BSMLS Bacteriology Lecture Semifinal Exam Answer Key PDF

LYCEUM-NORTHWESTERN UNIVERSITY COLLEGE OF MEDICAL LABORATORY SCIENCE BACTERIOLOGY LECTURE SEMIFINAL EXAMINATION Name: __________________________________ Date: ___________________________ Year and Section: _________________________ S...

LYCEUM-NORTHWESTERN UNIVERSITY COLLEGE OF MEDICAL LABORATORY SCIENCE BACTERIOLOGY LECTURE SEMIFINAL EXAMINATION Name: __________________________________ Date: ___________________________ Year and Section: _________________________ Student Number: __________________ I. MULTIPLE CHOICE Instructions: Read the questions carefully. Select the BEST answer. 1. Which of the following bacterial structures serves as the major virulence factor of Haemophilus influenzae? A. Cell Wall C. Pili B. Polysaccharide capsule D. Cell Membrane 2. During the paroxysmal stage of pertussis, which hematologic abnormality will most likely be present? A. Thrombocytopenia C. Neutropenia B. Lymphocytosis D. Eosinophilia 3. Serology is considered as the mainstay diagnosis for Brucella infection. Which titer indicates an active infection A. IgG of > 1: 16 C. IgG of > 1:80 B. IgM of > 1: 80 D. IgM of > 1: 16 4. Culture media used for the isolation of Francisella tularensis requires which of the following amino acids? A. Cysteine C. Aspartate B. Glutamine D. Selenocysteine 5. A 25-year-old sexually active individual presents with a painful genital ulcer. The ulcer is raised, soft, and has a ragged edge. Regional lymphadenopathy is also present. Gram stain from the ulcer revealed a gram-negative organism with a school of fish appearance. Which bacteria most likely caused the patient’s disease? A. Haemophilus haemolyticus C. Haemophilus ducreyi B. Haemophilus parainfluenzae D. Haemophilus parahaemolyticus 6. Which structure is lacking in Mycoplasma species making gram stain ineffective for these organisms? A. Cell membrane C. Nucleoli B. Cell wall D. Plasma membrane 7. Which of the following antimicrobial agents is added in Eaton’s agar to make it selective for Mycoplasma species? A. Gentamycin C. Nystatin B. Cephalosporin D. Penicillin 8. Mycoplasma hominis metabolizes which amino acid to facilitate its growth? A. Alanine C. Glycine B. Arginine D. Glutamine 9. Which of the following microorganism is considered as the causative agent of atypical pneumonia? A. Mycoplasma hominis C. Ureaplasma parvum B. Mycoplasma pneumoniae D. Ureaplasma urealyticum 10. All of the following Mycoplasma species inhabit the genitourinary tract, EXCEPT  A. Mycoplasma hominis C. Mycoplasma genitalium B. Mycoplasma pneumoniae D. Ureaplasma urealyticum 11. When requesting a cold agglutinin titer, which titer supports the diagnosis of Mycoplasma pneumoniae infection? A. 1: 8 C. 1: 32 B. 1: 16 D. 1: 64 12. All of the following statements are true about Mycoplasma pneumoniae, EXCEPT? A. Considered as one of the smallest free-living organism B. Highly pleomorphic organism C. Considered as a normal flora of the human respiratory tract D. Will not grow in the absence of oxygen 13. Mycoplasma species are generally resistant to which class of antibiotics? A. Penicillin C. Erythromycin B. Gentamycin D. Aztreonam 14. Considered as the gold standard in the diagnosis of Mycoplasma pneumoniae infection A. Culture C. Cold Agglutinin Titer B. Polymerase Chain Reaction D. Gram stain 15. Which stage of syphilis is characterized by the absence of signs and symptoms but will still yield a positive result to serologic tests? A. Latent stage C. Window stage B. Primordial stage D. Tertiary stage 16. Which of the following staining techniques is most useful in demonstrating spirochetes? A. Gram stain C. Giemsa stain B. India ink stain D. Silver stain 17. Which of the following diagnostic techniques is considered as the gold standard for detecting Leptospira interrogans infection? A. Culture C. MAT B. Darkfield microscopy D. PCR 18. Which of the following microorganisms causes louse-borne relapsing fever A. Bordetella pertussis C. Rickettsia rickettsii B. Borrelia recurrentis (bonus) D. Coxellia burnetii 19. Which of the following tests is useful for monitoring treatment for patients diagnosed with syphilis? A. FTA-ABS C. VDRL B. MHA-TP D. Darkfield Microscopy 20. HACEK bacteria are grouped because of their propensity to cause which disease? A. Rheumatic Heart Fever C. Glomerulonephritis B. Infective Endocarditis D. Pharyngitis 21. This microorganism grows well on blood agar exhibiting a colony with 4 – 6 pointed star-like configuration at the center resembling cross cigars A. A. actinomycetemcomitans C. E. corrodens B. C. hominis D. K. kingae 22. This bacteria is usually acquired from trauma associated with human teeth incurred during bits or from facial punches A. A. actinomycetemcomitans C. E. corrodens B. C. hominis D. K. kingae 23. This bacteria is named after its ability to pit the agar due to the presence of protein called pilin A. A. actinomycetemcomitans C. E. corrodens B. C. hominis D. K. kingae 24. Which bacteria has the ability to produce a small zone of beta-hemolysis, may pit the agar, and exhibits a twitching motility? A. A. actinomycetemcomitans C. E. corrodens B. C. hominis D. K. kingae 25. Which of the following sites serve as the habitat of HACEK