object and the ocular lens magnifies the image produced by the objective lens
3 basic magnifications of objective lens=
-low power = 10x
-high dry= 43x
-oil immersion= 100x
magnification of ocular lens is usually 10-20x
final magnification= objective x ocular
-lower power 10x x ocular 10x= 100x
-high dry 43x x ocular 10x= 430x
-oil immersion 100x x ocular 10x= 1000x
principle= light passes through a colored stained object
stain provides contrast
objects observed= arrangement, shape, size of killed microorganisms (except viruses)
What is a dark field microscope?
used to view live, unstained microorganisms and motility of live cells, such as Treponema pallidum (syphilis)
What is a flourescent microscope?
-image appears bright against a dark background
-uses fluorescent dyes called fluorochromes
-principle= UV light illuminates fluorescent coated objects
What is an immunofluorescent microscope?
a fluorescent dye is coupled to a specific antibody and this antibody can be used to stain the antigen
What is an electron microscope?
-uses beams of electrons to magnify and resolve specimens
-short wavelength of the beam of electrons dramatically increases the resolving power of the microscope and makes it possible to visualize viruses and detailed structures
2 types commonly used=
-transmission electron microscope (TEM) used to view and record detailed structures within cells
-scanning electron microscope (SEM) used to see the surfaces of objects in the natural state, provides vivid and undistorted views of an organism’s surface details
principle= a beam of electrons is passed through the specimen
What is a simple stain?
using one dye, to note the shape of the microbe
Who is gram stain named after?
Christian Gram
What is gram staining?
-differential staining procedure used to distingusih between gram pos (purple) or gram neg (red) cells (the color is due to the amount of peptidoglycan in their cell walls)
gram pos (purple) organisms are composed of a thick layer of peptidoglycan
gram neg (red) organisms have a thin layer of peptidoglycan and a thicker layer of LPS (lipid A endotoxin) and lipoprotein
Gram staining consists of 4 reagents, 2 of those being dyes. What are the 4 reagents?
1) crystal violet
2) iodine
3) alcohol 95% or alcohol acetone mixture
4) safranin (red)
For gram staining, what color would gram positive bacteria be when primary dye (crystal violet) is applied?
purple
For gram staining, what color would gram negative bacteria be when primary dye (crystal violet) is applied?
purple
For gram staining, what color would gram positive bacteria be when primary dye (crystal violet) is applied and then iodine?
purple
For gram staining, what color would gram negative bacteria be when primary dye (crystal violet) is applied and then iodine?
purple
For gram staining, what color would gram positive bacteria be when primary dye (crystal violet) is applied, then iodine and alcohol?
purple
For gram staining, what color would gram negative bacteria be when primary dye (crystal violet) is applied, then iodine and alcohol?
colorless
For gram staining, what color would gram positive bacteria be when primary dye (crystal violet) is applied, then iodine and alcohol, and finally safranin/carbol fuchsin?
purple
For gram staining, what color would gram negative bacteria be when primary dye (crystal violet) is applied, then iodine and alcohol, and finally safranin/carbol fuchsin?
pink or red
What is another name for acid fast stain? Who was it named after?
Ziehl-Neelsen stain
named after Paul Ehrlich
What organisms are identified in acid fast stains?
genus Mycobacterium
What is mycolic acid?
waxy lipid material in cell walls of mycobacteria that is associated with virulence (strongly disease capable) and the acid fast property (it sucks up the acid fast stain)
it has anti-phagocytic properties
What are the 3 reagents used in acid fast staining?
1) carbol fuchsin
2) acid/alcohol
3) methylene blue
What color is acid fast bacteria? What color is non-acid fast bacteria?
acid fast bacteria= red
non-acid fast bacteria= blue
What are the 2 main acid fast bacterias of clinical significance?
mycobacterium tuberculosis (TB) and mycobacterium leprae (leprosy)
What are the 3 nutritional types of cultivation based on carbon needs?
1) autotrophs (self-feeding)
2) heterotrophs (feed on others)
3) saprobe (a type of heterotroph that feeds on the dead)
What are autotrophs?
-self feeders
-synthesize their own foods from simple carbon sources such as CO2
-carbohydrates are their main source of energy
-found in many places like soil, water, etc (human body is not their normal habitat- speaking of bacteria)
What are heterotrophs?
