Unknown # 462 Lab Report

A mixed culture of two unknown bacteria was provided by the instructor. The methods used for

My unknown organism #6 is Morganella morganii, which is a gram-negative bacillus rods commonly found in the environment and also in the intestinal tracts of humans, mammals, and reptiles as a normal flora. (3, 5) This bacterium Morganella morganii, was first discovered in the 1906 by a British bacteriologist named H. de R. Morgan. (2) Despite its wide distribution, it is an uncommon cause of community-acquired infection and is most often encountered inpostoperative and other nosocomial settings. (2, 3) Morganella morganii infections respond well to appropriate antibiotic therapy; however, its

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 purpose of this study was to identify the unknown bacterium using biochemical tests and various methods that had been learned from previous the microbiology laboratory class. Identifying the unknown bacterium was determined by separating and differentiating possible

Purpose of Bergy’s Manual: based on ribosomal RNA sequences, which presumably reflect phylogenetic (evolutionary) relationships. Used for the identification of prokaryotes. 2nd edition on classification of prokaryotes.

The purpose of this project was to identify the identities of two unknown bacteria in a mixed broth culture by using several separation methods. To separate the organisms, a four-way streak plate technique was used to isolate the two unknown bacteria into separate visible colonies. Then after each colony were clearly isolated; the two unknowns were processed through Gram staining test to determine the Gram stain and morphology. After Gram staining, a carbohydrate test was performed on each unknown to determine if it had glucose, sucrose, or lactose fermentation. The results of the sugar test help determining which biochemical test should be performed next. The Gram positive organism was tested through a carbohydrate fermentation test, then further tested to confirm its identity through an indole and catalase test. The Gram negative organism was tested through carbohydrate fermentation test, then further tested to confirmed its identity through an indole, and TSIA test. After running four biochemical tests, the results conclude that the Gram positive unknown was Staphylococcus aureus. S. aureus was identified based on the fermentation results of the glucose test, negative indole test, and a positive catalase production. S. aureus is a Gram positive circular shaped bacterium that is very common in the U.S and is normally found in the nose, respiratory tract, and on the skin. This bacterium is usually the most common cause of infections after injury or surgery.

The purpose of this experiment was to isolate and identify an unknown Staphylococcus species based on its morphological and biochemical profile (Alachi, 2006). The Staphylococcus genus consists of Gram-Positive bacteria, arranged in grape-like clusters. These species are common residents of the skin and mucous membranes of humans and animals. Majority of Staphylococci are catalase-positive, oxidase negative, aerobic and facultatively anaerobic, and non-motile. They are considered opportunistic pathogens and cause roughly 80% of suppurative skin diseases (e.g., boils). Many Staphylococci

This experiment was conducted to first, determine if Staphylococcus is present in the nose cavity. Staphylococcus is very common in in the nasal cavities and therefor its highly likely that some type of Staphylococcus will be detected. In order to detect the presence of Staphylococcus a nose swab will be taken and incubated at 37.0˚C for 48hrs in a (m-G+C) broth. This broth has a 10% salt concentration and as Staphylococcus is a halophile and requires salt to flourish, the salt concentration in this broth will help to enable an ideal environment for the Staphylococcus. After the 48hrs a Mannitol Salt agar plate will be inoculated by the swab and then incubated for at the same temperature and length of time as before. The MSA plate, which contains sugars and salts will

After inoculating an agar plate with the bacteria taken from a phone screen in Durham during winter, various tests were performed to attempt to identify the organism’s genus. We hypothesized that the bacteria was a member of the Staphylococcus genus. The Gram Stain results indicate that the bacterium is either Gram negative, but the KOH test indicates a Gram-positive isolate. Upon further consideration, we decided that the bacterium is a Gram-positive destainer. Gram-positive bacteria have a thick cell wall composed of peptidoglycan. As expected, the Gas Pak and TSA stab results indicate that the bacterium cannot grow in the absence of oxygen. A motility stab indicated that the bacteria were motile. Motility provides an ability to change direction and move away from repellents and toward attractants. Thus, the microbe can avoid unfavorable conditions, and live longer. The positive lysine decarboxylase test indicates that the microbe can use the amino acid lysine as a source of carbon and energy for growth. First, the bacteria use glucose as its primary carbon source, which causes the pH to drop. The enzyme lysine decarboxylase degrades lysine to produce basic products. This change in pH is what causes the broth to turn purple again, a positive result. An endospore stain indicated that the bacterium does not produce spores under stress to protect the cells from dying. Spores are metabolically inactive and