bacteria? A. Oropharynx C. Genitourinary tract B. Gastrointestinal tract D. CNS 26. Which of the following microorganisms causes Lymphogranuloma venereum? A. Chlamydia trachomatis C. Chlamydia psittaci B. Chlamydia pneumoniae D. Rickettsia rickettsii 27. Which of the following Chlamydia species does not exhibit antigenic diversity? A. Chlamydia trachomatis C. Chlamydia psittaci B. Chlamydia pneumoniae D. Chlamydia abortus 28. Which of the following diagnostic techniques is commonly used to detect Chlamydia trachomatis infection? A. Culture C. NAAT B. Serology D. Gram stain 29. Which of the following characteristics is not seen with Pasteurella species? A. Glucose fermentation C. Penicillin susceptibility B. Positive oxidase reaction D. Growth on MacConkey 30. Although infections with Pasteurella spp. are relatively rare, when they are encountered they are most often seen in which type of infection? A. Respiratory Infections C. Wound infections B. Urinary Tract Infections D. Genital infections 31. Which of the following conditions is viewed as a risk factor for systemic disease caused by Pasteurella multocida subsp. multocida? A. Liver cirrhosis C. Hyperlipidemia B. End-stage renal disease D. Hereditary hemochromatosis 32. Legionella can be spread by all of the following, EXCEPT A. Cooling towers C. Lakes B. Person-to-person contact D. Humidifiers  33. All of the following are primary manifestations of Legionnaires’ disease, EXCEPT A. Trench fever C. Endocarditis B. Pontiac fever D. Pneumonia 34. Which of the following agars should be used for culturing Legionella? A. CIN C. SMAC B. BCYE D. XLD 35. What is the specimen of choice for isolating Legionella? A. Stool C. CSF B. Urine D. Respiratory secretions 36. Which of the following is not a characteristic of Legionella? A. Faintly staining, thin, gram-negative bacilli B. Requires iron and L-cysteine supplements C. Growth enhanced by microaerophilic conditions D. Medium buffered to pH 6.9 for optimal growth 37. Legionella can be definitively diagnosed by which of the following? A. Two-fold rise in anti-Legionella antibody with an IFA B. Single serum with a titer of 128 C. Monoclonal immunofluorescent stain D. Gram stain 38. All of the following are true of Legionella except: A. Thrives at warmer temperatures B. Can survive up to 5 years in water C. Has been isolated in rivers and lakes D. Is acquired from environmental sources II. MATCHING TYPE For numbers 39 – 43. Match the factor requirement for each Haemophilus species A. X only C. X and V B. V only D. Neither X nor V __C__ 39. Haemophilus influenzae __A__ 40. Haemophilus ducreyi __C__ 41. Haemophilus haemolyticus __B__ 42. Haemophilus parainfluenzae __B__ 43. Haemophilus parahaemolyticus For numbers 44 – 46. Match the following bacteria with their biochemical properties A. Mycoplasma pneumoniae B. Mycoplasma hominis C. Ureaplasma urealyticum __A__ 44. Glucose (+), Arginine (-), Urease (-) __B__ 45. Glucose (-), Arginine (+), Urease (-) __C__ 46. Glucose (-), Arginine (-), Urease (+) For number 47 – 50. Match the diseases with their causative agent A. Venereal Syphilis C. Pinta B. Bejel D. Yaws __D__ 47. T. pallidum subsp. perenue __C__ 48. T. pallidum subsp. carateum __B__ 49. T. pallidum subsp. endimicum __A__ 50. T. pallidum subsp. pallidum For number 51 – 54. Match the following clinical manifestations with their corresponding syphilis stage. A. Primary Syphilis C. Tertiary syphilis B. Secondary Syphilis D. Latent syphilis __A__ 51. Chancre __C__ 52. Tabes dorsalis __C__ 53. Gummas __B__ 54. Condyloma lata For numbers 55 – 58. Match the following bacteria with their corresponding properties A. A. actinomycetemcomitans C. E. corrodens B. C. hominis D. K. kingae __B__ 55. Oxidase (+), Catalase (-), Indole (+) __C__ 56. Oxidase (+), Catalase (-), Assacharolytic __A__ 57. Oxidase (-), Catalase (+), Star-like colony __D__ 58. Oxidase (+), Catalase (-), Twitching motility For numbers 59 – 63. Match the following descriptions with the corresponding forms of Chlamydia A. Elementary body B. Reticulate body __B__ 59. Replicative form __A__ 60. Infective form __A__ 61. Metabolically inert __B__ 62. Intracellular For numbers 63 – 66. Match the following descriptions with their corresponding Chlamydia species A. Chlamydia trachomatis B. Chlamydia psittaci C. Chlamydia pneumoniae __A__ 63. Round elementary body, (+) glycogen inclusions, causes LGV __B__ 64. Round elementary body, (-) glycogen inclusions, harbored by birds __C__ 65. Pear-shaped elementary body, (-) glycogen inclusions, (-) plasmid DNA For numbers 66 – 70. Match the following diseases with their causative agents A. Rocky Mountain Spotted fever D. Scrub typhus B. Epidemic typhus E. Japanese spotted fever C. Murine typhus __E__ 66. Rickettsia japonica __A__ 67. Rickettsia rickettsii __B__ 68. Rickettsia prowazekii __D__ 69. Orientia tsutsugamushi __C__ 70. Rickettsia typhi END OF EXAMINATION  LYCEUM-NORTHWESTERN UNIVERSITY COLLEGE OF MEDICAL LABORATORY SCIENCE BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION Name: __________________________________ Date: ___________________________ Year and Section: _________________________ Student Number: __________________ Instructions: Read the questions carefully then select the BEST answer. 