Escherichia Coli Case Study

AIM – The aim of the experiment is to determine the relative effectiveness of several anti-microbial substances on developing pathogens. (E. coli)

Over a two week period, eight prepared types of test media were provided to identify the assigned unknown mixed cultures. Not all of these tests were performed on every culture, as some were used only for gram positive or gram negative bacteria. The tests performed and what constituted a positive or negative test are as

This experiment was conducted to find the genus and species of an unknown bacteria prescribed by the lab teacher, which was unknown bacteria GA3 in my case. Identification of unknown bacteria techniques are used on an every day basis to figure out what type of bacteria it is and to find the best method of how to treat a patient with this bacteria (1). All five “I’s” of Microbiology were used in the testing for the unknown culture. Inoculation was used several times to put the unknown culture into agar plates or into biochemical test tubes. After Inoculation of these tubes or plates, they always were placed into the incubator for further growth and development. Isolation was used to make sure we got the correct bacteria we were testing for. After each further isolation, we gram stained the culture and inspected the culture under a microscope to further help in the identification process of the unknown bacteria. Multiple tests were done on the unknown culture to make sure we were confident in what kind of bacteria the unknown was.

The possible organisms in this lab included: Serratia marcescens, Escherichia coli, Bacillus subtilis, Sarcina lutea, Micrococcus luteus, Pseudomonas fragi, Staphylococcus epidermidis, Alcaligenes faecalis, Micrococcus roseus, and Clostridium sporogenes.1 In start of the elimination process, the two nutrient agar plates that were made by unknown tube number two were observed and characterized by their colonies. Gram positive: Plate A was incubated at 37 C and had a colony appearance of bright yellow dots on the nutrient agar. This eliminated the possibilities of S. marcescens, E. coli, B. subtilis, P. fragi, S. epidermidis, A. faecalis, M. roseus, and C. sporogenes. S. marcescens colonies are red; M. roseus colonies are orange; E. coli and A. faecalis colonies are beige; B. subtilis, C. sporogenes, and S. epidermidis colonies appear in white.2 This left

The purpose of the bacterial unknown independent study experiment completed throughout the course of this lab was to determine the identity of an unknown bacterial species. The unknown bacteria sample was chosen from numerous samples provided by the instructor. The starting unknown sample, unknown #15 was a mixed bacterial culture and a broad approach taken to identify the sample. Various biochemical tests were completed to identify the bacterial species along with the use of databases such as Gideon and Bergey’s to compare the test results of known bacteria to the results of the unknown sample. Information was gathered from the other sources and databases and phenotypic testing completed and the results compared to the database results. Aseptic

At the end of 2006 both Iowa and Minnesota suffered an out break of E.Coli from Taco Johns. The restaurants that were affected were in Cedar Falls, Albert Lea, and Austin. In December of 2013 Iowa health officials recorded that at least 50 of its residents became ill with E. coli and 27 from Minnesota. January of the following year the Food and drug administration stated that the FDA was close to identifying the source of the E. coli break out. According to the FDA 81 individuals became ill. 26 of those ill were hospitalized with E. coli infections and two even developed hemolytic uremic syndrome.

2. Why do you think Mrs. Garner's students did not become ill, while Ms. Hines' kids did?

In conclusion, after conducting previously mentioned biochemical tests in order to identify the unknown bacteria, became obvious that unknown gram negative was Proteus Vulgaris. Having eliminated all the bacteria that didn’t show expected results and confirming with such tests as catalase, glucose, indole, citrate, urea, and SIM, it was accurate to name the unknown gram negative. Furthermore, gram positive became obvious it was Streptococcus Pneumoniae. Having eliminated all the bacteria that didn’t show expected results and confirming with such tests as blood agar, catalase, and optochin and bacitracin tests, it was accurate to name the unknown gram positive. I have learned that it is extremely important to be to able to identify what kind

The CDC collaborated with public health officials in many states, the US FDA and the United States Department of Agriculture Food Safety and Inspection Service (FSIS) to investigate an outbreak of E. coli O157:H7 infections.

The Kirby-Bauer antibiotic tests indicated that the unknown is susceptible to chloramphenicol and ampicillin and resistant to penicillin G and tetracycline. The disinfectant sensitivity tests indicated that C. Freundii is resistant to all four of the disinfectants.

The study of two unknown microorganisms was completed by using methods taught in the microbiology laboratory. The basis of the study was identification of those two microorganisms. Identification of the microorganisms is important in many aspects of medicine. Some of these include source of infection, proper treatment, and which antibiotics are effective against the microorganism present.

: In the field of microbiology, there are times when a sample will contain more than one species of bacteria. The goal is to separate each bacterium and culture them independently from one another to identify them. This was the objective of this lab. Each stock contained two unknown bacterium, and the possible unknowns were Eserichia coli, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus vulgaris, Klebsiella pneumoniae, Shigella flexneri, Shigella sonnei, and Salmonella enterica. The tests available were MacConkey agar, Endo agar, Hektoen Enteric agar, Tryptone Soya Agar (TSA), carbohydrate sugar broths, Triple Sugar Iron (TSI) agar, decarboxylase broths (arginine, lysine, and ornithine), Simmon’s Citrate Agar, urease

In the world of microbiology it is vitally important to be able to discern the identities of microorganisms. Not only is it important in a lab setting but as well as in healthcare in general. Properly identify what strain of bacteria a person has will aid in the proper medicine and dose given. Throughout the semester we have learned about different types of bacteria and certain test that can clearly identify them. The purpose of this lab report is to identify a Gram-positive or Gram-negative bacterium. Using all the knowledge of procedures and lab techniques identify the unknown and discuss all the tests you performed.

Results and Discussion Our study was included 40 children patients and 10 healthy controls, their age was ranged from 3 to 12 years old, there were 25(62.5%) males and 15 (37.5%) females, as regard immunophenotyping 50% of patients were pre-B-ALL, 2.5% were mature B-ALL, early Int.J.Curr. Microbiol. App. Sci (2017) 6(9): 937-944 940 pre B 2.5%, Common B 35% (total: 90%) and 10% were T-ALL, as regard results of measuring BSP-1 levels by ELISA in patient group was 112.69 ± 11.54 ng/mL which was significantly higher than that of control group 8.58 ± 2.19 ng/mL (P value was 0.001) as shown in table 1, as regard CD44 variant 6 level by flowcytometry in patient group was 32.18 ± 15.26 which was significantly higher than that of control group 3.54

Each mixed culture that was tested had one gram positive and one gram negative bacterial species. The possible species of bacteria that could have been isolated from the mixtures included the following: Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella enterica, and Pseudomonas aeruginosa. The identities of the unknown species were determined through comparing the experimental data against data acquired from earlier experimentation.