Portage Microbiology Exam 5 Questions & Answers

Define the concept of universal precautions (short answer) - ANSWERUniversal precautions means any and all samples, whether known or unknown, are to be treated as potentially hazardous (or pathogenic) materials List at lease 3 observations a researcher would be sure to note while assessing and unknown microbial sample (short answer) - ANSWERNeed to note: 1. Size and shape 2. Any observable motility 3. Gram status (positive or negative) While observing an unknown sample of limited amounts, a researcher must determine the following observations: 1) the presence of any motility and 2) its Gram status using the same sample- the liquid sample cannot be divided. Which would you determine first and why? (short answer) - ANSWERYou must determine motility before determining Gram status. Motility requires a wet mount, while gram staining requires heat fixing the sample. If one were to begin with the gram stain, the heat fixation process would kill the organism, making any observations regarding motility impossible. The correct approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the same liquid culture can be heat fixed and gram stained. A facultative anaerobe is a microorganism capable of growth under what conditions? (short answer) - ANSWERA facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions True or False: The Lancefield groups are used to subdivide antigenic groups of alpha-hemolytic Streptococcus - ANSWERFalse. The Lancefield groups are used to subdivide beta-hemolytic strep The distinctions for Lancefield subgroups lie in its: (select all that apply) A. Catalase activity B. Carbohydrate composition of antigens C. Hemolytic activity D. All of the above - ANSWERB. Carbohydrate composition of antigens Rheumatic fever displays _____ hemolytic activity and occurs when _____ if left untreated - ANSWERBeta: strep. Pharyngitis True or False: Under most circumstances, staphylococcus can be found in ~80% of human population where it remains non-symptomatic - ANSWERFalse. Staphylococc