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100 Cards in this Set
- Front
- Back
Gram-negative bacilli and coccobacilli [rod-shaped, elongated], non-spore forming, facultatively anaerobic |
FAMILY ENTEROBACTERIACEAE – ENTERICS |
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ENTEROBACTERIACEAE DO NOT produce cytochrome C oxidase except for |
Plesiomonas spp. |
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FAMILY ENTEROBACTERIACEAE MOTILE at body temperatures except |
Klebsiella spp., Shigella spp., and Yersinia spp. |
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To ensure isolation of both opportunistic and fastidious pathogens, laboratories must provide appropriate transport media, such as |
Cary-Blair, Amies, or Stuart Media |
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enterobacteriaceae optimal growth in |
35 degrees Celsius to 37 degrees Celsius |
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Low temperatures (1 degree Celsius to 5 degrees |
Serratia and Yersinia) |
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tolerate high temperatures (45 to 50 degrees Celsius, |
E. coli) |
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General Culture Medi |
BAP AND CAP |
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Selective or Differential Medium: |
MacConkey Agar and other selective medium [HEA, MBA] |
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All Enterobacteriaceae produce similar growth on blood and chocolate agars; colonies |
large, gray, and smoot |
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may be mucoid – presence of polysaccharide capsule |
Klebsiella spp. or Enterobacter spp Klebsiella spp. or Enterobacter spp |
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“swarm” on blood and chocolate agars |
P. mirabilis, P. penneri, and P. vulgaris |
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Y. enterocolitica produces |
bull’s-eye colonies |
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Broth cultures of Y. pestis exhibit a characteristic |
“stalactite pattern” |
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5% SBA are pinpoint at 24 hours but exhibit a rough, cauliflower appearance at 48 hours |
Y. pestis |
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Best used to characterize gram-negative rods |
MACCONKEY AGAR |
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Lactose fermenters can be differentiated with non- lactose fermenters |
MACCONKEY AGAR |
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Lactose fermenter: appear as |
dark pink colonies |
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can ferment lactose within 18-24 hours of incubation |
Rapid Lactose Fermenters |
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can ferment lactose within 48-72 hours of incubation |
Late Lactose Fermenters |
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Rapid Lactose Fermenters: |
Escherichia o Enterobacter o Klebsiella |
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Late Lactose Fermenters: |
Hafnia, Serratia, Citrobacter o Salmonella arizonae o Shigella sonnei o Yersinia enterocolitica |
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even prolonged incubation, they cannot ferment lactose; |
Non-lactose fermenter |
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Non-lactose fermenter appear |
clear colonies |
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Non-lactose fermente |
All salmonella except Salmonella arizonae- All shigella except Shigella sonnei- All yersinia except Yersinia enterocolitica- Proteus- Providencia- Morganella- Edwardsiella |
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determines the presence of the cytochrome oxidase system that oxidizes reduced cytochrome with molecular oxygen. |
OXIDASE TEST |
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Kovac’s oxidase test uses a |
0.5% or 1% aqueous solution of tetramethyl-p-phenylenediamine dihydrochloride |
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positive result of oxidase test |
development of a lavender color within 10 to 15 seconds. |
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determines whether an organism has the ability to reduce nitrate to nitrite and reduce nitrite further to nitrogen gas (N2) |
NITRATE AND NITRITE REDUCTION |
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After 24 hours of incubation of NITRATE AND NITRITE REDUCTION _________ is added |
N,N-dimethyl-a- naphthylamine and sulfanilic acid |
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indicates the presence of nitrite |
red color |
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Ph indicator of MALONATE UTILIZATION |
Bromthymol blue |
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in MALONATE UTILIZATION bacteria able to use ____________ as sole carbon source |
malonate |
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in MALONATE UTILIZATION use _________ as a nitrogen source |
ammonium sulfate |
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A positive test result in increased alkalinity from utilization of the ammonium sulfate, changing the indicator from |
green to blue |
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Gelatinase activity is detected by loss of gelling (liquefaction) of gelatin |
GELATIN LIQUEFACTION |
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proteolytic enzymes that break down gelatin into amino acids |
gelatinases– |
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this test is used to differentiate organisms based on the production of deoxyribonuclease |
DNA HYDROLYSIS (DNAse TEST AGAR) |
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positive result of DNA HYDROLYSIS |
medium will turn colorless around the test organism |
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negative result of DNA HYDROLYSIS TEST |
if no degradation of DNA occurs, the medium remains green. |
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Slow Urease Producers: |
Citrobacter - Klebsiella - Enterobacter except Enterobacter gergoviae - Yersinia - Serratia |
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Rapid Urease Producers: |
Proteus - Providencia - Morganella |
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determines whether a microorganism can hydrolyze urea |
UREASE TEST |
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Urease hydrolyzes urea to form |
ammonia, water, and CO2 |
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agar use in urease test |
Christensen’s Urea Agar |
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positive result in urease test |
Change in color form Light orange (pH 6.1) to Magenta (pink) (pH 8.1) |
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negative result in urease test |
No change in color |
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it determines whether an organism can use sodium citrate as a sole carbon source. |
CITRATE UTILIZATION |
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Part of a series referred to as IMViC |
(indole, methyl red, Voges-Proskauer, and citrate) |
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Contains ammonium salts as the sole nitrogen sourc |
Simmon’s Citrate Agar |
