Eggs or larvae recovered in the stool are not routinely used to diagnose infections caused by which one of the following helminths? * 1/1 Trichinella spiralis Strongyloides stercoralis Ascaris lumbricoides Necator americanus

Which of the following is the most important feature in differentiating cysts of Entamoeba histolytica from E. dispar? * 0/1 Number of nuclei Size of the cyst Shape of the karyosome Distinguishing surface antigens by immunologic assays

Which species of malaria parasite usually has ameboid trophozoites and produces small reddish dots in the red blood cell cytoplasm? * 0/1 Plasmodium knowlesi Plasmodium falciparum Plasmodium malariae Plasmodium vivax

With a fecal specimen, which one of the following is the most dependable procedure for the accurate, specific diagnosis of an intestinal amebic infection? * 0/1 Direct saline wet mount Direct iodine wet mount Permanently stained smear Formalin-ethyl acetate sedimentation technique

Which of the following is a mercury-containing fixative used to preserve parasites in stool specimens? * 1/1 Formalin Sodium acetate Buffered glycerol Polyvinyl alcohol

Which Schistosoma species has a large terminal spine? 0/1 S. haematobium S. japonicum S. mansoni S. mekongi

Slowly multiplying trophozoite stage of Toxoplasma gondii: * 0/1 Gametocyte Sporozoite Bradyzoite Tachyzoite

Rapidly multiplying trophozoite stage of Toxoplasma gondii: * 0/1 Gametocyte Sporozoite Bradyzoite Tachyzoite

A 15-um pear-shaped flagellate with a visible parabasal body and "falling leaf" motility in a direct saline mount of a diarrheal stool specimen is most probably: * 1/1 Balantidium coli Chilomastix mesnili Giardia lamblia Trichomonas hominis

This parasitic infection may result in vitamin B12 deficiency, and individuals with pernicious anemia are predisposed to more severe symptoms. * 1/1 Diphyllobothrium latum Echinococcus granidosus Taenia saginata Hymenolepis diminuta

Which of the following helminths produces an elongate, barrel-shaped egg with a colorless polar plug at each end? * 1/1 Ascaris lumbricoides Hymenolepis nana Necator americanus Trichuris trichiura

Which species of Plasmodium may readily be identified when crescent-shaped gametocytes are found in stained blood films? * 1/1 P. falciparum P. malariae P. ovale P. vivax

Decontamination of drinking water, fruits, and vegetables before consumption is necessary in countries without well- developed public sanitation. Which of the following diseases would probably be least affected by that kind of precaution? 0/1 Amebiasis Ascariasis Filariasis Giardiasis

Which stage of Taenia saginata is usually infective for humans? 1/1 Cysticercus larva Embryonated egg Filariform larva Rhabditiform larva

Which stage of Trichuris trichiura is infective for humans? * 1/1 Proglottid Filariform larva Rhabditiform larva Embryonated ovum

Sanitary disposal of human feces is the most important factor in decreasing the incidence of most infections caused by intestinal parasites. Which of the following diseases would not be affected by that kind of sanitation? * 1/1 Ascariasis Taeniasis Trichinosis Hookworm infection

Which of the following nematode parasites is acquired from eating inadequately cooked, infected pork? * 0/1 Strongyloides stercoralis Taenia saginata Taenia solium Trichinella spiralis

Which of the following pairs of helminths cannot be reliably differentiated by the appearance of their eggs? * 0/1 Ascaris lumbricoides and Necator americanus Hymenolepis nana and Hymenolepis diminuta Necator americanus and Ancylostoma duodenale Diphyllobothrium latum and Fasciola hepatica

Which of the following is the vector for Babesia? * 1/1 Fleas Lice Ticks Mosquitoes

The incorrect match between the organism and one method of acquiring the infection is: * 0/1 Trypanosoma brucei rhodesiense — bite of sand fleas Giardia lamblia — ingestion of water contaminated with cysts Hookworm — skin penetration of larvae from soil Toxoplasma gondii — ingestion of raw or rare meats

Which of the following is the best technique to identify Dientamoeba fragilis in stool? * 1/1 Formalin concentrate Trichrome-stained smear Modified acid-fast–stained smear Giemsa’s stain

Characteristics of the rhabditiform (noninfective) larvae of Strongyloides stercoralis include a: * 1/1 Short buccal capsule and large genital primordium Long buccal capsule and pointed tail Short buccal capsule and small genital primordial Small genital primordium and notch in tail

Visceral larva migrans is associated with which of the following organisms? * 1/1 Toxocara — serology Onchocerca — skin snips Dracunculus — skin biopsy Angiostrongylus — CSF examination

