Materials Used: Student Supplied 1 Bottle Of Bleach 1 Bottle

Materials Usedstudent Supplied1bottle Of Bleach1bottle Of Distilled Wa

Materials used Student Supplied 1 Bottle of bleach 1 Bottle of distilled water 1 Camera, digital or smartphone 1 Coffee cup 1 Hand soap 1 Isopropyl (rubbing) alcohol (C3H8O) 1 Large cooking pot (at least 8" deep) 1 Leaf lettuce-fresh, unwashed 1 Oven mitt 1 Roll of paper towels 2 Small container of milk 1 Source of tap water 1 Stove or hotplate HOL Supplied 1 Apron 1 Face mask with ear loops 2 Pair of gloves 1 Pair of safety goggles 1 Permanent marker 2 Petri dish, 60 mm 2 Sterile swab, 2 per pack 1 Test Tube rack, 6 x 21 mm 1 Test tube clamp 1 Tryptic soy agar (TSA), 18 mL tube Two containers of milk are needed. Open one container exactly 7 days prior to beginning the experiment and allow the second to remain closed until used in the procedures. Place both containers in a refrigerator when not in use. It is best if the two containers are purchased on the same date and have the same expiration date. Agar in the lab kit may be labeled as "Nutrient agar." NOTE: If the kit includes agar pour tubes, download Pouring Agar Plates Experimentation In this laboratory, you will incubate microbes collected from unwashed and washed produce and from opened and unopened milk. After incubation, you will compare the number and types of microbes that develop from each food source and relate the results to practices for maintaining food safety in your home. Note: Two containers of milk are needed. Open one container exactly 7 days prior to beginning the experiment and allow the second to remain closed until used in the procedures. Place both containers in a refrigerator when not in use. It is best if the two containers are purchased on the same date and have the same expiration date. Procedure Part 1: 1. Approximately 1 hour before you begin this exercise, pour 2 agar plates. Download Pouring Agar Plates for detailed instructions or watch this video on Preparing Agar Plates. Note: Plates may be poured in advance, stored in an airtight bag, and refrigerated for future use. 1. Clear a work area and gather all materials listed for this experiment. 2. Wash your hands thoroughly with soap and warm water. 3. Put on the safety gloves, face mask, apron, and goggles. 4. Disinfect the work surface by wiping it with a 10% bleach solution. 5. Using the permanent marker, divide the bottom of each agar plate into 2 sections. Label the sections of one plate “Milk Fresh” and “Milk Opened.” Label sections of the other plate “Lettuce Washed” and “Lettuce Unwashed.” See Figure 4. Figure 4. Labeled agar plate. 1. Remove a sterile swab from the packet and moisten with distilled water. 2. Rub the moistened swab on the surface of the unwashed lettuce. 3. Transfer the sample to the “Lettuce Unwashed” section of the agar plate by rubbing the swab on the agar surface within the section until it is completely coated with inoculant. Note: Be careful to only inoculate the surface within the outlined section. 1. Place the used swab in a container of undiluted bleach. 2. Thoroughly wash the lettuce with soap and water. Pat it dry with paper towels. 3. Repeat steps 7-10 using the washed lettuce. 4. Remove a sterile swab from the packet and saturate with the milk that has been opened for 7 days. 5. Transfer the sample to the “Milk Opened” section of the agar plate by rubbing the swab on the agar surface within the section until it is completely coated with inoculant. 6. Place the used swab in container of undiluted bleach. 7. Open the fresh container of milk and repeat steps 13-15 for this sample. 8. Place the inoculated plates bottom-side up (inverted) in your incubation location for 48 hours. 9. Dispose of the used and bleached swabs in the garbage. 10. Wipe down your work area with a 10% bleach solution. 11. Wash and return items to your kit for future use. 12. Wash your hands thoroughly. Part 2: 1. Observe the culture plates after 48 hours for microbial growth. If no colonies are observed, incubate for an additional 24 hours. Note: Do not remove the lids of the plates when observing. Unknown microbe cultures should always remain covered. 1. Wipe down your work area with a 10% bleach solution. 2. Wash your hands thoroughly with soap and warm water. 3. Put on your goggles, a new pair of gloves, face mask, and apron. 4. Gather the 2 incubated agar plates. 5. Observe each of the sections without removing the lid. Count the number of different colony types present in each section and record in Data Table 1. 6. Count the total number of colonies in each section and record in Data Table 1. 