MLT 112 Final Exam Review

Systemic Mycoses: Candida auris

-An emerging multidrug-resistant yeast linked to high mortality rates in hospital-acquired infections worldwide (nosocomial) •In hospital setting, likely transmitted patient to patient •Colonized patients should be placed on contact precautions (recommendation of the CDC).

Mycology Reproduction: ASEXUAL REPRODUCTION

-Yeast form blastoconidia -Mold form conidum or spore ØMitotic division of haploid nucleus and budding production of conidia ØFruiting Bodies •Imperfect Fungi •specialized supportive hyphae •Blastoconidia are the beginning structures of Pseudohyphae •Chlamydoconidia -thick walled structures, typically terminal end, rich in lipid - resting stage •Arthroconidia-hyphal fragments at cross walls- Result of breaking off process of true septate hyphae •Ariel Structures Phialides Vase-like structures that produce phialoconidia

How many stool samples should be collected when the following the typical O & P Collection Protocol? a) 1 b) 2 c) 3 d) 4

3

The characteristic that most clearly differentiates cysts of Iodamoeba butschlii from other amebic cysts is (are): a) Chromatoid bars with rounded ends b) eight nuclei with eccentrically located Karyosome c) ingested bacteria and RBC's d) a large glycogen vacuole

A large glycogen vacuole

Dimorphism

Ability to exist in two forms based on growth conditions •Mold phase: 22 to 25° C (room temperature) •Yeast phase: 37° C with increased carbon dioxide (CO2)

Differences in which of the following morphologic forms serve as criteria necessary to speciate the hookworms? A. Eggs B. Rhabditiform larvae C. Encysted larvae D. Adult worms

Adult worms

Black water fever can be described by which of the following: a. Marked hemoglobinuria b. Development of autoantibodies c. Anemia & deposits of malarial pigments in organs d. All of the above

All of the above

Which of these parasites are contracted via penetration? a) Enterobius, Necator, Dracunculus b) Ascaris, Trichinella, Ancylostoma c) Ancylostoma, Strongyloids, Necator d) Trichuris, Strongyloides, Enterobium

Ancylostoma, Strongyloids, Necator

The species of mosquito most commonly known to serve as vector for the genus Plasmodium is? a) Ixodes b) Anopheles c) Culex d) Glossina

Anopheles

These two nematodes are similar in that they are both suspected of being transport hosts of Dientamoeba fragilis. A. Trichinella and Dracunculus B. Necator and Trichuris C. Strongyloides and Ancylostoma D. Ascaris and Enterobius

Ascaris and Enterobius

Opportunistic Mycoses: Aspergillus

Aspergillus - Dandelion-like •Septate and Hyaline Saprophytes • Pathogenic species of Interest --A. fumigatus—most often see- Green Conidia --A. flavus- Yellow Conidia --A. niger- Black Conidia Mortality is high, especially in the immune-compromised. Particularly neutropenic individuals Infection •Inhalation of spore-contaminated dust •Sinusitis or bronchopulmonary disease •Most frequent cause of disease in the bone marrow of transplant recipients Disseminates from the lungs homogenously to other organs Allergic reactions

A 15-year-old boy spend most of the summer at the northern Minnesota family cabin on a lake in a densely wooded area. After returning to school in the fall, he was frequently tired and listless with periods of fever and chills. A blood sample revealed the following organism at 1000x. The most likely identification is image shows RBCs with cross or tetrad in it a) Plasmodium falciparum b) Babesia microti c) Plasmodium vivax d) Plasmodium malariae

Babesia microti

Identify this parasite: "contains red blob covering almost entire parasite" a) Entamobea polecki b) Endolimax nana c) Entamoeba coli d) Blastocystis hominis

Blastocystis hominis

Stool specimens were collected from an asymptomatic 10-year-old boy from Panama as part of a refugee screening program. The stool was collected in 10% formalin and zinc PVA (Zn-PVA) and sent to the county health department for routine ova-and-parasite (O&P) examination. What is the suspected parasite? Image of three cells with large red vacuole. a) Naegleria fowleri b) Blastocystis hominis c) Dientamoeba fragilis d) Blantidium coli

Blastocystis hominis

The specimen of choice for the recovery of babesia microti is: a) Tissue b) CSF c) Blood d) Stool

Blood

There are very few procedures considered STAT in parasitology. The most obvious situation would be: a) O & P examination for Giardiasis b) Urine sample for Trichomonas c) Blood films for Malaria d) Sputum sample for larvae

Blood films for Malaria

A paroxysm is: a) Associated with the growth of the parasite b) A periodic episode characterized by fever and chills c) Both A & B are correct d) None of the above

Both A & B are correct

Which morphologic form can be seen in infectious Plasmodium malariae? a) Mature Schizont b) Maurer's dots c) Banana shaped gametocyte d) Birds-eye ring form

Brids-eye ring form

What is the purpose of fixatives for the collection of stool samples: a) Enhance the motility of protozoan b) Identify protozoan trophs only c) Detect and identify protozoan trophs and cysts d) identify protozoan cysts only

Detect and identify protozoan trophs and cysts

A patient from the Great Lakes area presents with vague abdominal symptoms and a macrocytic anemia. Lab results show a deficiency in Vitamin B12. Which Cestoda would be the most probable cause? a) Diphyllobothrium latum b) Echinococcus graulosus c) Taenia saginata d) Hymenolepsis nana

Diphyllobothrium latum

Hydatid cyst disease is usually identified by accident on a liver x-ray. When a cyst ruptures and releases foreign proteins (allergen) they can elicit an anaphylactic response? Which parasite causes hydatid sand predominately in the liver? a) Hymenolepsis nana b) Echinococcus granulosus c) Dipylidium caninum d) Taenia saginata

Dipylidium caninum

Which technique is used to detect the eggs of Enterobius vermicularis? a) duodenal aspirate b) sigmoidoscopy c) Cellophane tape prep d) Skin Nips

Cellophane tape prep

Infection with Enterobius vermicularis is best diagnosed by which one of the following methods? a) Examination of feces for eggs & adults b) Serology tests c) Perianal itching noted by patient d) Cellophane tape preparation

Cellophane tape preparation

Mycology Safety Issues

Class II biosafety cabinet Reduces personal exposure Enclosed electric incinerator Eliminates the hazards of open gas flames Use of Petri dishes is hazardous; use screw-top tubes to prevent aerosols.

This fungal element is the most virulent of all human mycotic agents. Found in the San Joaquin Valley of California and South-Central America. The fungus has both a tissue and mold phase. A) Aspergillus funigatus B) Coccidioides immitis C) Histoplasma capsulatum D) Blastomyces dermatitidis

Coccidioides immitis

This fungal element produces arthroconidia that form a block or barrel formation which have alternating empty space within the arthrocondidia. They are inhaled causing pulmonary or allergic manifestations. They are considered one of the most virulent of all human mycotic agents. A) Paracoccidioides brasiliensis B) Histoplasm Capsulatum C) Aspergillus Species D) Coccidioides immitis

Coccidioides immitis

Mycoses

Diseases caused by fungi (singular mycosis) •Disease categories: Based on sites of infection ØSuperficial, Cutaneous, Subcutaneous, Systemic 1. Superficial & Cutaneous ØInfections confined to the outermost layer of skin or hair. • Fungi degrade keratin (dermatophytes) •Fungi that cannot degrade keratin (nondermatophytes) 2.Subcutaneous Ø Infectious involve deeper skin layers, as well as muscle, connective tissue, and bone •Dissemination in blood does not occur •Nonhealing ulcers, draining sinus tracts 3. Systemic Ø Disseminated infections that affect internal organs or deep tissues of the body •Frequently initial site of infection is the lungs. Disseminates through the lymphatic system. •Important to note any fungus is capable of disseminating from the primary site in an immunocompromised patient

The largest adult nematode, found subcutaneously is in the lower extremities of the infected host? a) Ascaris lumbricoides b) Drancunculus medinensis c) Onchocerca volvulus d) Wuchereria bancrofti

Drancunculus medinensis

The incorrect match between the organism and the appropriate diagnostic procedure: a) Onchocerca volvulus- examination of skin snips b) Trichinella spiralis- encysted larvae in tissue biopsy c) Echinococcus granulosus- Routine O & P examination d) Schistosoma haematobium- Examination of urine sediment