An operculated cestode egg that can be recovered from human feces is: * 1/1 Clonorchis sinensis Diphyllobothrium latum Paragonimus westermani Dipylidium caninum

In infections with Taenia solium, humans can serve as the: * 1/1 Definitive host Intermediate host Either the definitive or the intermediate host None of these options

Organisms that should be considered in a waterborne outbreak of diarrheal disease include: * 1/1 Giardia lamblia and Cryptosporidium spp. Endolimax nana and Entamoeba histolytica Blastocystis hominis and Trichomonas vaginalis Toxoplasma gondii and Schistosoma mansoni

A 2-month-old infant in good health was scheduled for a checkup at the pediatrician’s office. After arriving for the appointment, the mother noted white patches on the baby’s tongue and in his mouth. The baby constantly used a pacifier. What is the most likely organism causing the white patches? * 1/1 Cryptococcus neoformans Candida albicans Aspergillus fumigatus None of these options

A dehydrated 25-year-old male patient was admitted to the hospital with symptoms similar to those of chronic fatigue syndrome. Serological testing proved negative for recent streptococcal infection, Epstein–Barr virus, and hepatitis. Which of the following viral serological tests should help with a possible diagnosis? * 0/1 CMV Echovirus Respiratory syncytial virus DMeasles virus

A wound (skin lesion) specimen obtained from a newborn grew predominantly β-hemolytic colonies of gram-positive cocci on 5% sheep blood agar. The newborn infant was covered with small skin eruptions that gave the appearance of a “scalding of the skin.” The gram-positive cocci proved to be catalase positive. Which tests should follow for the appropriate identification? * 0/1 Optochin, bile solubility, PYR Coagulase, glucose fermentation, DNase Bacitracin, PYR, 6.5% salt broth CAMP, bile-esculin, 6.5% salt broth

An isolate of Staphylococcus aureus was cultured from an ulcer obtained from the leg of a diabetic 79-year-old female patient. The organism showed resistance to methicillin. Additionally, this isolate should be tested for resistance or susceptibility to: * 1/1 Erythromycin Gentamicin Vancomycin Kanamycin

An isolate recovered from a vaginal culture obtained from a 25-year-old female patient who is 8 months pregnant is shown to be a gram-positive cocci, catalase negative, and β-hemolytic on blood agar. Which tests are needed for further identification? * 1/1 Optochin, bile solubility, PYR Bacitracin, CAMP, PYR Methicillin, PYR, trehalose Coagulase, glucose, PYR

A sputum specimen from an 89-year-old male patient with suspected bacterial pneumonia grew a predominance of gram-positive cocci displaying alpha-hemolysis on 5% sheep blood agar. The colonies appeared donut shaped and mucoidy and tested negative for catalase. The most appropriate tests for a final identification are: * 1/1 Coagulase, glucose fermentation, lysostaphin Penicillin, bacitracin, CAMP Optochin, bile solubility, PYR Bile esculin, hippurate hydrolysis

Anaerobic gram-negative rods were recovered from the blood of a patient after gallbladder surgery. The bacteria grew well on agar containing 20% bile, but were resistant to kanamycin and vancomycin. What is the most likely identification? * 0/1 Clostridium perfringens Bacteroides fragilis group Prevotella spp. Porphyromonas spp.

Which of the following groups of specimens would be acceptable for anaerobic culture? * 1/1 Vaginal swab, eye swab Intraoral surface swab, leg tissue Pleural fluid, brain abscess fluid Urine, sputum

The most important variable in the recovery of organisms in adult patients with bacteremia (bacterial sepsis) is: * 0/1 Subculture of all bottles at day 5 of incubation The recommended volume of blood cultured Collection of daily blood culture sets for 3 consecutive days Collection of multiple blood culture sets from a single venipuncture

Virus transport medium should contain agents that: * 0/1 Enable rapid viral growth during the transport time Inhibit bacterial and fungal growth Destroy nonpathogenic viruses Inhibit complement-fixing antibodies

A community hospital microbiology laboratory is processing significant numbers of stool cultures because of an outbreak of diarrhea following heavy rains and flooding in the county. A media that should be incorporated in the plating protocol is: 1/1 Colistin nalidixic acid for Listeria MacConkey agar with sorbitol for Campylobacter Mannitol salt agar for Enterococcus species Thiosulfate citrate bile salts sucrose for Vibrio species

Which of the following specimen requests is acceptable? * 1/1 Feces submitted for anaerobic culture Foley catheter tip submitted for aerobic culture Rectal swab submitted for direct smear for gonococci Urine for culture of acid-fast bacilli