1. This refers to the process by which most bacterial forms in non-living objects are destroyed without necessarily destroying bacterial endospores A. Antisepsis C. Disinfection B. Decontamination D. Sterilization 2. Considered as the most efficient method of sterilization A. Autoclaving C. HEPA Filter B. Tyndallization D. Ionizing Radiation 3. Considered as the safest method to ensure that no infective materials remain in samples when disposed A. Direct Flame C. Incineration B. Dry Oven D. Autoclaving 4. Which of the following serves as the biological indicator when using ionizing radiation? A. Bacillus stearothermophilus C. Bacillus subtilis var. niger B. Bacillus pumilus D. Bacillus subtilis var. globigii 5. Which of the following is considered as the most ideal temperature and duration of heating in the method of pasteurization A. 63C for 30 minutes C. 72C for 30 minutes B. 100C for 15 seconds D. 85C for 15 seconds 6. Which class of Biosafety cabinet is commonly used in hospital microbiology laboratories which allows 30% of air to be exhausted and 70% recirculated with a velocity of 75 fpm A. Class I C. Class IIA2 B. Class IIA1 D. Class IIB 7. These substances are frequently used as disinfectants for bench tops and other surfaces but is easily inactivated by organic matter? A. Phenols C. Silver Nitrate B. Aldehydes D. Quaternary Ammonium Compounds 8. A new disinfectant is being promoted in the market. Upon testing, its phenol coefficient is found to be 1.20. What can be concluded from this new disinfectant? A. The new disinfectant is equally effective as phenol B. The new disinfectant is less effective than phenol C. The new disinfectant is more effective than phenol D. Results are inconclusive 9. Which of the following is considered as the standard disinfectant? A. Phenol C. Aldehydes B. Alcohol D. Povidone-Iodine 10. Which preparation of ethyl alcohol is considered as most effective concentration? BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 1 of 10  A. 50% Ethyl alcohol C. 95% Ethyl alcohol B. 70% Ethyl alcohol D. 99.9% Ethyl alcohol 11. He is known as the father of Medical Microbiology and proposed the Germ Theory of Disease A. Anton van Leeuwenhoek C. Robert Koch B. Luis Pasteur D. Edward Jenner 12. In the Bacterial growth curve, which phase is characterized rapid cell division resulting to an exponential growth in the number of living cells A. Lag phase C. Plateau phase B. Log phase D. Death phase 13. This is considered as the major pathway of glucose metabolism wherein glucose is converted to pyruvate A. Entner-Doudoroff Pathway C. Embden-Meyerhof Pathway B. Pentose Phospohate Shunt D. Tricarboxylic Acid Cycle 14. The following bacteria will have a Gram positive reaction when subjected to Gram stain, EXCEPT A. Staphylococcus spp. C. Listeria spp. B. Bacillus spp. D. Meningococcus spp. 15. All encapsulated bacteria will have a polysaccharide capsule, EXCEPT A. Klebsiella pneumoniae C. Bacillus anthracis B. Haemophilus influenzae D. Neisseria meningitidis 16. During your rotation in the Microbiology section, you were asked to perform catalase test on the newly grown bacterial colony. Upon doing so, you noticed a bubble formation. Which of the following microorganism is most likely isolated? A. Staphylococcus aureus C. Enterococcus faecalis B. Streptococcus pneumoniae D. Streptococcus pyogenes 17. Slide Coagulase test aims to demonstrate the presence of which form of Coagulase enzyme? A. Bound Coagulase C. Complex Coagulase B. Free Coagulase D. Simple Coagulase 18. A positive Microdase test is indicated by the development of which color? A. Green C. Red B. Blue D. Yellow 19. The following biochemical tests are useful in differentiating Streptococcus species, EXCEPT A. CAMP Test C. Bacitracin Susceptibility Test B. Bile Esculin Test D. Citrate Utilization Test 20. After inoculating a sputum sample on blood agar plate and subjecting it to Bacitracin susceptibility testing, you noticed a zone of inhibition measuring 15mm in diameter. What microorganism is most likely present in the inoculated sputum sample? A. Streptococcus agalactiae C. Staphylococcus aureus B. Streptococcus pyogenes D. Viridans Streptococci 21. A positive Bile Esculin test result is indicated by which of the following? A. Blackening of the agar slant C. Disintegration of colonies B. Blackening of the agar butt D. Colonies are kept intact BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 2 of 10 22. Which of the following organisms will most likely exhibit an arrowhead shaped zone of beta hemolysis when streaked perpendicular to a S. aureus streak on blood agar plate? A. Streptococcus agalactiae C. Streptococcus pneumoniae B. Streptococcus pyogenes D. Viridans Streptococci 23. A positive PYR test is indicated by which of the following? A. Appearance of bright red color C. Appearance of pink ring B. Disappearance of bright red color D. Change in color of solution to yellow 24. The presence of which enzyme is being determined when Indole production test is being performed? A. Catalase C. Indolase B. Peroxidase D. Tryptophanase 25. Kovac’s reagent is used in which of the following biochemical tests? A. Methyl Red Test C. Indole Test B. Voges Proskauer Test D. Urease Test 26. Positive Methyl