Echinococcus granulosus- Routine O & P examination

When humans have hydatid cyst disease, the causative agent and host classification are: a) Echinococcus granulosus- accidental intermediate host b) Stronglyloides stercoralis- definitive host c) Taenia solium- accidental intermediate host d) Hymenolepsis nana- definitive host

Echinococcus granulosus- accidental intermediate host

Swelling of the lower extremities due to obstruction of the lymphatic system by adult filaria nematodes is known as: a) Cysticercosis b) Schistosomasis c) Elephantiasis d) Echinococcosis

Elephantiasis

Which of the following intestinal protozoa is not identified as a causative agent of diarrhea? a) Entamoeba histolytica b) Entamoeba coli c) Giardia intestinalis d) Balantidium coli

Entamoeba coli

A young couple returned from a honeymoon trip to Mexico. Two weeks later, the young man began having diarrhea that was very severe. Finally after three days he went to the doctor. The doctor ordered a stool culture and O & P. The technician noted bloody mucus in the liquid specimen and prepared a wet mount. An irregular motile organism measuring approximately 15 um was observed. The trophozoite has ingested RBC's. What parasite do you suspect? Two images side by side; both predominately blue. Image on right has cell with two "circles" and a bar a) Balantidium coli b) Entamoeba histolytica c) Iodamoeba butschlii d) Endolimax nana

Entamoeba histolytica

Amebic dysentery is caused by: a) Entamoeba histolytica b) Entamoeba coli c) Endolimax nana d) Entamoeba hartmanni

Entamoeba histolytica

The most prevalent helminth to infect humans is: a) Enterobius vermicularis b) Ascaris lumbricoides c) Taenia saginata d) Schistoma mansoni

Enterobius vermicularis

What genus and species is collected using the Cellophane Tape Test? a. Endolimax nana b. Entamoeba histolytica c. Iodamoeba butschlii d. Enterobius vermicularis

Enterobius vermicularis

The most prevalent helminith to infect humans is: a) Enterobius vermicularis, the pinworm b) Ascaris lumbricoides, large intestinal roundworm c) Taenia saginata, the beef tapeworm d) Schistosoma mansoni, one of the blood flukes

Enterobius vermicularis, the pinworm

Charcot-Keyden crystals in stool may be associated with an immune response and are thought to be formed from the breakdown products of: a) Macrophages b) Lymphocytes c) PMN's d) Eosinophils

Eosinophils

Charcot-Leyden crystals in stool may be associated with an immune response and are thought to be the breakdown products of: a) Neutrophils b) Eosinophils c) Monocytes d) Lymphocytes

Eosinophils

Solution used in sedimentation concentration technique a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Ether or Ethyl acetate

Human infection with onchoverva volvulus is best diagnosed by which of the following: a) Examination of the infected mosquito b) Examination of the blood smears c) Examination of the feces d) Examination of a skin scraping

Examination of a skin scraping

The eggs of the following intestinal and liver fluke are difficult to differentiate. What two parasites fits the description of this egg: Image of egg shaped cell a) C. sinensis, S. japonicum b) P. westermani, C. sinensis c) S. mansoni, S. japonicum d) F. buski, F. hepatica

F. buski, F. hepatica

True or False Dracunculosis is the disease or condition caused by the nematode hookworm.

False

True or False Hemoflagellates are typically found in stool samples,

False

True or False Humans and dogs are the definitive host of Necator americanus.

False

True or False Hydatid sand is caused by Toxocara species

False

True or False Hymenolepsis nana is known as the rat tapeworm.

False

True or False Plasmodium falciparum is commonly found in the United States.

False

True or False This nocturnal microfilarial is encased in a sheath, nuclei extend into the tail and is Onchocerca volvulus.

False

True or False Trypanosome brucei gambiense causes East African Sleeping sickness.

False

True/False Superficial & Cutaneous mycoses are infections that involve deeper skin layers, as well as muscle, connective tissue and bone.

False

True/False Trichophyton tonsurans microconidia show peg shaped microconidia growing along the hyphae.

False

True/False Yeast and molds are prokaryotic cells.

False

True/False Calcofluor white stain is a pink fluorescent stain.

False

True/False Dimorphism is the ability to form yeast and mold in the same culture

False

A small operculated egg was found in the feces of a patient with liver abnormalities including obstruction of the biliary ducts caused by the migration of the larvae in the liver. a) Paragonimus westermani b) Fasciolopsis buski c) Clonorchis sinensis d) Fasciola hepatica

Fasciola hepatica

The fluke acquired by eating contaminated vegetation is? a) Clonorchis sinensis b) Fasciolopsis buski c) Paragonimus westernami d) Schistosoma mansoni

Fasciolopsis buski

Which specimen is the least likely to provide recovery of Trichomonas vaginalis? a) Urine b) Urethral discharge c) Vaginal discharge d) Feces

Feces

Molds

Filamentous mycelium -Long strands of tubelike structures called hyphae Reproduction by spores asexually or sexually -Vegetative mycelium: Arthrospores, chlamydospores, blastospores; Rhizoids -Aerial mycelium: Conidia, sporangia

The infective stage of strongyloides stercoralis is: a) Filariform larvae b) Ova c) Free Living adult d) Rhabditiform larvae

Filariform larvae

An E. histolytica (true pathogen) trophozoite has the following characteristics: a) Finely granular cytoplasm, ground glass appearance, clear single pseudopod, compact, small karyosome and ingested RBC's b) Finely granular cytoplasm, ground glass appearance clear single pseudopod, compact, small karyosome and ingested bacteria c) Junky cytoplasm, multiple pseudopod, 8 nuclei and 4 chromatoidal bars d) Large blot-like karyosome, ingested RBC's and PMN's, granular pseudopods

Finely granular cytoplasm, ground glass appearance, clear single pseudopod, compact, small karyosome and ingested RBC's

Crytococcus neoformans results

Growth at: -37oC: pos -42oC: neg -45oC: neg Cornmeal Agar: -Pseudohyphae: neg -True Hyphae: neg -Arthroconidia: neg Urea: POSITIVE Nitrate: neg Germ tube: neg --INDIA INK

C. parapsilosis results

Growth at: -37oC: pos -42oC: neg -45oC: neg Cornmeal Agar: -Pseudohyphae: pos -True Hyphae: neg -Arthroconidia: neg Urea: neg Nitrate: neg Germ tube: neg

C. krusei results

Growth at: -37oC: pos -42oC: pos -45oC: neg Cornmeal Agar: -Pseudohyphae: pos -True Hyphae: neg -Arthroconidia: neg Urea: variable Nitrate: neg Germ tube: neg

C. glabrata results

Growth at: -37oC: pos -42oC: pos -45oC: pos Cornmeal Agar: -Pseudohyphae: neg -True Hyphae: neg -Arthroconidia: neg Urea: neg Nitrate: neg Germ tube: neg

C. tropicalis results

Growth at: -37oC: pos -42oC: pos -45oC: pos Cornmeal Agar: -Pseudohyphae: pos -True Hyphae: neg -Arthroconidia: neg Urea: neg Nitrate: neg Germ tube: neg

C. albicans results

Growth at: -37oC: pos -42oC: pos -45oC: pos Cornmeal Agar: -Pseudohyphae: pos -True Hyphae: pos -Arthroconidia: neg Urea: neg Nitrate: neg Germ tube: pos

Dracunculus medinensis

Guinea worm

Necator americanus and Ancylostoma duodenale

Hookworms

Microsporidia are protozoans that have been implicated in human disease primarily in: a) Pediatric patients b) Elderly patients c) Immunocompromised patients d) Patients that travel in the tropics

Immunocompromised patients

The cysticercus larvae form is found where noted as part of the life cycle of which parasite? a) On aquatic vegetation; Fasciola hepatica b) In fish muscle; D. latum c) In pork muscle; Taenia solium d) In mosquitos; Dracunculus medinsis

In pork muscle; Taenia solium

This stain can be added directly to CSF fluid and examined under the microscope for the presence of Cryptococcus neoformans. The large encapsulated yeast appears as a halo around the cell against a dark background. What is the stain used? A) Gram stain B) Calcofluor White Stain C) Kinyoun stain D) India Ink