The primary isolation of Neisseria gonorrhoeae requires: * 0/1 Anaerobic conditions Starch media Carbon dioxide Blood agar

Which of these specimen types is considered to be the most sensitive for the recovery of Brucella in cases of chronic infection? * 0/1 Blood Urine Bone marrow Lymph node

A patient has a suspected diagnosis of subacute bacterial endocarditis. His blood cultures grow non-spore-forming pleomorphic gram-positive bacilli only in the anaerobic bottle. What test(s) will give a presumptive identification of this microorganism? * 0/1 Beta-hemolysis and oxidase Esculin hydrolysis Hydrolysis of gelatin Catalase and spot indole

Cerebrospinal fluid test results that are most consistent with viral meningitis include: * 0/1 Decreased protein level Increased glucose level Increased lactate level Lymphocytes predominant

A Gram stain of a peritoneal fluid shows large gram-positive bacilli. There is 3+ growth on anaerobic media only, with colonies producing a double zone of hemolysis. To assist with the classic identification of the organism, the microbiologist could: * 0/1 Determine if the organism ferments glucose Perform the oxidase test Set up egg yolk agar plate Test for bile tolerance

The Gram stain of drainage from a pulmonary sinus tract shows many WBCs and 3+ branching gram-positive bacilli. Colonies grow only on anaerobic media after 3 days incubation. They are yellow-tan and have a molar tooth appearance. The most likely genus is: * 1/1 Actinomyces Bacteroides Fusobacterium Nocardia

A common cause of acute exudative pharyngitis is: * 0/1 Staphylococcus aureus (beta-hemolytic) Streptococcus pneumoniae Streptococcus agalactiae Streptococcus pyogenes

Which test can be used to diagnose infection and confirm eradication of Helicobacter pylori? * 1/1 DNase Hippurate hydrolysis String test Urea breath test

The characteristic that is most commonly associated with the presence of strict anaerobic bacteria and can be taken as presumptive evidence of their presence in a clinical specimen is the: * 0/1 Presence of a single bacterial species Production of gas in a thioglycolate broth culture Growth on a blood agar plate incubated in an anaerobic jar Presence of a foul, putrid odor from tissue specimens and cultures

Anaerobic, box-car shaped, beta-hemolytic gram-positive bacilli isolated from a foot wound are most likely: * 1/1 Actinomyces israelii Clostridium perfringens Bacillus subtilis Eggerthella lenta

A clean-catch urine culture (obtained with a 0.01 ml calibrated loop) grows 60 colonies of Escherichia coli. Which of the following represents the final colony count in CFU/ml? * 1/1 60 CFU/ml 600 CFU/ml 6,000 CFU/ml 60,000 CFU/ml

Which testing platform meets this description? An isolated colony is irradiated by a laser, which ionizes the biomolecules and causes them to become accelerated in an electric field. The ionized biomolecules then enter a flight tube where they are separated by their mass-to-charge ratio. * 1/1 MALDI-TOF Multiplex PCR Pulsed-field gel electrophoresis Sequencing

The lowest concentration of antibiotic that inhibits growth of a test organism is the: * 1/1 Minimum bactericidal concentration Minimum inhibitory concentration Serum bactericidal concentration Serum inhibitory concentration

In disk diffusion susceptibility testing, as an antimicrobial agent diffuses away from the disk, the concentration of antibiotic is: * 1/1 Increased Decreased Unchanged Inoculum dependent

In the disk diffusion method of determining antibiotic susceptibility, the size of the inhibition zone used to indicate susceptibility has been determined by: * 1/1 Testing 30 strains of 1 genus of bacteria Correlating the zone size with minimum inhibitory concentrations Correlating the zone size with minimum bactericidal concentrations Correlating the zone size with the antibiotic content of the disk

Examples of Category A agents of bioterrorism include: * 0/1 Bacillus anthracis, MDR tuberculosis Francisella tularensis, Yersinia pestis Hanta virus, variola major virus VRE, Bacillus cereus

BSL-3 organisms are those that: * 1/1 Cause human disease but are not readily transmitted among hosts Do not ordinarily cause human disease; they require minimal safety procedures Have very high risk of serious disease and no available treatment or vaccine Produce serious disease and are transmitted by respiratory route

