ipl-logo

Gram Test Lab Report

836 Words4 Pages

INTRODUCTION Discovering an unknown organism or pathogen is a very common project done in microbiology classes. The study of microbiology requires not only knowledge about various types of organisms but also requires a practical knowledge on how to identify those organisms. This project utilizes students abilities to apply the practical knowledge they have learned. At the beginning of the project the professor presented each student with a numbered test tube. The possible organisms were Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Citrobacter freundii, Moraxella morganii, Providencia stuartii, Serratia marcescens, Citrobacter freundii, Pseudomonas aeruginosa, Alcaligenes faecalis, Enterococcus faecalis, Micrococcus luteus, …show more content…

The gram stain was done to identify whether the organism was a gram positive or gram negative organism. A few colonies were selected from the nutrient agar. The steps of the gram stain were executed. The stain resulted in gram negative rods. This result eliminated all gram positive organisms. Leaving the possible organisms to be Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Citrobacter freundii, Moraxella morganii, Providencia stuartii, Serratia marcescens, Citrobacter freundii, Pseudomonas aeruginosa, or Alcaligenes …show more content…

The EMB plate served two purposes. It inhibited gram positive growth, and tested for the organisms ability to ferment lactose. After 48 hours the inoculated EMB plate presented with strong, but colorless growth. This result reconfirmed that the organism was gram negative, it also determined that the organism was non-lactose fermenting. The possible organisms were now limited to Proteus mirabilis, Proteus vulgaris, Moraxella morganii, Providencia stuartii, Serratia marcescens, Pseudomonas aeruginosa, and Alcaligenes faecalis. Following the EMB test, a TSI agar was inoculated. The TSI agar was used as a differential medium to determine the organisms ability to ferment lactose, sucrose, and glucose. The agar was also used as a PH indicator. The TSI was read after 48 hours, its butt was red, as well as its slant. This result reconfirmed that the organism did not ferment lactose, as well as it did not ferment sucrose, or glucose. This test also determined that the organism was alkaline. This limited the possible organisms to only Pseudomonas aeruginosa, and Alcaligenes

Show More
Related
532 Words | 3 Pages

Methods Unknown microbial #398 went through several of tests in order to identify its characteristics when isolated from a urine sample of Doris, a 64- year old patient with a kidney infection. To identify unknown #398, must prepare a working and a reserve stock by the inoculation from a broth culture and by quadrant streaking method on a PEM and EMP plates. The following test procedures were incubated at 37°C for 48 hours for observation and identification for unknown #398. The identification of unknown #398 followed test procedures from Brown1.

Read More
636 Words | 3 Pages

According to the series of test that my group ran for our unknown specimen, we had a match with the bacteria known as Alcaligenes Faecalis. This bacterium belongs to one of the major group of gram-negative bacteria (Phylum Proteobacteria). Alcaligenes Faecalis (Genus, species) is a rod shaped (bacillus), 0.5-1.2 x 1.0-3.0 µm, round with scalloped margin (colony configuration growth), motile (with one to nine peritrichous flagella), gram-negative, non-fermentative bacteria, obligate aerobic, having oxygen as the principal terminal electron acceptor in the electron transport chain (ETC). We consider we have a match with the species Alcaligenes Faecalis because of the following reasons: Fermentation tests performed (Durham sugars) were negative, which indicate that our bacteria use a different metabolic means for growth (non-fermentative gram-negative bacteria).

Read More
449 Words | 2 Pages

The second ½ of the organism was used for gram staining. The gram stain method was performed on the unknown organism per lab manual page 42 and two gram stain reactions were identified. Organism B was gram positive cocci in grape like clusters. Because organism B was positive I could eliminate Escherichia coli, Enterobacter aerogenes and Proteus vulgaris because these bacteria would be rod shapes. Organism A was gram negative pink rod shaped and because of gram positive morphology I could eliminate Staphylococcus aureus, Streptococcus lactis and Bacillus subtilis.

Read More
1200 Words | 5 Pages

Mannitol Salt Agar (MSA) plate, MacConkey agar (MC) plate, Eosin Methylene Blue agar (EMB), and Hektoen Enteric Agar (HEA) (3). The MacConkey agar plate and the Mannitol Salt agar plate are both used in the identification of the unknown. The MC plate is a selective and differential medium. It is considered a selective medium because the bile salts and crystal violet aspect of the medium prevent the growth of gram positive bacteria (3). This medium is differential because of the lactose and neutral red.

