Elsevier Mycology, Virology, and Parasitology

Which of the following terms is best described as the process of reproduction in yeast that begins with a weakening and outpouching of the yeast cell wall and then formation of a cell wall septum between the mother and daughter yeast cells?

Budding

The loose intertwined network of basic structural units of the molds that penetrates the substrate from which it obtains the necessary nutrients for growth is called which of the following?

Mycelium

The term hyaline molds is used to describe which of the following?

Molds that have septate, nonpigmented hyphae

Large, usually multiseptate and club-shaped or spindle-

shaped spores are called which of the following?

Macroconidia

A Scotch tape preparation is made from a mold

growing on solid media in the mycology laboratory. The structure shown in the image is best described as which of the following?

conidiophore

A patient with a Wood's lamp-positive, dermatophytic infection has a skin scraping taken for culture. The organism grows on SDA agar with a light-tan front and salmon-colored reverse. Microscopically the organism produces rare distorted macroconidia and rare microconidia. Additionally, there was no growth on sterile rice media. What is the most likely organism?

Microsporum audouinii

A KOH preparation of respiratory secretions of a 78- year-old man reveals large, spherical, thick-walled yeast cells 8 to 15 mm in diameter, usually with a single bud that is connected to the parent cell by a broad base. Which fungus will likely be isolated from the culture?

Blastomyces dermatitidis

Which of the following is a key characteristic of Coc-

cidioides immitis?

produces endosporulating spherules in tissue

Using PAS to stain a respiratory specimen from a patient with lung disease, the technologists observed the organisms in the image. Based on the microscopic morphology shown in the image, the most likely iden- tification of the dimorphic fungi is which of the following?

Blastomyces dermatitidis

A landscaper noticed a hard, unmovable lump under the skin of his index finger but decided to ignore it. A month later, the lump ulcerated to present a necrotic appearance, and two more lesions developed further up the wrist and forearm. A histologic stain of mate- rial from deep in the lesions showed elongated yeast cells resembling cigars. What disease is suspected?

Sporotrichosis

A germ tube-negative yeast is isolated in the labora- tory. The isolate is found to be negative for urease and unable to assimilate dextrose, maltose, or sucrose. CMT agar morphology showed blastoconi- dia only. The organism is most likely:

Torulopsis glabrata

Which of the following is a key characteristic by which an unknown Cryptococcus spp. can be identi- fied as Cryptococcus neoformans?

positive niger seed agar test

Which of the following statements concerning the germ tube test is true?

Candida albicans and Candida tropicalis can be used as positive and negative controls, respectively

An immunocompromised patient exhibited fever, nonproductive cough, and shortness of breath. Rou- tine and fungal cultures did not grow. The respira- tory specimen was stained with a silver stain in anatomic pathology. Based on the microscopic mor- phology in the image, what is the most likely identi- fication of this organism?

Pneumocystis jiroveci

A significant amount of yeast was isolated from a vaginal culture of a patient in the teen clinic of your hospital. It exhibited the following characteristics: Microscopic: Clusters of blastoconidia along pseu-

dohyphae, terminal chlamydoconidiaPositive germ tubePositive sucroseWhich of the following is the most likely identifica-

tion of this fungi? (Image from primary plate, gram-stained smear, 40.)

Candida albicans

The pharmacy at your hospital was concerned about the hyperalimentation fluid they were preparing. The high lipid contact was a concern for contamination. A PAS stain of the suspect fluid is shown. Which of the following organism would most likely demon- strate this morphology?

Malassezia furfur

Several important types of conidiation of dematiac- eous fungi exist. The image is an example of which one of these forms? (Lactophenol cotton blue stain.)

Rhinocladiella type

A mold isolated in the laboratory displays a white cottony macroscopic morphology. On microscopic evaluation, hyaline, septate hyphae, and "tooth- brush"-like conidiophres are seen. The most likely organism is which of the following?

Acremonium sp.

A mold is isolated in the laboratory that displays a velvety, gray-green colony morphology. On micro- scopic evaluation, flask-shaped conidiophores arranged in a brushlike formation are seen. The most likely organism is which of the following?

Penicillium sp.

A patient who underwent solid organ transplant

appears to have systemic fungemia. The organism that has grown from the blood cultures macroscopi- cally had a blue-green color to the colony, matured in 3 days, and grew well at 45 C. Microscopically, foot cells were seen and the phialides were uniserate with a round vesicle and columnar conidia. Which of the following is the most likely identification of this mold?

