Latest AAB MT Microbiology

What term describes the morphology of organisms that vary in shape and size? - ANSWER Pleomorphic Capsules are the basis of which test? - ANSWER Serotyping A mucoid colony on blood agar medium indicates that which of the following characteristics may be present? - ANSWER Organism has a capsule. What are dark staining granules called? - ANSWER Metachromatic Which of the following organisms are non-motile? - ANSWER Shigella and Klebsiella In the bacterial growth cycle, growth ceases because nutrients are exhausted or toxic metabolic products have accumulated in which phase? - ANSWER Stationary phase Which of the following genera of bacteria form spores? - ANSWER Bacillus and Clostridium What term is used to describe bacteria that grow in the absence of atmospheric oxygen and obtain oxygen from oxygen-containing compounds? - ANSWER Anaerobes What is the temperature at which bacteria grow best known as? - ANSWER Optimum On blood agar plates a small zone of alpha hemolysis surrounded by a zone of beta hemolysis after refrigeration is known as what type of hemolysis? - ANSWER Alpha- prime hemolysis What is the most effective method of sterilization? - ANSWER Autoclaving Which of the following is used for quality control for the dry heat oven? - ANSWER Bacillus subtilis Media that cannot be heated can be sterilized by what alternate method? - ANSWER Filtration Which one of the following disinfectants is the most effective germicide against bacteria, spores, tubercle bacilli, fungi, and viruses? - ANSWER Chlorine What is a term that describes a process or treatment that renders a medical device, instrument, or environmental surface safe to handle? - ANSWER Decontamination What color do gram-positive bacteria stain? - ANSWER Purple Acid-fast bacteria appear what color microscopically? - ANSWER Red Acid-fast organisms in tissue are best stained by which of the following methods? - ANSWER Kinyoun Which of the following should be used to remove antimicrobials before culturing? - ANSWER Antimicrobial removal device Which statement concerning sodium polyanethol sulfonate (SPS) is NOT true? - ANSWER Activates some antimicrobials What are some functions of sodium polyanethol sulfonate (SPS)? - ANSWER Prevents blood from clotting, prevents phagocytosis, and neutralizes the bactericidal effect of human serum. What is the most abundant normal flora in throat cultures? - ANSWER Alpha-hemolytic streptococci Why is it recommended to stab the blood agar plate when setting up throat cultures? - ANSWER Some streptococci may not produce beta hemolysis under aerobic conditions. What is the most common pathogen is throat cultures? - ANSWER Streptococcus pyogenes Nasopharangeal swabs are recommended for the detection of which carriers? - ANSWER H. influenzae, N. meningitidis, and B. pertussis Why is a first morning urine specimen preferred for urine cultures? - ANSWER Specimen is more concentrated. What indicates vaginal or urethral contamination of urine? - ANSWER Greater than 10 squamous epithelial cells per hpf. How are smears of cerebrospinal fluid prepared? - ANSWER Centrifuged CSF sediment Smears of CSF are usually stained with which stain? - ANSWER Gram stain