-feed on others
-derives its nutritional requirements from complex organic substances
-cannot synthesize its own food and relies on other organisms (both plant and animals for nutrition)
-obtain carbon by feeding on organic material present in other organisms
What are saprobes?
-a specific type of heterotroph that requires dead organic matter as a source of energy
-found in large intestine, manure, dead decaying animals, etc
What is enriched media?
-media that enhances growth
-contains substances which will enhance the growth of fastidious organisms (complex nutritional requirements)
-may contain blood, serum, heat treated blood, etc
What is selective media?
-media that selects whats to grow
-contains ingredients to inhibit the growth of certain microbes while allowing the growth of others (crystal violet inhibits gram positive organisms without inhibiting gram negative organisms)
What is differential media?
-media that can differentiate between different bacteria
-contains one or more compounds that allow one to differentiate between similar species based on specific biochemical or physiological properties
-can easily distinguish colonies from each other based on color, hemolytic patterns, etc
define optimum growth temp
temp which allows for the most growth within a short period of time
What is one of the most important physical factors for governing growth in bacteria?
optimum growth temp
What are psychrophiles?
psychro= cold
-able to grow at 0 degrees celsius (ideally) but can also grow between 15-20 degrees celsius
What are mesophiles?
meso= middle
-like temp between 20-40 degrees celsius, or body temp of humans (37 degrees celsius)
What are thermophiles?
thermo= hot
-multiply best at temps around 60 degrees celsius but can still grow between 40-70 degrees celsius
What are aerobes?
organisms that require oxygen like humans (approx 21.5% oxygen)
What are microaerophiles?
organisms that like lower conc. of oxygen (less than 21.5%)
What are anerobes?
-do not or cannot use oxygen
-fail to process an enzyme which is able to breakdown hydrogen peroxide (H2O2) which is toxic
define facultative
grow in the presence or reduced conc. of oxygen
-there 2 types: anaerobe and aerobe
What are facultative anaerobes?
can grow anaerobically but prefers aerobic growth
What are facultative aerobes?
can grow aerobically but prefers to grow anaerobically
Do bacteria cells reproduce sexually or asexually? Explain
-asexual reproduction or cell division of 2 daughter cells
-called binary fission
What is binary fission?
how bacteria reproduces
-occurs after a period of growth in which the cell doubles in mass
-DNA replicates and the 2 DNA molecules separate
-population of bacteria grows in a geometric progression (exponentially, doubles)
define generation time
time interval for the bacterial cell to divide/double (average is 20-60 min depending on species)
note: useful in determining the amount of time that passes before symptoms appear in an infected individual (faster division means shorter incubation time for a disease)
What are the 4 parts of a growth curve?
1) lag phase (preparation for division, period of adjustment, slow cell growth but no division)
2) log (exponential) phase (steady division at a constant rate)
3) stationary phase (organisms dying = organisms being produced, population is in a plateau)
4) decline or death phase (number of dying cells exceeds the number being reproduced, the numbers begin to decrease because of environmental changes like pH, decrease in nutrients, toxic by-product build up, etc)
T/F: microbial growth can be measured by direct and indirect methods
true
What is the direct method for measuring microbial growth?
viable cell count enumeration (samples of a broth cultures from a serial dilution are poured into agar plates, after incubation the number of viable cells can be estimated)
What is the indirect method for measuring microbial growth?
turbidometric enumeration (increase in growth is measured by turbidity in optical density (OD) or precent transmission units on a spectrophotometer
T/F: bacteria occur in nature as single species
true but RARELY (usually occur in mixed culture)
To study a species, one must use a ______ culture that is a population consisting of only one species
pure
What is the most common method used for bacteria isolation in pure culture?
streak plate!
Besides streak plate, what is another common method used for isolating a bacteria in pure culture?
dilution method or pour plate method
-most frequently used in research settings
-its the dilution of specimens (serial dilution) in tube of liquid nutrient agar, poured into plates to solidify
-colonies emerge in poured plates and show isolation
What type of mediums are the most beneficial when doing streak plate or pour plate technique?
differential and/or selective media
What are the 4 techniques for preservation of bacteria?