Red and Voges Proskauer test is indicated by which of the following? A. Red colored solution C. Colorless solution B. Yellow colored solution D. Blue colored solution 27. This biochemical test aims to detect an organism’s ability to convert acid products to neutral end products such as acetoin or 2,3-butanediol A. Indole Test C. Lysine Iron Agar B. Citrate Utilization Test D. Voges Proskauer Test 28. Which microorganism will most likely match the following IMViC test results? Indole: positive Voges Proskauer: negative Methyl red: positive Citrate: negative A. Pseudomonas aeruginosa C. Escherichia coli B. Salmonella typhi D. Klebsiella pneumoniae 29. Which of the following results indicates the presence of lysine decarboxylase-positive bacteria? A. Purple-colored agar butt C. Red-colored agar slant B. Yellow-colored agar butt D. Purple-colored agar slant 30. Which microorganism will most likely match the following IMViC test results? Indole: negative Voges Proskauer: positive Methyl red: negative Citrate: positive A. Pseudomonas aeruginosa C. Escherichia coli B. Salmonella typhi D. Klebsiella pneumoniae 31. Ehrlich’s reagent is used in which of the following biochemical tests? A. Methyl Red Test C. Indole Test B. Voges Proskauer Test D. Urease Test 32. What color change will occur in a triple sugar iron agar when an organism ferments glucose, sucrose, and lactose? A. Yellow slant and butt C. Yellow slant, Red butt B. Red slant, Yellow butt D. Red slant, Red butt BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 3 of 10 33. Bubbles or cracks in TSI tube agar indicates which of the following? A. Hydrogen sulfide production C. Glucose fermenter B. Gas production D. Sucrose fermenter 34. What is the indicator used in performing Urease test? A. Bromcresol purple C. Phenol red B. Bromcresol blue D. Methyl red 35. What is the reagent used in performing Catalase test? A. 3% Hydrogen peroxide C.10% NaClO B. 75% Ethyl alcohol D. Povidone-Iodine 36. Which of the following microorganism will test positive in optochin susceptibility test? A. Streptococcus agalactiae C. Streptococcus pneumoniae B. Streptococcus pyogenes D. Viridans Streptococci 37. Which microorganism will most likely match the following IMViC test results? Indole: negative Voges Proskauer: negative Methyl red: negative Citrate: positive A. Pseudomonas aeruginosa C. Escherichia coli B. Salmonella typhi D. Klebsiella pneumoniae 38. What is the indicator used in performing Citrate Utilization test? A. Bromcresol purple C. Phenol red B. Bromthymol blue D. Methyl red 39. What is the reagent used in performing bile solubility test? A. Ox bile C. 5% sheep blood B. 10% Sodium deoxycholate D. Ferric ammonium citrate 40. Methyl red test detects mixed acid formation. At a pH of less than or equal to 4.4, the indicator used for this test will turn into which color? A. Red C. Blue B. Yellow D. Pink 41. A red-colored colony is observed on a nutrient agar. What is the most likely microorganism present? A. Staphylococcus aureus C. Serratia marcescens B. Pseudomonas aeruginosa D. Escherichia coli 42. In preparing a plated culture media, which of the following is the correct sequence of preparation? A. Weigh à Dissolve à Dispense à Sterilize B. Weigh à Dissolve à Sterilize à Dispense C. Sterilize à Weigh à Dissolve à Dispense D. Dissolve à Weigh à Dispense à Sterilize 43. What is the best source of blood in preparing blood agar plate? A. Horse blood C. Human blood B. Rabbit blood D. 5% Sheep blood 44. The following are used as inhibitors for Gram positive bacteria EXCEPT A. Gentian violet C. Sodium deoxycholate B. Crystal violet D. Sodium azide BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 4 of 10 45. Lowenstein-Jensen is an artificial medium used to grow Mycobacterium tuberculosis, which inhibitor is incorporated in this medium to prevent the growth of unwanted organisms? A. Crystal violet C. Potassium tellurite B. Malachite green D. Methylene blue 46. Modified Thayer-Martin is a selective medium used to isolate N. gonorrhoeae which contains antimicrobials as inhibitors. Which of the following antimicrobial is not added in Modified Thayer-Martin agar? A. Vancomycin C. Trimethoprim lactate B. Anisomycin D. Colistin 47. This type of culture medium provides distinct colonial appearances of microorganisms to aid their identification A. Enriched media C. Selective media B. Enrichment media D. Differential media 48. Colonies of mannitol-fermenting bacteria, when grown in Mannitol Salt Agar will exhibit which color? A. Yellow C. Red B. Green D. Colorless 49. Which of the following microorganisms will have a distinct yellow-colored colonies on Thiosulfate Citrate Bile Salt Sucrose agar? A. Vibrio cholerae C. Staphylococcus aureus B. Vibrio parahaemolyticus D. Escherichia coli 50. Bacteria that are able to ferment lactose and produce hydrogen sulfide will have which colony appearance? A. Yellow colonies without black center C. Green colonies with black center B. Yellow colonies with black center D. Green colonies without black center 51. He is responsible for the discovery of Mycobacterium tuberculosis and Bacillus anthracis A. Anton van Leeuwenhoek C. Robert Koch B. Luis Pasteur D. Edward Jenner 52. He is responsible for the discovery of