Microbiology Final Exam (Previous Quiz Questions)

The "hands on" portion of clinical specimen laboratory testing is called a(n): Pre-analytic activity Analytic activity Post-analytic activity Research activity Extracurricular Activity

Analytic activity

The HACEK organisms all share the following characteristics EXCEPT: Require increased CO2 to grow Are all oxidase and catalase positive Causative agents of bacterial endocarditis Part of the normal human oral flora

Are all oxidase and catalase positive

If a patient was bitten by a dog or cat, which of the following organisms could likely be found as a potential pathogen in the resulting wound? Streptobacillus moniliformis or Brucella canis Capnocytophaga species or Pasteurella multocida. Francisella tularensis or Haemophilus parahemolyticus Bartonella henslae or Legionella species

Capnocytophaga species or Pasteurella multocida

In the Kirby Bauer susceptibility, and D test, image below what is the correct set of interpretations: D test Erythromycin susceptible, Clindamycin susceptible Erythromycin susceptible, Clindamycin resistant Erythromycin resistant, Clindamycin susceptible Erythromycin resistant, Clindamycin resistant (due to inducible enzyme.) Erythromycin resistant, Chloramphenicol resistant (due to inducible enzyme.)

Erythromycin resistant, Clindamycin resistant (due to inducible enzyme)

Which of the carbapenems is the best at detecting the presence of carbapenemase in a CRE (Carbapenem Resistant Enterobacteriaceae) ? A. Imipenem B. Ertapenem C. Meropenem D. Lipopenem E. Gentamycin F. Teicoplanin

Ertapenem

Which one of the following organisms would produce a yellow slant and a yellow butt on TSI agar after incubating 18 hours? Escherichia coli Morganella morgannii Salmonella Typhi Shigella sonnei

Escherichia coli

Which of the following antibiotics are used for Urinary Tract Infections (UTI) ONLY. IE the laboratory would not include/report this drug out unless the sample was a urine Nitrofurantoin Bacitracin Ceftaroline Penicillin

Nitrofurantoin

The breakdown (hydrolysis) of casein, tyrosine, and xanthine is useful in the differentiation of: Pseudomonas spp. Nocardia spp. Enterobacteriacae Haemophilus spp

Nocardia spp.

A positive DNase would be seen with: Escherichia coli Klebsiella oxytoca Proteus mirabilis Serratia marcescens

Serratia mercescens

Neisseria meningitidis can be carried ________ , which serves as a reservoir for infection. in the blood in the nasopharynx in the genital area on the skin

in the nasopharynx

A GNB is recovered from a leg wound of a 68 year old man. The organism grows on blood agar and has small clear colonies on MAC. What test(s) could be used to determine if the organism is a nonfermenter? A. TSI B. Glucose O/F C. Oxidase D. None of the above E. A or B

A or B

A gram negative coccobacillus was isolated from the ventilators of several patients in ICU. The organism grew well on BA with tiny pinpoint colonies on MAC. The oxidase reaction was negative, motility was negative, and glucose was oxidized in the OF reaction. What is the most likely organism? Stenotrophomonas maltophilia Pseudomonas aeruginosa Acinetobacter lwoffii Acinetobacter baumanii

Acinetobacter baumanii

A gram-negative rod isolated from a fishhook injury in the right thumb of a 15-year-old healthy male produced the following reactions: BAP = large gray colonies with beta hemolysis MAC = pink colonies TSI = yellow slant over yellow butt Oxidase = positive TCBS = no growth Spot Indole = positive 0% NaCl = growth 6% NaCl = no growth DNase = positive The most likely identification is: Vibrio vulnificus Vibrio parahaemolyticus Aeromonas hydrophilia Plesiomonas shigelloides

Aeromonas hydrophilia

Which of the following antibiotic classes act on the organism's protein synthesis and are often useful in treating Pseudomonas aeruginosa ? Beta-lactams Glycopeptides (Vancomycin) Quinolones/Fluoroquinolones Aminoglycosides

Aminoglycosides

What is the antibiotic MIC result/value of the organism in the image provided: MP=meropenem; CL=colistin MIC A. Colistin = 19mm B. Meropenem = 0.25 ug/mL C. Meropenem = 1.0 ug/mL D. A and B E. None: All the results on that plate are qualitative, not quantitative

B. Meropenem = 0.25 ug/mL

In determination of requirements for X and V factors, a suspected Haemophilus species grew only between the X and V strips. This Haemophilus species requires: Only V factor Only X factor Both X and V factors Neither X and V factors