1) periodic transfer from agar plate (short term)
2) mineral oil overlay (short term)
3) lyophilization (rapid freezing followed by desiccation, long term)
4) liquid nitrogen slow freeze (long term)
define (taxonomy) nomenclature
giving names of appropriate taxonomic rank to the classified organisms
define (taxonomy) classifications
assignment of organisms into an organized scheme of naming
define (taxonomy) identifications
obtaining data on the properties of the organism (characterization) and determination of which species it belongs to
The most fundamental form of classification was introduced by Linnaeus. This classification is known as ______________________, where each organism has 2 names
binomial nomenclature
What is binomial nomenclature?
the first name is Genus classification, the second name is the species classification
Most life forms are divided on a broad scale into 6 kingdoms. What are the 6 kingdoms?
1) archaebacterium (ex: thermophils)
2) eubacteria (ex: pathogens and commensals)
3) protista (ex: algae and protozoans)
4) fungi (ex: yeast and molds)
5) plantae (ex: seed plants and mosses)
6) animalia (ex: humans)
Are all 6 kingdoms made up of cellular organisms?
yes!!!!!
What are the 3 domains?
1) eukarya (all eukaryotic cells)
2) bacteria (prokaryotic cells)
3) archaea (prokaryotic cells)
What is the formal rank classifications in order?
1) domain (largest rank)
2) kingom
3) division
4) class
5) order
6) family
7) genus
8) species
8a) subtype (smallest rank)
Are viruses and prions included in taxonomy classification system?
no!!!! because they’re acellular
define sterilization
the removal or destruction of all microbes, including viruses and bacterial endospores in or on an object (kills everything)
define antiseptic
DEPENDS ON CONTENTS (yes these are both in his notes)
A) an environment or procedure that is free of contamination by pathogens
B) chemical used to inhibit or kill microorganisms on skin or tissue
What is bacteremia?
-presence of bacteria in the bloodstream
-can occur from vigorous tooth brushing, dental or medical procedures, infections such as pneumonia or UTIs
What is septicemia?
bacterial infection that starts in the body within the lungs or skin and then travels into the bloodstream
What is sepsis?
-serious complication of septicemia (infection that starts in the lungs or skin and travels to blood stream)
-causes inflammation through entire body
-can progress to septic shock and has a death rate of 50%
-sepsis is considered a medical emergency because it can lead to tissue damage, organ failure, and death
What is pyaemia (pyemia)?
-type of septicemia that leads to widespread abscesses of a metastatic nature
-usually caused by the staphylococcus bacteria by pus-forming organisms in the blood
define disinfection
refers to the use of physical or chemical agents (disinfectants) to inhibit or destroy microorganisms, especially pathogens
-acide= ?
killing
ex: germicide, viracide, bacteracide
What is bacteriostasis?
inhibits microbial metabolism and growth, but does not necessarily kill microbes (“maintains equilibrium”)
What is autoclaving?
-using high temp and pressure for sterilization including destruction of spores
-kills by protein denaturation (coagulation)
-medical and lab supplies that can tolerate heat and moisture
What is boiling used for?
-if its used for sterilizing exposure then it must be boiled for at least 30 min
-kills by protein denaturation (coagulation)
-disinfection of baby bottles and sanitization of restaurant cookware
What is pasteurization?
-reduces bacterial population and destroys pathogens
-spores are not affected by pasteurization
-used in dairy products, fruit juices, beer, and wine
3 methods of pasteurization:
-holding or batch method
-flash pasteurization method
-ultra-high temp method (provides sterilization)
define pathogen
organism that may cause disease
What is dry heat used for?
-destroy spores
-heat changes microbial proteins by oxidation
-used for water sensitive materials like powders, oils, and metals
What is non-ionizing radiation?
-UV light
-cellular DNA absorbs energy and adjacent thymine molecules link together kinking the double helix and disrupting DNA replication
-used for disinfection/sterilization of surfaces and of transparent fluids/gases
What is ionizing radiation?
-electron beams, gamma rays, and some X-rays
-rays pass through microbial molecules and forces electrons out of their shells creating ions
-electron beams are produced by cathode ray machines
-sterilization of medical and lab equipment and preservation of food
-more dangerous than non-ionizing radiation
What is filtration used for?
-passage of fluid, liquid, or gas though a sieve designed to trap particles and separate them from the fluid
-anything that cannot be heated such as antibiotics, vaccines, heat sensitive ophthalmic and enzyme solutions
What is osmotic pressure used for?
-use of hypertonic solution (high salt or sugar conc.)
-used for preservation of food
What is desiccation?
-removal of water
-if no water is present, then there is no growth
-used for the preservation of food
What is refrigeration/freezing used for?
