2016.4.Microbiology
Match the organism to the disease produced outside a bioterrorism event.
Bacillus anthracis Anthrax Yersinia pestis Pneumonic plague Burkholderia pseudomallei Melioidosis Brucella species Brucellosis Francisella tularensis Tularemia Burkholderia mallei Glanders
Match the Gram-stained image to the organism it MOST closely represents.
Bacillus anthrasis Large, gram-positive rods with square ends appearing in single and short chains
The bacterial species most likely associated with bacillary angiomatosis is:
Bartonella henselae
What is the best term to describe the clear areas seen around the colonies on this blood agar plate:
Beta Hemolysis
Which of the following enzymes, produced by Staphylococcus aureus is responsible for preventing penicillin antibiotics from being effective against a Staph infection?
Beta-lactamase
Which of the following dimorphic molds produces spherical or oval conidia, each supported by an individual conidiophore ("lollipop") as represented in the image on the right?
Blastomyces dermatitidis
Match the names of the species of dimorphic fungi listed in the drop-down box with its corresponding yeast form as illustrated in the images.
Blastomyces dermatitidis Upper left Coccidioides immitis Upper right Paracoccidioides brasiliensis Lower left Sporothrix schenckii Lower right
The pair of nonfermentative gram negative bacilli producing the motility reactions illustrated in the left (motile) and right (nonmotile) tubes respectively shown in the photograph are:
Bordetella bronchiseptica and Acinetobacter baumannii
Illustrated in this photograph is a positive slide coagulase test (Image B) compared to a negative control (Image A). The clumping of the bacterial cells, as seen in Image B, results from the bacterial production of:
Bound coagulase
Match the names of each of the Corynebacterium species into Bucket A if it is "lipid requiring" and into Bucket B if it does not require supplemental lipids for growth.
Bucket A Corynebacterium jeikeium Bucket B Corynebacterium cystitidis Bucket A Corynebacterium ureolyticum Bucket B Corynebacterium flavescens
A small, microaerophilic, curved, gram-negative rod which was isolated from a diarrhea stool specimen gave the following results: Grew best at 42 ºC Oxidase-positive Resistant to cephalosporin Susceptible to nalidixic acid Hippurate hydrolysis-positive The MOST probable identification of this organism is:
Campylobacter jejuni
Please match the names of each of the infectious diseases humans may incur from the animals that can transmit the disease. Your answers are on the left. The correct answers are on the right and highlighted.
Cats Pasteurellosis Pigs Brucellosis Rabbits Tularemia Chicken Salmonellosis
The biochemical testing results of an alpha-hemolytic streptococcus show that the isolate is bile esculin-positive, but does not grow in the presence of 6.5% NaCl. The MOST probable identity of this isolate is what?
Group D streptococcus, non-enterococcus
Match the hepatitis B test with the appropriate disease phase.
HBsAg Late incubation, acute Anti-HBs Recovery Anti-HBc IgM Acute, convalescent Anti-HBc Total Acute, convalescent, recovery
Match each of the names of the bacterial species with the appearance and reactions of the colonies seen in the photographs. Image A is delta amino levulinic acid viewed with UV light; Image B, buffered charcoal yeast extract agar viewed with UV light; Image C, MacConkey agar; and Image D DNA'se agar.
Haemophilus parainfluenzae A Legionella dumoffii B Pseudomonas aeruginosa C Aeromonas hydrophila D
Adult Ascaris lumbricoides worms live in the:
Small Intestines
Match the names of each of the bacterial species with its most likely appearance on blood agar, as illustrated in the photographs.
Staphylococcus aureus A Streptococcus milleri (anginosus) B Viridans streptococcus C Beta hemolytic streptococcus, group C D
Who are we huddled here so tight Like clusters of stars in the night.
Staphylococcus epidermidis
The bacteria illustrated in this image were observed in a gram stain of a positive blood culture. The bacterial species most likely to grow out in culture is (surprise):
Staphylococcus hominis
Which of the following species of hyaline molds produce conidia in chains?
