Bacteriology Flashcards
a subdivision of microbiology which involves the identification, classification, and characterization of bacterial species.
Bacteriology
why was the diminutive “bakteria” used in the latinization of the word bacterium?
because bakteria means “staff, cane” and the first discovered bacteria were rod-shaped
what type of microorganisms do bacteria constitute?
a large domain of prokaryotic microorganisms
what do single-celled bacteria fail to have around their nucleus or organelles because of their prokaryotic nature?
membrane enclosure (and membrane enclosed organelles like mitochondria and chloroplasts)
(based on growth requirements)
do not grow on ordinary culture media, requiring additional growth factors for successful cultivation
fastidious microorganism
(based on growth requirements)
are easily cultivated because of their ability to grow on ordinary media such as NA and NB
non-fastidious microoganisms
(based on growth on media)
state all types of media
- non-selective media (usually enriched medium)
- differential media
- selective media
(based on growth on media)
suppresses growth of unwanted bacteria and encourage growth of desired ones
selective media
(based on growth on media)
list well known selective media
- Bismuth Sulfite Agar (BSA)
- Potato/Sabouraud’s Dextrose Agar
- Loeffler Medium
- Tellurite Media
- Bordet-Gengou Agar
- Thayer-Martin Agar Plates
(selective media)
what cultivates mostly Salmonella species (S. typhi) from feces
Bismuth Sulfite Agar (BSA)
(selective media)
what does BSA inhibit?
gram positive and most gram negative intestinal bacteria
(selective media)
what is used to cultivate fungi, yeasts, and molds from foodstuffs
Potato/Sabouraud’s Dextrose Agar
(selective media)
what is Potato//Sabouraud’s Dextrose Agar’s pH?
5.6
(selective media)
what is used to cultivate Corynebacterium diptheriae?
Loeffler Medium and Tellurite Media
(selective media)
what is used to cultivate Bordetella pertussis?
Bordet-Gengou Agar
(selective media)
what chocolate agar is used to cultivate Neisseria gonorrhoeae?
Thayer-Martin Agar Plates
(selective media)
why do Thayer-Martin Agar Plates contain antibiotics?
in order to suppress normal flora from mixed bacteria and fungi (it is both selective and enrichment)
(selective media)
what is used to cultivate Legionella?
Charcoal Yeast Agar
(based on growth on media)
distinguish colonies of the desired organism from other colonies
differential media
(differential media)
based on pattern of hemolysis
Blood Agar Plate
(differential media)
Blood Agar Plate that is incomplete, light greenish
alpha-hemolysis
(differential media)
Blood Agar Plate that is complete, light transparent
beta-hemolysis
(differential media)
Blood Agar Plate that has no reaction
gamma-hemolysis
(based on growth on media)
MSA and Mannitol
Selective and Differential Media
(selective and differential media)
what is used to cultivate Staphylococcus aureus?
Mannitol Salt Agar
(selective and differential media)
what makes MSA selective?
7.5% NaCl
(selective and differential media)
differential for fermenters and non-fermenters
mannitol
(selective and differential media)
fermentation changes color of phenol red via
red to yellow
round or oval bacterial shape
cocci
rod shaped bacteria
bacilli
twisted or coiled shaped bacteria
spirals
curved rod shaped bacteria
vibrio
bacteria that do not have a definite shape
pleomorphic
developed by Hans Christian Gram
Differential Gram Stain
steps for gram staining
-Crystal Violet
-Iodine
-Alcohol
-Safranin
disperse in nigrosine or india ink -> spread using another slide -> gently heat -> stain w/ crystal violet/safranin
-to distinguish capsular material from the bacterial cell
capsular staining
results of capsular staining
halo appearance (purple/pink cell + dark background + colorless capsule)
positive for capsule staining (Some Killers Have Pretty Nice Capsules)
- Streptococcus pneumoniae
- Klebsiella pneumoniae
- Haemophilus influenzae
- Pseudomonas aeruginosa
- Neisseria meningitidis
- Cryptococcus neoformans (fungi)
binds to waxy material in cell walls and resists decolorization with acid alcohol
acid-fast stain
acid fast bacteria (May Nuno)
- Mycobacterium
- Nocardia
steps for acid fast staining (CHAM)
Ziehl-Neelsen Method
- Crystal Violet
- Heat
- Alcohol
- Methylene blue
spore forming bacteria (BaCcla)
- Bacillus
- Clostridium
results of spore staining?
green endospore w/n red or pink cells
steps for spore staining (MHWS)
Schaeffer-Fulton Method
- Malachite green
- Heat
- Water
- Safranin
ALL COCCI are gram-positive, except NVM
- Neisseria
- Veillonella
- Moraxella
require O2 for survival
obligate aerobes
bacteria that are obligate aerobes (PutaNginaBabyMoCya)
- Pseudomonas
- Nocardia
- Bacillus
- Mycobacterium
- Corynebacterium
grow only in the absence of O2
obligate anaerobes
bacteria that are obligate anaerobes (ABCEFP)
- Actinomyces
- Bacteroides
- Clostridium
- Eubacterium
- Fusobacterium
- Prevotella
microorganism that requires environments containing lower levels of dioxygen than that are present in the atmosphere
-require ↓ O2, however ↑ O2 concentration -> toxic)
microaerophiles
microaerophilic bacteria (CollegeHumor)
- Campylobacter
- Helicobacter
tolerates O2 but cannot replicate in its presence
aerotolerant
aerotolerant bacteria (LaPilluz)
- Lactobacillus
- Propionibacterium
used to distinguish organisms on the basis of the presence or absence of a certain respiratory enzyme, in which the family Enterobacteriaceae can be differentiated from other gram-negative rods
oxidase test
what respiratory enzyme is often absent in the Enterobacteriaceae family?
cytochrome C
this test is particularly useful for the differentiation of gram positive cocci
catalase test
what cocci can be differentiated from the catalase test?
staphylococci (positive) from streptococci (negative)
what bacteria can H2O2 kill?
staphylococci
used to differentiate Staphylococcus aureus from other less pathogenic staphylococci
coagulase test
can not only differentiate among microbial species, but also
serological testing (immunologic test)
strains with different antigens are called
serotypes, serovars, or biovars
strains with different antigens are called
serotypes, serovars, or biovars
different serological test/two blood antibody tests that may be used to detect HIV
ELISA and Western blotting