-decreasing microbial metabolism, growth, and reproduction because chemical reactions occur slower at low temp
-used for preservation of foods, drugs, and cultures
What are phenol and phenolics (carbolic acid) used for?
-reduce infection during surgery
-denatures protein and disrupts cell membranes
-may have skin irritation
What are alcohols used for?
-bactericidal, fungicidal, virucidal
-not effective against spores
-denatures proteins and disrupts cytoplasmic membranes
-70% ethyl is the most effective conc. which denatures proteins but requires water
-used as disinfectant and antiseptic
What are halogens used for?
-effective against vegetative bacterial and fungal cells, fungal spores, some bacterial endospores and protozoan cysts and many viruses
-unfolds and denatures essential proteins including enzymes
What are the 4 halogens we talked about in class used to unfold and denature essential proteins/enzymes?
1) iodine
2) chlorine
3) bromine
4) fluorine
What is iodine used for (its a halogen)?
to disinfect water and is used as an antiseptic
What is chlorine used for (its a halogen)?
treat drinking water, pools, wastewater from sewage plants, and disinfectants
What is bromine used for (its a halogen)?
disinfectant in hot tubs, swimming pools, and cooling towers
What is fluorine used for (its a halogen)?
used in drinking water and toothpastes
What heavy metals are used in medical/lab settings?
mercury, silver, and copper
What are heavy metals (mercury, silver, and copper) used for?
-to denature proteins
-used on fungistats in plants, in silver nitrate cream, surgical dressings, catheters
-some states require 1% silver nitrate eye drops for newborns to prevent blindness by Neisseria gonorrhea
What are the aldehydes used in medical/lab settings?
glutaraldehyde and formaldehyde
What are aldehydes (glutaraldehyde and formaldehyde) used for?
-denatures proteins and inactivates nucleic acids
-used as a disinfectant and embalming fluid
What gaseous agents are used in medical/ lab settings?
-ethylene oxide (commonly used in hospitals and dental offices for sterilization)
-propylene oxide
-beta propiolactone
What are gaseous agents (ethylene oxide, propylene oxide, beta propiolactone) used for?
-denatures proteins and DNA
-sterilizes heat/water sensitive objects
What are surfactants (soap and detergents) used for?
-decreases surface tension of water and disrupts cell membranes
-used as degerming and antiseptic
Is chemotherapy natural or synthetic material?
synthetic
Paul Ehrlich proposed the term chemotherapy to describe the use of chemicals that would selectively kill pathogens while having little effect on a patient “magic bullet” would bind on bacterial receptors to bring about death. He discovered an arsenic compound that kills trypanosome parasites and another that killed against the agent of….
syphilis (Treponema pallidum)
Selman Waksman coined the term ___________ to describe antimicrobial agents that are produced naturally by an organism
antibiotic
What are the 2 antimicrobials we talked about in class?
1) sulfa drugs (sulfonamides)
2) isoniazid (INH)
What are sulfa drugs (sulfonamides)?
-antimicrobial drug that is a competitive inhibitor
-bacterial cells need folic acid for nucleic acid synthesis and this drug inhibits this
What is isoniaszid (INH)?
-antimicrobial drug used for treatment of mycobacterium sp.
-it disrupts the formation of mycolic acid in cell wall
What are the 5 major antibiotics we should know?
1) penicillin
2) streptomyocins
3) tetracyclines
4) rifampin
5) vancomycin
Where does penicillin come from?
potential test q
-from molds of the genus penicillium
-isolated from common green mold by Alexander Fleming
What is the mechanism of action (MOA) of penicillin?
inhibits cell wall synthesis
What are the 2 disadvantages of penicillin?
1) anaphylactic reactions
2) penicillin resistence in bacteria
Where do streptomyocins come from?
streptomyces griseus bacteria
What is the MOA of streptomyocins?
inhibits protein synthesis
note: effectiveness is limited due to bacterias growing resistant
What is the major con of taking streptomyocins besides resistance?
its toxic for the vestibular portion of the 8th cranial nerve, causing tinnitus, vertigo, and ataxia (neural problem, you lack coordination), which are often irreversible
Which antibiotic out of the major 5 is considered a broad-spectrum antibiotic (can be used for basically any bacteria- “broad”)?
tetracyclines
What is the MOA of tetracyclines?
inhibits protein synthesis
note: discoloration of teeth in babies may occur if taken for prolonged periods by pregnant mother
What is the MOA of rifampin?
inhibits RNA synthesis
What is rifampin usually used for?
used against meningococcus or leprosy
What are the side effects of rifampin?
urine, tears, feces, and other body secretions to turn orange-red color
What is the MOA of vancomyocin?
blocks formation of peptidoglycans in the cell wall
How is vancomyosin administered?
through IV
What is vancomyosin usually used for?