India Ink

Histoplasma capsulatum

Infection is usually limited and asymptomatic. •Inhalation of spores •Calcification in the lungs, liver, and spleen Heavy exposure may result in acute pulmonary disease. Infects Reticuloendothelial System (RES) In immunocompromised patients •Progressive and potentially fatal disseminated disease possible Chronic pulmonary histoplasmosis in patients with COPD may occur. Histoplasmosis is also known as •Reticuloendothelial cytomycosis •Cave disease •Spelunker's disease •Darling disease Worldwide distribution •Highest endemicity—Ohio, Missouri, Mississippi river deltas •Found in Bird & Bat droppings Inhalation of microconidia which are phagocytized by pulmonary macrophages. Bone Marrow specimen of choice Mycelial form exhibits tuberculate macroconidia-diagnostic

Concerning Enterocytozoon bieneusi, all of the following are true EXCEPT? a) It's most frequent Microsporidium infection found in Aids patients b) Infection occurs when spores are ingested c) Infection occurs from a blood transfusion d) Infection occurs when spores are inhaled

Infection occurs from a blood transfusion

Systemic Mycoses

Infections that affect internal organs or deep tissues of the body Frequently enter via the lungs, then spread Symptoms: Fever, fatigue, sometimes chronic cough and chest pain Yeast Infections: •Disease ranges from superficial disease to systemic. •Premier cause of yeast infection in the world: Candida albicans •May be opportunists in immunocompromised people •Recovered as normal biota from multiple sites: Skin, oral, mucosa, digestive tract, vagina Macroscopic characteristics •Colony color—ranges from white to cream or tan, with some species forming a pink- to salmon-color •Colony texture—varies: Mucoid and flowing across the culture plate; Butter-like; Velvetty to wrinkled

Humans acquire infections with Diphyllobothrium latum adult worms by: a) Ingestion of freshwater fish b) Skin penetration of cercariae c) Ingestion of water chestnuts d) Ingestion of fresh water crabs

Ingestion of freshwater fish

Which of the following is considered a human consequence of parasitic infections? a) mononucleosis b) Iron deficiency anemia c) Leukemia d) Granuloma

Iron Deficiency Anemia

This superficial mycoses requires a high lipid content for growth. Adding olive oil to the Sabouraud Dextrose tube supplies the required lipids. I appear as "spaghetti and meatballs" on the KOH prep. Who am I A) Trichophyton B) Microsporum C) Hortae werneckii D) Malassezia furfur

Malassezia furfur

In clinical cases of Wuchereria bancrofti, the most favorable time to find parasites in the blood is: a) Early morning b) Late afternoon c) Middle of the night d) Anytime

Middle of the night

Dimorphic fungi

Mold form in the environment •Infective form: inhalation of spores or direct traumatic implantation •room temperature- 22° C Yeasts at 35 to 37° C "body temperature" •Tend to form "deep-seated" infections •Highly virulent in susceptible hosts with deep invasions that can become systemic

Blastomyces dermititidis

Most prevalent in middle-aged men •Presumably of occupational and recreational exposure to the soil •Mode of Transmission: Inhalation Patients with primary infection •Flu-like symptoms, most are asymptomatic When primary disease fails to resolve, pulmonary disease may ensue. •Cough, weight loss, chest pain, and fever Immunocompromised patients may experience •Multiple organ systems involvement •Rapid death possible Causes blastosmycosis •a.k.a. Gilchrist disease, North American blastomycosis, Chicago disease Occurs primarily in North America and parts of Africa •Endemic in the Mississippi and Ohio river basins Specimens of choice •Tissue or purulent material in cutaneous skin lesions Yeast phase: Budding Mold phase: lollipop like

This agar will inhibit Candida and Crytococcus. The media contains cyclohexidmide, BHI, sheep RBC's , gentamicin and chloramphenicol. A) Sabouraud Dextrose Agar B) Bird Seed Agar C) Potato Dextrose agar D) Mycosel

Mycosel

Which of the following causes primary amoebic meingoencephalitis? a) Entamoeba histolytica b) Acanthamoeba c) Balamuthia mandrillaris d) Naegleria

Naegleria

A 25-year old man was admitted to the hospital with a severe headache, fever, nausea, and vomiting. Symptoms began suddenly 2 days after water skiing on the intercoastal waterway. A spinal tap revealed a purulent CSF with no bacteria. A motile form resembling a leukocyte was observed on direct examination of the fluid. The most likely causative organism is: a) Naegleria fowleri b) Blastocystis hominis c) Entamoeba histolytica d) Balamuthia mandrillaris

Naegleria fowleri

Which of the following sets of nematodes can cause a pneumonia-like syndrome in a person exposed to heavy infection with any of the three parasites? a) Ascaris lumbricoides, Trichuris trichiura or Onchocera volvulus b) Enterobius vermicularis, Dracunculus medinensis, Trichuris trichura c) Strongyloides stercoralis, Wuchereria bancrofti, Angiostronglylus constaricensis d) Necator americanus, Ascaris lumbricoides, Strongyloides sterocoralis

Necator americanus, Ascaris lumbricoides, Strongyloides sterocoralis

A 44-year old man was admitted to the hospital following a 2-week history of low-grade fever, malasie, and anorexia. Examination of a Giemsa-stained blood film revealed intracellular parasites. Further history revealed frequent East Coast camping trips near Martha's Vineyard and Nantucket Island but no travel outside the continental United States, Most likely, this parasite is? a) Trypanosoma cruzi b) Leishmani donovani c) Toxoplasma gondii d) None of the above

None of the above

Which of the following characteristic match the microfilariea: No sheathed & no terminal nuclei in the tip of the tail, the bite of the Simulian fly and can cause Calabar sweillings & blindness. a) Wurchereria bancrofti b) Brugia maylai c) Loa Loda d) Onchoceria volvulus

Onchoceria volvulus

Which stage of Cryptosporidium parvum is considered infectious? a) Oocyst b) Merozoites c) Gametocytes d) Sporozoites

Oocyst

Modified Acid Fast a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Oocysts

Cryptococcus neoformans info

Opportunistic infection •Meningitis, pneumonia, and septicemia Characteristics •Mucoid appearance due to capsule --India ink test: Black background with clear halos around organism; Being replaced by cryptococcal antigen tests •Blastoconidia only

In a patient with diarrhea, occasionally Entamoeba histolytica/E. dispar (four nucleated cysts, no chromatoidal bars) are identifes as being present. However, these cells, which are misdiagnosed as protozoan are really? a) Macrophages b) Epithelial Cells c) PMN's d) Eosinophils

PMN's

Which of the following preservatives contains murcuric chloride? a) 10% Formalin b) PVA c) SAF d) MIF

PVA

Relationship where one species lives at expense of another species and causes harm. a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Parasitism

What are the three modes of transmission for parasitic infections? a) Ingestion, contact, vector b) Vector, Airborne, Ingestion c) Penetration, contact, vector d) Penetration, Vector, Ingestion

Penetration, Vector, Ingestion

Candida albicans is normal flora of mucous membranes linings of the respiratory, GI and female genital tract. Most adult infections are endogenous, whereas infant infections are exogenous. C. albicans is the major pathogen causing human yeast infections. Germ tube production is a simple test microbiologist can use to ID C. albicans. Candida albican is the only species that is germ tube positive. All other Candida species are germ tube negative. Select the picture below that represents Germ tube positive

Picture with multiple cell with "tail"

this superficial mycoses forms a hard superficial pigmented nodule around the hair shaft. Who am I? A) Piedraia hortae B) Microsporum audouinii C) Trichosporon D) Maleaazezia furfur

Piedraia hortae

Several children at a daycare center are having trouble sleeping and are showing increasing signs of restlessness. Because one child was recently diagnosed with an intestinal parasite, the parents are informed that other children should be tested. The organism below is found at 400× during examination. This organism is A) Guinea worm B) Pinworm C) Hookworm D) Whipworm

Pinworm

A recent emigrant from Somalia develops high fever, chills, and severe headache. Blood work on admission to the hospital reveals the following in his blood smear at 1000x. This patient is most likely infected with Image of banana shaped cell a) Plasmodium falciparum b) Plasmodium vivax c) Plasmodium ovale d) Plasmodium knowles

Plasmodium falciparum

A stained blood smear reveals giant platelets and many reticulocytes containing Maurer's Dots, Accole or Applique ring forms and Schizonts with 18-24 merzoites. You would report this parasite as: a) Plasmodium vivax b) Plasmodium falciparum c) Plasmodium ovale d) Plasmodium malariae

