MLT Microbiology Final Exam Solved 100% Correct /Verified Answers () Guide

1 MLT Microbiology Final Exam MLT Microbiology Final Exam Solved 100% Correct /Verified Answers (2024 -2025) Guide What tests are used to identify Enterococcus sp? [Ans: - Bile Esculin, 6.5% NaCl broth and PYR What test(s) can be used to differentiate Streptococcus agalactiae from other beta hemolytic streptococci? [Ans: - Both Hippurate hydrolysis and latex agglutination A pathogen, isolated from stool, was inoculated to a TSI tube and gave the following reactions: K/A, H2S positive, small amount of gas produced. The organism mos t likely is: [Ans: - Salmonella sp. While swimming in a lake near his home, a young man cut his foot, and developed an infection. The culture grew a Gram -negative, oxidase positive, beta -hemolytic, motile bacilli that produced deoxyribonuclease. The most likely identification is: [Ans: - Aeromonas hydrophila A woman in her 20s goes to her physician complaining of burning upon urination, frequency, and general malaise. Her physician does a urine culture. It grows out 25,000 colony -forming units (CFU/mL) of a catalase -positive, coagulase -negative, novobiocin -resistant Gram positive cocci. what is the most likely pathogen? [Ans: - Staph. saprophyticus A branching Gram positive bacilli, partially acid -fast organism isolated from the sputum of a patient receiv ing chemotherapy most likely is: [Ans: - A Nocardia sp. What is the name of the organism that is strongly associated with gastric, peptic, and duodenal ulcers as well as GI carcinoma? [Ans: - Helicobacter pylori All of the following are general characteristics of Corynebacteria sp. EXCEPT: [Ans: - Gram negative coccobacilli The HACEK group includes all of the following EXCEPT: [Ans: - Clostridium difficile What biochemical test will differentiate nonfermenters f rom Enterobacteriaceae (except Plesiomonas)? [Ans: - Oxidase All of the following are characteristics of nonfermenters EXCEPT: [Ans: - All Indole positive 2 MLT Microbiology Final Exam The primary pathogens of the Enterobacteriaceae include all the following EXCEPT: [Ans: - Proteus mirabilis Why can't direct microscopy be used to provide a presumptive identification of the enteric bacteria? [Ans: - The microscopic characteristics are indistinguishable from other Gram negative bacteria Which of the following is a stool pathogen that is a curved, gram -negative rod that grows on TCBS (Thiosulfate Citrate Bile Salts Sucrose) agar at 35°C? [Ans: - Vibrio An aerobic, Gram positive, spore -forming bacillus was isolated from raw vegetables that were associated with an outbreak of gastroenter itis, The organism produced beta hemolysis, was catalase positive and was motile. The most likely organism is: [Ans: - Bacillus cereus A commercial fisherman who was complaining of red sores on his hands was seen by his physician. One of the lesions was b iopsied and cultured. The culture grew an organism with the following characteristic: -Nonhemolytic on sheep blood agar, Gram positive bacilli with no spores observed, Catalase negative, H2S production positive, Growth in gelatin resembled a test tube brus h The organism is most likely: [Ans: - Erysipelothrix rhusiopathiae Enterotoxins, Toxic shock syndrome toxin, Exfoliative toxin and Leukocidens are: [Ans: - Virulence factors associated with Staphylococcus aureus Two serious complications of an infection with Group A Streptococcal disease are: [Ans: - Acute glomerulonephritis and rheumatic fever MacConkey agar is used to: [Ans: - Differentiate between lactose fermenters and lactose nonfermenters. A direct smear can provide: [Ans: - All these answers are correct Which method does CLSI suggest is most reliable for detecting oxacillin resistance in staphylococci? [Ans: - Cefoxitin disk diffusion test