M(ASCP) LabCE Questions

This organism is gram(+) cocci in pairs that are often Lancelet-shaped (or "cat-eyes")

Streptococcus pneumoniae

These colonies were slow growing, small, entire and show soft beta hemolysis. Plump, Gram-negative coccobacilli, lying singly, in pairs and short chains, are seen on gram stain. Most strains are chemically non-reactive except for a positive oxidase reaction and acid produced from dextrose and maltose. What is the name of the isolate?

Kingella kingae

The oxidase test is utilized to presumptively ID which of the following: Serratia, Enterobacter, Escherichia, Neisseria

Neisseria

This anaerobic bacteria produces double zone of beta-hemolysis on SBA

C. perfringens

Edwardsiella tarda is known to be associated with what animal?

reptiles

There are tiny, gray-white, non-hemolytic colonies growing on the surface of blood agar. Recovery is most often from infections in immune-suppressed hospitalized patients.

The Gram stain shows Gram-positive bacilli arranged in a "diphtheroid" pattern. Characteristic for making a species identification of this isolate are negative reactions for all enzymes.

What is the presumptive ID?

Corynebacterium jeikeium

What is the first step of the ethyl acetate concentration procedure?

Mix stool with 10% formalin and strain for sediment

A suspected nocardioform bacterial species was recovered from sputum. The isolate produced mucoid colonies with pink pigment after 4 days on SBA.

Staining demonstrated diphtheroid, Gram positive rods with a few branching filaments. It also stained partially acid fast.

The most likely identification is:

Rhodococcus equi

Acinetobacter does or does not denitrify nitrogen like Pseudomonas does?

Does not

Slow-growing Streptococcus-like species variously known as "satelliting," "nutritionally dependent," or "thiol requiring" need thiol compounds, such as cysteine or the active form of vitamin B6 (pyridoxal), added to culture media to promote growth.

This organism may appear as satellite colonies on a CAMP test and is GPC in chains:

Abiotrophia defectiva

The ingredient added to culture media to enhance the recovery of the dimorphic fungi by preventing the overgrowth of more rapidly growing, saprophytic molds is:

cyclohexamide

Which of the following terms is used to describe the appearance of rod-shaped bacteria: budding, lancet, filamentous, septate

filamentous

Which HPV are associated with cervical cancer?

16 and 18

A ß-hemolytic isolate on SBA revealed a Gram-positive cocci arranged in chains. The isolate was catalase negative, PYR negative, bacitracin resistant, and positive for CAMP and hippurate hydrolysis. What is the presumptive identification of this isolate?

Group B Strept

Calcofluor white will bind to the cell wall of fungi and enhance the visibility in tissue. This stain can also be used to aid in the detection of what species?

Microsporidia

Which organism's troph has a small central karyosome in the nucleus and ingested RBCs?

Entamoeba histolytica

The organisms Klebsiella pneumonia, Enterobacter cloacae, and Escherichia coli can produce carbapenemases due to which of the following genes?

blaKPC

Nocardia farcinica is negative for what test?

gelatin hydrolysis

A sputum specimen submitted for culture is brick red in color. The organism causing this sputum color, also has a distinct polysaccharide capsule and is non motile. What organism can be associated with this sputum?

Klebsiella

Which of the following viruses require a complex lymphoblastoid cell culture, and is rarely, if ever, diagnosed by culture?

1. HSV

2. EBV

3. CMV

4. VZV

EBV

Among the non-fermenters, which of the following is the only bacterial species to produce hydrolyze esculin?

1. Paracoccus yeei

2. Psychrobacter immobilis

3. Shewanella putrifaciens

4. Rhizobium radiobacter

Rhizobium radiobacter

This organism is an intestinal-tissue nematode whose larvae encyst by coiling in muscle tissue. Humans are an accidental host that becomes infected when encysted larvae are ingested through poorly cooked pork.

Trichinella spiralis

Which organisms trophozoite has a blot-like karyosome with no peripheral chromatin?

E. nana

Large, one-celled, smooth-to-tuberculate macroconidia, and smooth or echinulate microconidia are typical of mycelial phase growth of which organism?

H. capsulatum

Which of the following substances may mask parasites in a stool sample?

1. Barium

2. Saline

3. Phosphasoda

4. Antimicrobials

Barium

Which of the following dematiaceous fungi can cause Chromoblastomycosis?

1. Curvularia species

2. Cladophialophora species

3. Bipolaris species

4. Exophiala species

Cladophialophora species

Several dematiaceous hyphae with long, flask-shaped, tapered phialides that have flat saucer-like terminus are seen. This feature is most characteristic of which fungal species?

Pleurostomophora richardsiae

Anaerobic plates are rarely utilized to culture CSF specimens because anaerobic organisms rarely cause what disease?

meningitis

A 20-year-old female was admitted into the hospital complaining of 10 to 15 bloody mucous stools per day, fever, gastrointestinal disturbances, abdominal pain, and nausea. The preliminary O & P report went out as "Probable Entamoeba histolytica trophozoites and cysts, confirmation pending." What is this patient most likely suffering from?