Plasmodium falciparum

This plasmodium species has a banana or crescent gametocyte. Who am I? a) Plasmodium vivax b) Plasmodium falciparum c) Plasmodium ovale d) Plasmodium malariae

Plasmodium falciparum

Babesia microti is an organism that morphologically resembles: a) Leishmania donovani b) Trypanosoma cruzi c) Plasmodium falciparum rings d) Pneumoncystis carinii cysts

Plasmodium falciparum rings

Blackwater fever is caused by: a) Plasmodium vivax b) Plasmodium fulciparum c) Plasmodium knowles d) Plasmodium ovale

Plasmodium fulciparum

Which malarial species is particularly susceptible to temperatures below 20 oC (68 oF). At this temperature the parasite cannot complete its growth cycle in the Anophles mosquito. a) Plasmodium vivax b) Plasmodium fulciparum c) Plasmodium ovale d) Plasmodium malariae

Plasmodium fulciparum

A blood parasite that invades reticulocytes, enlarged RBC's, is characterized by single ring forms and Schuffner's dots, and may cause a true relapse is: a) Plasmodium falciparum b) Plasmodium ovale c) Plasmodium malariae d) Plasmodium vivax

Plasmodium vivax

This parasite is the causative agent of atypical interstitial plasma-cell pneumonia (PCP) and can be identified using Gomori's methenamine silver stain. a) Toxoplasma gondii b) Cyclospora cayetanensis c) Isospora belli d) Pneumocystis jirovecii

Pneumocystis jirovecii

One segment of tapeworm contains both male and female organs a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Proglottid

Which of the following measures that when taken can prevent the spread of Blastocystis hominis? a. Avoid swimming in potentially contaminated water b. Proper sewage treatment c. Avoid unprotected sex d. Use of insect repellent

Proper sewage treatment

Paracoccidioides brasiliensis

Pulmonary in nature •Causative agent of paracoccidioidomycosis •Infection is usually unapparent and asymptomatic. •Subsequent dissemination leads to --ulcerative granulomatous lesions of the buccal, nasal, and occasionally gastrointestinal mucosa. Modes of transmission •Inhalation of small conidia •Direct inoculation of the skin with contaminated dirt •Found primarily in Central America and South America in areas that are typically humid and experience high-rainfall, with acidic soil conditions Direct microscopic examination of cutaneous and mucosal lesions •Budding yeast cells 15 to 30 μm in diameter •Multipolar budding at the periphery resembling a "mariner's wheel"

Mycology Primary Growth Agars

Sabbouraud's Dextrose Agar -SAB ØGlucose, peptone, pH 5.6 Mycosel- Similar to SAB but contains antimicrobials (gentamicin, chloramphenicol), 5% SRBC's and Brain Heart Infusion (BHI) Specialty Growth Media: 1. Bird-Seed agar - Cryptocccus neoformans brown colonies pictured below. Produces phenol oxidase within the growth 2. Corn Meal Agar- Reduces the surface tension of agar promotes Cultivation of Chlamydoconidia, Hyphae, Blastocondia 3. Rice Infusion Oxgall Tween 80 (RIOT) Cultivation of Chlamydoconidia

The vector responsible for the transmission of Leishmania donovani is: a) Sand fly b) Anophles mosquito c) Tsetse fly d) Triatoma

Sand fly

Mecuric Chloride a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Schaudinn's Solution

Which of the Platyhelminthes infects humans by skin penetration and has an association with bladder cancer? a) Schistosoma mansoni b) Schistosoma hematobium c) Schistosoma knowles d) Schistosoma japonicum

Schistosoma hematobium

The egg of which of the following has a large lateral spine: a) Schistosoma haematobium b) Clonorchis sinensis c) Fasciola hepatica d) Schistosoma mansoni

Schistosoma mansoni

This blood fluke is known to have the profile of a "man" which fluke is this? a) Schistosoma mansoni b) Schistosoma japonicum c) Schistosoma haematobium d) Fasciola hepatica

Schistosoma mansoni

According to the World Health Organization what five infections is the most harmful to humanity? a) Schistosomiasis, Malaria, Leishmaniasis, Oncocerciasis, Trypansomiasis b) Malaria, Leshmaniasis, Endolimax nana, Trypansomiasis, Schistosomiasis c) Trypanosomiasis, Schistosomiasis, Malaria, Endolimax nana, Leshmaniasis d) Malaria, Entamoeba histolytica, Schistosomiasis, Endolimax nana, Trypanosomiasis

Schistosomiasis, Malaria, Leishmaniasis, Oncocerciasis, Trypansomiasis

Yeasts

Single vegetative cells -Form a smooth, creamy, bacterial-like colony without aerial hyphae ID is primarily based on biochemical testing and molecular diagnostic methods. Reproduction via budding or fission Mother cell buds to form a blastoconidium A chain of blastoconidia can form a filamentous-like pseudohyphae -Constriction visible between mother and daughter cells Can produce germ tube from mother cell with no constriction (Germ Tube Positive) Germ Tubes are the beginning of true hyphae Some produce yeast or mold phases depending on temperature of growth

The infective stage of Plasmodium is? a) Merozoites b) Sporozoites c) Oocyst d) Gametocytes

Sporozoites

The preferred specimen for the diagnosis of Paragonimiasis is? a) Bile drainage b) Rectal biopsy c) Sputum d) Duodenal aspirate

Sputum

A transplant patient is currently receiving steroids. The patient is now complaining of abdominal pain & has pneumonia. The individual has been living in the United States for 20 years but grew up in Central America. The most likely parasite causing these symptoms are: a) Schistosoma mansoni b) Wuchereria bancrofti c) Strongyloides stercoralis d) Ancylostoma duodenale

Strongyloides stercoralis

An immunosuppressed patient, often their T-lymphocytes don't function properly is susceptible to autoreinfection with which one of the follow nematodes? a) Strongyloides stercoralis b) Trichinella spiralis c) Ascaris lumbricoides d) Paragonomius westermani

Strongyloides stercoralis

Which parasite can have both a parasitic and a free-living life cycle? a) Ancylostoma duodenale b) Strongyloides stercoralis c) Ancylostoma ceylanicum d) Necator americanus

Strongyloides stercoralis

A child who plays in dirt contaminated with human and pet feces is susceptible to which of the following set of parasites: a) Ascaris lumbricoides, Trichuris trichiura, Trichnella spiralis, Wuchereria bancrofti b) Loa loa, Capollaria philippinensis, Enterbius vermicularis, Trichnella spiralis c) Strongyloides stercoralis, Toxocara canis, Ascaris lumbricoides, Trichuris trichiura d) Trichnella spiralis, Wuchereria bancrofti, Toxocara canis, Loa loa

Strongyloides stercoralis, Toxocara canis, Ascaris lumbricoides, Trichuris trichiura

Sporothrix schenckii

Subcutaneous & Dimorphic fungi Traumatic inoculation through skin usually on hand. "gardener's mycosis" or Rose handler's disease Found in soil, plants, decaying matter. Pyogenic and granulomatous inflammatory reaction Mycelial phase: delicate branching hyphae clustered in a rosette Yeast phase: ovoid cigar bodies The Mycelial Phase (above) is found in the environment on plants and decaying matter. When the fungus makes the transition into a host, the yeast (below) morphology predominates. At 37 °C (99 °F) either in the laboratory or in host tissue, S. schenckii assumes its yeast form. Microscopically, yeast cells are 2 to 6μm long and show an elongated cigar-shaped morphology.

living together-positive relationship between species a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Symbiosis

Recovery in human feces of 7-mm long gravid proglottid containing 8-lateral uterine branches indicates an infection with: a) Hymenolepsis nana b) Taenia saginata c) Taenia solium d) Diphyllobothrium latum

Taenia solium

The causative agent of cysticercosis is: a) Echinococcus granulosus b) Taenia saginata c) Trichnella spiralis d) Taenia solium

Taenia solium

Eating poorly cooked pork can lead to an infection with: a) Taenia solium & trichnella spiralis b) Taenia saginata & Hymenolepis diminuta c) D. latum & Ascaris lumbricoides d) Trichuris trichiura & Taenia saginata

Taenia solium & trichnella spiralis

Polymorphism

The ability to form yeast and mold in same culture •Generally yeast first moving to mold as culture ages Ex. Exophiala spp.