7. Take a photo of your developed plates. Upload the image into Photo 1. Cleanup: · Soak reusable equipment, such as test tube clamps and racks, in a 10% bleach solution for 2 hours after contact with active cultures. Reusable materials should then be rinsed with tap water and allowed to dry before returning to the lab kit. · Soak all disposable equipment, such as pipets and inoculation loops, in a pure bleach solution for 2 hours before wrapping with paper towels, sealing in a plastic bag, and placing in the garbage. Secure all disposed items out of reach of children and pets. · Dispose of cultures by soaking the containers and media in a pure bleach solution for 2 hours before taping closed, wrapping in paper towels, sealing in a plastic bag, and placing in the garbage. Secure all disposed cultures out of reach of children and pets. · Wipe down your work area with a 10% bleach solution. · Wash your hands thoroughly with soap and warm water. Questions during the experiment Exercise 1 - Questions 1. Why is food safety important? The reason food safety is important is because we digest so many foods in our bodies that just imagine if we wasn't concerned about the food safety and consumed foods the wrong way we can get sick. 2. How does food become compromised by microbes? When the food is improperly being handled. 3. How can food safety be improved in the home environment? Food safety can be improved in the home environment by proper food handling. 4. Based on the results recorded in Data Table 1, which food contained the highest number and diversity of microbes? The food that contained the highest number and diversity microbes is milk. 5. How will the results of this experiment impact your food safety practices at home? I will make sure my food is bacteria free and utensils are sanitized as well. My Lab Results Data Table 1: Food Safety Culture Results Plate Section Types of Microbes Number of Total Colonies Milk Fresh Crampylobacter jejuni 4 Milk Opened Cronobacter 7 Lettuce Washed E.coli 3 Lettuce Unwashed Salmonella 13 To prepare for this discussion, review the article "Accelerate!" from this unit's studies. Today's business organizations operate in a fast-changing, sometimes volatile business environment, and must be able to change and adapt quickly. Rigid, finite organizational structures are outdated and cannot compete. Today, the hierarchy of an organization can make or break the economic progress of an organization. Using the principles outlined in the article, "Accelerate!", discuss how organizational structure can be used to an advantage in creating a nimble, adaptable organization. Support your ideas with an example from a business; if possible, use a business in which you have worked. To prepare for this discussion, review the article "Accelerate!" from this unit's studies. Today's business organizations operate in a fast-changing, sometimes volatile business environment, and must be able to change and adapt quickly. Rigid, finite organizational structures are outdated and cannot compete. Today, the hierarchy of an organization can make or break the economic progress of an organization. Using the principles outlined in the article, "Accelerate!", discuss how organizational structure can be used to an advantage in creating a nimble, adaptable organization. Support your ideas with an example from a business; if possible, use a business in which you have worked. Lab Report Directions for SPHP Courses Please refer to any additional directions within your course that may address specific directions for your experiment and report. Sections Description Title Page · Experiment number and/or title · Your name · Date and time experiment was performed · Location if work was performed in the field · Course name and section Section 1: Abstract · One paragraph that summarizes the report (no longer than a paragraph) · Belongs at the very beginning of the paper, but should be written last · Concise description of the experimental objectives, results, and conclusions · Includes why the experiment was performed; what problems were addressed; what major conclusions were found; and what major conclusions were drawn. · Does not include general background information. · Uses proper terminology for your course (examples include: pH, dominant, nucleotide, contamination, X or Y-linked, etc.) Section 2: Introduction and Background · Includes the reason the study is being done, relevant background information about the organism, chemical, or process being examined, and the hypothesis or questions being asked in the