Scopulariopsis species
Illustrated in this photograph, reading from left to right, are tubes of Kligler Iron agar (KIA), Sulfide Indole Motility agar, indole broth, Voges Proskauer broth and Simmons citrate. The bacterial species most likely producing the reactions illustrated here is:
Shigella sonnei
Which of the following specimens is the most sensitive for detecting active CMV infection:
Urine
Which of the following tests would you employ to examine a CSF for syphilis:
VDRL
Each of the following bacterial species have the common characteristic of the failure to decarboxylate lysine, ornithine and arginine except:
Yersinia enterocolitica
A 27-year-old man who had recently worked as a medical laboratory scientist on the Navajo Indian reservation presented to the emergency department with high fever, diarrhea and prostration. Axillary lymph nodes were hemorrhagic and enlarged. A smear was prepared from a lymph node aspirate and many Gram-negative bacilli were noted. The bacilli demonstrated a marked bipolar staining reaction described as a "safety-pin appearance" with Wayson stain. The most likely identification of this organism is:
Yersinia pestis
A major difference between Salmonella enterica and Shigella infections is that only in salmonellosis can:
animals serve as a reservoir of infection
When subcultured some Brucella microorganisms may exhibit a switch from smooth colonies to rough colonies, and this may also be associated with their:
diminished reactivity with Brucella specific antibodies
Which of the following sugars has been fermented by a gram-negative rod that has produced an alkaline slant and an acid butt on triple sugar iron agar (TSI).?
glucose
Neisseria gonococci and Neisseria meningococci have the ability to oxidize which of the following chemicals?
tetramethyl-p-phenylenediamine dihydrochloride
The trophozoite state of the intestinal flagellate Giardia lamblia is characterized by:
two nuclei
Match each of the laboratory tests listed with the corresponding gas listed that is produced as the end stage of reaction.
Lysine decarboxylase CO2 Urease NH4 Catalase O2 Denitrification N2
Examples of organisms where molecular methods currently provide GREATER specificity in identification (compared to current phenotypic methods) include: (Choose all that apply.)
- Corynebacterium and related genera - Nocardia and related genera - Dimorphic mycologic pathogens
Match the name of the bacterial species listed with its most likely associated infectious disease syndrome listed.
- Dematophylus congloensis - "Foot rot" or "pitted karyolysis" - Nocardia brasiliensis - Subcutaneous mycetoma - Bacillus cereus - Food borne enteritis - Corynebacterium ureolyticum- Alkaline crusted cystitis
Match the type of media from the drop down box with the phrase listed below that best describes that media:
- Differential - Contains certain factors that allow colonies of specific organisms to appear different than other colonies. - Selective - Media that contains agents that inhibit all but one specific organism. - Enrichment- Encourages the growth of specific types of organisms.
Place in proper sequence the four steps to satisfy Koch's postulates.
- Fourth - Recover same organism from lesions of experimental animal - Second - Inoculate pure culture of organism isolate into experimental animal - Third - Observe development of a similar disease in inoculated animal - First - Observe the same organism in all cases of a newly suspected disease
Match type of hemolysis on the right with best description:
- Gamma hemolysis - No visible effect on blood - Alpha hemolysis - Green area around bacteria incomplete hemolysis - Beta hemolysis - Clear area around bacteria complete hemolysis
A clean catch urine was streaked to a sheep blood agar plate and a MacConkey plate with a one microliter loop. The images below demonstrate what grew. How would you report the colony count and growth?
10^3 colony forming units per milliliter of a gram negative bacillus.
The glycoproteins associated with the HIV "spike" are:
120 and 41
The recommended temperature/time/pressure for routine steam sterilization of media is:
121° C for 12-15 minutes @ 15 psi
The subsurface umbrella-shaped zone of motility seen in this SIM tube (arrow) is characteristic of Listeria monocytogenes. The optimum temperature of incubation to best illustrate this property is:
25°C
The appropriate media for the isolation of anaerobic bacteria from any source would normally include all of the following EXCEPT:
MacConkey's agar
Which of the following best describes yeast cells on a Gram stain as to size and staining characteristics?