For suspected cases of blood parasites what type smear is best for the detection of parasites? a) Thick smear fixed with methanol b) Thick smear- air dried 6-hours c) Thin smear fixed with methanol d) Thin smear air dried 6-hours

Thick smear- air dried 6-hours

Strongyloides stercoralis

Threadworm

Visceral Larval migrans is caused by: a) Ascaris lumbricoides b) Ancylostoma braziliense c) Dirofilaria species d) Toxocara canis

Toxocara canis

The eggs of these two nematodes are never to rarely seen in stool samples. A. Trichina and threadworm B. Whipworm and roundworm of man C. Guinea worm and pinworm D. Threadworm roundworm and hookworm

Trichina and threadworm

Trichinella spiralis

Trichina worm

A 45 year old hunter developed fever, malaise and periorbital edema. He has a history of bear meat consumption. The most likely causative agent? a) Necator americanus b) Trichinella spiralis c) E. histolytica d) Balantidium coli

Trichinella spiralis

A 45- year old hunter developed fever, myalgia, and periorbital edema. He has a history of bear meat consumption. The most likey causative agent is: a) Necator americanus b) Strongyloides stercoralis c) Trichinella spiralis d) Taenia solium

Trichinella spiralis

A 22-year old woman was admitted to the ED at 3 am complaining of burning urination and severe vaginal itching. The physician ordered a routine urinalysis and a vaginal swab for microscopic examination. the technologist observed many motile organisms measuring approximately 12 um in diameter in both the urine microscopic wet mount and the vaginal wet-mount preparation. What is the likely organism? "image of two cells that look like sting ray with pink nucleus in center" a) Giardia lamblia b) Blastocystis hominis c) Trichomonas vaginalis d) Balantidium coli

Trichomonas vaginalis

From the narrative what permanent stain is described: Eggs, larvae stain red, RBC's stain purple, and Cyst's/Troph's stain blue/green. a) Trichrome stain b) Iron Hematoxylin stain c) Modified Acid-Fast Stain d) Schaudinn's Solution

Trichrome stain

Noninfective form- replicates in host & responsible for causing damage a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Trophozoite

E. histolytica infection is traditionally diagnosed by finding which of the following? a) Adult and egg forms of the parasite suspected stool samples b) Cysts found in suspected urine sample c) Trophozoites and/or cysts in a suspected stool sample d) Larvae in suspected CSF sample

Trophozoites and/or cysts in a suspected stool sample

Which of the following statements is not true about amebic trophozoites? a) Trophozoites are delicate & motile b) Trophozoites are resistant to the environment outside the host c) Replication occurs in the trophozoite stage d) Trophozoites are easily destroyed by gastric juices

Trophozoites are resistant to the environment outside the host

True or False Ancylostoma duodnelae buccal capsule contains pointed teeth.

True

True or False Ancylostomiasis is a hookworm infection.

True

True or False Babesi microti causes Texas Cattle Fever in the United States.

True

True or False Flukes or trematodes are hermaphroditic meaning they possess both male and female sex organs.

True

True or False Outbreaks of this intestinal Coccidia, Cyclospora cayetanesis, has been associated with fresh berries.

True

True or False Schistosomiasis transmission occurs when cercariae penetrate the skin from contaminated water while swimming.

True

True or False T. rhodesience & T. gambiense clinical features of the disease (sleeping sickness) are the same, but they differ in severity and duration.

True

True or False The highest transmission of malaria is found in Africa, south of the Sahara and in parts of Oceania and New Guinea.

True

True/False Ancylostoma duodenale buccal capsule contains pointed teeth

True

True/False Ascomycetes produce both sexual and asexual forms and produce encased spores in ascospores.

True

True/False Blastoconidia in yeast occurs from a mother cell to the budding daughter cell.

True

True/False Blastomyces dermatitidis is also known as Gilchrist disease and is endemic in the Mississippi and Ohio River basins.

True

True/False P. vivax usually invades young RBC's (reticulocytes) and therefore are characterized by enlarged infected RBC's often double the normal size and have a fine pink stippling known as Schuffner stippling or dots.

True

True/False Penicillium is an opportunistic mycoses rarely cause disease, it has a brush-like conidia and produces blue/green colonies in its mold phase.

True

True/False The cellophane tape preparation is used to collect the aerial mycelim of the mold on the culture plate.

True

True/False The infective stage of microsporidia in humans is the environmentally resistant spore, which can survive outside the host for as long as 1-year.

True

True/False The mature Schizont of Plasmodium falciparum has largest number of merozoites within the schizont.

True

True/False The traditional method of diagnosing T. cruzi trypomastigotes in South America is known as Xenodiagnosis. In this procedure a noninfected reduviid bug is allowed to feed on a person suspected of having Chagas Disease. Several weeks later, the feces of the bug is examined for the presence of the trypomastigotes.

True

True/False Trophozoites from Amebiasis infections when passed through the stool are rapidly destroyed once outside the body and if ingested would not survive the gastric environment.

True

True/False Trypanosoma cruzi is transmitted by the Triatoma bug also known as the kissing bug or reduviid bug.

True

True/False Vegetative mycelium is the filamentous mat found beneath the mold.

True

Which of the following trypanosomal parasites that causes sleeping sickness is the more aggressive form: a) Trypanosoma brucei gambiense b) Trypanosoma brucei rhodesiense c) Trypanosoma cruzi d) Trypanosoma rangeli

Trypanosoma brucei rhodesiense

A 60 year old Brazilian patient with cardiac irregularities & congestive heart failure was diagnosed with Chagas' disease and suddenly dies. Examination of the myocardium revealed amastigotes in the striated cardiac muscle tissue. The cause of death was most likely: a) Leishmania braziliense b) Trypanosoma cruzi c) Leishmania donovani d) Trypanosoma gambiense

Trypanosoma cruzi

Determine the incorrect match between the organism and one method of acquiring the organism: a) Trypanosoma cruzi bite of the sandfly b) Toxoplasma gondii eating undercooked meat c) Malaria bite of female Anopheles mosquito d) Babesia microti bite of a deer tick

Trypanosoma cruzi bite of the sandfly

A yound man who returned a week ago from a family vacation to East African country of Kenya develops a high fever and delirium. Although he was compliant with his antimalarial medications, a blood sample is taken to rule out malaria. The laboratory scientist sees the following on the blood smear at 1000x. This organism is most likely Image with several dark pink "swirls" with pink background a) Trypanosoma gambiense b) Babesia microti c) Toxoplasma gondii tacozoites d) Trypanosoma rhodesiense

Trypanosoma rhodesiense

The diagnostic stage of Trypanosoma species is the: a) Trypomastigote b) Epimatigote c) Promatigote d) Amastigote

Trypomastigote

Hyphae

Tube-like structures with thick parallel walls •Septate - has cross walls •Aseptate- rare cross walls Hyaline -Nonpigmented -Lightly pigmented Phaeoid (Dematiaceous) -Darkly pigmented: Melanin production in cell wall -Shape: Antler, Racquet, Spiral, Rhizoids Pseudohyphae -elongated budding yeast cells (blastoconidia) with constrictions between cells (buds) Mycelium is a mat of hyphae-two types: -Vegetative growth into the medium -Aerial growth above the medium

Infections with intestinal amebas are prevalent in which of the following? a) Underdeveloped countries with poor sanitary conditions b) Beef consumers in the USA c) People traveling to Europe d) Japan, because of seafood diet

Underdeveloped countries with poor sanitary conditions

Molds are multi-cellular fungi and they have two types of mycelia: Aerial and Vegetative. Which of the two is found extended into the medium and absorb nutrients. A) Saprobe B) Vegetative C) Aerial D) Conidia

Vegetative

A helminth egg is described as having terminal polar plugs, the most likely helminth is: a) Hookworm b) Whipworm c) Pinworm d) Threadworm

Whipworm

Trichuris trichiura

Whipworm

General Characteristics of Molds and Yeast

Yeast are single cell organisms Molds are multi-cellular filamentous organisms Eukaryotic Lack chlorophyll Thick cell walls: Made of chitin Mostly obligate aerobes: Tend to grow well in room air at an optimum temperature of 25-370C in a moist environment Prefer neutral pH

