Gram staining is used for the identification and classification of what?
bacteria
Gram negative bacteria will appear what color:
red or pink
Gram positive bacteria will appear what color?
purple
In the first step of gram staining, what dye is used and how long should it remain on the slide before washing?
Crystal-violet; 30 seonds
In the second step of gram staining, what is the mordant used and how long should itremain on the slide before washing?
Gram's iodine; 10 seconds
In the third step of gram staining, what is the decolorizing agent used and how long should it remain on the slide before washing?
ethyl alcohol; 1-2 seconds
In the final step of gram staining, what is the counter-stain used and how long should it remain on the slide before washing?
Safranin; 30 seconds
What are the three bacteria used in this lab?
Staphylococcus epidermidis
Escherichia coli
Bacillus subtilis
In the first step of gram staining, what color will a gram positive bacteria appear?
Purple
In the first step of gra staining, what color will a gram negative bacteria appear?
purple
In the second step of gram staining, what color will a gram negative bacteria appear?
purple
In the second step of gram staining, what color will a gram positive bacteria appear?
purple
In the third step of gram staining, what color will a gram negative bacteria appear?
clear
In the third step of gram staining, what color will a gram positive bacteria appear?
purple
In the fourth step of gram staining, what color will a gram negative bacteria appear?
pink
In the fourth step of gram staining, what color will a gram positive bacteria appear?
purple
What is a pure culture?
A culture containing only one kind of microbe.
What is contamination?
The presence of unwanted microorganisms.
On an isolation plate, bacteria grows:
into a visible colony that consists of one kind of bcterium.
What is streak plate method?
In which a loop is used to streak along the surface of several sections of solid agar, dragging from the first into the second and from the second into the third and from the third into the fourth.
What were the agars used in Lab # 11: Isolation of Bacteria by Dilution Techniques?
2 Petri plates with nutrient agar
3 Test tubes with melted nutrient agar
1 Nutrient agar slant
What were the cultures used in Lab # 11: Isolation of Bacteria by Dilution Techniques?
Mixed broth
Turbid nutrient broth
What is reduction?
A gain of electrons or hydrogen atoms
What acts as an electron acceptor in fermentative metabolism?
organic molecules
What act as electron acceptors in oxidative metabolism or respiration?
Inorganic molecules
What is the final electron acceptor in aerobic respiration?
molecular oxygen
In aerobic bacteria, what carries electrons to oxygen?
cytochromes
What is used to determine the presence of cytochrome c and is useful in identifying bacteria?
the oxidase test
What agar was used in Lab # 13: Respiration?
TSA (trypticase soy agar)
What bacteria were used in Lab # 13: Respiration?
Strep
Staph
Bacillus
What was the reaction of Strep in Lab # 13: Respiration?
No change - negative catalase test
What was the reaction of Staphin Lab # 13: Respiration?
Bubbles - positive catalase test
What was the reaction of Bacillus in Lab # 13: Respiration?
Bubbles - positive catalase test
In Lab # 14, what was the device used for the Rapid Identification test?
Enterotube II
What is the purpose of the Rapid Identification tests?
to provide a large number of results from one inoculation
How many compartments are in an Enterotube?
12, each with a different substrate in agar
All coliforms feed on what?
glucose
What are the four unknown bacteria used for Lab # 14?
Citrobacter freundii
Enterobacter aerogenes
Serratia marcescens
Proteus vulgaris
What are coliforms?
bacteria that grow in the intestines or colon
What agents are used for the control of the growth of microbes?
antimicrobial agents
What are disinfectants?
chemical agents used on inanimate objects to lower the level of microbes on their surface
What are antiseptics?
chemical agents used on living tissue to decrease the number of microbes
What does bactericidal mean?
results in death of bacteria
What does bacteriostatic mean?
temporarily inhibits the growth of bacteria
What are the agars used for Lab # 17: Chemical Methods of Control?
Petri plates with nutrient agar
What is the bacteria used for Lab # 17: Chemical Methods of Control?
Staphylococcus aureus
The observation that some microbes inhibit others was first made in what year and by whom? (they observed that infecting an animal with Pseudomonas aeruginosa protected the animal from Bacillus anthracis)
1874 by Pasteur and other scientists
Antibiosis means:
against life for its inhibition properties
In 1928, Alexander Fleming observed what?
antibiosis around a mold (Penicillium) growth on a culture of Staphylococci. He found that culture filtrates of Penicillium inhibited the growth of many gram positive cocci and Neisseria spp
What are chemotherapeutic agents?
antimicrobial cemicals absorbed or used internally, whether natural (antibiotics) or synthetic
What us a pathogen?
a disease causing organism
What is MIC?
the concentration of chemotherapeutic agent at the edge of the zone of inhibition and is determined by comparing the zone of inhibition with the MIC values on a standard table. The zone size is affected by such factors as the diffusion rate of the chemo. agent and the growth rate of the organism
What test is used for Lab # 18: Chemical Methods of Control?