About the same size as red blood cells/will stain blue
The bacterial species growing on the surface of the MacConkey agar plate shown in this photograph, a coccobacillary nonfermenter and a common cause of nosocomial hospital acquired pneumonia, can be presumptively identified as:
Acinetobacter baumannii
For each of the spot tests illustrated in the photographs, match each of the bacterial species for which the positive reaction shown is most helpful in making a presumptive identification:
Aeromonas hydrophila A Staphylococcus intermedius B Beta streptococcus, group A C Escherichia coli D
What is the most likely identification of a rapidly growing hyaline mold that began as a white colony and later develops a black "pepper" effect on the agar surface. As the colony aged it produced a black matte making it resemble a dematiaceous mold
Aspergillus niger
The clinical Gram stain taken from an endocervix revealed many WBC's with both intracellular and extracellular gram- negative diplococci. The specimen was plated onto a Modified Thayer-Martin plate and incubated. Following incubation, colonies resembling N. gonorrheae were inoculated into separate CTA tubes containing glucose, lactose, sucrose and maltose. The fluorescent monoclonal antibody test was positive as well as the CTA maltose and glucose tubes. What is the most appropriate next step?
Analyze another maltose tube using a known strain of N. gonorrhoeae
The OF dextrose activity is a key initial assessment in the presumptive identification of the nonfermentative gram negative bacilli. Place each of the bacterial species into Bucket A if it utilizes dextrose oxidatively (yellow reaction in the open tube) or into Bucket B if it is non-oxidative (produces no acid in either the open or the closed tube).
Bucket B Comamonas testosteroni Bucket A Burkholderia pickettii Bucket B Alcaligenes faecalis (odorans) Bucket B Moraxella osloensis
Match the culture media on the right with possible organism on the left:
Macconkey agar Shigella Lowenstein-Jensen media Mycobacteria Thayer-Martin Neisseria PPLO agar Mycoplasma
Which of the following fungal species do not produce pseudohyphae on cornmeal agar?
Cryptococcus laurentii
Which antibiotic is used to suppress or kill saprophytic molds in media?
Cycloheximide
A stool from a two-year-old girl grew clear colonies on MacConkey agar, red colonies on XLD, and green colonies on HE without black centers. It was ornithine positive and indole negative. It should agglutinate in antisera of which serogroup?
D
Illustrated in this photograph are colonies growing on the surface of a chocolate agar plate. The colonies were recovered from a subcutaneous infection of the forearm and had a bleach odor. The most likely identification is:
Eikenella corrodens
Match each organism listed below with the culture medium from the drop down box that is used for organism differentiation and/or optimum organism recovery.
Enriched thioglycolate medium Anaerobes Hektoen enteric agar Salmonella/Shigella Sabourand dextrose agar Fungi
Match the name of each of the bacterial species listed with its most likely associated clinical condition.
Enterobacter sakasakii Neonatal meningitis Morganella morganii Alkaline cysitits Klebsiella ozaenae Atrophic rhinitis Yersinia pseudotuberculosis Mesenteric adenitis
This suspicious form, seen in a scotch tape prep, measures 54 micro meters by 28 micro meters.
Enterobius vermicularis egg
Illustrated in the photograph is a bile esculin agar plate inoculated with a bacterial isolate from a urinary tract infection. The most likely identification is:
Enterococcus faecalis
The upper image is a photomicrograph of a gram stain prepared from a positive blood culture obtained from a 68 year old female with an indwelling urinary bladder catheter. Smooth, gray, faintly beta hemolytic colonies were recovered in subcultures of the positive bottle. The tubes shown in the lower photograph are: an esculin slant (left) displaying intense brown coloration a 6.5% sodium chloride broth (right) showing cloudy growth The most likely identification is
Enterococcus faecalis
An alpha-hemolytic, catalase negative, gram-positive coccus from a wound culture gave these additional results: A disc negative Bile esculin hydrolysis positive CAMP negative Na hippurate hydrolysis negative PYR positive Which of the following would be the MOST probable identification?