Both X and V factors

All the following Brucella species are associated with human illness EXCEPT: Brucella melitensis Brucella ovis Brucella suis Brucella canis Brucella abortus

Brucella ovis

A Brucella species gave the following reactions: Oxidase positive Catalase positive Urease positive in 10 minutes H2S week positive Growth in presence of: Thionin: positive Fuchsin: negative The most likely species is: Brucella melitensis Brucella abortus Brucella suis Brucella canis

Brucella suis

Which organism has colonies that, upon reincubation, turn dry and wrinkled looking similar to Pseudomonas stutzeri: however this organism causes meliodosis and is considered a possible agent of bioterrorism? Stenotrophomonas maltophilia Burkholderia pseudomallei Pseudomonas fluorescens Acinetobacter sp.

Burkholderia pseudomallei

The ear drainage gram stain is seen in the previous question. 28 : For the culture: The ear drainage from #27 was plated to sheep blood, MacConkey, and chocolate agars. The next day, nothing grew on MacConkey agar, but the sheep blood and chocolate agars grew a pure culture. The BA grew Alpha hemolytic colonies resembling the picture below. Which group of tests would be the most appropriate for identification? colonies Catalase, bile esculin, PYR Catalase, TSI (for H2S production) Oxidase, indole, TSI, motility Catalase, bile solubility, optochin, bile esculin

Catalase, bile suability, optochin, bile esculin

Which antibiotic is unique in that it is a member of the Cephamycins, which is a sub-group of the 2nd generation Cephalosporins. It is also unique in that it is the only only Beta-lactam ring drug, other than the carbapenems, that is resistant to the ESBLs (extended spectrum Beta-lactamases) Penicillin Methicillin Oxacillin Cephalothin Cefuroxime Cefoxitin Cefaclor Ceftazidime Cefotaxime Cefa-zaxo-furo-something-or-other

Cefoxitin

The medium most frequently used to isolate Haemophilus is: Sheep blood agar Chocolate agar MacConkey CNA

Chocolate agar

A technician is reading stool culture plates. She is looking for enteric pathogens on the MacConkey (MAC) plate. What do they typically look like? Clear, colorless colonies Large, bright pink colonies Small, mucoid, green colonies Small, orange colonies

Clear, colorless colonies

A wound (skin lesion) specimen obtained from a newborn grew predominantly β-hemolytic colonies of gram-positive cocci on 5% sheep blood agar. The newborn infant was covered with small skin eruptions that gave the appearance of a "scalding of the skin." The gram-positive cocci proved to be catalase-positive. Which tests would be appropriate for obtaining the identification? Optochin, bile solubility, PYR Coagulase, glucose fermentation, DNase Bacitracin, PYR, 6.5% salt broth CAMP, bile-esculin, 6.5% salt broth

Coagulase, glucose fermentation, DNase

A microbiologist is getting ready to report out a vaginal isolate that is an oxidase positive Gram Negative Diplococci (GNDC) that biochemically fits the ID of Neisseria gonorrhoeae when they notice that the patient's age is 12 years old. The best next step is to: Report out the culture as positive for Neisseria gonorrhoeae Report out the isolate as Neisseria species; unable to speciate Request a second sample and turn out the first sample as unsatisfactory Consult with the immediate supervisor and repeat testing, including a second confirmatory methodology if available.

Consult with the immediate supervisor and repeat testing, including a second confirmatory methodology if available.

A catalase negative, Gram positive coccus that is susceptible to optochin, will also be: A. Alpha hemolytic B. Bile soluble C. Bile esculin positive D. A and B E. A, B, and C

D. A and B

A catalase negative, non-spore forming, long gram positive rod could be: A. Lactobacillus B. Erysipelothrix C. Listeria D. A and B E. B and C F. A and C G. A, B, and C

D. A and B

In the porphyrin (ALA) test, a positive result on a Haemophilus species means the organism: ______________ Requires exogenous NAD Does not require exogenous NAD Requires exogenous hemin Does not require exogenous hemin

Does not require exogenous hem in

A pale yellow-pigmented GNB, isolated from the patients, and a sink, in a neonatal unit where an out an outbreak of meningitis occurred, oxidized (slowly) glucose in the OF reactions, was oxidase positive, and non-motile . It did not grow on MAC. Due to the associated outbreak and biochemical reactions the organism is most likely: Stenotrophomonas maltophilia Pseudomonas aeruginosa Elizabethkingia (Chryseobacterium) meningosepticum Acinetobacter baumanii

