microbiology lab 2 Flashcards
how can you describe a colony?
punctiform, circular, rhizoid, irregular, filamentous
how can you describe the edge?
entire, undulate, lobate, filamentous, curled
how can you describe the surface?
smooth and glistening, rough, wrinkled, dry or powdery
how can you describe the elevation?
flat, raised, covex, pulvinate, umbonate
what is enteric?
bacteria that exist in the intestines of animals/humans
what is aerobic?
bacteria that can grow/live when oxygen is present
what is anaerobic?
bacteria that do not require oxygen for growth and cannot have present
what is pathogenic?
a microbe able to cause damage in susceptible host
what does it mean when colonies on BAP present with red surrounding colonies?
non-hemolytic bacteria present (gamma hemolysis)
what does it mean if colonies are present and surrounded by a green zone?
partially hemolytic bacteria present (alpha hemolysis)
what does it mean if colonies are present and surrounded by a transparent clear zone?
completely hemolytic bacteria present (beta hemolysis)
what does it mean if no colonies are present?
no bacteria present in sampel or accidentally killed in incubation of plate by overheating
what will the make plate grow?
designed to grow gram negative bacteria
what does it mean if no bacteria are present on MAC plate?
cannot grow in prescene of bile salts/ crystal violet
gm+ and non-enteric
what does it mean if colonies are visable and are white?
gm- enteric bacteria are lac- therefore, cannot use lactose and instead metabolize the peptide in the media,
what does it mean if colonies are visible and pink?
gm- enteric bacteria are lac+ and use lactose, produce acid, and activate neutral red dye
what is purpose of flaming loop?
ensures bacteria are not transferred to bench
what is purpose of heat fixing?
kills the bacteria and causes bacteria cells to adhere to slide
what is prupose of crystal violot?
stains peptidoglycan in bacteria cell wall, especially in thick layer (gm+)
what is purpose of grams iodine?
application of mordant, forms insoluable complex with crystal violet fixing the stain in cell wall
what is purpose of acetone- alcohol?
gm+ dehydrates cell, trapping crystal violet and iodine, (gm-) dissolves lipopolysaccride in outer membrane and washes stain excess
what is safranin?
stains thinner peptidoglycan coat of gram- cells pink, so can see these cells lost their stain
what causes nasocomial infections?
poor hand hygeine
contaminated fomites
surgeries (poor aspesis)
what are impacts of nasocomial infections?
loss of rom or mobility
250,000 deaths
longer stay in hosptial
prevention of nasocomial infections? a
aspesis, hand hygiene, disinfecting surfaces
what is MRSA?
antiobiotic resistant staph infection
what is VRE?
cause of antibiotic resistant gastrointestinal infection