Emerging opportunistic pathogen that has been identified as a cause of skin lesions and granulomatous amebic encephalitis (GAE). What parasite is causing this? a. Balamuthia mandrillaris b. Naegleria fowleri c. Endolimax nana d. Iodamoeba butschilii

a. Balamuthia mandrillaris

Charcot Leyden crystals are: a. Breakdown remnants of Eosinophils b. Ingested RBC's c. Larvae in a suspected CSF sample d. Glycogen mass

a. Breakdown remnants of Eosinophils

What is the first step to be performed in the identification of an unknown yeast isolate? a. Germ tube test b. Catalase test c. India Ink test d. Tease test

a. Germ tube test

Of the following, which tests are considered diagnostic for trypanosomiasis? a. Giemsa-stained blood slides revealing the trypomastigote b. Increased serum and CSF IgG levels c. Giemsa-stained blood slides revealing the epimastigote d. Decreased serum and CSF IgG levels

a. Giemsa-stained blood slides revealing the trypomastigote

Blastoconidia are the beginning of which structure? a. Pseudohyphae b. Chlamydoconidia c. Anthroconidia d. Germ Tubes

a. Pseudohyphae

Which of the following is the vector for Leishamania? a. Sand Flies of genus Phlebtomus & Lutzomyia b. Reduvid bug c. Tsetse fly d. Stink bug

a. Sand Flies of genus Phlebtomus & Lutzomyia

A liquid stool is the specimen of choice for the recovery of which of these morphologic forms of Chilomastix mesnili? a. Trophozoites and cysts b. Trophozoites only c. Adult larvae d. Cysts only

a. Trophozoites and cysts

Which of the following characteristics is observed during the macroscopic examination of stool specimens? a) consistency b) color c) search for adult worms d) all of the above

all of the above

The three species of human blood flukes and an intermediate host? a) A cyclops b) an aquatic snail c) a mosquito d) a freshwater fish

an aquatic snail

Plasmodium vivax has a tertian life cycle. Which indicates a. 24 hours b. 48 hours c. 72 hours d. 96 hours

b. 48 hours

The specimen of choice for the recovery of N. fowleri is which of the following: a. Sputum b. CSF c. Urine d. Stool

b. CSF

The fungal cell wall is made out of what substance? a. Peptidoglycan b. Chitin c. Porin protiens d. Cholesterol

b. Chitin

Packets of tapeworm eggs encapsulated in a single membrane were recovered in feces. This tapeworm is: a. Diphyllobotherium latum b. Dipylidium caninum c. Hymenolepsis nana d. Trichinella sprialis

b. Dipylidium caninum

The first intermediate host for all trematodes is which of the following? a. Dog b. Snail c. Cat d. Shrimp

b. Snail

The preferred specimen for the diagnosis of paragonimus westermani is: a. Duodenal aspirate b. Sputum c. Rectal biopsy d. Bile drainage

b. Sputum

A construction worker in Tucson, AZ, presents with flu-like symptoms and productive cough. A sputum specimen is submitted for fungal culture. The fungal culture reveals a white, cottony mould at both 25 and 35 degrees. On microscopic examination, arthrospores are noted. This isolate is probably a member of the _________ group of fungi. a. Subcutaneous b. Systemic c. Cutaneous d. Superficial

b. Systemic

Which Aspergillus species, recovered from material of a "fungus-ball" produced green colonies on Sabouraud Agar. This species is the most often seen and is the primary cause of pulmonary aspergillosis? a. A. niger b. A. flavus c. A. fumigatus d. All of the above

c. A. fumigatus

This prominent structure found in T. vaginalis trophozoites that often extend beyond the body provides support for the parasite. a. Axoneme b. Granule c. Axostyle d. Nucleus

c. Axostyle

The maltese cross is a classic tetrad formation within a RBC is indicative of what organism? a. Toxoplasma gondii b. B. burgorferi c. Babesia microti d. Plasmodium vivax

c. Babesia microti

Acanthamoeba keratitis is usually associated with a. Wearing contacts while swimming b. Macular Degeneration c. Contaminated contact lens solution d. Torn Cornea

c. Contaminated contact lens solution

Babesiosis is characterized by all the following except: a. Respiratory, liver, renal failure and DIC b. A mild to severe hemolytic anemia & other malarial type symptoms c. Cyclic fever d. Trophozoites resembling the ring form seen in Plasmodium species

c. Cyclic fever

What condition is considered an inflammatory response to tissue invasion & parasite death. a. Hemoptysis b. Metacercaria c. Cysticercosis d. Schistosomiasis

c. Cysticercosis

The term that describes the lack of an outer mammillated albuminous coating is called what a. Chitin b. Albumin c. Decorticated d. Corticated

c. Decorticated

India Ink stain preparations is used for the identification of a. Spores b. Germ tube c. Encapsulated yeast d. Oospore

c. Encapsulated yeast

The diagnostic stage of Trichinella spiralis is which of the following: a. Eggs b. Adult worm c. Encysted larvae d. Cysts

c. Encysted larvae

Trichuris trichiura eggs are characterized by the presence of which of the following: a. Prominent cyctotome b. Flattened side c. Hyaline polar plugs d. Triple layer cell wall

c. Hyaline polar plugs

A type of tapeworm embryo with a large central cavity (bladder), brood capsules and numerous protoscolices (Hydatid sand) is: a. Procercoid b. Cysticercus c. Hydatid cyst d. Cysticeroide

c. Hydatid cyst

What properties of Sabourand Dextrose agar make the medium inhibitory to the growth of most bacteria? a. Addition of inhibitory dyes b. Addition of bile salts c. Low pH 5.6 and high glucose concentration d. High ph 10.0 and high sucrose concentration

c. Low pH 5.6 and high glucose concentration

Tinea versicolor is a skin infection caused by: a. Microsporum gypeseum b. Trichophyton rubrum c. Malassezia furfur d. Trichophyton schoenleinii

c. Malassezia furfur

What is the preferred method of staining oocysts for the identification of Cryptosporidium species a. Trichrome stain b. Giemsa -thin smear c. Modified acid fast stain d. Iron Hematoxylin stain

c. Modified acid fast stain

Malarial clinical infections have two phases: prodromal and paroxysm. Which of the following phase is described by the following: Involves headache, bone pain, nausea and/or flulike symptoms. A shaking chill of 15-60 minutes initiates a high fever (104F), myalagia, and nausea. This stage lasts 2-4 hours after the fever breaks, the patient begins to sweat profusely and is left exhausted. a. Prodromal b. Apicomplexa c. Paroxysm d. Erythrocytic

c. Paroxysm

Malarial clinical infections have two phases: prodromal and paroxysm. Which of the following phase is described by the following: Phase begins 10-15 days after the bite of the infected mosquito, is associated with the growth of the parasites in RBC's and high levels of cytokines. Symptoms are linked to the rupture of RBC's and release of merozoites, malarial metabolites and endotoxin-like substance into the bloodstream. a. Exoerthrocytic b. Apicomplexa c. Paroxysm d. Prodromal

c. Paroxysm

Which of the following yeast enzymes is detected using birdseed agar? a. Catalase b. Urease c. Phenol oxidase d. Nitrate reductase

c. Phenol oxidase

Individuals contract hookworm via which of the following: a. Ingestion b. Contaminated water c. Skin penetration d. Insect bite

c. Skin penetration

Acanthamoeba keratitis is usually associated with: a) contaminated medications b) ingestion of the trophozoites c) contact lens solutions & water activities while wearing lenses d) contaminated food and water

contact lens solutions & water activities while wearing lenses

This protozoan form is inactive, characterized by the formation of a thick protective wall that is resistant to environmental factors: a) Oocyst b) Trophozoite c) Cyst d) Sporozoites

cyst

Cornmeal agar is used to identify which characteristic of an unknown yeast isolate? a. Hyphae (True & pseudo) b. Blastoconidia c. Chlamydoconida d. All of the above

d. All of the above

This emerging multi-drug resistant yeast is linked to high mortality rates in hospital-acquired infections world wide. a. Candida glabrata b. Candida albican c. Candida tropicalis d. Candida auris

d. Candida auris

The mycelial form of which dimorphic molds show barrel-shaped arthroconidia separated by empty cells (ghost cells) that cause an uneven staining effect when they are examined microscopically. a. Histoplasma capsulatum b. Blastomyces dematiditidis c. Sporothrix schenckii d. Coccidioides immitis