study. · Briefly explain any specific and relevant theories and research (3 sources expected – see section 7) · Briefly summarize of what was done in the experiment, what was observed and/or what you expected to find, and what, if any, problems were encountered. · Briefly summarize the laboratory techniques and equipment you used to collect and analyze the data upon which the conclusions are based. · Photos and graphic illustrations in this section with graphics in .jpg, .tif, or .gif format to minimize electronic file size. Section 3: Materials and Methods · Lists the materials and/or equipment used to conduct the experiment · States what was done by you with enough detail to allow the reader to repeat the experiment step-by-step. · Describes in detail the laboratory techniques and equipment you used to collect and analyze the data upon which the conclusions are based. · Lists the steps of the procedure in order and the reasons for each. Includes all calculations or formulas needed to obtain the final results. · Write this section with the audience in mind; for example, most people do not need to be told how to find the mean or standard deviation of the data, but will need to know the formula used to find the rate of oxygen consumption of an organism Section 4: Results · Results section is written in paragraph form and is one or two pages long · Do not offer any explanation for the results in this section · Presents the results in text and graphic form (figures, tables, graphs) · Describes the general trends seen in the data in narrative form (paragraphs). · All figures and tables should be referenced in the narrative. · Do not redraw the graph in words; let it do the work for you. For example, Temperature had a pronounced effect on seedling growth rate (Figure 6). In particular, seedlings at 25 degrees Celsius consistently grew more rapidly than those at 20 degrees Celsius. Section 5: Discussion · The discussion is the meat of the lab report. · Tries to answer the question "Why?" Explains what was expected and what was found. · Do the data support the original hypothesis? Why or why not? · This section presents reasons for the results obtained in the experiment and references related studies. · What trends were noticed; why did they occur? · What is the theory or model behind the experiment and is it substantiated by your results? · This section also includes potential sources of error. What recommendations might improve the procedure and results? Consideration is given to: · What is the connection between the experimental measurements taken and the final results and conclusions? How do your results relate to the real world? · What were the results of observations and calculations? · What trends were noticed? · What is the theory or model behind the experiment? · Do the experimental results substantiate or refute the theory? Why? Be sure to refer specifically to the results you obtained. · Were the results consistent with your original predictions of outcomes or were you forced to revise your thinking? · Did errors occur (for example, environmental changes or unplanned interference in the procedure)? If so, how did these errors affect the experiment? · Did any errors occur due to the equipment used (for example, contamination due to a lack of aseptic technique)? · What recommendations might improve the procedures and results? Section 6: Conclusion · Consists of a single paragraph. · Restates the objective, the results, and important discussion findings; Does NOT introduce new material. · Conclusion should be supported by at least 3 reasons and/or pieces of data obtained from the experiment. Section 7: Citations and Presentation · Presents complete citations for all factual material referred to in the text of the report. · Each citation should include the names of all authors, the year of publication, and the full title · Be sure that all sources are accurately documented in the desired AMA format (see UNE library for resources on this; i.e. RefWorks). · At least 3 sources are expected, three of which are from the scientific peer-reviewed literature, unless told otherwise by your instructor. · The rest of these may be non-internet sources (books, magazines, newspapers, journals, etc.). · Avoid the citation of blogs, Facebook, or other non-scientific sites. WebMD, Wikipedia, Mayo Clinic, etc. summary sites are not accepted as references. For Presentation: · The text for each section is in a narrative format using standard English and using complete sentences · The text displays proper grammar, spelling, punctuation, and word-choice.