Kirby-Bauer
What agar is used with the Kirby-Bauer test?
Mueller-Hinton agar because it allows the chemotherapeutic agent to diffuse freely
What bacteria were used in Lab # 18?
Staphylococcus aureus (gram +)
Escherichia coli (gram -)
Pseudomonas aeruginosa (gram -)
What are the five chemotherapeutic agents used in Lab # 18?
CIP5 - Ciprofloxacin (worked in all)
S10 - Streptomycin
TE30 - Tetracycline (ok on all)
VA30 - Vancomycin
P10 - Penicillin G (for growth on STap and other bacteria)
To convert cm to mm, what do you need to do?
multiply by 10
Who noted that the lack of aseptic technique was directly related to the incidence of puerperal fever and other diseases?
Ignas Semmelweis @ Vienna General Hospital in 1846 (the medical students wouldgo directly from autopsy of infected patients to delivering babies without washing their hands)
According to the CDC (Center for Disease Control), what is the single most important procedure for preventing nosocomial infections?
handwashing
Surgical scrubbing removes what?
transient microbiota and some resident microbiota
In Lab # 19, what type of organisms where observed?
only those capable of growing aerobically on nutrient agar
In the Dental Caries Lab, what amount of saliva was needed for the Snyder test?
0.25ml
What are some of the ways to prevent Caries?
healthy diet
no tobacco use
regular dental visits
good oral hyggiene
cut out sweets
What is the upper respiratory system?
nose and throat
What is the lower respiratory system?
larynx
trachea
bronchial tubes
alveoli
Unlike the upper respiratory system, the lower respiratory system is usually sterile because of what feature?
ciliary escalator
What are the four normal microbiota usually found in the throat?
Staphylococcus, Streptococcus (dominant organisms in throat cultures), Neisseria, and Haemophilus
What agar was used for Lab # 22: Bacteria of the Respiratory Tract?
BAP
What are the chemotherapeutic agents used in Lab # 22?
Bacitracin and Optochin
What is the name for the area swabbed for Lab # 22?
glossopalatine arches or Golden Arches
What system is the antigenic characteristics of Strep identified by?
Lancefield's
Why is blood agar made with defibrinated sheep blood (5.0%), sodium chloride (0.5%), and nutrient agar?
The sodium chloride minimizes spontaneous hemolysis
What are the tree patterns of hemolysis?
Alpha, Beta, and Gamma
What is Alpha hemolysis?
incomplete hemolysis, producing methemoglobinm and a green, cloudy zone around te colony (normal microbiota)
What is Beta hemolysis?
complete hemolysis, givig a clear zone with a clean edge around the colony (BAD PATHOGEN)
What is Gamma hemolysis?
no hemolysis, no change, normal microbiota
90% of streptococcal infections are caused by?
Beta-hemolytic group A streptococci
S. pyogenes is sensitive to what antibiotic?
Bacitracin
S. pneumoniae is sensitive to what antibiotic?
Optichin
The presence of bacteria in urine is not considered an indication of UTI unless?
there are 1000 bacteria of one species or 100 coliforms per milliliter of urine
True or Flase: Urine is normally sterile?
True
What is cystitis?
inflammation of the urinary bladder
What is pyelonephritis?
inflammation of the kidney
Cystitis and pyelonephritis are caused by?
opportunistic pathogens and usually related to fecal contamination of the urethra and/or medical procedures
Pseudomonas is what type of bacteria?
gram negative aerobic rod
P. aeruginosa infections are characterized by:
blue-green pus and it produces an extracellular, water-soluble pigment called pyocyanin (blue pus) that diffuses into its growth medium
What is the most commonly reported communicable disease in the US?
gonorrhea (an STD caused by the gram negative diplococci Neisseria gonorrheae)
What agar was used in Lab #24: Bacteria of the Urogenital Tract?
BAP
MacConkey (shows coliforms)
What was the calibration fo the loop used to transfer the urine to the plates?
10 microliters
What type of catch was used?
midstream
What does light pink growth on the MacConkey agar mean?