Elizabethkingia meningosepticum

A 20-year-old female patient entered the emergency clinic complaining of abdominal pain, fever, and a burning sensation during urination. An above normal WBC count along with pus cells and bacteria in the urine specimen prompted the emergency physician to order a urine culture. The colony count reported for this patient revealed >100,000 col/mL of a non-hemolytic, catalase-negative, gram- positive cocci on 5% sheep blood agar. The following test results indicate which organism? PYR pos Bile Esculin pos 6.5% Salt Broth growth Hippurate neg Enterococcus species Streptococcus pyogenes Streptococcus agalactiae Streptococcus bovis

Enterococcus sp

ESBL stands for: Extended Susceptibility Beta-Lactams Extremely Susceptible Beta-Lactamase Extended Spectrum Beta-Lactamase Extra Special Beta-Lactamase

Extended Spectrum Beta-Lactamase

All of the following are rapid methods used to identify Legionella species EXCEPT A. Direct fluorescent antibody (DFA) B. DNA detection C. Culture D. Urine antigen testing E. PBP2a detection F. C and E

F. C and E

Which statement is INCORRECT for Staphylococcus epidermidis ? Coagulase negative Catalase positive Novobiocin susceptible Fails to grow on Mannitol Salt Agar

Fails to grow on Mannitol Salt Agar

This gram stain was obtained from ear drainage collected from a 3 year old male: Gram Stain 27: This gram stain was obtained from ear drainage collected from a 3 year old male. What is the most appropriate Gram stain, morphology, and arrangement of the organism? Gram positive cocci in clusters Gram positive cocci in pairs (Lancet shaped) Gram positive bacilli in chains Gram negative diplococci

Gram positive cocci in pairs (Lancet shaped)

A dark pigmented colony is isolated from the leg of a fisherman in Florida. The Gram- negative rod grows on sheep blood and MacConkey agars. The organism provides the following reactions: TSI: K/A Indole: negative Motility: positive Growth at 42C : positive The microbiologist cannot read the oxidase reaction due to dark violet pigment. What can he/she do to achieve a valid oxidase reaction? Perform a modified oxidase test Grow the organism under anaerobic conditions, to stop pigment production, and retest The oxidase test is not necessary for this organism Grow the organism on non-nutrient agar and retest Flip a coin: heads + tails =

Grow the organism under anaerobic conditions, to stop pigment production, and retest

For questions 12 thru 15 use the following table to match the biochemicals to the Haemophilus species identification: 14 X factor = (+) V factor = (+) Hemolysis on rabbit blood = (+) ALA = (-) H. parainfluenzae H. parahaemolyticus H. influenzae H. haemolyticus

H. haemolyticus

For questions 12 thru 15 use the following table to match the biochemicals to the Haemophilus species identification: 13 X factor = (+) V factor = (+) Hemolysis on rabbit blood = (-) ALA = (-) H. parainfluenzae H. parahaemolyticus H. influenzae H. haemolyticus

H. influenzae

For questions 12 thru 15 use the following table to match the biochemicals to the Haemophilus species identification: 15 X factor = (-) V factor = (+) Hemolysis on rabbit blood = (+) ALA = (+) H. parainfluenzae H. parahaemolyticus H. influenzae H. haemolyticus

H. parahaemolyticus

For questions 12 thru 15 use the following table to match the biochemicals to the Haemophilus species identification: 12. X factor = (-) V factor = (+) Hemolysis on rabbit blood = (-) ALA = (+) H. parainfluenzae H. parahaemolyticus H. influenzae H. haemolyticus

H. parainflunzae

A microbiologist is reading a CSF culture and notices that there is no growth on the sheep blood and MacConkey agars, but there is growth on the chocolate plate. The colonies on the plate are translucent, moist, smooth, and convex, with a mousy odor. What is the most likely identification of the organism? Moraxella catarrhalis Haemophilus influenzae Neisseria lactamica Haemophilus ducreyi Mus musculus

Haemophilus influenzae

A mother brings her lethargic, feverish baby into the emergency department. The baby is diagnosed with meningitis and the doctor does a spinal tap. The cerebrospinal fluid (CSF) Gram stain shows WBCs and many tiny gram-negative rods. What is the most probable identification of this organism? Neisseria meningitidis Haemophilus meningitidis Haemophilus influenzae serotype b Haemophilus haemolyticus Haemophilus parainfluenzae