Aspergillus fumigatus

The protein coat that surrounds the nucleic acid of a virion is called which of the following?

Capsid

During viral assembly, how are viral envelopes acquired?

As the virion buds from a host cell membrane

Prions are best described by which of the following?

infectious protein with no associated nucleic acid

The viral nucleocapsid always contains which of the following?

Viral genome

Which of the following viruses are thought to predominately cause gastroenteritis?

Noroviruses

Which of the following groups contains the SARS virus?

Coronavirus

Which of the following groups of virus is best described as:

ssRNA, enveloped,Pleomorphic/spherical capsidLarge club-shaped spikes on surface gives "corona"

effectCauses approximately 15% of coldlike illness

Coronaviruses

Which of the following is the specimen of choice for detecting rotavirus?

feces sample

The test of choice and most sensitive assay for use with CSF to diagnose aseptic meningitis caused by enterovirus is which of the following?

PCR

A specimen from a genital lesion was inoculated into a standard set of cells for virus isolation. On day 1 the human foreskin fibroblasts exhibited the CPE shown in the figure.

Herpes simplex virus

Trophozoite forms of amoebae are found in what type of stool specimen?

watery

Which preservation method is most suitable and the most widely used for subsequent fixed smear preparation?

PVA

If the ova of this parasite are ingested by humans, the oncosphere form can migrate through the body via the bloodstream, resulting in the condition known as cysticercosis. Which of the following is correct?

Taenia solium

Ova recovered from the stool are routinely used to diagnose infections caused by all of the following except?

Strongyloides stercoralis

An MLS finds an E.colicystona wet mount of a fresh stool specimen. Which of the following should be done?

Examine the remaining area of the wet preparation

Which of the following parasites have migration through the lungs as part of their lifecycle?

Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis

The image below is of a suspected parasite seen on direct examination of material taken from a corneal scraping in an ophthalmology clinic. The most likely identification of the parasite in this specimen is which of the following?

Acanthamoeba sp.

The organism shown below was recovered from the stool of a patient who resides in rural Texas. The most likely identification is which of the following?

Trichuris trichiura

The eggs in the figure below were found in the urine of a Peace Corp worker who had just returned to the United State after spending 2 years in the Middle East. The eggs measured about 160 mm long 60 mm wide. Which of the following organisms is the most likely identity?

Schistosoma haematobium

A patient was diagnosed with cysts in his liver. He is originally from Australia, where he was involved in a sheep herding operation. The adult parasite shown below was passed by his pet dog. It measured 5 mm. What is the most likely identification of this organism?

Echinococcus granulosus

These trophozoites were found in a trichrome- stained slide of a stool sample, measuring an average of 25 microns in diameter. Which of the following is the most likely identity of this organism?

Entamoeba coli

The cyst in the image below was observed in a stool sample of a child at a daycare center. The ovoid cyst measures approximately 10 8 microns. Which organism is the most likely cause of the child's diarrhea?

Giardia lambia

The image below is a cyst found in a human fecal smear. The cyst measured about 12 mm in length and contained four nuclei and a rounded chromatoid bar. The patient had severe diarrhea and some blood in the stool. What is the most likely identification of this organism?

Entamoeba histolytica

_

Microfilariae found in the blood that have a sheath, demonstrate nocturnal periodicity and exhibit nuclei that do not extend to the tail tip are which of the following?

Wuchereria bancrofti

Necator americanus rhabditiform larvae can be dif- ferentiated from Strongyloides stercoralis rhabditi- form larvae by:

size of the genital primordium

The image below is from a fecal smear of an individ- ual complaining of diarrhea and intestinal discom- fort. The parasites were numerous and quite variable in size, but the majority measured about 15 to 20 mm in diameter. What is the most likely iden- tification of this organism?

Blastocystis hominis

The only known human tapeworm with an opercu- lum is:

Diphyllobothrium latum

Identify the following organism as it appears in this peripheral blood smear.

Trypanosoma sp.

Plasmodium falciparum

Delicate ring forms, multiple rings per cell, crecent-shaped gametocytes after 7-10 days

Plasmodium malariae

RBC normal in size and color, troph compact, band forms may be seen, gametocytes seen after weeks

Plasmodium ovale

RBC enlarged, oval, Schuffner's dots, gametocytes seen by day 4 to 18

Plasmodium vivax

Large RBC, troph irregular, multiple phases seen, gametocytes appear early

Body louse

Pediculus humanus humanus

Ixodes Scapularis

Lyme disease

Bedbug

Cimex lectularius

Scabies

Sarcoptes scabiei