Penicillin A. Anton van Leeuwenhoek C. Alexander Flemming B. Robert Koch D. Edward Jenner 53. Which of the following correctly describes the cell wall of a Gram positive bacteria? A. Has a thin peptidoglycan wall B. Characterized by the presence of a periplasmic space C. Has a lipopolysaccharides attached on its surface D. Has a teichoic acid attached on its surface 54. Which structure is responsible for the acid-fast characteristic of Mycobacterium tuberculosis? A. Teichoic acid C. Mycolic acid B. Mesosome D. Lipoic acid 55. Bacterial endospores are mainly made up of which compound? A. Sodium deoxycholate C. Calcium dipicolinate B. Calcium hydroxyapatite D. Lipopolysaccharide BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 5 of 10 56. Bacteria requiring 5%-10% Carbon dioxide as classified as A. Lithotrophs C. Capnophile B. Organotrophs D. Halophile 57. Bacteria that can grow under both aerobic and anaerobic conditions are classified as: A. Obligate Anaerobe C. Microaerophilic B. Facultative Anaerobe D. Aerotolerant 58. Bacteria that are able to grow on high salt concentration are classified as A. Halophile C. Psychrophile B. Capnophile D. Mesophile 59. Which phase of the bacterial growth curve is characterized by increase in cell size without an increase in the number of living bacteria A. Lag Phase C. Plateau Phase B. Log Phase D. Death Phase 60. Which bacterial structure serves as the source of H antigen A. Capsule C. Flagella B. Cell Wall D. Nucleus 61. Which of the following culture media will be the most appropriate for growing Campylobacter jejuni? A. Skirrow Agar C. BCYE Agar B. Bordet-Gengou Agar D. CIN Agar 62. Which hydrogen sulfide indicator incorporated in Lysine Iron Agar? A. Ferric Ammonium Citrate C. Ferric sulfate B. Ferrous sulfate D. Ferric Citrate 63. Which culture medium is used in performing Antimicrobial Susceptibility Testing? A. Blood Agar Plate C. Sulfide Indole Motility Agar B. Mueller Hinton Agar D. Nutrient Agar 64. Which of the following culture medium will be the most appropriate for growing and isolating Corynebacterium diphtheriae A. Lowenstein-Jensen C. Bordet-Gengou Agar B. Potassium Tellurite D. MacConkey Agar 65. Which anti-fungal is incorporated in New York City Agar? A. Colistin C. Amphotericin B B. Nystatin D. Anisomycin 66. The following are indole-negative bacteria, EXCEPT A. Klebsiella pneumoniae C. Escherichia coli B. Enterobacter cloacae D. Citrobacter freundii 67. A blue-green-colored colony is observed on a nutrient agar. What is the most likely microorganism present? A. Staphylococcus aureus C. Serratia marcescens B. Pseudomonas aeruginosa D. Escherichia coli 68. After inoculating a sputum sample on blood agar plate and subjecting it to Bacitracin susceptibility testing, you noticed a zone of inhibition measuring 15mm in diameter. What microorganism is most likely present in the inoculated sputum sample? BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 6 of 10  C. Streptococcus agalactiae C. Staphylococcus aureus D. Streptococcus pyogenes D. Viridans Streptococci 69. Which of the following results indicates the presence of lysine decarboxylase-positive bacteria? C. Purple-colored agar butt C. Red-colored agar slant D. Yellow-colored agar butt D. Purple-colored agar slant 70. The presence of which enzyme is being determined when Indole production test is being performed? C. Catalase C. Indolase D. Peroxidase D. Tryptophanase END OF EXAMINATION BACTERIOLOGY LECTURE PRELIMINARY EXAMINATION | 7 of 10  LYCEUM-NORTHWESTERN UNIVERSITY COLLEGE OF MEDICAL LABORATORY SCIENCE BACTERIOLOGY LECTURE MIDTERM EXAMINATION Name: __________________________________ Date: ___________________________ Year and Section: _________________________ Student Number: __________________ Instructions: Read the questions carefully then select the BEST answer. 1. During your Bacteriology section rotation, a wound swab specimen was submitted. Series of tests were done. Identify the bacteria present from the specimen submitted based on the following results: Gram stain Gram positive cocci in clusters Coagulase Formation of clot Catalase Formation of bubbles Modified Oxidase No change in color Growth on MSA Growth of golden yellow colonies A. Streptococcus pyogenes C. Staphylococcus aureus B. Staphylococcus saprophyticus D. Streptococcus agalactiae 2. The VanA gene causes resistance of Staphylococcus aureus against Vancomycin by which of the following mechanisms? A. Altering the sequence from D-ala D-ala to D-ala D-ser B. Altering the sequence from D-ala D-ala to D-ala D-lac C. Altering the sequence from D-ala D-ala to D-ala D-glu D. Altering the sequence from D-ala D-ala to D-ala D-gly 3. Which test will best differentiate Staphylococcus epidermidis from Staphylococcus saprophyticus? A. Novobiocin Susceptibility Test C. Coagulase Test B. Modified Oxidase Test D. Bacitracin Susceptibility Test 4. Which of the following toxins released by Staphylococcus aureus is associated with Ritter disease? A. Panton-Valentine Leukocidin C. Exfoliative Toxin B. Enterotoxin A D. Enterotoxin F 5. Which of the following tests will best differentiate Staphylococcus aureus from Staphylococcus epidermidis? A. Catalase Test C. Oxidase Test B. Coagulase Test D. Superoxol Test 6. A