Haemophilus influenzae serotype b

The human oral isolates of Capnocytophaga species can be differentiated from the dog and cat isolates of Capnocytophaga species because: Human isolates are oxidase and catalase positive; animal isolates are oxidase and catalase negative Human isolates are oxidase and catalase negative; animal isolates are oxidase and catalase positive Human isolates are oxidase positive and catalase negative; animal isolates are oxidase negative and catalase positive Human isolates are oxidase negative and catalase positive; animal isolates are oxidase positive and catalase negative

Human isolates are oxidase and catalase negative; animal isolates are oxidase and catalos positive

In this type of antimicrobial susceptibility test, a McFarland 0.5 standardized suspension of bacteria is swabbed over the surface of a Mueller-Hinton agar plate, and paper disks containing single concentrations of each antimicrobial agent are placed onto the inoculated surface. Results are read as zone diameters, which are then converted by CLSI standards in M100 as Susceptible, Resistant, or Intermediate. What is the name of this test MIC MBC Kirby Bauer Agar Dilution None of the abov

Kirby Bauer

Which statement correctly describes X factor: Inactivated by NADase Known as hemin or hematin Derived from yeast and potato extract Produced by nonhemolytic Staphylococcus species

Known as hemin or hematin

Neisseria lactamica closely resembles Neisseria meningitidis. N. lactamica can be differentiated by the ability to utilize the carbohydrate: Glucose Maltose Lactose Sucrose

Lactose

The following results were obtained when a cephalothin microdilution panel was performed: Test Well Result Sterility - Clear Growth - Turbid 1ug/mL - Turbid 2 ug/mL - Turbid 4ug/mL - Turbid 8ug/mL - Clear 16ug/mL - Clear An evaluation of these results indicates that: Minimum inhibitory concentration (MIC) is 4ug/mL MIC is 8ug/mL Minimum bactericidal concentration (MBC) is 4ug/mL MBC is 8 ug/mL Test is invalid

MIC is 8ug/mL

If a male is infected with Neisseria gonorrhoeae, what would be the Gram stain results of the purulent discharge from his urethra? Many polymorphonuclear white blood cells, intracellular gram-negative diplococci, and gram-negative diplococci GNDC Many polymorphonuclear white blood cells and gram-positive cocci Many polymorphonuclear white blood cells, intracellular gram-negative rods, and gram-negative rods Many polymorphonuclear white blood cells, intracellular gram-negative coccobacilli, and gram-negative coccobacilli GNCB

Many polymorphonuclear white blood cells, intracellular gram-negative diplococci, and gram-negative diplococci GNDC

Which of the following atmospheres or environments is required for the isolation of a gram-negative rod (curved rods resembling "seagull wings") that is a stool pathogen and oxidase positive, catalase positive, and able to hydrolyze hippurate? Halophilic Microaerophilic and capnophilic Ambient air 4 C Refrigerator

Microaerophilic and capnophilic

Which of the following organisms is DNase positive? Neisseria meningitidis N. gonorrhoeae N. lactamica Moraxella catarrhalis

Moraxella catarrhalis

Which of the following descriptions is correct for Campylobacter jejuni? Motile, curved rod, halophilic, catalase negative. Nonmotile, curved rod, grows best at 42C, catalase negative, microaerophilic Motile, curved rod, grows best at 42C, catalase positive, microaerophilic Motile, curved rod, cannot grow at 42C, strict aerobe.

Motile, curved rod, grows best at 42C, catalase positive, microaerophilic

A 1-month-old infant underwent a spinal tap to rule out bacterial meningitis. The CSF was cloudy, and the smear showed many pus cells and short gram-positive rods. After 18 hours, many colonies appeared on blood agar that resembled Streptococcus agalactiae (Group B Beta Strep) or L. monocytogenes. Which of the following preliminary tests should be performed on the colonies to best differentiate L. monocytogenes from Streptococcus agalactiae? Motility (25°C) and catalase PYR and bacitracin Oxidase and glucose Coagulase and catalase

Motility (25C) and catalase

A sputum from a cancer patient grew a pink colony on MacConkey. The biochemical reactions were as follows: TSI: A/A with gas Oxidase: negative Indole: negative MR: negative VP: Positive Citrate: Positive Motility: negative Urea: 2+ positive What colony characteristic is often associated with this organism? Mucoid Swarming Red pigment Green pigment