MRSA (methicillin resistant Staphylococcus aureus)
What are bacteriophages used for?
bacterial viruses used to control bacteria
Is S. aureus gram pos or neg? What shape is it?
-gram pos
-cocci (in grape-like/irregular clusters)
What color are S. aureus colonies?
gold (pigmented, chromogenic)
Is S. aureus highly resistant?
yes
What does S. aureus produce that makes it increase its virulence and pathogenicity?
-produces coagulase (shows up coagulase pos in test, this increases virulence)
-produces several toxins (increases pathogenicity)
Where is S. aureus found? How common is it?
-found on the skin
-carried asymptomatically in nasopharynx in 20-40% of normal adults
-seen commonly in hospitals 50-70%
What is toxic shock syndrome (TSS)?
-toxin brought on by S. aureus
-associated with tampons and leaving them in for too long/forgetting to take out
-caused by TSS exotoxin
What are the S&S of Toxin Shock Syndrome (TSS)?
-may be fatal
-fever
-rash
-desquamation (peeling of skin on palms and soles)
-hypotension
-diarrhea
-vomiting
What food borne disease is caused by S. aureus?
gastroenteritis
What is gastroenteritis? What are the S&S?
-food poisoning/ toxemia brought on by S. aureus
-due to enterotoxin (exotoxin) produced on food, usually starchy foods like potatoes
-the toxin is heat stable (cannot be destroyed by heat)
-diarrhea and vomiting
What is scalded skin syndrome?
-due to diffusible exotoxin (exfoliatin)
-causes the epidermis to peel away from dermis
-usually seen in infants and children under 5 y/o
What are the 4 types of skin infections brought on my S. aureus? How are they usually brought on?
1) folliculitis (inflammation around hair follicles)
2) furuncles (skin boils/bumps with pus)
3) carbuncles (hair follicle infection that spreads into deep subcutaneous tissue)
4) impetigo (epidermal infection causing crust, scabs, and fever)
these 4 types are usually spread after wound infection, typically nosocomial wound infection
What is the rare bone infection brought on by S. aureus?
osteomyelitis
What is the intestinal infection following surgery brought on by S. aureus called?
enteritis
What lung infection can be caused by S. aureus, but is usually only pertaining to immunocompromised individuals?
pneumonia
What infection is in the inner membrane of the heart and is caused by S. aureus?
infective endocarditis
What is pyogenic arthritis?
arthritis caused by S. aureus
What are the 2 lab tests that can be done to diagnose pt with S. aureus?
1) coagulase test (positive test= blood serum coagulates= s. aureus)
2) mannitol salt agar (s. aureus will grow and agar will change from pink to yellow)
What genus is the only one that will grow on Mannitol Salt Agar?
Staphylococcus
Is mannitol salt agar differential, selective, or both
both
What is the treatment for S. aureus?
antibiotics
How can you prevent S. aureus bacterial infections?
-hygiene for wounds and wound dressings
-refrigerate starchy foods to prevent food poisoning
-use hygiene practices when cooking
What is the S. aureus super bug? What is it resistant to?
methicillin resistant Staphylococcus aureus (MRSA)
-MRSA is resistant to all common antibiotics like methicillin, oxacillin, penicillin, and amoxicillin
-MRSA is usually a nosocomial infection
How is MRSA treated?
vancomycin
Is S. epidermidis gram pos or neg? What shape is it? What disease comes from it?
-gram pos
-cocci (grape-like/irregular clusters)
-opportunistic infections
S. epidermidis is normal flora where?
on human skin
How is S. epidermidis similar to S. aureus in terms of growth?
both grow on the same agars, but S. aureus would appear gold/yellow, whereas S. epidermidis would appear with white colonies
S. aureus is pigmented yellow = chromogenic
S. epidermidis is not pigmented/white= non-chromogenic
S. aureus will ferment on mannitol salt agar, while S. epidermidis will not ferment
Where is S. epidermidis found?
remember that its an opportunistic infection!
