Bacterial Identification Tests - UNLV Microbiology
Bacterial Identification TestsSome tests may be absent from this ppt presentation.These pictures are from students. If you see an error,please email me at fester@unlv.nevada.edu. Most ofthese pictures were given to me by Austin McDonald,from 351 Fall 2007. Thanks Austin!!
Phenol Red (PR)- Fermentationglucose, sucrose, lactose forEscherichia coli Lac (left) gas Glu( middle) gas Suc (right) no gas – Phenol red indicator used to see iffermentation has occurred. Durhamtubes are red before anyfermentation has occurred.Fermentation produces gas and/oracid from the breadkdown ofcarbohydrates
Phenol Red (PR) Fermentationglucose, sucrose, lactose forAlcaligenes faecalis Suc (left) – Lac (middle) – Glu (right) – Think about why A. faecaliscould not breakdownglu,suc, or lac?This is a negativeresult, must havefull yellow to bepositive. Don’Don’tworry the examones will be moreobvious !
Phenol Red (PR) Fermentationglucose, sucrose, lactose forSaccharomyces cerevisiae Lac (left) – Glu (middle) gas Suc (right) –Why did S. cerevisiaeNOT change color?
Starch hydrolysis Zone of clearing No zone – Bacillus subtillis ,Alcaligenes faecalis –Escherichia coli – (Clockwise) Iodine must be on the plate tovisualize the zone of clearingsurrounding the bacteria. Thiszone indicates starch wasbroken down to dextrins,maltose, and glucose/alphaamylase
Lipid Hydrolysis Dark blue precipitant zone /clearer blue zone No color change – Bacillus subtilis &Staphylococcus epidermidis w / clearer blue zone aroundbacterial growth Spirit blue agar w/3%Bactolipase reagent is used to see iftriglycerides are hydrolyzed intoglycerol and free fattyacids/lipase
Lipid HydrolysisFor the Egg Yolk agar,the growth must havea white halo aroundthe colony growth if itutilizes the lipidstherefore having theenzyme lipase (hardto see in pics!).Bacillus spp. Escherichia coli –Alcaligenes faecalis –
Casein hydrolysis Zone of clearing No zone – Test used to see Ifcasein is degradedinto amino acids foruse as a carbonsource/proteolyticenzymes Escherichia coli – ,Alcaligenes faecalis –Bacillus subtilis
Gelatin hydrolysis Liquid on gelatin No liquid – Hydrolysis of gelatininto amino acids to beused asnutrients/gelatinase Escherichia coli (top) – Bacillus spp.
Catalase Bubbles No bubbles – Reagents 3% H2O2Tests for the ability to break down toxic O 2 products/superoxidedismutase (catalyzes the destruction of superoxide) & catalase operoxidase (catalyzes the destruction of hydrogen peroxide)2 O2- 2 H ---superstable dismutate2 H2O2 ---catalase2 H2O O2O 2 H2O2
Oxidase Blue (30 sec) No color change –Tests done on Oxidase stripsTests for the oxidation of reduced cytochrome c to formwater and reduced cytochrome c / Cytochrome oxidaseOxidized cyt C reagentclearWurster’s blue red cyt Cdark purpleoxidized
Sulfur reduction test, Indoleproduction, Motility (SIM) deepsall 3 tests done w/SIM deeps just add Kovac’s reagent for Indole test Alcaligenes faecalis (left) Escherichia coli (middle) – Proteus vulgaris (blackprecipitate) Reagent: Ferrous ammoniumsulfate-indicator. H2S reacts w/ferrous sulfate forming theblack precipitate Sodiumthiosulfate is reduced tosulfite/thiosulfate
Motility Spreading growth (Spreading growth looks like amascara brush in the deep)Escherichia coli (right)Proteus vulgaris (left) Linear growth –Staphylococcus epidermidis(middle) To test for the ability of bacteriumto migrate in solid agar deep
Indole (IMViC tests) Enterobacter aerogenes – Escherichia coli (pink/red) Kovac’s reagent detects iftryptophan has beenhydrolyzed toindol/tryptophanase
Methyl Red (MR) (IMViC tests) Enterobacteraerogenes (left) – E. coli (bright red) Reagent: Methyl redindicator identifies pHchange due to mixedacid fermentation
Voges – Proskauer (VP)(IMViC tests) Enterobacter aerogenes E. coli – (left) Barritt’s reagent Tests foracetoin, precursor to 2,3butanediol fermentation Addition of alpha-naptholand KOH
Citrate (IMViC tests) E. coli (left green) – Enterobacter aerogenes(right royal blue) Reagent: Bromothymolblue indicator tests forability to use citrate assole carbon source/citratepermease
UreaseE. coli – (left)Proteus vulgaris Phenol Red a pH indicator turnstube bright pink because NH3decreases the pHCO(NH3)2 2 H2O –urease CO2 H2O 2 NH3
B-galactosidase E. coli (yellow) no color change clear –(not shown) Reagent ONPG Hydrolysis of lactose toglucose and use oflactose as sole carbonsource / B-galactosidase We use ONPG disks forthis test
Nitrate Red color after reagents/no color afterzinc Escherichia coli (right)No color change after zinc is a fordenitrification to nitrogen gas orammoniaSoil- (not pictured, would have a gasbubble in durham tube) Color change after Zn added will be –for nitrate reductaseMicrococcus luteus (left)Alcaligenes faecalis (middle) Reduction of nitrate to nitrite to beused as a final electronacceptor/Nitrate reductase
Coagulase Results: clotting in thebottom of the broth Reagents:Plasma Reason/EnzymesClots plasma to avoid attack byhost’s defenses/CoagulaseStaphylococcus aureus ;Staphylococcus epidermidis –
Mannitol salt Mannitol salt agar is aselective and differentialmedium used fordifferentiating betweendifferent stapylococci Staphylococcus aureuschanges medium to yellow Staphylococcus epidermidiswill not change the medium Why does S. aureus changethe color of this medium?