Read More
408 Words | 2 Pages

The unknown bacteria was then tested on multiple selective and differential media. Growth was present on the MacConkey Agar and the colonies were the same color as the plate, which told me my bacteria was gram negative and did not ferment lactose. There was no growth on the Mannitol Salt Agar, and this told me the unknown was not salt tolerant and did not

Read More
1444 Words | 6 Pages

A starch agar plate was inoculated with a streak of the unknown bacteria and then incubated. On the second day of incubation, the plate was removed from the incubator and placed over a hot plate heating Iodine solids. The smoke of the Iodine stained the plate to display the presence or absence of a halo around the bacteria 2.12 Lipid Hydrolysis This test was done by making a single line streak inoculation on a tributyrin agar plate and allowing incubation. After the incubation period, the plate was observed for the presence or absence of a halo around the bacteria.

Read More
3385 Words | 14 Pages

Unknown Lab Report Abiola Oyewumi March 16, 2015 Unknown #16 Abstract An experiment was conducted to determine which of the following unknown bacteria was in test tube number 16: Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Salmonella typhimurium. Biochemical tests were used to help identify the unknown bacteria. The Citrate test, Urease test, Triple Sugar Iron Agar test, Voges-Proskauer test, and Methyl Red test were the biochemical tests used in this experiment.

Read More
1034 Words | 5 Pages

Introduction Our world is composed of many bacteria’s’ that can either help or destroy us. Therefore, its’s imperative to learn and study them. The purpose of the lab was to put into action the methods that have been learned in the laboratory to determine our unknown bacteria. Bacteria’s can have different features, shapes, and or arrangements that help microbiologist determined their role in our life (whether they are good or bad for humans).

Read More
2054 Words | 9 Pages

Analysis of Unknown Samples Through Staining and Chemical Testing (Unknown 8) Abstract: Identifying bacteria by culture is possible due to various tests ranging from staining techniques to biochemical testing. Bacteria have a wide range of variances. To help identify unknown bacteria, gram staining, selective and differential media, analytical profile index (API), and BLAST tests were performed. It resulted in gram negative, rod shaped, lactose fermenting bacteria. The most likely bacterium it could be is Klebsiella pneumoniae.

Read More
1706 Words | 7 Pages

The student is to use studied tests to eliminate possible generas and to isolate the correct genus and identify it to the given unknown. This proves the diversity of microorganisms and their uniquely varying traits. The resulting data obtained in class will enhance students’ laboratory skills and knowledge regarding microbial laboratory. Introduction

Read More
1057 Words | 5 Pages

The importance of this experiment stems from E. Coli’s factors. E. Coli is known to be a predominant coliform and they cannot endure living in non-enteric conditions (Megraw and Farkas 1993). Since this bacteria can form diseases in the body, it is critical to distinguish

Read More
1556 Words | 7 Pages

Introduction: Microbiology is the study of the microbial world, which is composed of microorganisms that are too tiny to be seen with a naked eye. This project demonstrates the significance of correctly identifying unknown organisms with methods and techniques acquired in the laboratory as they can make or break one's ability to accurately isolate and identify various species. Studying microbes enables oneself to have an insight on not just their structure or how they function, but how they have an impact on organisms and their environment around them as they can be found nearly anywhere. The importance of the process of identifying unknown bacteria vary from determining the causative agent of a disease, to testing if a specific food or fluid is safe to consume, and simply knowing what is present

Read More
517 Words | 3 Pages

Being able to identify unknown microbes from systematic testing is what makes the field of microbiology so important, especially in infectious disease control. Using the testing procedure laid out by the microbiology field we are able to identify unknown bacteria present in our everyday lives, and along the way learn a lot about their characteristics that separate them from other types of bacteria. Being able to do this is vital in order for us to understand why microbes are present in certain places, how they are able to grow and what restricts their growth, that way they can be combatted if necessary. These techniques for determining unknowns are also important for isolating and testing infectious disease microbes in order to prevent spreading. Another important aspect of being able to identify unknown microbes is the

Read More
1405 Words | 6 Pages

MICROBIOLOGICAL PROFILE : TABLE-9 MICROBIOLOGICAL PROFILE DISTRIBUTION Microorganism Cystic Cylindrical Varicose Total Streptococcus pneumonia 16(22.85%) 6(8.57%) 2(2.8%) 24(34.28%) Hemophilus influenza 10(14.28%) 6(8.57%) 0(0 %) 16(22.85%) Pseudomonas aeroginosa 24(34.28%) 4(5.71%) 0(0 %) 28(40%) Sterile 2(2.8%) 0(0

Read More
1057 Words | 5 Pages

After a gram stain was done unknown #257 was identified as a gram positive organism because when observed under the microscope the organism appeared purple with cocci in clusters. The organism was also catalase positive which means that it produced enzyme catalase and bubbled when hydrogen peroxide was added to it. Three test were conducted based on the result of the gram staining procedure. Blood agar with a Novobiocin disk was chosen as well as DNase (DNA) and Mannitol Salts (MSA) agar. The Blood agar is a bright red, opaque plate and the streaking or the inoculation technique was a modified streaking for isolation with a heavy quadrant one.

Read More

More about Gram Test Lab Report

Open Document