wound discharge specimen was submitted to the laboratory and was subsequently cultured on blood agar plate (BAP). After 24 hours, small, whitish, non-hemolytic colonies were observed. Identify which microorganism was isolated based on the results of other tests. Gram stain Gram positive cocci in clusters Catalase Formation of bubbles Coagulase test No formation of clot Glucose Change in color of medium from red to yellow fermentation Novobiocin 20mm zone of inhibition Susceptibility test BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 1 of 8  A. Staphylococcus saprophyticus C. Staphylococcus epidermidis B. Staphylococcus aureus D. Staphylococcus intermedius 7. This microorganism has a glycocalyx which allows it to adhere to foreign bodies forming biofilms and is one of the known causes of prosthetic heart valve endocarditis. A. Staphylococcus saprophyticus C. Staphylococcus epidermidis B. Staphylococcus aureus D. Staphylococcus intermedius 8. Which of the following statements is TRUE about Staphylococcus aureus? A. Presence of high salt concentration inhibits the growth of S. aureus B. S. aureus are considered microaerophilic organisms C. S. aureus are non-motile and are considered spore formers D. Exhibits variable patterns of hemolysis but mostly are beta-hemolytic 9. Which of the following Staphylococcal toxins is not considered as superantigen? A. Enterotoxin A C. Exfoliative toxin B. Hemolysin D. Toxic Shock Syndrome Toxin 10. Which of the following tests will best differentiate Staphylococcus species From Streptococcus species? A. Catalase Test C. Oxidase Test B. Coagulase Test D. Superoxol Test 11. Which of the following bacteria will exhibit beta-hemolysis when cultured on blood agar plate (BAP)? A. Streptococcus pyogenes C. Enterococcus faecalis B. Streptococcus pneumoniae D. Viridans streptococci 12. When using the Lancefield classification, which amino sugar is predominantly present in the cell wall of Streptococcus pyogenes? A. Rhamnose-glucosamine B. Rhamnose-N-acetylgalactosamine C. Rhamnose-N-acetylglucosamine D. Glucopyranosyl-N-acetylgalactosamine 13. A sputum specimen was submitted to the laboratory. The specimen was inoculated on a blood agar plate which demonstrated alpha-hemolysis. Identify which microorganism was isolated based on the results of other tests. Catalase No formation of bubbles Bile Solubility Test Clearing of the solution Optochin Zone of inhibition measuring 15mm in diameter Susceptibility Test A. Staphylococcus aureus C. Streptococcus pneumoniae B. Staphylococcus epidermidis D. Streptococcus agalactiae 14. Which of the following tests will best differentiate Viridans streptococci from Streptococcus pneumoniae? A. Optochin Susceptibility Test C. Bacitracin Susceptibility Test B. Novobiocin Resistance Test D. Bile Esculin Test BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 2 of 8 15. Gram stain from blood culture bottles demonstrated gram-positive cocci in pairs and in chains and no hemolysis appreciated on BAP. Identify which microorganism was isolated based on the results of other tests. Catalase No formation of bubbles Bile Esculin Growth and blackening of agar slant Growth in 6.5% Turbid medium NaCl PYR Test Formation of bright red color A. Streptococcus pyogenes C. Enterococcus faecalis B. Streptococcus agalactiae D. Viridans Streptococci 16. Which of the following bacteria will exhibit positive Quellung reaction? A. Streptococcus pyogenes C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Viridans Streptococci 17. Considered as the most common cause of Community-Acquired Pneumonia across all ages A. Streptococcus pyogenes C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Viridans Streptococci 18. Which of the following will most likely be detected if there is a recent Streptococcal skin infection? A. Anti-Streptolysin O (ASO) C. Pyrogenic Exotoxin B. Anti-DNase D. Fibrinolysin 19. Which of the following is considered as the major antigenic and virulence factor of S. pyogenes? A. M protein C. Streptokinase B. Streptolysin O D. Pyrogenic Exotoxin 20. Which of the following tests will best differentiate Streptococcus agalactiae from Streptococcus pyogenes? A. Optochin Susceptibility Test C. Novobiocin Resistance Test B. Bacitracin Susceptibility Test D. Bile Esculin Test 21. Which toxin is associated with Streptococcal Toxic Shock Syndrome? A. Erythrogenic Toxin C. Hyaluronidase B. Pyrogenic Exotoxin A D. Streptolysin S 22. Which of the following bacteria is able to exhibit a purple color on Hippurate hydrolysis test A. Streptococcus pyogenes C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Viridans Streptococci 23. Which of the following bacteria is associated with Marantic endocarditis? A. Streptococcus bovis C. Viridans Streptococcus B. Streptococcus pneumoniae D. Enterococcus faecalis 24. Which of the following bacteria will most likely be inhibited by Bacitracin? A. Streptococcus bovis C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Streptococcus pyogenes BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 3 of 8 25. When using the Lancefield classification, which amino sugar is predominantly present in the cell wall of Streptococcus agalactiae? A. Rhamnose-glucosamine B. Rhamnose-N-acetylgalactosamine