-found in biofilms (aggregate of interactive bacteria attached to a solid surface or each other and is encased in an exopolysaccharide matrix)
-found in IV catheters
-contact lenses and intraocular lenses (when theres an eye infection)
-dental plaque
-prosthetics (when theres joint infections)
Will a coagulase test appear positive or negative for S. epidermidis?
negative! S. epidermidis does not produce coagulase
What is the treatment for S. epidermidis?
antibiotics
What does pyogenic mean?
bacteria that produces pus
What are the 2 types of pyogenic staphylococci?
1) S. aureus
2) S. epidermidis
What are the 4 types of pyogenic streptococci?
1) S. pyogenes
2) S. agalactiae
3) S. viridans + S. mitis
4) S. pneumoniae
There are 4 types of pyogenic streptococci. Are they all gram pos or neg bacteria? What shape are they?
-gram pos
-cocci chains
There are 4 types of pyogenic streptococci. They are classified into groups based on the C carbohydrate in the cell wall, called the Lancefield groups (A-H and K-U). What are the 2 groups we need to know?
Group A- primarily human pathogens
Group B- cattle and human pathogens
There are 4 types of pyogenic streptococci, and 2 groups (A and B) we need to know. Each group also contains a cell wall associated with M protein which can further be divided into 60 types. What is the M protein?
-anti-phagocytic protein
-important in virulence
-induces type specific immunity (there are at least 60 types of infections for just Group A, theres a bunch of variations)
There are 4 types of pyogenic streptococci and 2 groups (A and B) which we need to know. Generally within strep, they produce 4 different extracellular products which can enhance their pathogenicity and virulence. What are these 4 extracellular products?
1) hylauronidase
2) streptokinase
3) pyrogenic exotoxins
4) hemolysins
What is hylauronidase?
-extracellular product from strep
-spreading factor enzyme
-aids in spreading infected microorganisms by digesting hyaluronic acid (a polysaccharide that binds cells together in CT)
What is streptokinase?
-extracellular product from strep
-produced by many strains of group A strep
-digests clots allowing the bacteria to escape from blood clots
What are pyogenic exotoxins?
-extracellular product from strep
-stimulates leukocytes to release cytokines that in turn stimulate fever, rash, and shock
What are hemolysins?
-extracellular product from strep
-lyses membranes of erythrocytes and damages a variety of other cells
-specifically called streptolysin S or O depending on the strep
Which strep do we need to know that is a part of Group A strep?
S. pyogenes
What 5 diseases does S. pyogenes cause?
-strep pharyngitis
-endocarditis
-rheumatic fever
-glomerulonephritis
-necrotizing fasciitis
Is S. pyogenes gram pos or neg? What shape is it?
-gram pos
-cocci chains
How does S. pyogenes initially begin in terms of infections?
initially starts off as respiratory infection
What is streptococcus pharyngitis?
-strep throat from S. pyogenes (Group A)
-septic sore throat
What is the most common manifestation of Group A infections?
streptococcus pharyngitis (strep throat from S. pyogenes)
What is scarlet fever?
-streptococcus pharyngitis (strep throat from S. pyogenes) together with body rash from an erythrogenic strain of S. pyogenes
-rash is due to diffusible toxin
What is the lab test done to diagnose scarlet fever (streptococcus pharyngitis/strep throat from S. pyogenes w/rash)?
Schultz Charlton test
-skin test
-uses antitoxin to the erythrogenic toxin of S. pyogenes subcutaneously
-a positive reaction is blanching of the rash in the area around the injection site
What is steptococcal impetigo?
-brought on by S. pyogenes
-most common in young children
-thin amber crust on skin (golden yellow color), begins on nose and spreads throughout face and body
What is erysipelas?
-specific type of cellulitis (inflammation of dermis/subcutaneous layer), brought on by S. pyogenes
-most common among infants, children, and elderly
-appears as fiery red, swollen, warm, and painful rash
What are the 4 signs of inflammation?
-redness
-swelling/inflammation
-pain
-heat/warmth
What are the 2 big complications of group A strep (S. pyogenes)?
Rheumatic fever and post-streptococcal glomerulonephritis
What is rheumatic fever?
potential test q
-complication of group A strep (S. pyogenes)
-most common in school age children
-primarily affects joints and the heart
-characterized by fever and joint pain
-can lead to permanent scarring and distortion of the heart valves (type 2 hypersensitivity)
-can cause damage in the endocardium
note: this is not an infection, its an inflammatory response post strep throat
What is post-streptococcal glomerulonephritis?