Staphylococcus aureus embraces many characteristics which are derived by a variety of test to identify if someone has this certain bacteria. This specific species is recognized by the anaerobic fermentation, beta hemolytic halo, coagulase positive testing, the Kirby-Bauer disk diffusion test resistance, clumps of gram positive cocci that is identified through the microscope, and the a positive catalase test (Kiser 67-87). First in the series of test was the mannitol salt agar MSA plates, which contains a high concentration of salt (Kiser 73). Staphylococcus aureus tolerates salt and its results give off fermentation of acidic PH (Kiser 74). Next, was to evaluate the blood hemolysis and DNA digestion test. Aureus means “gold” and these two test are useful for further

Seeing how the results of each urine sample do not match the characteristics of healthy urine, it should be noted that all samples tested throughout the lab experiment each contain problems caused by diseases existing in the kidneys. To start, sample W comprises of one common scenario that indicates the presence of a kidney condition - that is the high concentrations of the macromolecule glucose that were found. When significant amounts of glucose are detected in urinalysis, it is most likely that the individual has a case of diabetes, notably type 1 and type 2. Complications arise when excessive amounts of glucose take up the liver. To illustrate, due to the large size of the glucose molecule, in comparison to other molecules that the kidneys filter, it harms the

The results from the identification tests all indicates that the isolated species is S. aureus, except for the Bacitracin test. According to the literature, S. aureus should be resistant to Bacitracin and that result is a way of separating Staphylococcus from Micrococcus (Basey & Perkins, 2016). However, some strains isolated were susceptible to Bacitracin. It is possible that Micrococcus could have grown in the M-Staphylococcus broth, but all the other result identifying the strain as S. aureus makes this possibility highly unlikely. More possibly, it could be that some strains of S. aureus are Bacitracin susceptible. The study done by Freidlin et al. reported that a total of 63.6 % of MRSA isolates collected between 1998 and 2006 were sensitive to Bacitracin.

After conducting the necessary experiments, it was found that the two bacteria in the mixed culture of TSB test tube labeled 10, were Proteus mirabilis and Staphylococcus saprophyticus. Proteus mirabilis being the rod shaped, gram-negative bacteria that grew were the small, shiny, and round with a convex elevation, and Staphylococcus saprophyticus being the cocci shaped, gram-positive bacteria that grew a creamy, off white color and round. Proteus mirabilis comes from the Enterobacteriaceae family, which consist of gram-negative bacteria some being harmless, while the majority ae considered as pathogens. “Within this family are genera such as, Shigella, Salmonella, Klebsiella, Serratia, and Enterobacter (Guentzel, 1996).” Staphylococcus saprophyticus

The pre-treatment frequency of bacterial species in the cultures from both groups is detailed in Table III. Streptococcus spp. made up 15 per cent of isolated bac-teria in gr0up A” and 55 per cent in gr0up B (Table III). Haemophilus influenzae was 10 per cent of isolated bacteria in gr0up A and 0 per cent in gr0up B”, and Moraxella catarrhalis was 5 per cent of isolated bac-teria in group A and in group B. Staphylococcus aureus was 0 per cent of isolated bacteria in group A and 15 per cent in group B. S viridans was 10 per cent of isolated bacteria in group A and 0 per cent in group B. S epidermidis was 35 per cent of isolated bac-teria in group A and 10 per cent in group B, while no growth of bacteria made up 30 per cent of group A and 2O per cent of group B”, as shown in Table

Microbiological examination: Coagulase-negative Staphylococcus sp. were found, although they might have been a secondary infection.