C. Rhamnose-N-acetylglucosamine D. Glucopyranosyl-N-acetylgalactosamine 26. Which of the following virulence factors associated with Streptococcus pyogenes allows the bacteria to escape from blood clots by via fibrinolysis? A. Deoxyribonuclease C. Streptokinase B. Hyaluronidase D. Hemolysin 27. Which of the following virulence factors present in Streptococcus pyogenes is associated with Scarlet fever? A. Pyrogenic Exotoxin A C. Erythrogenic toxin B. Streptolysin O D. Hyaluronidase 28. Throat swab specimen was submitted to the laboratory. Gram stain showed gram- positive cocci in chains and exhibited a beta-hemolytic pattern of hemolysis on BAP. Identify which microorganism was isolated based on the results of other tests. Catalase No formation of bubbles PYR Test Red-colored disk Bacitracin Zone of inhibition of 12mm in diameter susceptibility Test A. Streptococcus pyogenes C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Viridans Streptococci 29. Aside from Bacitracin susceptibility testing, what other test can best differentiate Streptococcus pyogenes from Streptococcus agalactiae? A. Optochin Susceptibility Test C. PYR test B. Novobiocin Resistance Test D. Bile Solubility Test 30. Which of the following bacteria is considered to be microaerophilic? A. Peptostreptococcus C. Streptococcus pneumoniae B. Streptococcus agalactiae D. Viridans. Streptococci 31. A vaginal discharge was submitted to the laboratory. Gram stain was done revealing gram-negative intracellular diplococci. What is the most likely microorganism present? A. Neisseria gonorrhoeae C. Neisseria flava B. Neisseria meningitidis D. Moraxella catarrhalis 32. All of the following organisms will grow well on Blood Agar Plate (BAP), EXCEPT A. Staphylococcus aureus C. Bacillus anthracis B. Streptococcus pyogenes D. Neisseria gonorrhoeae 33. Which of the following structures found in Neisseria species is responsible for antigenic variation allowing the microorganism to escape the host immune system A. Capsule C. Opa protein BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 4 of 8  B. Lipooligosaccharide D. Pili 34. All of the following inhibitors are found in Martin Lewis agar, EXCEPT A. Vancomycin C. Anisomycin B. Colistin D. Nystatin 35. Neisseria gonorrhoeae can ferment which of the following sugar/s? A. Glucose C. Both B. Maltose D. Neither 36. Which of the following statements is TRUE about Moraxella catarrhalis? A. Classified as a gram-negative, intracellular diplococci B. Motile and exhibits gamma hemolysis when grown on BAP C. Lacks the ability to ferment any sugar D. Exhibits effervescence when a drop of 3% H2O2 is placed over the colony 37. An unknown isolate of microorganism was submitted to the laboratory. You are tasked to perform carbohydrate utilization test. Tube A contains glucose, Tube B contains maltose, and Tube C contains sucrose. After inoculating the microorganism, the following colors were observed: Tube A, red; Tube B, red; Tube C, yellow. What is the most likely microorganism present? A. Neisseria gonorrhoeae C. Moraxella catarrhalis B. Neisseria meningitidis D. Neisseria flava 38. Which of the following bacteria is able to change the color of a Tributyrin-containing disk from white to blue? A. Neisseria gonorrhoeae C. Moraxella catarrhalis B. Neisseria meningitidis D. Neisseria flava 39. Which of the following types of swabbing material should be used to collect specimens for possible gonococcal infection? A. Calcium alginate swab C. Scotch tape swab B. Cotton swab D. Dacron swab 40. Which culture medium is incorporated in JEMBEC used for commercial transport of Neisseria gonorrhoeae? A. Thayer Martin Agar C. Martin Lewis B. Modified Thayer Martin D. New York City Agar 41. What is the base culture medium used to prepare Martin Lewis agar? A. Chocolate Agar C. Trypticase Soy Agar B. Blood Agar D. Nutrient Agar 42. Which is the preferred antimicrobial used in preventing Ophthalmia neonatorum? A. Ceftriaxone C. Erythromycin B. Doxycycline D. Silver nitrate 43. Which test is considered as the gold standard in diagnosing Neisseria infection? A. Nucleic Acid Amplification Test C. Gram stain B. Culture D. Superoxol Test BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 5 of 8 44. Which of the following pathogenic determinants associated with Neisseria gonorrhea allows it to colonize the epithelial mucosal surfaces? A. Polysaccharide capsule C. IgA protease B. Lipooligosaccharide D. Pili 45. Which type of cell does Neisseria gonorrhoeae evade and enter which makes them an intracellular bacteria A. Red Blood Cells C. Neutrophils B. Platelet D. Lymphocytes 46. An unknown clinical isolate was submitted to the laboratory. Gram stain was done revealing gram-positive rods in chains with centrally located spores and having the appearance of a bamboo pole. What is the most likely microorganism present? A. Bacillus cereus C. Bacillus anthracis B. Bacillus subtilis D. Bacillus stearothermophilus 47. If Bacillus anthracis is grown on BAP, what would be the expected hemolytic pattern? A. Alpha hemolysis C. Beta hemolysis B. Gamma hemolysis D. Could not be determined 48. Which form of Anthrax is considered to be the most lethal? A. Cutaneous Anthrax C. Gastrointestinal Anthrax B. Inhalational Anthrax D. Subcutaneous Anthrax 49. String of pearls reaction is seen in colonies of Bacillus anthracis when grown on BAP with the addition of which antimicrobial agent? A. 0.05U Penicillin C. 0.05U Vancomycin B. 10U Penicillin D. 10U Vancomycin 50. J.A., a 25-year-old male attended a birthday party. Upon arriving at the venue, he immediately munched on the garlic rice served on their table. 