d. Coccidioides immitis

Once inside a human, these two nematodes take up residence outside the intestinal tract? a. Enterobius vermicularis and Strongyloides stercoralis b. Necator americanus and Ancylostoma duodenale c. Trichuris trichiura and Ascaris lumbricoides d. Dracunculus medinensis and Trichinella spiralis

d. Dracunculus medinensis and Trichinella spiralis

Microscopic examination of a fungus cultured from a patient with athlete's foot showed large, smooth-walled, club shaped macroconidia appearing singly or in clusters of two -six cells. The colonies did not produce microconidia. What is the most likely identification? a, Microsporum species b. Trichophyton species c. Alternaria species d. Epidermophyton species

d. Epidermophyton species

The eggs of which group of nematodes are indistinguishable? a. Guinea worm, roundworm b. Whipworm, Trichuris trichiura c. Pinworm, Whipworm d. Hookworm & Threadworm

d. Hookworm & Threadworm

Individuals contract Ascaris lumbricoides via which of the following: a. Insect bite b. Sexual practices c. Inhalation d. Ingestion

d. Ingestion

The juvenile stage of developing nematode worms is referred to as: a. Adults b. Cysts c. Eggs d. Larvae

d. Larvae

Growth on Cornmeal Tween 80 Agar Pseudohyphae- positive Blastoconidia- positive Chlamydospore- positive Blastoconidia - positive Germ tube - positive Yeast recovered from the urine of a catheterized patient receiving chemotherapy for cancer gave the following results highlighted above: What further testing is necessary? a. Carbohydrate assimilation and urease b. Urease and niger seed agar c. Nitrate reductase & carbohydrate assimilation d. No further testing is needed for identification

d. No further testing is needed for identification

Congenital transmission of this organism occurs when the tachyzoites, the motile, rapidly dividing forms in maternal circulation, cross the placenta and enter fetal circulation and tissues. What is the invading parasite a. Babesia microtic b. Cryptosporidium parvum c. Plasmodium falciparum d. Toxoplasma gondii

d. Toxoplasma gondii

A main difference between the trophozoites of E. hartmanni and E. histolytica is which of the following: a. Presence of pseudopods b. Trophozoites of E. histolytica are smaller in size c. Nuclear structure and peripheral chromatin d. Trophozoites of E. hartmani do not contain ingested red blood cells

d. Trophozoites of E. hartmani do not contain ingested red blood cells

Dimorphic molds are found in infected tissue in which form? a. Latent b Mold phase c. Encapsulated d. Yeast phase

d. Yeast phase

The trophozoites of entamoeba coli: a) have eight nuclei b) have a typical large nucleus and a eccentrically placed karyosome with Junky cytoplasm c) contain ingested RBC's d) contained ingested bacteria

have a typical large nucleus and a eccentrically placed karyosome with Junky cytoplasm

Which is considered a consequence of a parasitic infection? a) Thyroid disorders b) Perforated Bowel c) Iron Deficiency Anemia d) Pneumonia

iron deficiency anemia

What three stains listed best describe the most common stains used in parasitology? a) Modified acid fast, Iron Hematoxylin, New Methylene blue b) Trichrome, Schaudinn's, Modified Acid-Fast c) Trichrome, New Methylene blue, Wright' stain d) Modified Acid Fast, Trichrome, Iron Hematoxylin

modified acid fast, trichrome, iron hematoxylin

This is usually an obligatory relationship in which both organisms benefit. a) Parasitism b) Mutualism c) Symbiosis d) Commensalism

mutualism

Which of these procedures is involved in the microscopic examination of stool specimens for parasites? a) performing a concentration technique b) determining the specimen consistency c) scan for intact worms d) analyze sample for color

performing a concentration technique

Enterobius vermicularis

pinworm

Toxoplasma gondii is characterized by: a) possible congenital implications due to ingestion/inhalation of oocysts b) Ingestion of water chestnuts c) penetration y the oncosphere d) cysts containing schizonts

possible congenital implications due to ingestion/inhalation of oocysts

Ascaris lumbricoides

roundworm

Concentration Techniques are based on the difference in specific gravity between parasites and the concentrating solution. What are the two types of methods? a) Gradient and Flotation b) Flotation and Column Chromatography c) Sedimentation and Flotation d) Column Chromatography and Sedimentation

sedimentation and flotation

The two parasitology concentration methods are designed to concentrate parasites into small volume of fluid and remove as much fecal material as possible. Both methods are based on a) centrifugal force between parasites and the solution b) specific gravity between parasites and the solution c) laminar flow between the parasites and the solution d) variations between Ethyl acetate and Zinc sulfate solutions

specific gravity between parasites and the solution

When using preservatives, what is the appropriate ratio of fixative to stool? a) one part fixative to one part stool b) two parts fixative to one part stool c) three parts fixative to one part stool d) four parts fixative to one part stool

three parts fixative to one part stool

When analysis of blood smears for malaria are requested, What patient information should be obtained? a) diet, gender, travel history b) age, gender, fever patterns c) travel history, antimalarial mediation, date of return to USA d) fever patterns, diet, age

travel history, antimalarial mediation, date of return to USA

In the collection and transport of stool specimens for parasites, which parasitic stage is most affected by the length of time from collection to examination? a) cysts b) adult larvae c) trophozoites d) None are affected

trophozoites

True or False Whipworm is the common name for Trichuris trichiura

true

Which Separation technique causes operculated eggs to open and collapse? a) Ethyl acetate b) Schaudinn's Solution c) Zinc-Sulfate d) Kinyoun Carbolfusion

zinc-sulfate

Predisposed to fungal infection:

ØMetabolic imbalances such as diabetes or pregnancy ØImmunocompromised from any disease ØImmunosuppression with corticosteroids or cytotoxic drugs ØAdministration of long-term broad-spectrum antibiotics

Mycology Reproduction: SEXUAL REPRODUCTION

ØTeleomorph ØFusion of two haploid nuclei ØHomosexual - Zygospore ØHeterosexual- Oospore Ascomycetes, Basidiomycete and Zygomycetes produce both sexual and asexual forms: 1. Ascomycetes = spores encased in ascospores produce asci 2. Basidomycete = basidospores on a stalk (mushroom-like) 3. Zygomycetes = thick walled (ribbon-like) zygosporium containing single zygospore Mycelial structure is Stolon. Rhizoid

System Mycoses: other notable species

•Candida krusei •Candida tropicalis •Candida parapsilosis •Becoming major cause of outbreaks of nosocomial infections

Systemic Mycoses: Candida glabrate

•May account for 21% of all urinary yeast isolates •Tend to be aggressive and difficult to treat with traditional antifungal therapy

Opportunistic Mycoses: Penicillium

•Penicillium Rarely cause disease, fungal sinusitis Brushlike conidia, green or blue-green colonies Penicillium is a mold fungus that causes food spoilage, used in cheese production and produces antibiotic penicillin --looks like a mop

how to distinguish systemic mycoses species

•Species can be distinguished by differences in their carbohydrate assimilation patterns and other secondary procedures.

Systemic Mycoses: Candida albicans

•Thrush •Recognized as in indicator of immunosuppression •Can evolve into serious infection in patients receiving long-term antibiotics or other chemotherapeutic agents

What is the recommend ratio of preservative to stool? a) 1:3 b) 1:2 c) 1:5 d) 1:1

1:3

Which stains are considered permanent stains?

1. Iron Hematoxylin stain 2. Trichrome stain

What are the stains used in Parasitology?