-complication of group A strep (S. pyogenes)
-most common in young people
-occurs about 1 week post pharyngeal infection
-inflammatory response to M protein in the bacteria
-antigen-antibody complexes form and accumulate in glomerulus of the kidney (type 3 hypersensitivity reaction)
-progressive irreversible kidney damage may occur in adults
What are the tests for Group A strep (S. pyogenes)?
-bacitracin antibiotic disk test
-blood agar test
-anti-streptolysin O test
What is the bacitracin antibiotic disk test?
differentiates group A strep from other groups
only group A strep is sensitive to this antibiotic, whereas other bacterias would still grow in presence of this antibiotic
What is the blood agar test used for diagnosis of group A strep (S. pyogenes)?
when S. pyogenes is plated on blood agar, an area of complete clearing occurs around the bacterial colonies, this is called complete hemolysis or beta hemolysis (only group A strep does this, others will have alpha or gamma hemolysis)
also note, dewdrop/pinpoint colonies are characteristic of Group A strep here
What is the ASO- anti streptolysin O test?
-anti-streptolysin is an antibody that appears after an infection with a streptococci that produces streptolysin O
-this test measures the titer/antibody levels in the blood
-can be used to determine if symptoms like joint pain, heart problems, etc are associated with the strep infection
What is the treatment for group A strep (S. pyogenes)?
antibiotics
What is the one group B strep we have to know?
S. agalactiae
What diseases does S. agalactiae cause?
-post partum infection
-infant pneumonia
-meningitis
Is S. agalactiae a gram pos or neg bacteria? What is its shape?
-gram pos
-cocci chains
What are the 2 streps we have to know that are beta hemolytic?
S. pyogenes and S. agalactiae
What are the 3 streps we have to know that are alpha hemolytic?
S. viridans, S. mitis, and S. pneumonia
S. agalactiae is a part of the normal human flora. Where?
-vagina
-lower GI in 5-30% of women
Are there complications for S. agalactiae? If so, what are they?
not really, only for immunocompromised or elderly
in this case, they may get:
-bacteremia
-skin and soft tissue infections
-respiratory infections
-genitourinary infections
In newborns, if they are born to a mother with group B strep (S. agalactiae), they may develop ____________ within the first 5 days of life. What also may occur?
pneumonia
meningitis
What is recommended for pregnant women when it comes to group B strep (S. agalactiae)?
-to be screened at 35-37 weeks
-if they test pos for group B strep= administer IV ampicillin to prevent infection in baby post labor
What 2 bacterias cause endocarditis besides S. aureus?
strep!
- S. viridans and S. mitis
Is S. viridans and S. mitis gram pos or neg? What shape are they?
-gram pos
-cocci chains
S. viridans and S. mitis are normal flora where?
throat and nasopharynx
What 3 streps do not possess C carbohydrate and are not classified in the Lancefield classification?
S. viridans, S. mitis, and S. pneumonia
What happens to the heart in patients exposed to S. viridans and S. mitis?
-upon reaching heart and damaged valve, the bacterias multiple and cause further damage, frequently causing the valve to fragment
-bacterial colonization of the endocardium triggers inflammation aka endocarditis and the formation of vegetation
-usually occurs in individuals who already have injured heart
What are the symptoms for endocarditis brought on by S. viridans and S. mitis?
-fever
-extreme fatigue
-malaise
-breathing difficulty
-death, if left untreated
How do you diagnose S. viridans and S. mitis endocarditis?
colonies produce alpha (partial/greenish) hemolysis on blood agar test
What is the treatment for S. viridans and S. mitis endocarditis?
antibiotics
What is the synonym for S. pneumonia?
pneumococcus
Is S. pneumonia a gram pos or neg bacteria? What shape is it?
-gram pos
-lancet shaped diplococci OR chains
What enhances S. pneumonia virulence?
has a polysaccharide capsule that enhances its virulence
Is S. pneumonia a part of normal flora? If so, where?
upper respiratory tract in 4-50% of humans
Are there different types of S. pneumonia?
yes, over 90 types, each differentiated by a different type of polysaccharide capsule
Pneumococcal pneumonia is one of the major causes of pneumonia in humans. What are the symptoms?
