Microbiology Quiz #4 Lab #9 and 10 Correctly Answered Questions| UpToDate | Already Graded A+

What are Coliform bacteria? : Gram negative non spore forming bacteria that are capable of fermenting lactose to produce acid and gas. What fecal coliform bacteria is used as an indicator species? : E. coli. (If E. coli is present than this suggest that serious pathogens such as Salmonella and Campylobacter species are also present as well.) Does every food from the FDA get tested? : No, unless an outbreak occurs What are the most common bacteria present in milk? : Lactobacillus, Micrococcus, Streptococcus 2 | P a g e T/F? Milk that has undergone a regular pasteurization procedure can still contain bacteria? : True Define Indicator organisms : Fecal coliform present in large numbers. (They are easily identified in lactose tubes.) What type of bacteria could you identify by using the EMB plates, and why would these bacteria be of concern for human health? : E. coli, these bacteria are concerning because they indicate that fecal particles are in areas of concern and cause severe food poisoning. What does CFU stand for? : Colony forming unit What is the range of CFU that is statistically significant? : 30-300 CFUs T/F? If done correctly Ultra High Temperature pasteurization (UHT) can sterilize food. : True List the Microorganisms that can spoil milk : Camplyobater jejuni, 3 | P a g e Escherichia coli, Listeria monocytogenes, Mycobacterium bovis, Mycobacterium tuberculosis, Salmonella enteritidis, Salmonella typhimirium, Yersinia enterocolitica. What is salmonellosis ? : one of the most common serious foodborne infection caused by contaminated food such as poultry or water. Define Colony Forming Unit : a unit used to estimate the number of viable bacteria or fungal cells in a sample. What is the most common method in determining the amount of bacteria in a food product? 4 | P a g e : Standard plate count Define serial dilution : A stepwise dilution of a substance in solution Out of the four choices; apple, broccoli, hamburger, and bread list the order of what yielded the most to the least bacteria? : Broccoli, Hamburger, Bread, Apple You are testing ground beef to determine how many bacteria are present per gram of meat. You place 1 gram of meat in sterile water, mix vigorously, and then do serial dilution as shown below. You innoculate a plate with 0.1 ml of the sample from the last tube (they are three). The next day you count 122 colonies. How many bacteria/ml were in the undiluted sample? : 122 x 10^4 = 1,220,000 but placed in scientific notation is 12.2 *10^