The Quizzes about Bacteriology – Part 5 (end)

A 25-year-old male, with a history of hepatitis C, has to wade through brackish water in post-Katrina New Orleans. He develops worsening abdominal pain and jaundice. Regarding Vibrio vulnificus, which of the following best describes this organism?

Yersinia enterocolitica, formerly a Pasteurella, has more than 50 sero-types that can be isolated from rodents, sheep, cattle, swine, dogs, and cats and water contaminated by them, and is best described by which of the following?

Four weeks after assisting in several calf deliveries, a farmer develops fever, weakness, muscle aches, and sweats. The fever rises in the afternoon and falls during the night. Brucella abortus is isolated. Which one of the three Brucella species is a possible bioterrorism agent and is best described by one of the following?

Bordetella bronchiseptica could be confused with the agent of whooping cough since it occasionally causes chronic respiratory tract infections in humans, but has less intensive symptoms (rhinitis and cough). It is best described by which of the following?

Pasteurella species can produce a range of human diseases and formerly included all yersiniae and francisellae organisms. Pasteurella multocida occurs worldwide in the URT and GI tracts of domestic and wild animals. It is best described by which of the following?

A 26-year-old male presents to his family physician with complaints of painful burning during urination and a milky discharge. The purulent discharge reveals many neutrophils with intracellular gram-negative diplococci. Which of the following mediums would most likely be used for isolating Neisseria gonorrhoeae, the suspected organism?

Twenty-four hours after returning from a short trip to Asia, a 35-year-old female has a sudden onset of vomiting and massive watery diarrhea that is colorless, odorless, and contains flecks of mucus. Which of the following mediums would most likely be used for isolating V. cholerae, the suspected organism?

A 32-year-old female prostitute is seen at the public health clinic with fever, night sweats, and reports coughing up blood. Her medical history reveals that she is HIV positive and has lost 20 lbs over the past month. Acid-fast bacilli are observed in the sputum. After digestion of the sputum, isolation of the suspected organism is best accomplished by using which one of the following media?

Bacillus and Clostridium species are spore-forming bacilli and can survive in the environment for years. Several species cause important disease in humans, although most will respond quickly to appropriate antibiotic therapy. However, which organism listed below would not benefit from such prompt antibiotic treatment?

A 12-year-old boy has sudden onset of fever, headache, and stiff neck. Two days earlier, he swam in a lake that is believed to have been contaminated with dog excreta. Leptospirosis is suspected. Which of the following laboratory tests is most appropriate to determine whether he has been infected with leptospira?

A 60-year-old female complains of tenderness and pain around a peritoneal catheter. Blood cultures reveal gram-positive, catalase-positive cocci. Which of the following is the most likely organism that is also considered a predominant organism on skin?

A healthy 45-year-old female had root canal treatment about 3 weeks ago. She now presents with a new heart murmur, fever, painful skin nodules, abdominal pain, and an abnormal liver function test. Which of the following organisms would mostly likely cause endocarditis and is implicated in dental caries or root canal infections?

A 17-year-old man is hospitalized with trauma to the abdomen following a gang-related fight. He develops an intraabdominal abscess, which is drained and sent to the laboratory. A mixture of gram-negative anaerobes is detected. Which of the following microorganisms is the most likely and is also the most prevalent bacterium in the gut?

A 25-year-old female is treated with a course of broad-spectrum antibiotics for severe pelvic inflammatory disease. She now reports a thick milky white pruritic vaginal discharge. Which of the following is the most prevalent microorganism in the vagina and may also be protective?

Viridans streptococci (S. mutans, S. mitis) usually have α-hemolysis and are optochin-resistant. They are becoming increasingly important as causes of endocarditis and abscesses (mixed infections). Which of the following best describes S. mutans?

Streptococcus salivarius, a common isolate, which is considered as normal, nonpathogenic flora in the clinical laboratory, is best described by which of the following?

