The pathogenesis of which one of the following organisms is MOST likely to involve invasion of the intestinal mucosa?

The total magnification of a microscope is calculated by:

How is a prophage created?

The presence of a capsule around bacterial cells usually indicates their increased disease-causing potential and resistance to disinfection. Capsules are generally viewed by:

Which one of the following organisms that infects the gastrointestinal tract is the MOST frequent cause of bacteremia?

The process by which bacterial or plasmid DNA may be mistakenly incorporated (during assembly) into one phage being produced by the lytic life cycle and then that DNA-transferred to another bacterial cell which may acquire some new genetic traits is called

A specimen suspected of containing members of the Enterobacteriaceae was subjected to a few laboratory diagnostic tests and generated the following results: Gram negative rod; colorless/pale colonies on MacConkey agar. All of the following microorganisms may be included in the diagnosis, EXCEPT

Which of the following events is most likely due to bacterial transformation?

Each of the following agents is a recognized cause of diarrhea EXCEPT:

The form of genetic exchange in which donor DNA is introduced to the recipient by a bacterial virus is

Which genetic material is found in pathogenic Corynebacterium diphtheriae but not in nonpathogenic normal flora diphtheroids?

Which of the following microscopic techniques provide three-dimensional images of a bacterial cell?

The following organisms are recognized causes of diarrhea EXCEPT

A 27-year-old IV drug user presents with difficulty swallowing. Examination of the oropharynx reveals white plaques along the tongue and the oral mucosa. Which of the following best describes the microscopic appearance of the microorganism responsible for this patient’s illness?

The order of reagents used in the Gram stain are:

Diarrhea associated with prolonged antibiotic treatment, including pseudomembranous colitis, is MOST FREQUENTLY caused by

Which one of the following bacteria has the LOWEST 50% infectious dose (ID50)?

The formation of a mating pair during the process of conjugation in Escherichia coli requires

The first vaccine for human use produced using recombinant DNA technology was the:

Two hours after a delicious Thanksgiving dinner of barley soup, roast turkey, stuffing, sweet potato, green beans, cranberry sauce, and pumpkin pie topped with whipped cream, the Smith family of four experience vomiting and diarrhea. Which one of the following organisms is MOST likely to cause these symptoms?

A local day care center has several simultaneous cases of diarrhea. A methylene blue fecal smear was taken during the outbreak from one of the children and revealed numerous PMN’s and occult blood. Culture of the stool revealed a typical gram negative rod which fermented glucose but not lactose, was nonmotile and did not produce H2S. The agent which MAY have caused this outbreak was

A 26-year-old male with AIDS presents with painful bloody diarrhea. Stool culture on MacConkey agar medium and subsequent analyses reveals predominantly a gram -negative facultative anaerobic rod, which is oxidase negative, lactose negative, H2S negative and non-motile. Which of the following is the most likely cause of this infection?

A 29-year-old man with a long history of heartburn and dyspepsia presents to the primary care doctor with severe mid-epigastric pain. He was initially treated with an H2 blocker twice a day. He immediately had relief but his symptoms returned after two weeks. What is the most likely cause for the relapse in his symptoms?

Which type of genetic exchange in bacteria is susceptible to the activity of deoxyribonuclease?

Which of the following stains is used to classify microorganisms based on their cell wall content?

Which one of the following processes involves a sex pilus?

Five hours after eating reheated rice at a restaurant, a 24-year-old woman and her husband both developed nausea, vomiting, and diarrhea. Which one of the following organisms is the MOST likely to be involved?

For which one of the following enteric illnesses is a chronic carrier state MOST likely to develop?

Which of the following statements concerning recombinant DNA technology is false?

Conjugation with a cell with chromosomal drug resistance appears in the genome of a bacteriophage that has infected it.

Which one of the following host defense mechanisms is the MOST important for preventing dysentery caused by Salmonella?

Hybridomas are formed by fusing antibody-producing white blood cells with:

Which of the following pathogenic bacteria is MOST COMMONLY associated with traveler’s diarrhea?

In light microscopes, what function does a condenser serve?

Which of the following events is MOST likely to be due to bacterial conjugation?

A family has a diarrhea after eating raw shellfish due to an oxidase positive, gram-negative curved bacillus that requires a special media for growth. Which of the following is the most likely cause?

Which of the following statements is most correct about the differential Gram stain?

Drumstick appearance in the microscopy is the distinguishing characteristics of:

Which of the following mechanisms is most likely to be involved in multiple drug resistance transfer from one cell to another?

Which of the following is defined as the ability to distinguish or separate two adjacent objects or points from one another in a microscopic specimen?

A 70-year-old man underwent bowel surgery for colon cancer 3 days ago. He now has a fever and abdominal pain. Attending physician is concerned that he may have peritonitis. Which one of the following pairs of organisms is MOST likely to be the cause?

Each of the following statements concerning Mycobacterium tuberculosis is correct EXCEPT:

Transmission electron microscopy is best for high magnification viewing of

All of the following are examples of special stains except:

Your patient is a 30-year-old woman with nonbloody diarrhea for the past 14 hours. Which one of the following organisms is LEAST likely to cause this illness?

The compound light microscope can be used to observe:

Following specialized transduction, if any of the bacterial genes transferred in are to be stabilized, what process must occur?

The ability of a cell to bind DNA to its surface and import it is required for which genetic process?

What type of microscopy allows for the visualization of internal components within live, unstained specimens?

A 25-year-old female medical student reports that she had lunch at a Indian restaurant in the afternoon. She is presented in the emergency department of hospital with the complaints of abdominal cramps, nausea and vomiting. Culture and gram stain reveal gram- positive aerobic rods. Which of the following is the most likely cause of this infection?