Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Food Micro Lectue 7
Food Micro Midterm 2
| What are the three types of microbial detection testing? | Investigational testing, acceptance testing, professional reasons |
| Investigational testing is used to determine if a _____ is present. | hazard |
| Investigational testing verifies that ____ ____ have been met in HACCP. | critical limits |
| Challenge testing is a part of _____ testing. | investigational |
| ______ testing must comply with legal or contractual requirements. | Acceptance |
| _____ testing is useful in determining the quality of incoming materials and purchase specifications. | Acceptance |
| Professional reasons usually involve _____ studies to establish methodology. | collaborative |
| In environmental sampling, one must be aware of ____ cells. | VBNC (viable but non culturable cells) |
| What are the three types of diluents used for quantitative detection? | Buffered peptone water, 0.1% peptone water, physiological saline |
| How is the most probable number (MPN) technique advantageous over plate count? | Can detect a lower number of bacteria. |
| What are the cons to MPN? | Not as accurate, needs a lot of glassware. |
| What is the sensitivity of direct microscopic count? | 1 cell/field (1000x magnification) ~1E6/mL |
| What are the cons to DMC? | Cannot distinguish between viable and dead cells; un-uniformally stained. |
| Describe the direct epifluorescent filter technique (DEFT). | Filtration of "stomached" food suspensions through nylon filters; used widely in the dairy industry; captures viable cells only. |
| Plaque forming units are commonly used in the detection of _____. | viruses |
| What are two rapid methods of cell detection? | Measure of ATP, flow cytometry (particle enumeration). |
| _____ detection can be done through microbial enrichment. | Qualitative |
| T or F: Sub-lethally injured bacteria will grow on selective media. | False |
| How can the number of injured microorganisms be counted? | Grow on non-selective and selective media and find the difference between them. |
| What are the three criterion for media selection? | productivity (ability to support growth), selectivity (discourage growth of competitors), electivity (easy differentiation between cells) |
| Name three types of media which can be used for aerobic plate count. | brain heart infusion, trypticase soy agar, plate count agar |
| Total Plate Count and Viable Plate Count are ________ media. | non-selective. |
| Yeast and mold will grow on _____ _____ agar. | rose bengal |
| How can bacteria be identified based on structure? | size, shape, extra-cellular characters, differential staining |
| Name three ways to identify bacteria biochemically. | Growth media, serological tests, protein analysis. |
| Define serotype. | Groups within a single species of microorganism with distinctive surface structures. |
| How are Salmonella serotyped? | By a pattern of O antigens present. |
| What does ELIA stand for and how does it work? | Enzyme-Linked ImmunoSorbant Assay; a plate-based technique which can detect substances such as peptides, proteins, antibodies, etc. |
| What are three genomic methods of identifying bacteria? | PCR, DNA fingerprinting, sequencing. |
| Define whole genome sequencing. | Determining the complete DNA sequence of an organism's genome at one time. |
| ____ are a form of global gene expression profiling. | Microarrays |
| RT-PCR uses ______ in order to detect levels of ____ ____. | fluorophores, gene expression |
| What does PFGE stand for? | Pulsed-Field Gel Electrophoresis |
Created by:
goberoi