Enterococcus species
A dermatophyte that produces thin-walled, two or three-celled macroconidia, and no microconidia, most likely belongs to the genus:
Epidermophyton
Match the names of each of the bacterial species with its most likely appearance in the agar plates shown in the photographs. Images A, B and D are MacConkey agar; Image C is Hektoen Enteric (HE) agar.
Escherichia coli A Shigella sonnei B Citrobacter freundii C Klebsiella pneumoniae D
A stool culture was received and inoculated to XLD, Sorbitol MacConkey, Campy blood agar, and Yersinia Selective Agar. Which one of the organisms below can you rule-out if the colonies on the XLD were red, all the colonies on the Sorbitol MacConkey were red, all the colonies Cefsulodin Irgasan Novobiocin (CIN) Agar on were clear with red centers, and the Campy agar had small, gray colonies?
Escherichia coli O157:H7
Fermentation, with the end production of mixed acids, and oxidation, with the final production of CO2 and H2O, are two metabolic pathways that help to separate different species of bacteria. Match the names of each of the bacterial species listed below into the appropriate bucket - A (fermenter) or B (oxidizer).
Fermenter Aeromonas hydrophila Oxidizer Pseudomonas aeruginosa Fermenter Yersinia enterocolitica Oxidizer Acinetobacter baumannii
Based on the reactions observed in the tubes shown in the photograph (including open and closed OF dextrose and a positive nitrate reaction only after addition of zinc dust, as shown in the right tube of this pair), the most likely identification is:
Flavobacterium odoratum
The well circumscribed cutaneous papule with the distinct outer erythematous border illustrated in the upper photograph developed over a period of 5 days at the site of a tick bite. The lower photograph illustrates colonies growing on a buffered charcoal yeast extract agar plate that had been inoculated with material from the ulcer bed three days before. Tiny, pale-staining gram negative coccobacilli were seen on gram stain. The most likely causative agent is:
Francisella tularensis
Which one of the following organisms is sensitive to bacitracin:
Group A Streptococcus
Which one of the following statements is true regarding the 2009 H1N1 virus?
In 2009, the novel H1N1 virus spread during warmer months.
It is common practice to perform a spot indole test on all swarming Proteus species recovered from wound infections. The rationale for this practice is:
Indole positive strains tend to be penicillin resistant
Which of these describes the mode of action of the beta-lactam class of antibiotics?
Inhibits cell wall synthesis
Which one of the following comments about Francisella is not true?
Is a strict anaerobe
Which one of the following statements about Coxiella burnetii is not true:
It is best diagnosed by culture of the organism
Illustrated in this photograph, reading from left to right, are biochemical reactions for indole, Voges Proskauer, Simmons citrate and Christensen's urea. The bacterial species providing the best fit for the reactions illustrated is:
Klebsiella oxytoca
The beta hemolysis seen around the opaque, flat, spreading colonies illustrated in this photograph of a 5% blood agar plate is helpful in differentiating Bacillus cereus (hemolytic) from Bacillus anthracis (not hemolytic). Each of the following characteristics is also helpful in differentiating these two species except:
Lecithinase production
Match the names of each of the conditions listed with the name of its most likely associated bacterial agent:
Liver abscess Streptococcus "milleri" Pseudomembranous colitis Clostridium difficile Carcinoma of the colon Streptococcus bovis Acute food poisoning Bacillus cereus
Which of the hyaline mold colonies that are represented in the composite picture on the right is typical of Penicillium species?