Mucoid

What is the most likely identification of an oxidase positive, Gram negative cocci (GNC) isolated in a pure culture from a sample of synovial fluid with a carbohydrate utilization pattern as follows: Maltose: Negative Sucrose: Negative Glucose: Positive Lactose: Negative Neisseria gonorrhoeae Neisseria lactamica Moraxella catarrhalis Neisseria meningitidis

Neisseria gonorrhoeae

A microbiologist is reading four CTA sugars from a vaginal culture isolate that grew an oxidase positive, gram-negative diplococcus. Only the glucose tube is yellow. What is the most likely organism? Neisseria meningitidis but would need to gram stain the glucose growth to confirm purity Neisseria sicca Neisseria gonorrhoeae but would need to gram stain the glucose growth to confirm purity Neisseria lactamica

Neisseria gonorrhoeae but would need to gram stain the glucose growth to confirm purity

A microbiologist receives cerebrospinal fluid (CSF) in the laboratory and does a Gram stain on it. Much to their surprise, they see intracellular and extracellular gram-negative diplococci. Based on the gram stain and body site: What is the most likely organism? Neisseria meningitidis N. gonorrhoeae N. sicca N. lactamica

Neisseria meningitidis

A technologist is reading the four CTA sugars. Only the maltose and glucose tubes are positive. What organism produces acid in these two tubes? Neisseria meningitidis Moraxella catarrhalis N. gonorrhoeae N. lactamica

Neisseria meningitidis

Which statement best describes the mode of action with the antibiotic/antifungal listed for Modified Thayer-Martin medium? Vancomycin inhibits gram-negative bacteria Colistin inhibits gram-positive bacteria Nystatin inhibits yeast and molds Trimethoprim inhibits gram-positive bacteria

Nystatin inhibits yeast and molds

Colonies growing on cefsulodin-irgasan-novobiocin (CIN) agar appear to be either Aeromonas spp. or Yersinia enterocolitica. Which test should be performed to differentiate between these two organisms? Coagulase Glucose fermentation Gram stain Oxidase

Oxidase

In addition to motility, which test best differentiates Acinetobacter sp. and Alcaligenes sp? TSI Oxidase Gram stain All of the above

Oxidase

A sputum culture grows: 4+ gray colonies on sheep blood agar No growth on MacConkey 4+ gray colonies on chocolate agar Gram stain: GNDC Oxidase: positive All CTA carbohydrates: negative What would be the most appropriate next course of action? Report out nonpathogenic Neisseria sp. Repeat the CTA sugars Identify as N. gonorrhoeae and perform susceptibility tests Perform a butyrate esterase or DNase test

Perform a butyrate esterase or DNase test

Lactobacillus spp. (which are normal flora in vaginal cultures) typically produce colonies that are: White and chalky Large and beta hemolytic Pinpoint and alpha hemolytic Translucent with subtle beta hemolysis

Pinpoint and alpha hemolytic

Chromobacterium violaceum can be differentiated from Vibrio spp, Aeromonas spp, and Plesiomonas spp. as the colonies smell of almonds and by its ability to: Ferment glucose Produce oxidase Produce violet pigment Grow on Skirrow's media

Produce violet pigment

A 13 year old child is brought to the emergency room with severe burns on 75% of his body. The burn sites became infected during the first week of hospitalization and a typical "blue pus" infection was suspected. A culture of the material revealed a GNB with greenish-pigment and a grape-like odor. The organism is most likely: Stenotrophomonas maltophilia Pseudomonas aeruginosa Elizabethkingia (Chryseobacterium) meningosepticum Acinetobacter baumanii

Pseudomonas aeruginosa

A microbiologist is reading the plates from a sputum culture. On the sheep blood agar, she sees flat spreading colonies with a metallic sheen. On cetrimide agar, she sees fluorescent green colored colonies. On MacConkey, she sees medium clear colonies that have a fruity or grape-like odor. What is the most likely organism? Stenotrophomonas maltophilia Pseudomonas aeruginosa Elizabethkingia (Chryseobacterium) meningosepticum Acinetobacter baumanii

Pseudomonas aeruginosa

Gram negative diplococci are seen in a Gram stain of a female genital tract specimen. Which of the following is the most appropriate action? Report "Neisseria gonorrhoeae" seen Report out amount of Gram-negative diplococci and WBCs seen on smear and then plate the specimen on blood agar, chocolate agar, and Modified Thayer-Martin. Do not report the Gram stain and then plate specimen on blood agar only Report "Normal flora seen" and discard specimen