1. Iron Hematoxylin stain 2. Trichrome stain 3. Modified Acid Fast stain

Mycology: Laboratory Methods

10-20% KOH Wet Prep (Potassium Hydroxide) •10% to 20% solution of KOH •Some may contain dimethyl sulfoxide (DMSO) and a stain •Equal parts sample to KOH •Cover slipped and heated gently then cooled for 15 minutes Lactophenol Cotton Blue •Stains and kills organism •Use with culture material India Ink- stains capsule of cyptococcus neoformans - What is visualized is the encapsulated yeast in CSF Calcofluor white -Fluorescent stain observe fungal elements in tissues, sputum, body fluids, skin scrapings, and corneal scrapings

Mycology: Specimen Collection, Handling, and Transport

Common specimen types ØRespiratory secretions, hair, skin, nails, tissue, blood, bone marrow, CSF Use antimicrobial containing media to inhibit bacterial growth Optimum temperature 25-300C Hold Cultures 4-6-weeks ØExamine twice a week for growth. Hair ØA Wood lamp emits UV light >365 nm and can be useful in identifying infected hairs. ØThe Wood light can be shown on the scalp. ØSterile forceps should be used to pull affected hair. ØHairs are placed directly into a sterile Petri Dish then inoculated onto fungal medium and incubated at 22 to 30° C. Skin and Nails ØArea is clean with 70% alcohol before sampling. ØOuter edge of a surface legion is scraped (skin); nails are cut or removed. ØA KOH wet mount is prepared with some of the sample collected. •KOH breaks down tissue making it easier to view fungal hyphae. ØSample material is inoculated directly onto the agar. Tissue biopsy Aspirate of Exudate Blood and bone marrow ØLysis centrifugation system •Isolator 10 system -like drawing vacutainer tube •Release organisms from cells CSF (and other sterile fluids) ØConcentrate via centrifugation before inoculation. ØOne drop for India ink or cryptococcal antigen test for C. neoformans Plated directly (sterile)

Coccidioides immitis

Considered as the probable most virulent of all human mycotic agents Two very similar species infect humans •C. immitis and C. posadasii Mode of transmission •Inhalation of only a few arthroconidia produces primary coccidioidomycosis Types clinical infections •Asymptomatic pulmonary disease and allergic manifestations •Known as "Valley Fever" Endemic to Southwestern United States •Soil; easily windborne in clouds of dust and penetrate deep into the respiratory tree, into the alveoli •Semiarid & low rainfall Geographic locations •C. immitis—San Joaquin Valley of California •C. posadasii—desert southwest, Mexico, South America

This parasite, the Oocysts stain red against a blue background (acid fast positive). The infective Oocysts transmitted via fecal-oral route. a) Cryptosporidium parvum b) Microsporidium c) Cyclospora cayetanensis d) Isopora belli

Cryptosporidium parvum

Within the United States, sporadic mini-outbreaks of diarrheal disease have been associated with ingestion of strawberries, raspberries, fresh basil and mesclun lettuce leaves. The most likely causative agent is: a) Dientamoeba fragilis b) Isopora belli c) Cyclospora cayetanensis d) Schistosoma mansoni

Cyclospora cayetanensis

Infective form of a protozoan-has thick protective layer a) Parasitism b) Schaudinn's Solution c) Cyst d) Symbiosis e) Proglottid f) Oocysts g) Ether or Ethyl acetate h) Trophozoite

Cyst

Identify the following parasite: "picture has two bulls eye looking circles and a bar" a) Cyst of Iodamoeba butschilii b) Trophozoite of Entamoeba gingivalis c) Trophozoite of Endolimax nana d) Cyst of Entamoeba histolytica

Cyst of Entamoeba histolytica

Given the following chart what is the interpretation. Use all six terms in your discussion. Picture showing: -row of Formed stool, soft stool, loose stool, watery stool -Upside down triangle labeled cysts -triangle labeled trophs

Cysts are more common in formed and soft stools. Trophs are more common in loose or watery stool.

Mature eggs of an adult tapeworm accumulate in the: a) Gravid proglottid b) Mature proglottid c) Neck region of strobila d) Scolex

Gravid proglottid

Miscellaneous Tests for Yeasts

Germ tube production ØMost important and easiest test to perform Carbohydrate assimilation ØIDs which carbohydrates a yeast can use aerobically as a sole carbon source creating an assimilation pattern Chromogenic substrates ØBased on different colors Cornmeal agar ØFor recognition of blastoconidia, chlamydoconidia, pseudohyphae, arthroconidia Urease -Christensen urea agar ØCandida Sp - Neg ØCryptococcus - Pos Carbohydrate Assimilation Test: -yellow = positive Chromogenic test Cryptococcal antigen ØMultiple assays available BactiCard Candida showing positive results for L-proline aminopeptidase (PRO) and β-galactosaminidase (MUGAL).

Two 16-year old boys returned from a 4-week camping trip in the northwest United States. For 2 weeks both boys experienced abdominal cramps and diarrhea, usually 1-hour after eating. Foul-smelling flatulence was present as well. On questioning the boys denied drinking water that was not treated with Halazone tablets (water purification). Three stools for each boy was submitted for culture and O&P. All the results were negative for bacterial pathogens and only one trichrome stain from a single sample revealed the parasite form seen below: "image of yellow cell that looks like a face" What genus and species do you report? a) Dientamoeba fragilis b) Entamoeba histolytica c) Blastocystis hominis d) Giardia duodenalis

Giardia duodenalis

Which of these could be found in the feces of a patient complaining of abdominal distress and foul smelling diarrhea? a) Giardia duodenalis b) Chilomastix mesnili c) Entamoeba nana d) Enterobius vermicularis

Giardia duodenalis

Although a patient is strongly suspected of having giardiasis and is still symptomatic, three routine stool examinations have been performed correctly and reported negative. Biopsy confirmed the patient has giardiasis. Reasons for these findings may include: a) The patient coinfected with several bacterial species b) Giardia intestinalis tend to adhere to the mucosal surface by means of the sucking disk & more than three samples may be required to confirm c) The organisms present did not stain with trichrome stain, and therefore the morphology is very atypical d) Special diagnostic procedures, such as the knott concentration and nutrient-free agar cultures, should have been used

Giardia intestinalis tend to adhere to the mucosal surface by means of the sucking disk & more than three samples may be required to confirm

Organisms that should be considered in a waterborne outbreak of diarrheal disease include: a) Giardia lamblia & Crytosporidium parvum b) Endoliman nana & Entamoeba histolytica c) Blastocystis hominis & Trichomonas vaginalis d) Toxoplasma gondii & Schistosoma mansoni

Giardia lamblia & Crytosporidium parvum

Fungal ID

It typically takes a group of tests to sufficiently identify fungi Typically start by determining if the isolate is a yeast or a mold. ØMolds do not always produce structures to facilitate ID. Molecular and proteomic tests can be used with traditional procedures. ØDNA hybridization, MALDI-TOF, PCR Macroscopic ØColony growth time ØColor ØTexture ØPigment on reverse of colony Microscopic ØSeptate versus sparsely septate hyphae ØHyaline or dematiaceous hyphae ØFruiting structures ØTypes, size, shape, and arrangement of conidia Tease mount ØRemove part of colony ØMount in drop of lactophenol aniline (cotton) blue ØTease apart the colony (teasing needle) and overlay with cover slip to disperse ØExamine at ×100 or ×400 Cellophane tape preparation ØPress cellophane tape gently but firmly to surface of the colony. ØPress one side of tape to slide with drop of LPCB. ØStretch tape across slide, lowering it into the stain. ØPull taught and affix other side of tape, avoiding air bubbles.

A common disease caused by Leishamani donovani is? a. Chagas Disease b. Kala-azar c. West African Sleeping Sickness d. All of the above b. Kala-azar

Kala-azar

The trophozoites of Entamoeba coli: a. Contains red cell inclusions b. Central karyosome with evenly distributed peripheral chromatin c. Large eccentric karyosome with "Junky" cytoplasm d. Have eight nuclei

Large eccentric karyosome with "Junky" cytoplasm

Kala Azar is the most severe type of Leishmaniasis by infecting the lymphatic system, liver, spleen, and bone marrow. What is the infecting parasite? a) Leishmania donovani b) Leishmania mexicana c) Leishmania tropica d) Leishmania brazilienes

Leishmania donovani

The parasite that may invade and multiple in the liver or spleen is: a) Leishmania brazilensis b) Leishmania mexicanna c) Leishmania donovani d) Leishmani tropica

Leishmania donovani

This vector is the mango or deer fly and the larvae enters the wound from the bite of the fly. A blood smear will show a microfilaria encased in a sheath with nuclei extended into the tip. Shows diurnal periodicity. Calabar swellings can occur due to localized inflammatory reaction to the worm. Also known as African Eye worm. a) Onchocerca volvulus b) Brugia malayi c) Loa loa d) Ancylostoma brazilense

Loa loa

Which of the following filaria nematodes is transmitted by the Chrysops fly? a) Loa loa b) Brugia malayi c) Mansonella ozzardi d) Onchocerva volvulus

Loa loa