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ph indicator of CITRATE UTILIZATION |
Bromthymol Blue |
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positive result of citrate utilizatoon |
blue |
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negative result of citrate utilization |
green |
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use light inoculum |
citrate utilization |
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citrate utilization incubate up to what degree of celcuis and up to what. |
35-37°C and 7 days |
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Presence of cloudiness spreading from the inoculation line |
Motility |
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This can be indicated by the presence of a black precipitate |
Sulfide (H2S) |
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Organisms that possess the enzyme tryptophanase are capable of deaminating tryptophan with the formation of the intermediate degradation products of indole, pyruvic acid, and ammonia |
indole |
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reagent of sim agar |
0.5 mL Ehrlich’s reagent |
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positive result of sim agar |
red |
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miscellaneous test |
-Sulfide indole motility agar - citrate utilization -urease test - DNA hydrolysis test - gelatin liquefaction - malonate utilization - nitrate and nitrate reduction - oxidase test |
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Amino acid utilization |
- lysine iron agar - phenylalanine deaminase test |
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deamination of phenylalanine |
phenylalanine- phenylalanine deaminase-phenyl pyruvic acid + Ferric chloride |
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Determines whether an organism possesses the enzyme that deaminates phenylalanine to phenylpyruvic acid |
PHENYLALANINE DEAMINASE (PAD) TES |
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positive result of PHENYLALANINE DEAMINASE (PAD) TES |
green color |
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H2S Producing of LIA |
SACE [Salmonella, Arizona, Citrobacter, Edwardsiella] |
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Deaminase producing |
Proteus, Providencia, and Morganella |
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in LIA Red Slant/Acid Butt (yellow) |
Lysine deamination and glucose fermentation |
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in LIA Alkaline Slant (purple)/Acid butt (yellow) |
Glucose fermentation |
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Alkaline Slant (purple)/Alkaline butt (purple) |
Lysine decarboxylation and no fermentation of glucose |
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to differentiate gram-negative bacilli based on decarboxylation or deamination of lysine and the formation of hydrogen sulfide (H2S) |
LYSINE IRON AGAR |
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medium of LYSINE IRON AGAR |
has an anaerobic slant and anaerobic butt |
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ph indicator of LIA |
Bromcresol purple |
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positive and negative result of Lysine Deaminase (Slant) |
Positive: Burgundy/Red - Negative: Purple |
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positive and negative result of Lysine Decarboxylase (Butt) |
Positive: Purple (CADAVERINE – neutralize organic acid formed during the glucose fermentation; revert into alkaline state) - Negative: Yellow (acidic – glucose is fermented) |
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method of LIA |
With a straight inoculating needle, inoculate LIA by twice stabbing through the center of the medium to the bottom of the tube and then streaking the slant 2. Cap the tube tightly and incubate at 35-37 degrees Celsius in ambient air for 18-24 hrs. |
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GLUCOSE METABOLISM AND ITS METABOLIC PRODUCTS |
- METHYL RED TEST - VOGES-PROSKAUER TEST |
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im VP test Detects the organism’s ability to convert the acid products to |
acetoin and 2,3-butanediol (butylene gycol pathway) |
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after incubation of VP test what reagent we will add first as a catalyst |
a- naphthol |
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after adding a-naphthol in VP text next we add what |
40% potassium hydroxide or sodium hydroxide |
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poristive resukt of VP test |
red color |
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negative result of VP test |
yellow color |
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If glucose is metabolized by the mixed acid fermentation pathway, stable acid end products are produced, which results in |
low Ph |
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methyl red test |
glucose- pyruvic acid - mixed acid fermentation - red color of methyl indicator |
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reagent of methyl red test |
methyl red |
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postive result of MR TEST |
red |
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negative resukt of MR test |
yellow |
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MRVP broth → inoculate → incubate for |
48hrs - 35/37 |
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B-Galactosidase hydrolyzes ONPG, a colorless compound, into galactose and o-nitrophenol, a YELLOW compound. – L |
LACTOSE FERMENTER ONPG TEST |
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The test can be performed by making a heavy suspension of bacteria in sterile saline and adding commercially prepared |
ONPG disks or tablets. |
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can be observe on the formation of bubbles or splitting of the medium in butt |
Gas Production |
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There are members of the Enterobacteriaceae family that are H2S producers in TSI |
SPACE – Salmonella, Proteus, Arizona, Citrobacter, Edwardsiella |
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H2S production |
black precipitate – requires an ACID ENVIRONMENT |
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A/A ((yellow) slant/acid (yellow) butt) – |
Lactose/sucrose, Glucose fermenter |
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K/A (Alkaline (red) slant/acid (yellow) butt) |
glucose fermenter |
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K/K (Alkaline (red) slant/alkaline (red) butt) |
No fermentation – not a member of the Enterobacteriaceae family [ |
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Used to determine glucose and lactose or sucrose utilization and H2S production, gas production |
TRIPLE SUGAR IRON (TSI) |
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Composition: of TSI |
10 parts lactose, 10 parts sucrose, 1 part glucose, and peptone |
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ph indicator of TSI |
phenol red [yellow – pH 6.8 – acidic] |
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H²s indicator of TSI |
Ferrous sulfate and sodium thiosulfate |