Lower left quadrant
Each of the following tests is helpful in the species identification of Staphylococcus aureus except:
Modified dimethyl sulfoxide (DMSO) test
Thirty nine of 99 school children developed signs and symptoms of conjunctivitis (Ringvold, et al, Acta Ophthalmol 63:527-431, 1985). Itching of the eyes, reddening of the conjunctiva, purulent secretion and lid edema were experienced in varying degrees of severity. Based on the colony morphology as seen in the upper photograph, representative of the growth recovered from conjunctival secretions and the gram stain features shown in the lower photomicrograph, the most likely identification is:
Moraxella lacunata
Illustrated in this photograph are two Middlebrook 7H-11 plates incubated at 35°C, on which are growing colonies of an unknown Mycobacterium species. The plate on the left was incubated in the dark; the plate on the right had been exposed to light for 24 hours. The most likely identification is:
Mycobacterium kansasii
A 67-year-old homeless man was seen in the ambulatory clinic for chest pain and sputum production. A mycobacterial culture showed the following: rough, non-pigmented colonies, which grew after 2 weeks at 35oC and failed to grow at other temperatures, serpentine cording, a strongly positive niacin test, nitrate reduction, and loss of catalase activity after heating at 68oC in pH 7. What is the most likely identification?
Mycobacterium tuberculosis
All of the following observations are consistent with the laboratory identification of Cryptococcus neoformans except:
Negative urease test
The oxidase test is used to presumptively identify:
Neisseria
Match the names of the Neisseria species listed with its corresponding biochemical profile indicated.
Neisseria gonorrhoeae Glucose +, maltose -, lactose - Neisseria cinerea Glucose -, maltose -, lactose - Neisseria lactamica Glucose +, maltose +, lactose + Neisseria meningitidis Glucose +, maltose +, lactose -
The type of sporulation of the dematiaceous mold that is illustrated in this photomicrograph is called:
Rhinocladiella
What is successful molecular identification of methicillin-resistant Staphylococcus aureus (MRSA) based upon? (Choose the BEST answer)
SIMULTANEOUS detection of the S. aureus orfX gene and SEVERAL variants of the mecA gene.
This suspicious form, found in urine, measures 120 micro meters by 50 micro meters.
Schistosoma haematobium
Illustrated in this photograph is an agar quadrant plate containing casein (A), tyrosine (B), nitrate (C) and xanthine (D). None of the substrates have been hydrolyzed and nitrate has been reduced. The most likely identification is
Nocardia asteroides
Enterococcus faecium is:
Often vancomycin resistant
The yeast forms of which of the following species of dimorphic fungi (represented in the image on the right) can be described as large yeast cells with multiple buds that are attached by narrow necks, giving the appearance of a "mariner's wheel"?
Paracoccidioides brasiliensis
Recovered from a sputum sample, this suspicious form measures 112 micro meters by 55 micro meters.
Paragonimus westermani egg
Which of the following is used as the indicator in the rapid carbohydrate utilization tests:
Phenol red
A nitrate test is performed on a glucose nonfermenter. When the nitrate reagents were added, no color change occurred. When zinc dust was added, no color developed. This test should be reported as:
Positive for molecular nitrogen and negative for nitrite production
A flagellar strain would show peritrichous flagellae for each of the following organisms except:
Pseudomonas aeruginosa
Which one of the following tests should be used to monitor a patient's response to treatment for syphilis:
RPR titer
The disappearance of HBsAg and HBeAg, the persistence of anti-HBc (total), the appearance of anti-HBs, and often of anti-Hbe indicate:
Recovery phase of HBV infection
This intestinal parasite, found in stool, measures 170 micro meters by 63 micro meters.
Schistosoma mansoni egg
Match the names of the bacterial species listed with the animal source from which humans are most likely to become infected.
Streptobacillus moniliformis Wild rats Francisella tularensis Wild rabbits Brucella abortis Dairy cattle Pasteurella multocida Domestic cats
What are the two general categories of nucleic acid amplification (NAA) techniques?
Target amplification and signal amplification
What is the identifying characteristic of Aureobasidium pullulans?
The production of a black yeast-like colony
The arrows in the image on the right point to single, long, tapered phialides that extend laterally from either side of the hyphae. This is an identifying feature of which of the fungi listed below?
Trichoderma species
The oxacillin screen test alone is not sufficient for determining the susceptibility to penicillin for S. pneumoniae isolates recovered from cerebrospinal fluid (CSF).
True
The reactions seen in the portion of the API strip shown in the photograph, effectively rules out Escherichia coli.
True