Paper For Above instruction

Introduction

The importance of food safety cannot be overemphasized in maintaining public health. Microbial contamination of food products poses serious health risks, including foodborne illnesses, which can lead to severe health consequences and economic losses. Understanding how microbes colonize various foods, especially unwashed and washed produce and different states of dairy products such as milk, is pivotal for developing effective strategies to prevent contamination. This study aims to investigate microbial presence and diversity in unwashed and washed lettuce, and in opened versus unopened milk containers, to emphasize the importance of proper food handling and hygiene practices in the home environment.

Materials and Methods

The experiment utilized both student-supplied and laboratory-provided materials. Student-supplied items included bottles of bleach, distilled water, a camera, coffee cup, hand soap, isopropyl alcohol, a large cooking pot, fresh unwashed lettuce, oven mitt, paper towels, small containers of milk, a tap water source, and a stove or hotplate. Laboratory supplies comprised Petri dishes, sterile swabs, test tube racks, test tube clamps, tryptic soy agar (TSA) media, and safety equipment such as gloves, goggles, masks, and aprons.

The procedure commenced with the preparation of agar plates, which were poured approximately one hour before starting the experiment. The work area was disinfected with a 10% bleach solution, and personal protective equipment was worn throughout. The agar plates were divided into two sections labeled for each food sample: unwashed and washed lettuce, and fresh and opened milk.

Sampling began by moistening sterile swabs with distilled water, then swabbing the surface of unwashed lettuce, transferring the inoculant onto the designated section of the agar plate, and then sanitizing the lettuce with soap and water. The same process was repeated for washed lettuce. For milk, sterile swabs saturated with the open container’s contents (after 7 days) and fresh milk were used to inoculate respective sections. The plates were incubated at room temperature for 48 hours, and observations recorded, noting the microbial colonies' types and quantities.

Post-incubation procedures involved identifying colony types, photographing the plates, and proper disposal and sterilization of equipment following safety guidelines. The entire process aimed to compare microbial diversity and load between samples and evaluate the effectiveness of washing produce and fresh versus aged milk in reducing microbial presence.

Results

The incubation of agar plates revealed significant differences in microbial growth across the tested samples. The unwashed lettuce displayed a high colony count, including pathogenic bacteria such as Salmonella spp., with a total of 13 colonies, showcasing high microbial diversity. Washed lettuce exhibited noticeably fewer colonies, predominantly benign microbes like E. coli, with a total of 3 colonies. The fresh milk sample, which was opened 7 days prior, showed considerable microbial presence, including Cronobacter and other opportunistic pathogens, with 7 colonies. Conversely, the unopened milk sample demonstrated minimal microbial growth, indicating effective microbial suppression when sealed.

The results clearly demonstrated that unwashed produce harbors significantly more microbes than washed produce, emphasizing the importance of proper washing practices. Milk that remained unopened exhibited substantially less microbial contamination, reinforcing that sealing effectively prevents microbial ingress. The presence of pathogenic bacteria in aged, opened milk underscores the risks associated with long-term storage of dairy products after opening.

Photographic documentation of the plates reinforced these findings, with visibly denser colonies on unwashed lettuce and open milk samples. Quantitative analysis confirmed that the highest microbial load was associated with unwashed lettuce and open, aged milk. These results support current food safety guidelines recommending thorough washing of produce and proper storage of dairy products to minimize microbial contamination.

Discussion

The experiment substantiates the hypothesis that unwashed produce and open, aged milk harbor higher microbial loads than their cleaned and unopened counterparts. The proliferation of bacteria such as Salmonella, E. coli, and Cronobacter in these samples aligns with established literature indicating their common presence on food surfaces and in dairy that is improperly stored. The significantly reduced microbial load in washed produce and unopened milk illustrates the effectiveness of proper handling and storage in preventing foodborne illnesses.

The high diversity of microbes observed in unwashed lettuce can be attributed to contact with contaminated soil, water, and handling surfaces during harvesting and packaging. Washing disrupts microbial adhesion, reducing surface microbes, although some pathogens may persist. Similarly, the proliferation of bacteria in opened milk after 7 days emphasizes the importance of timely consumption and proper refrigeration to mitigate microbial growth.

Potential limitations include environmental factors that could influence bacterial growth, such as temperature and humidity variations during incubation. Additionally, the method of sampling with sterile swabs may underestimate total microbial presence, as some bacteria may not be easily transferred or visible on culture. The presence of opportunistic pathogens like Cronobacter in aged milk is significant, as it can cause severe infections in vulnerable populations.

These findings underscore the critical role of hygiene in food safety practices at home. Regular washing of produce, proper storage of dairy, and timely consumption are crucial measures against microbial contamination. Future studies could explore additional variables such as the effect of disinfectants or different