Intestinal amebiasis

All of the following are usually associated with Group A Beta Strep, EXCEPT?

1. Scalded Skin Syndrome

2. Necrotizing fasciitis

3. Pharyngitis

4. Rheumatic fever

Scalded Skin Syndrome

The colonies seen growing on a blood agar are gray-white and have a delicate cob-web appearance. This appearance plus the delayed growth is characteristic of one of the dimorphic fungi.

The lactophenol blue mount reveals delicate background hyphae and the production of macroconidia with a conspicuous prickly surface, characteristic of what?

Histoplasma capsulatum

What is the most commonly encountered enterococcal species?

E. faecialis

The optimum growth temperature of ________________ is 42°C, which enables it to survive and replicate as an environmental contaminant in hot water systems.

This differs than other Mycobacterium as they like to grow at 37 C or below.

M. xenopi

__________________ is an enriched media that supports the growth of Gardnerella vaginalis. The media usually contains 5% human blood without the presence of inhibitors.

Human blood agar

What causes the hemolysis associated with infection by malaria organisms?

Multiplication of merozoites within erythrocytes

Four specimens are received in the laboratory at the same time. The specimens are:

-Urine in specimen cup for urine culture

-Feces in preservative for stool culture

-Cerebrospinal fluid for culture

-Synovial Fluid for culture

Which specimen should be processed first?

CSF for culture

Malassezia furfur is the cause of tinea versicolor. To cultivate this organism, the agar should be overlaid with:

olive oil

What is used for the visualization of bacteria in specimens where debris may be present?

acridine orange

All of the following fungal species produce pseudohyphae on cornmeal agar, EXCEPT:

1. Candida albicans

2. Candida guillirmondii

3. Cryptococcus laurentii

4. Geotrichum candidum

Cryptococcus laurentii

Bacitracin susceptibility testing is useful for:

differentiating staphylococci from micrococci

The saccharolytic anaerobe that produces red fluorescing colonies when illuminated with a Wood's lamp, as shown in this photograph, is:

Prevotella

The following morphologic structure identifies Candida albicans and distinguishes it from most of the other Candida species.

Chlamydospore

Which Aspergillus species has been recovered from the cornea?

Aspergillus fumigatus

The promastigote stage of ________________ is identified by its long slender shape, anteriorly located kinetoplast, lack of an undulating membrane, and presence of a free flagellum. Human hosts are injected with promastigotes when the sand fly takes a blood meal.

Leishmania

Leishmania does not have a __________________ form.

epimastigote

Rocky Mountain spotted fever (RMSF), caused by Rickettsia rickettsii, is MOST reliably diagnosed by which laboratory technique?

IFA testing

This Klebsiella is Indole positive, in addition to VP and Citrate positive.

K. oxytoca

An encapsulated yeast that fails to produce a germ tube, is urease positive and produces brown pigment on bird seed agar is found in a blood culture bottle from a patient with septicemia. What is the MOST likely identification?

C. neoformans

Tiny 4 - 6 µm in diameter acid-fast oocysts that typically adhere to intestinal lining cells, resulting in mal-absorption and other symptoms including cholera-like watery diarrhea.

C. parvum

An organism isolated from the spinal fluid of a newborn produced small, grayish, slightly translucent beta-hemolytic colonies on sheep blood agar. A Gram stain of the colony showed small Gram-positive rods that look like diphtheroids. The organism is MOST likely:

L. monocytogenes

Babesia is a parasitic organism that morphologically resembles which of the following?

1. Pneumocystis jiroveci (carinii) trophozoites

2. Plasmodium falciparum rings

3. Leishmania donovani amastigotes

4. Trypanosoma cruzi trypomastigotes

Plasmodium falciparum rings

Which of the following causative agents (Mycobacterium) is most likely associated with the "swimming pool granualoma" skin lesions ?

1. M. kansasii

2. M. ulcerous

3. M. marinum

4. M. xenopi

M. marinum

The most common organism that causes septic arthritis in patients under 30 years of age is:

Neisseria gonorrhoeae

In patients who present with a classic "strep throat", the beta-hemolytic, catalase negative, Gram positive bacillus that must be included in the differential diagnosis is:

Arcanobacterium haemolyticum

These conidia are distinctive in being long and pencil-shaped, with a large number of cells (8 - 10) separated by transverse septa. Of particular note is the extended, prominent protruding extension from the hilar cells.

Exserohilum spp.

Which of the following specimen processing techniques is based on the principle that parasites are heavier than sample debris and will be present in the sediment after being processed?

1. Ethyl acetate concentration

2. Zinc sulfate flotation

3. Cellophane tape preparation

4. Entero-test

Ethyl acetate concentration