Microbiology & Parasitology Pre-Boards Exam (Psalm 94:18-19)

The exchange of cellular DNA between two living bacterial cells that involves an intercellular bridge is which of the following processes?

TRANSDUCTION is defined as which of the following?

Standard precautions state:

The optimal time to collect blood cultures is:

The aseptic collection of blood cultures requires that the skin be cleansed with:

When cleansing skin with alcohol and then iodine for collection of blood culture, the iodine (or iodophor) should remain intact on the skin for at least:

A listless 12-month-old boy with a fever of 103°F was taken to the emergency department. He had been diagnosed with an ear infection 3 days earlier. A spinal tap was performed, but only one tube of CSF was obtained from the lumbar puncture. The single tube of CSF should be submitted first to which department?

Media that contain dyes, antibiotics, or other chemical compounds that inhibit certain bacteria while allowing others to grow are called:

Media that contain factors such as carbohydrates that give colonies of particular organisms distinctive characteristics are called:

The amount of antibiotic used in disk diffusion susceptibility testing is standardized and constant. Once the disk is placed on the inoculated plate and makes contact, with the agar, the antibiotic in the disk begins to diffuse out. As it diffuses into the media, the concentration of antibiotic gets ___ the further it diffuses from the disk.

In disk diffusion testing, zone diameters are too large or too small with all antimicrobials:

Which of the following tests is most frequently used in the identification of Gardnerella vaginalis, Streptococcus agalactiae, Campylobacter jejuni, and Listeria monocytogenes?

Brown or green color surrounding the colony:

Chocolate agar contains:

The most common cause of bacterial food poisoning is:

Which of the following bacteria should be considered important pathogens when reading gram-stained smears of soft tissue abscess?

Resistance to which drug categorizes a strain of Staphylococcus aureus as methicillin-resistant Staphylococcus aureus (MRSA)?

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:

Cultures of the posterior pharynx are most commonly submitted to the clinical laboratory for the detection of:

A child presented in August at the pediatric clinic with a superficial skin infection of the neck. The large, itchy lesions were cultured, and the diagnosis of IMPETIGO was made. One of the etiologic agents of this clinical condition is:

The organism most commonly associated with otitis media infections is associated with which of the following positive test results?

Which organism is the most often recovered grampositive cocci (catalase negative) from a series of blood cultures obtained from individuals with endocarditis?

Which group of tests, along with colonial morphology on primary media, aids most in the rapid identification of the Enterobacteriaceae?

A positive indole reaction is characteristic of:

What two reagents must be added to determine if the bacterium is VP positive?

A patient presents with diarrhea and abdominal cramping. The organism isolated from the stool culture is identified as Shigella dysenteriae (group A). The TSI reaction would have indicated:

Which of the following bacteria is able to hydrolyze urea via urease production, which results in an increase in urine pH that is toxic to kidney cells and stimulates the formation of kidney stones?

Which biochemical tests should be performed in order to identify colorless colonies growing on MacConkey agar (swarming colonies on blood agar) from a catheterized urine specimen?

The gram-negative bacillus that can be described as oxidase-negative, nitrate- positive, indole-negative, citrate-positive, methyl red-positive, urease-negative, and H₂S-positive is most likely which of the following?

An organism was inoculated in to a TSI tube and gave the following reactions:

• Alkaline slant
• Acid butt
• H₂S: not produced
• Gas: not produced

The organism is most likely which of the following?

Which of the listed Pseudomonas spp. is associated with the following virulence factors: exotoxin A, endotoxins, proteolytic enzymes, antimicrobial resistance, and production of alginate?

Which group of tests best differentiates Helicobacter pylori from C. jejuni?

Which Brucella species may require CO₂ for growth, is urea positive in 2 hours, and is inhibited by thionine dye?

The use of 0.1% FUCHSIN substituted for safranin in the Gram-stain procedure may enhance the visibility of the organisms:

Specimen characteristics of an anaerobic infection include:

In a clinical specimen, the presence of sulfur granules strongly indicates the presence of which anaerobic bacterium?

Which gram-negative bacilli produce black pigment and brick red fluorescence when exposed to an ultraviolet light source?

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?

Which is the specimen of choice for proof of food poisoning by Bacillus cereus?

The ETHANOL SHOCK procedure is used to differentiate:

Egg yolk agar is used to detect which enzyme produced by Clostridium species?

Identification of Clostridium tetani is based upon:

Perhaps the most common cause of food poisoning is from ___, which produces toxin in the host after ingestion. Meats and gravies are typical foods associated with this type of food poisoning.

The classic form of foodborne botulism is characterized by the ingestion of:

Which mechanism is responsible for botulism in infants caused by Clostridium botulinum?

Cycloserine-cefoxitin-fructose agar (CCFA) is used for the recovery of:

Loeffler's agar slant is a special culture medium used to recover which organism?

A blood culture is positive for gram-positive bacilli that gave the following growth characteristics and biochemical reactions:

• MacConkey agar = no growth
• H₂S on TSI = negative
• Growth on blood agar = nonhemolytic
• Catalase = positive
• Nonmotile
• No spore

These reactions are consistent with which of the following organisms?