-sudden chill
-fever
-cough
-pleuritic pain
-red/brown rusty color sputum
often occurs in conjunction with viral disease of the upper respiratory tract
Who is more prone to S. pneumonia?
patients;
-with impaired respiratory drainage
-bedridded
-that are heavy smokers
-with emphysema
S. pneumonia can cause pneumonia but what else is common? What other bacterias cause this, as well?
meningitis
other bacterias that cause meningitis:
-Neisseria meningitis
-Haemophilus influenza
S. pneumonia commonly causes pneumonia and meningitis. What are the less common infections/diseases?
-sinusitis
-otitis
-bronchitis
-bacteremia
What are the common symptoms of meningitis?
-high temp
-severe headache
-stiff neck
-chills
What are the diagnostic tests done for S. pneumonia?
-direct smears from sputum show gram pos lancet shaped diplococci
-alpha (incomplete/greenish) hemolysis on blood agar test
-optochin antibiotic disk sensitive test (S. pneumonia will show no growth, other streps will still grow in presence of optochin)
-quellung reaction positive (related to polysaccharides/capsules, if bacteria has it then test is pos)
What is a synonym for Neisseria gonorrhoeae?
gonococcus
What disease does Neisseria gonorrhoeae cause?
gonorrhea (gonococcal urethritis)
Is N. gonorrhoeae gram pos or neg bacteria? What shape is it?
-gram neg
-diplococci (coffee bean shape)
What is the incubation period for N. gonorrhoeae? What happens during this time?
2-9 days, disease of mucus membranes of genitourinary tract, eyes, throat, and rectum
Which gender tends to have more acute symptoms with gonorrhea?
males
What are the male signs, symptoms, and complications for gonorrhea?
-urethral inflammation with pus and painful urination
-swollen lymph nodes in groin area
-unchecked infection of the epididymis may lead to sterility
Are sexual partners considered horizontal or vertical transmission when infections are spread?
horizontal transmission
What are the female signs, symptoms, and complications of gonorrhea?
-red cervix with discharge
-abdominal pain
-burning sensation when urinating
-may spread to fallopian tubes, which become riddled with pouches and adhesions
-salpingitis (inflammation of the fallopian tubes)
-can lead to pelvic inflammatory disease (PID)
-scar tissue in fallopian tubes can lead to sterility or ectopic pregnancies
Which gender is more difficult to diagnose with gonorrhea? Why?
females bc they are usually asymptomatic carriers till bacteria spreads far and wide
What is ophthalmia neonatorum (neonatal conjunctivitis)?
infant eye infection due to going through birth canal (with mom who has gonorrhea)
What tests are used to diagnose gonorrhea?
-secretions taken from site of infection will show gram neg intracellular diplococci (bacteria is within neutrophils)
-culture on thayer martin medium that contains antibiotics to inhibit growth of normal flora
-nucleic acid amplification test (NAAT) is preferred for genitourinary specimens
What is gonorrhea resistant to? What antibiotic is used to treat it?
resistant to penicillin
ceftriaxone is used as gonorrhea tx
What disease does Neisseria meningitis cause?
meningococcal meningitis
is N. meningitis gram pos or neg? What shape is it?
-gram neg
-encapsulated
-diplococci (kidney or coffee bean shape)
How many serogroups are there for N. meningitis?
14+
Are there any more hosts besides humans for N. meningitis?
nope, just humans
What bacteria may harbor organism in respiratory tract asymptomatically in 5-30% of the population?
N. meningitis
What is the transmission route for N. meningitis?
direct contact with respiratory droplets or oral secretions (coughing, kissing, or exchange of respiratory sections)
What is a common site for isolation of N. meningitis? Where can it spread?
nasopharynx
from nasopharynx, it may reach the bloodstream producing bacteremia and then move into meninges causing meningitis
-on top of the meningitis symptoms (severe headache, chills, high fever, and stiff neck), there can also be a hemorrhagic rash known as petechial hemorrhage all over body (small pinpoint non-raised round red dots)
How fast can N. meningitis spread?
fast, can be acute and fatal and death may occur within 24 hours
How is N. meningitis diagnosed?
-gram stain shows gram neg intracellular or extracellular diplococci
-clinical specimens of CSF, blood, and nasopharynx may be cultured
-CSF of a cultured chocolate medium and gram stained
How is N. meningitis treated?
penicillin G
Which bacteria leads to a disease that occurs in epidemic waves within military encampments, schools, etc where the carrier rate goes up to 70-80%? Vaccination is recommended for high schoolers and people 11-55 y/o who are high risk like college freshman, military, medical workers, etc.
N. meningitis