BSL-3 organisms produce serious disease and are transmitted by respiratory route. BSL-2 organisms are not readily transmitted; BSL-1 organisms don't cause human disease; BSL-4 organisms cause serious disease for which there is neither treatment nor vaccine. Mycobacterium tuberculosis complex can be identified directly in AFB smear positive respiratory specimens the same day the smear is read by: * 0/1 Cording seen on the AFB smear Molecular testing QuantiFERON®-TB test MALDI-TOF testing

Organisms that are part of the Mycobacterium tuberculosis complex (MTBC) include Mycobacterium tuberculosis and: * 0/1 M. africanum and M. bovis M. africanum and M. kansasii M. avium and M. bovis M. avium hominissuis

Which of the following organisms is the causative agent of hand, foot and mouth disease? * 1/1 Adenovirus Coxsackie A Coxsackie B Human herpes virus 6

In a person vaccinated against hepatitis B virus several years prior, which serological marker would be expected? * 1/1 HBs Ag HBe Ag Anti-HBs Anti-HBc

Polyvinyl alcohol used in the preparation of permanently stained smears of fecal material: * 0/1 Concentrates eggs Dissolves artifacts Serves as an adhesive Enhances stain penetration

A liquid stool specimen is collected at 10:00 PM and brought to the laboratory for culture and ova and parasite examination. It is refrigerated until 10:10 AM the next day, when the physician requests that the technologist look for amoebic trophozoites. The best course of action would be to: * 1/1 Request a fresh specimen Perform a concentration on the original specimen Perform a trichrome stain on the original specimen Perform a saline wet mount on the original specimen

Which one of the following routine tests for Entamoeba histolytica has the highest sensitivity and specificity? * 0/1 Colonic ulcer biopsy Stool microscopy Stool EIA Urine PCR

Which organism has the largest egg? * 0/1 Clonorchis Diphyllobothrium Fasciola Paragonimus

Which fungal organism is urease+ and phenol oxidase+? * 1/1 Cryptococcus neoformans Malassezia furfur Rhodotorula Trichophyton mentagrophytes

Microbiology-related urgent or critical results include positive: * 1/1 Blood cultures, cerebrospinal fluid cultures and acid-fast smears Blood cultures, urine cultures and ova & parasite examinations Cerebrospinal fluid cultures, fungal cultures and ova & parasite examinations Streptococcus pyogenes throat screens, bronchial washing cultures and fungal cultures

Streptococci obtain all their energy from the fermentation of sugars to: * 1/1 Formic acid Lactic acid Succinic acid Valeric acid

Streptococci obtain all their energy from the fermentation of sugars to: * 1/1 Formic acid Lactic acid Succinic acid Valeric acid

Cultures of the posterior pharynx are most commonly submitted to the clinical laboratory for the detection of: * 0/1 Corynebacterium diphtheriae Staphylococcus aureus Streptococcus pneumoniae Streptococcus pyogenes

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The classic toxigenic strains of which serogroup are implicated in epidemic infections of Vibrio cholerae? * 1/1 O2 O3 O4

Which of the following is a fluorescent stain for mycobacteria? * 0/1 Auramine-rhodamine Calcofluor white Fluorescein isothiocyanate Ziehl-Neelsen

Which of the following is an important cause of food poisoning? 1/1 Bacteroides fragilis Bacteroides ureolyticus Clostridium perfringens Clostridium histolyticum

A suspension of the test organism for use in broth dilution and disk diffusion testing is adjusted to match the turbidity of a: * 1/1 0.5 McFarland standard 1.0 McFarland standard 2.0 McFarland standard 3.0 McFarland standard

The minimum bactericidal concentration (MBC) of an antimicrobial agent is defined as the lowest concentration of that antimicrobial agent that kill at least ____ of the original inoculum. * 1/1 95.5% 97% 99.9% 100%

The phenomenon of bacterial resistance to the bactericidal activity of penicillins and cephalosporins, with only inhibition of the organism's growth, is known as: * 0/1 High-level resistance Intrinsic resistance Inducible resistance Tolerance

The process is mediated through viruses capable of infecting bacteria (BACTERIOPHAGES): * 1/1 Transformation Transduction Conjugation

Recipient CELL UPTAKE OF NAKED (FREE) DNA released into the environment when another bacterial cell (i.e., donor) dies and undergoes lysis: * 0/1 Transformation Transduction Conjugation

In addition to chromosomal DNA, genes encoded in extrachromosomal genetic elements, such as PLASMIDS and TRANSPOSONS, may be transferred by: * 0/1 Transformation Transduction Conjugation

The exchange of cellular DNA between two living bacterial cells that involves an intercellular bridge is which of the following processes? * 1/1 Transformation Transduction Plasmidization Conjugation

