BIOCHEMICAL IDENTIFICATION OF GRAM NEGATIVE BACTERIA Flashcards
(21 cards)
oxidase test is used to detect the presence of cetain ___
cytochrome C oxidases
tripple sugar iron or TSI agar or Kligler iron agar (KIA) is used to determine ____
glucose
lactose
sucrose - (in TSI only )
carbs utilization and hydrogen sulfide production
MRVP
methyl red voges proskauer tests is used to determine ___
end products of glucose fermentation
indole test is used to determine whether indole is formed from ____
tryptophan by tryptophanase
urease test is used to determine hydrolysis of
urea
simmon’s citrate is used to determine whether citrate can be used as __
sole carbon source
LIA or lysine iron agar is used to determine ___
lysine decarboxylase activity
SIM or MIO
means
sulfide-indole-motility
motility-indole-ornithine
pH indicator in TSI mediym
bromothymol blue
the uninoculated medium is of TSI is color
green
the TSI medium in an acid environment is color
yellow
the TSI medium in an alkaline environment is color
blue
difference in formula of TSI and KLIA
TSI has sucrose aside from glucose and lactose
in TSI which one is the glucose
the butt
so if glucose fermentation
K/A
TSI and KIA contain how many percent of glucose
0.1%
lactose and sucrose fermentation
A/A
h2s production requires acid environment, even if the yellow color is cannot be seen, it is safe to assume glucose fermentation
terue or flase
terue
2 steps in producing H2S
bacterium (acid environment) + sodium thiosulfate
= h2s gas
h2s + ferric irons = black precipitate
why do we need to incubate TSI for 18-24 hrs
less than 12 hrs - hindi pa tapos ung fermentation kasi nga si slant part after 12 hrs pa makikita ung tamang result. Diba si bacteria nacoconsume niya si peptone turning the medium into red, mag iistart lang yon after 12 hrs
above 24 hrs - bawal din to kasi kpag naman lactose or sucrose fermented, both top and bottom yellow, after 24 hrs, mauutilize na si peptone, magiging red na siya imbis na yellow
MRVP is a modification of
clark and lubs medium