Hemolysis Check which bacteria arecapable of lysing red blood cells(RBCs) by using blood agar(sheep blood). α partial lysis of red bloodcells blood looks greenish β complete lysis of bloodclearing γ no lysing Clockwise starting from the left:Staphylococcus aureus β,Staphylococcus epidermidis γ ,teeth α
Antibiotic Ability of antibiotics to inhibitgrowth on Mueller-Hinton agarplates (Whether bacteria aresusceptible, intermediate, orresistant depends on the amountof antibiotic and the diameter ofzone of inhibition, check table43.1 of your lab manual )
Normal Microbiota on thehuman body Both picturesshow examples ofnormal microbiotathat grow on theear,arm, palm,and feet. What bacteria doyou think thesecoloniesrepresent?
Temperature Escherichia coli,Serratiamarcesens, Bacillusstearothermophilus are on all threeplatesAt 4 C (top) no bacteria grewAt 30 C (middle) both Serratiamarcesens and Escherichia coligrewAt 60 C (bottom) only Bacillusstearothermophilus growsWhat range of temperaturescategorizes bacteria intopsychrophiles, mesophiles, andthermophiles?Why isn’t Serratia marcesens red?
pH Bacterial tolerance to No Demos – will notdifferent pH varies much be a stationmore than humantolerance. Can you remember thepH ranges foracidophiles,neutrophiles, andalkalophiles?
Osmotic PressureNaCl% 0 on TSA plate Detects ability of anorganism’s salttolerance Staphylococcusepidermidis Escherichia coli Halobacteriumsalinarium --
Osmotic PressureNaCl% 0.5 on TSA plate Detects ability of anorganism’s salttolerance Staphylococcusepidermidis Escherichia coli Halobacteriumsalinarium --
Osmotic PressureNaCl% 5 on TSA plate Detects ability of anorganism’s salttolerance Staphylococcusepidermidis Escherichia coli Halobacteriumsalinarium --
Osmotic PressureNaCl% 10 on TSA plate Detects ability of anorganism’s salttolerance Staphylococcusepidermidis Escherichia coli - Halobacteriumsalinarium --
Osmotic PressureNaCl% 20 on TSA plate Detects ability of anorganism’s salttolerance Staphylococcusepidermidis - Escherichia coli - Halobacteriumsalinarium
Compare how well the 3 bacteria grow oneach plate of different NaCl conc. Is thestreak thickness the same on all of them?
Voges – Proskauer (VP) (IMViC tests) Enterobacter aerogenes E. coli – (left) Barritt’s reagent Tests for acetoin, precursor to 2,3 butanediol fermentation
1. The history and scope of medical microbiology. General characteristic and classification of cellular and acellular microorganisms (e.g. bacteria, fungi, viruses, prions). Structure of 2 h bacterial cells. 2. Bacterial metabolism. Bacterial genetics. 2 h 3. Determinants of bacterial pathogenicity. Mechanisms of bacterial infections. Virulence
(iii) Biochemical tests The staining is followed by use of various biochemical reagents and tests to get closer to the identification of bacteria. There are many biochemical tests available for bacterial identification. Few of them are required to be carried out depending upon the bacteria. The commonly used biochemical tests are as mentioned below
to join the UNLV community, students accept the expectations of the Student Academic Misconduct Policy and are encouraged when faced with choices to always take the ethical path. Students enrolling in UNLV assume the obligation to conduct themselves in a manner compatible with UNLV’s function as an educational institution.
UNLV Self-Supporting Anaplan Budget Manual UNLV FPB&A P a g e 3 February 4, 2021 Anaplan Overview Anaplan is a budgeting and planning tool that utilizes more advanced technology and will provide greater value to the UNLV community. Anaplan is a cloud-based platform for developing, maintaining and reporting for budgets and forecasts.
An Introduction to Clinical Microbiology Susan M. Poutanen, MD, MPH, FRCPC . Objectives 1. To provide an introduction to a typical microbiology laboratory 2. To address specific microbiology laboratory test issues as they apply to public health. Department of Microbiology Who we are Shared microbiology service between TML (UHN & MDS) and MSH
Industrial microbiology Medical and pharmaceutical microbiology Rumen microbiology Space microbiology 1.2 Definitions Milk and milk products occupy a more significant role in the human food profiles. The study of microorganisms that are associated with milk and milk products in all aspects is defined as "Dairy Microbiology". 1.2 .
NFP121 5 Sommaire 1) Tests et tests unitaires - Outil : junit www.junit.org une présentation Tests d'une application - Une pile et son IHM Tests unitaires de la pile Tests de plusieurs implémentations de piles Tests d'une IHM Tests de sources java Invariant et fonction d'abstraction comme tests - Tests en boîte noire - Tests en boîte blanche
Voice banking usually involves recording yourself saying a number of phrases, using a computer program. Depending on which voice banking service you choose, the number of phrases you need to record can range from 220-3000. Depending on the strength of your voice and how tired you become, voice banking can take a different length of time for different people. For some it may take a few hours .
