Staining

Investigating Enterococcus faecalis’s structures and resistances to antibiotics Introduction Bacteria’s phenotype is commonly described as gram-negative or gram-positive from conducting a gram stain. A bacterium that is gram-negative tends to have cells composed of a thin peptidoglycan layer, and a gram stain of gram-negative bacteria are seen as red or pink through a microscope (Smith and Hussey, 2005). On the other hand, a bacterium that is gram-positive will have cells made of a thick…

1. Summary of how I identified Bacillus cereus. a. First, I performed the gram stain test, I then went on to do the spore stain. b. The results I obtained from the gram stain were gram positive rods, I could tell they were positive by the purple color to them and the rod shape by the comparison provided in the lab manual (Wilkosz, Peterson). After I confirmed the results I performed the spore stain, which indicated that my sample was positive so it contained endospores. The sample should have…

Table 1 shows the all the isolates that produced a zone of inhibition for the ESKAPE pathogen, Staphylococcus aureus. In total, twenty six isolates were tested against Staphylococcus aureus. However, only eight showed a zone of inhibition. The size of the zones varied for each microorganism. Table 2 shows the results of the biochemical and morphological tests. The test that were performed were Sim, FTM, oxidase, catalase, MSA, blood agar, Acid fast stain and endospore stain. The sim and…

Week 3 of lab, we received our unknown microorganisms. That week we performed a differential staining to determine whether our unknown has a gram-negative envelope which stains red or gram positive envelope which stains blue. Gram-negative microorganisms stain red because of their inability to bind crystal violet and their ability to bind the safranin. Gram-positive microorganism, however, stains blue due to their ability to retain the primary stain, crystal violet. I determined my unknown…

Burkholderia pseudomallei also called as pseudomonas pseudomallei is an intracellular gram negative bipolar staining aerobic motile shaped rod with a safety pin appearance when seen microscopically measuring 25 micro metre in length and 0.4 -0.8 micro metre in diameter . It is capable of self population using flagella. In vitro , it requires a temperature of 40 degree and grows in an acidic environment fermenting glucose and galactose . It produces both exotoxin and endotoxins. It causes…

After gram staining both the gram positive and gram-negative bacteria, the groupings were observed. For the unknown gram-positive bacteria, the cells were arranged in a cocci cluster, while in the gram-negative bacteria, the cells were arranged in a rod cluster. Both the gram negative and gram-positive bacteria exhibit a small yellow colony on the TSA plate. After 48 hours, the MSA plate was observed. Individual isolated colonies were found throughout the plate, with a yellowish color. The…

Proteus Mirabilis Proteus mirabilis is defined by the slide share website as a disease caused by microbial invasion of the genitourinary track that extends from the renal cortex of the kidney to the urethral meatus. Proteus mirabilis can be laboratory diagnosed by the specimen collection, transported and storage and laboratory methods, but the laboratory methods that would be focused on is specimen collection. It is often the first determine diagnosis and treatment which would give a more…

iodine. While some bacteria have the ability to retain the primary stain, others discolor when exposed to the acetone and alcohol (95%). Hence, the Gram stain divides bacteria into two groups- these bacteria are grouped according to their differential staining properties. One group is Gram positive bacteria and the other group is Gram negative bacteria. The Gram positive bacteria have cell walls with thick layer of protein-sugar and low content of lipids. During the decolorization…

Introduction: The name Pseudomonas is derived from the greek and latin words which means “false unit“ (pseudo = false, greek; monas = single unit, latin). “Monas” was used in the early history of microbiology to define single-celled organisms. In 1786 Otto Friedrich Müller, from Copenhagen, classified the bacteria and named the pseudomonads, they came into the group of vibriones (which was defined as group of shaking bacteria). Many years later it was detected that Pseudomonas are motile. They…

The lab instructor issued out a test tube labeled with letter ‘I’, which consisted of two unknown bacteria, Gram-positive or Gram-negative that were streaked from a pure culture. Sterile techniques were followed while performing precise instructions as stated in the referenced Laboratory Manual. Example 1: The first procedure performed was done by isolating a pure culture from the mixture onto a solid Trypticase soy agar (TSA) media. Sterile technique was done by flaming the loop until it…