Transduction is defined as which of the following? * 0/1 The change of the bacterial genotypes through the exchange of DNA from one cell to another An internal change in the original nucleotide sequence of a gene or genes within an organism’s genome The process by which genetic elements such as plasmids and transposons excise from one genomic location and insert into another A mechanism that is mediated by viruses, by which DNA from two bacteria may come together in one cell, thus allowing for recombination

Which of the following bacteria should be considered important pathogens when reading gram-stained smears of soft tissue abscess? * 1/1 Streptococcus pneumoniae Neisseria gonorrhoeae Pseudomonas aeruginosa Staphylococcus aureus

Oxidase and urease positive: * 1/1 B. pertussis B. parapertussis B. bronchiseptica None of these

Oxidase positive, urease negative: * 1/1 B. pertussis B. parapertussis B. bronchiseptica None of these

Oxidase negative, urease positive: * 1/1 B. pertussis B. parapertussis B. bronchiseptica None of these

Alcaligenes faecalis (formerly A. odorans) is distinguished from Bordetella bronchiseptica with which test? * 1/1 Urease (rapid) Oxidase Growth on MacConkey agar Motility

When performing antimicrobial susceptibility test- ing, the following definition of the minimum inhibitory concentration (MIC) is correct: * 1/1 The highest concentration of an antibiotic in a dilution series that inhibits growth The lowest concentration of an antibiotic in a dilution series that inhibits growth The lowest concentration of an antibiotic in a dilution series that kills the bacteria The lowest concentration of the antibiotic obtain- able in the patient without toxicity

In a quality control (QC) procedure on a new batch of Mueller-Hinton plates using a standard QC stock strain of Staphylococcus aureus, the disk inhibition zone sizes for three of the drugs tested were too small and fell below the expected QC range. Which of the following is the most likely reason for this observation? * 1/1 These three antibiotic disks were outdated and had lost potency These three disks were faulty in that the antibiotic content was too high Bacterial suspension of Staphylococcus was probably contaminated with another organism The plates received insufficient incubation time

The organism most commonly associated with otitis media infections is associated with which of the following positive test results? * 1/1 Coagulase VP Optochin Bacitracin

Gram staining and reading a glass slide with a mixed smear of Staphylococcus and Escherichia coli along with each Gram staining run of specimens examined within the microbiology laboratory that day is an example of which of the following? * 1/1 Quality assurance (QA) activity Quality control (QC) activity National regulatory activity Office of Safety and Health Administration activity

Tracking the rate of skin organism contamination among a laboratory’s blood culture results on a monthly basis and introducing specific training to phlebotomists when rates exceed the norm would be an example of which of the following? * 1/1 Good laboratory practice Quality control Universal standards Quality assurance

The only known human tapeworm with an operculum is: * 1/1 Diphyllobothrium latum Giardia lamblia Schistosoma haematobium Hymenolepis nana

The only trematode with separate sexes: * 1/1 Schistosoma Fasciola Fasciolopsis Paragonimus

The specific gravity of the approved zinc sulfate solution for the flotation method: * 1/1 1.01 1.04 1.18 1.48

What is the preferred concentration method for opercolated eggs? * 1/1 Flotation using zinc sulfate Saline - glycerol Iodine - salt Formalin - ether sedimentation

Microfilariae can be detected in the blood throughout the day but are detected at higher levels during the late afternoon or at night: * 1/1 Diurnal Nocturnal Subperiodic Nonperiodic

In disk diffusion testing, zone diameters are too large or too small with all antimicrobials: * 1/1 Check inoculum sizes Obtain a fresh culture from an appropriate culture collection Standardize illumination Take a fresh culture from stock

Chocolate agar contains: * 1/1 Chocolate Clotted blood Brown nutrient agar Hemolyzed red blood cells

Several attendees of a medical conference in the Gulf coast area became ill after frequenting a seafood restaurant. A presumptive identification of Vibrio cholerae was made after stool specimens from several subjects grew clear colonies on MacConkey agar and yellow colonies on TCBS agar. Which key tests would help eliminate Aeromonas and Plesiomonas spp.? * 0/1 Mannitol fermentation, Na+ requirement Oxidase, motility Oxidase, nitrate Hemolysis on blood agar, catalase

The use of 0.1% FUCHSIN substituted for safranin in the Gram-stain procedure may enhance the visibility of the organisms: * 1/1 Bordetella spp. Capnocytophaga spp. Francisella spp. Legionella spp.

A patient report states the presence of serum antibodies to OspC. What disease does the patient most likely have? * 1/1 Syphilis Strep throat Lyme disease Rubella