Report out amount of Gram-negative diplococci and WBCs seen on smear and then plate the specimen on blood agar, chocolate agar, and Modified Thayer-Martin

A leg wound culture from a 16 year-old football player grows: 4+ Staphylococcus aureus 1+ coagulase negative Staphylococcus 1+ diphtheroids 1+ Viridans group Streptococcus The technologist should: Report the 4+ Staphylococcus aureus and report the other organisms as 1+ "normal skin flora" Report each organism isolated individually Perform further testing on the diphtheroids Report all four organisms as "normal skin flora" Call the State Health Authority immediately to report a suspected LRN Select agent organism identification.

Report the 4+ Staphylococcus aureus and report the other organisms as 1+ "normal skin flora"

An oxacillin screen was performed on the Streptococcus pneumoniae isolate in the image below. What is the next appropriate action? oxacillin Report the isolate as oxacillin resistant Report the isolate as oxacillin susceptible Report the isolate as penicillin resistant Report the isolate as penicillin susceptible Report the isolate as methicillin susceptible Repeat testing with another method such as Etest

Report the isolate as penicillin susceptible

Which organism has smooth, shiny, pale yellow colonies on blood agar and may smell of ammonia Pseudomonas aeruginosa Stenotrophomonas maltophilia Alcaligenes faecalis Burkholderia pseudomallei

Stenotrophomonas maltophilia

A sputum culture from a 13-year-old hospitalized cystic fibrosis patient grew a predominance of gram- negative rods that tested oxidase-negative. On the blood agar plate, the organism appeared to have a yellowish pigment. Further testing showed: Motility + DNase + Glucose + (oxidative) Maltose + (strongly oxidative) Lysine decarboxylase + What is the most likely identification? Stenotrophomonas maltophilia Acinetobacter baumanii Pseudomonas aeruginosa Burkholderia cepacia

Stenotrophonomas maltophilia

Match the Lancefield group to the correct organism : Streptococcus pyogenes Streptococcus pneumoniae Streptococcus bovis Streptococcus agalactiae All Answer Choices A. Group B B. Group D C. Group A D. No Lancefield group

Streptococcus pyogenes = C Streptococcus pneumoniae = D Streptococcus bovis = B Streptococcus agalactiae = A

Match the medium with the bacterium that the agar is primarily used to isolate: (each answer used only once: ) TCBS Regan-Lowe BCYE Tinsdale Starch and HBT biplate (V agar) A. Corynebacterium diphtheriae B. Legionella pneumophilia C. Gardnerella vaginalis D. Vibrio cholerae E. Bordetella pertussis

TCBS = D Regan-Lowe = A BCYE = B Tinsdale = C Starch and HBT biplate (V agar) = E

The antibiotic groups that are useful for screening for possible ESBL production by a bacteria are: The 1st generation cephalosporins and the Monobactam (Aztreonam) The 2nd generation cephalosporins and the Monobactam (Aztreonam) The 3rd generation cephalosporins and the Monobactam (Aztreonam) The Carbapenems and the Cephamycin (Cefoxitin)

The 3rd generation cephalosporins and the Monobactam (Aztreonam)

Helicobacter pylori can be presumptively identified from a gastric biopsy based on which of the following tests? H2S production Oxidase Urease Gram stain

Urease

What antibiotic is often used to treat severe infections of Staphylococcus aureus especially MRSA, and can also used for treating Enterococci ? Penicillin Methicillin Tobramycin Vancomycin

Vancomycin

A Vibrio yielded the following biochemical reactions: Growth in nutrient broth (0% NaCl): Negative Growth in nutrient broth with 6% NaCl: Positive Oxidase: Positive TCBS: Green colonies Which of the following Vibrio species could be the identification? Vibrio cholera Vibrio alginolyticus Vibrio parahaemolyticus None of the above

Vibrio parahaemolyticus

A curved gram-negative rod producing oxidase-positive colonies on blood agar was recovered from a stool culture. Given the following results, what is the most likely identification? Lysine decarboxylase: positive Arginine decarboxylase: negative Indole: positive KIA = Alk/Acid VP = Neg TCBS agar = Green colonies Urease = ± Vibrio cholerae Vibrio parahaemolyticus Shigella species Salmonella species

Vibrio parahaemolyticus