A skin lesion was opened and drained in surgery. The culture was positive for a gram-positive bacillus, which gave the following growth characteristics and biochemical reactions:

• MacConkey agar = no growth
• H₂S on TSI = positive
• Growth on blood agar = nonhemolytic
• Catalase = negative
• Nonmotile
• No spores

These reactions are consistent with which of the following organisms?

Which of the following sets of tests provide the best differentiation of Erysipelothrix from Listeria monocytogenes?

Neonatal meningitis is an uncommon but significant disease. Two important causes of this disease may be somewhat difficult to differentiate on preliminary observation. Which of the following sets of tests provide the best differentiation of Streptococcus agalactiae from Listeria monocytogenes?

When 10% CYANOGEN BROMIDE and 4% aniline in 96% ethanol are added to a suspension of the culture, a CANARY YELLOW color indicates a positive reaction:

What substance added to the antigen in the RPR test allows for more macroscopically visible flocculation?

A patient report states the presence of serum antibodies to OspC. What disease does the patient most likely have?

Traditional specimen for diagnosis of Chlamydia trachomatis infection in a male patient:

Specimen for the Nucleic Acid Amplification Test (NAAT) for diagnosis of Chlamydia trachomatis infection:

Which of the following is the most sensitive method for the diagnosis of Chlamydia trachomatis?

What are the optimal temperature and incubation time before a FUNGAL BLOOD CULTURE is reported as negative?

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?

A young male patient with a fungus of the feet visited the podiatrist for relief from the itching. A culture was sent to the microbiology laboratory that grew after 8 days on Sabouraud dextrose agar. Colonies were powdery pink with concentric and radial folds, with the reverse side showing brownish-tan to red in color. Other observations were:

• Hyphae = Septate
• Macroconidia = Cigar shaped, thin walled with 1-6 cells
• Microconidia = Round and clustered on branched conidiophores
• Red pigment on cornmeal (1% dextrose) = Neg
• In vitro hair perforation = +
• Urease = +

The most likely identification is:

Which Aspergillus species, recovered from sputum or bronchial mucus, is the most common cause of pulmonary aspergillosis?

A rapidly growing hyaline mold began as a white colony but soon developed a black "pepper" effect on the agar surface. The older colony produced a black matte, making it resemble a dematiaceous mold. What is the most likely identification?

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

The viral nucleocapsid always contains which of the following?

Specimens collected for virus isolation should be kept at:

At what temperature should clinical specimen suspected of containing viruses be kept for transport that takes days?

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?

Transcription is:

The process of transferring the digested DNA out of a gel after electrophoresis and onto a nylon membrane is referred to as:

The technique that uses fluorescent DNA probes to detect chromosomal abnormalities within cells in cytogenetic studies is referred to as:

Stool specimens kept under refrigeration when preservatives are not available are suitable for:

The formalin-ether (ethyl acetate) concentration procedure for feces is used to demonstrate:

Trophozoites are characterized with progressive motility, hyaline, finger-like pseudopodia; motility may be rapid:

Eye infections with Acanthamoeba spp. have most commonly been traced to:

Select the most sensitive recovery method for Acanthamoeba spp. from lens care solutions or corneal biopsies.

Which of the following is the best technique to identify Dientamoeba fragilis in stool?

Organisms that should be considered in a waterborne outbreak of diarrheal disease include:

Blood specimens for diagnosis of malaria are ideally collected:

A regular periodicity of 72 HOURS is seen from the beginning of the erythrocytic cycle:

"CRESCENT" or "SAUSAGE" shaped gametocytes; may appear in "SHOWERS" with black pigment near chromatin dot, which is often central:

Autofluorescence requires no stain and is recommended for the identification of:

Oocysts of Cryptosporidium spp. can be detected in stool specimens using:

Microsporidial infections can be confirmed using:

Hermaphroditic, EXCEPT:

Nematode parasites that inhabit the large intestines:

1. Ascaris lumbricoides
2. Capillaria philippinensis
3. Threadworm, hookworm
4. Enterobius vermicularis
5. Trichuris trichiura

VISCERAL LARVA MIGRANS (VLM) and OCULAR LARVA MIGRANS (OLM) are caused by accidental ingestion of eggs of:

CREEPING ERUPTION or CUTANEOUS LARVA MIGRANS (CLM) is caused by skin penetration of infective larvae of:

Ingestion of which of the following eggs will result in infection?

The nematode Loa loa is transmitted to humans by:

The nematode Onchocerca volvulus is transmitted to humans by:

The infective life cycle stage of a fluke (except blood fluke) is the:

Infection with Fasciolopsis buski may result from eating raw or undercooked:

Infection with Clonorchis or Opisthorchis may result from eating raw or undercooked:

The mode of transmission of schistosomal infection is by:

In infections with Taenia saginata, humans can serve as the:

In infections with Taenia solium, humans can serve as the:

Proglottids with 15 to 20 lateral branches in a dichotomous or tree-like arrangement:

Proglottids with 7 to 13 lateral branches in dendritic or finger-like arrangement:

Eggs HAVE POLAR FILAMENTS present in the space between the oncospheres and the eggshell:

The eggs contain a six-hooked oncosphere with the ABSENCE OF POLAR FILAMENTS in the space between the oncosphere and the eggshell: