F- MEDICALLY IMPORTANT BACTERIA Flashcards
___ one of the most useful staining procedures because it classifies bacteria into two large groups: ___
Gram Stain
gram-positive and gram-negative
when was gram stain developed and by who?
1884 by the Danish bacteriologist, Hans Christian Gram.
enumerate the process of staining 1- 2- 3- 4-
1st dye- crystal violet, rinse with water
2nd- add iodine- mordant (intensifies the crystal violet)
3rd- alcohol- decolorize
4- safranin- a red dye
STAINING ALLOWS FOR VISIBILITY
this type of bacteria will appear violet under the microscope indicating that it has a thicker cell wall
GRAM POSITIVE BACTERIA ( the harder it is to remove the first color stain even through alcohol and safranin the thicker the cell wall)
golden yellow, fried egg appearance. Gram-positive, grape-like arrangement, beta-hemolytic (destroys rbc), halophile (they love salt)
staphylococcus aureus
this bacteria causes 9 diseases they are:
- gastroenteritis (diarrhea/stomach ache)
- scalded skin syndrome
- toxic shock syndrome
- impetigo
- folliculitis
- furuncle or boil
- carbuncle
- acute endocarditis
- osteomyelitis
. staphylococcus aureus
part of the normal bacterial flora widely found on the body, but compromised patient can become infected with this microorganisms, causes infections on prosthetic devices on the body and catheters
STAPHYLOCOCCUS EPIDERMIDIS
this bacteria is the second leading cause of UTI in sexually active young women
*2nd only to e.coli
STAPHYLOCOCCUS SAPROPHYTICUS
spherical to ovoid, gram-positive tend to occur in pairs or chains when grown in liquid media, non spore former and generally nonmotile
STREPTOCOCCI
based on physiologic properties (PYOGENIC, VIRIDANS GROUP)
Academic/Bergey’s classification
in chains and violet, PYROGENIC GROUP
streptococcus pyogenes
classic strep throat with swollen tonsils, pharynx, purulent exudate on the tonsils, high temp, swollen lymph nodes. Usually lasts 5 days
STREPTOCOCCAL PHARYNGITIS
SCARLET FEVER- RED RASH THAT SPARES THE FACE AND CAUSES FEVER. THIS IS CAUSED BY WHICH BACTERIA
Streptococcus pyogenes
PYODERMA, NECROTIZING FASCIITIS, RHEUMATIC HEART DISEASE- IS CAUSED BY WHICH BACTERIA?
group A Streptococcus- streptococcus pyogenes
PNEUMONIA OR CAP, is caused by this bacteria
STREPTOCOCCUS PNEUMONIAE
OTITIS MEDIA- middle ear infection in children is caused by which bacteria?
STREPTOCOCCUS PNEUMONIAE
causes neonatal meningitis, pneumonia and sepsis (from contaminated milk)
STREPTOCOCCUS AGALACTIAE
bind to teeth and ferment sugar which produces acid and dental caries (normally in the flora of the mouth, not following proper oral hygiene afterwards causes the acid and forms cavities)
STREPTOCOCCUS MUTANS (this falls under VIRDANS GROUP)
this bacteria can implant on heart valve can lead to (mitral valve prolapse)
SUBACUTE BACTERIAL ENDOCARDITIS (this falls under VIRDANS group)
based on hemolytic reaction (beta-hemolytic streptococci, alpha-hemolytic streptococci, gamma)
SMITH BROWN’S CLASSIFICATION
clear, colorless zone indicating COMPLETE hemolysis of the RBC
beta-hemolytic streptococci
produce a zone of PARTIAL hemolysis with a greenish or brownish discoloration
alpha-hemolytic streptococci
hemolytic or non-hemolytic or INDIFFERENT streptococci- colonies do not produce any hemolysis
gamma
gram-positive, form endospores, either strict aerobes or aerotolerant anaerobes (can grow in presence of oxygen but do not require it)
bacillus species
SPORE forming (bacillus, clostridium), non-spore forming (corynebacterium, literia, propionibacterium)
GRAM POSITIVE RODS (BACILLI) - most are found in soil and water
amino acid capsule, cutaneous anthrax, pulmonary anthrax (wool sorter’s disease) is caused by which bacteria?
Bacillus anthracis