3 hours after, he developed vomiting accompanied by abdominal cramps and epigastric pain. Which toxin most likely caused his illness? A. B. cereus Heat-labile Enterotoxin C. Cholera toxin B. B. cereus Heat-stable Enterotoxin D. Staphylococcal enterotoxin 51. Which of the following bacteria, when grown on BAP will exhibit a wide zone of beta hemolysis? A. Listeria monocytogenes C. Bacillus cereus B. Corynebacterium diphtheriae D. Clostridium perfringens 52. Tetanospasmin, a neurotoxin, inhibits the release of which of the following neurotransmitters? A. Acetylcholine C. Glutamate B. Serotonin D. GABA 53. Clostridium species are known as spore-forming rods, which species will demonstrate terminally located spores? A. Clostridium tetani C. Both A and B B. Clostridium difficile D. Neither A nor B BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 6 of 8 54. Which of the following statements about Clostridium perfringens is correct? A. C. perfringens has an inner zone of alpha hemolysis and an outer zone of beta hemolysis B. Reverse CAMP uses Staphylococcus aureus to identify C. perfringens C. Lactose formation in Litmus milk test is indicated by formation of a whitish curd D. C. perfringens is associated with food poisoning 55. Which antibiotic is most commonly associated with pseudomembranous colitis? A. Clindamycin C. Doxycycline B. Ceftriaxone D. Ampicillin 56. What is the preferred laboratory procedure in detecting pathogenic strains of Clostridium difficile? A. Gram stain C. Culture B. Polymerase chain reaction D. Enzyme Immunoassays 57. An unknown clinical isolate was submitted to the laboratory. After doing a gram stain, the specimen was subjected to different other tests. Identify the microorganism present based on the following test results Gram stain Gram positive bacilli Sulfide Indole Growth only along the site of inoculation Motility Test Nagler Test Precipitate around the line of growth Lactose Red-colored medium fermentation A. Clostridium perfringens C. Clostridium difficile B. Bacillus anthracis D. Bacillus cereus 58. Which of the following statements is TRUE about Listeria monocytogenes? A. Classified as aerobic, gram-positive, spore-forming bacilli B. Motile at body temperature, non-motile at room temperature C. Has a toxin called internalin which allows bacteria to escape phagosome D. Exhibits paradoxical growth in warm temperature 59. Which of the following inhibitors is not included in the preparation of McBride medium? A. Glycine C. Lithium chloride B. Potassium chloride D. Phenylethyl alcohol 60. By which of the following mechanisms does Diphtheria toxin inhibits protein synthesis? A. Damaging ribosomes attached to the Rough endoplasmic reticulum B. Changing D-ala D-ala sequence to D-ala D-lac C. Addition of ADP-ribose to Elongation factor-2 D. All of the above 61. When grown on Tinsdale agar, Corynebacterium diphtheriae will appear as: A. Gray colonies with black halo B. Gray-black mucoid colonies C. Black colonies with brown halo BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 7 of 8  D. Gray colonies with wide zone of hemolysis 62. Which of the following pathogenic determinants present in L. monocytogenes is responsible for propelling the bacteria from one cell to another? A. Internalin C. Actin rockets B. Cadherin D. Listeriolysin 63. When grown on a semi-solid medium, the motility of Listeria monocytogenes is described as: A. Tumbling motility C. Falling leaf motility B. Umbrella growth pattern D. Corkscrew motility 64. At which temperature should you incubate Listeria monocytogenes in order to enhance its growth? A. 4ºC C. 37ºC B. 25ºC D. 45ºC 65. Which medium is most appropriate to use if one would want to enhance granule formation of C. diphtheriae? A. Tinsdale agar C. MacLeod agar B. Loeffler’s serum medium D. Potassium Tellurite agar 66. Which of the following Corynebacterium species is associated with the development of conjunctivitis? A. C. jeikeium C. C. amycolatum B. C. auris D. C. xerosis 67. The following statements about diphtheroids are true, EXCEPT A. Considered as normal flora of the skin, oral cavity, and GUT B. They are non-toxigenic species of Corynebacterium, hence, unable to cause any disease C. Do not produce gray-black colonies on tellurite medium D. All statements are true 68. Positive schick test is demonstrated by which of the following? A. Induration of 15mm after 48 hours B. Induration of 13mm after 24 hours C. Induration of 5mm after 36 hours D. Induration of 10mm after 72 hours 69. Corynebacterium diphtheriae is able to ferment which of the following sugars? A. Salicin C. Maltose B. Sucrose D. Fructose 70. Which of the following bacteria will most likely test negative on CAMP test? A. L. monocytogenes C. Clostridium perfringens B. S. agalactiae D. None of the choices END OF EXAMINATION BACTERIOLOGY LECTURE MIDTERM EXAMINATION | 8 of 8