Actinomyces species are a large, diverse group of gram-positive bacilli. Actinomyces israelii is an organism that causes pyogenic lesions with interconnecting sinus tracts that contain granules of microcolonies embedded in the tissues. It is best described by which of the following?

Actinomyces viscosus, a ubiquitous actinomycete, grows under micro-aerophilic or strict anaerobic conditions and produces a yellow-orange granule in the typical tissue exudates. It is best described by which of the following?

A 3-year-old girl from a family that does not believe in immunization presents to the emergency room with a sore throat, fever, malaise, and difficulty breathing. A gray membrane covering the pharynx is observed on physical examination. Which of the following best describes C. diphtheriae, the etiologic agent?

A 4-year-old boy is taken to see his pediatrician because of a persistent cough that gradually worsened over a 12-day period. On the day of the examination, the cough is so severe that it is frequently followed by vomiting. A blood cell count shows marked leukocytosis with a predominance of lymphocytes. Which of the following best characterizes this microorganism?

A 48-year-old deer hunter presents to the emergency room with lymphadenopathy and a skin lesion, which started as a painful papule at the site of a tick bite. The papule then ulcerates with a necrotic center and raised border. Aspirate of the ulcer is positive for F. tularensis. Which one of the following best characterizes this bacterium?

Ten boy scouts are hospitalized with bloody diarrhea and severe hematological abnormalities. An investigation establishes that all of the boys developed symptoms following consumption of hamburgers from the same fast-food restaurant chain. Which of the following best describes E. coli 0157/H7, the etiologic bacterium responsible for the outbreak?

A 4-year-old girl awakens at midnight complaining of a sore throat and headache, and she has a fever of 101°F. Physical examination reveals an erythematous throat. A rapid strep test is positive. A throat swab is sent to the laboratory for further testing. Which of the following best characterizes S. pyogenes as the presumed etiologic agent?

A 19-year-old military recruit who lives in the barracks develops a macular papular skin rash, severe headache, photophobia, fever, stiff neck, and blurred vision. He is presumed to have N. meningitidis. Which of the following is a characteristic physiological trait of this organism?

A 45-year-old cattle-farm worker goes to the public health clinic after experiencing 6 weeks of undulating fever, chills, sweating, headache, fatigue, muscle pain, and weight loss. History reveals that he enjoys drinking fresh unpasteurized milk with his other coworkers during the midmorning breaks. A blood sample is sent to the state laboratory for serologic testing because the physician assistant suspects Brucella infection. Which of the following best characterizes this organism?

An 18-year-old male patient presents to the emergency room with a 3-day history of fever, dry cough, difficulty in breathing, and muscle aches and pains. His chest x-ray shows a diffuse left upper lobe infiltrate. Mycoplasma pneumoniae pneumonia (walking pneumonia) may be rapidly identified by which of the following procedures?

A 50-year-old male presents with severe bilateral pulmonary infiltrate, elevated temperature leucocytosis, elevated enzymes, and elevated creatine kinase. He recently visited his favorite restaurant that had a large water fountain, which was misty on the day of his visit. Which of the following procedures would most rapidly diagnose the suspected organism that is the etiologic agent of Legionnaires disease in this patient?

A group of elementary school-age children meet for a birthday party, and in the next few days, about half of them experience a mild upper respiratory illness, with sore throat and runny nose. One family gets laboratory work done and finds that Chlamydia pneumoniae (TWAR) is involved. Which of the following procedures would be best if the laboratory wanted to isolate this bacterium?

A 70-year-old man with a history of diabetes presents with severe pain in his right ear. The patient was diagnosed with external otitis. Further tests suggested that the patient suffered bone and nerve damage. Clinical laboratory analysis showed that the isolated microorganism produced a distinct blue pigment as well as an ADP-ribosylating toxin. What is the most likely causative agent?

A 40-year-old woman has a history of several months of gastric pain that was temporarily relieved with antacid. Stomach biopsies revealed the presence of comma-shaped organisms. The patient responded very well to a combined treatment of proton pump inhibitors and amoxicillin. Which of the following factors produced by the etiologic agent is associated with the development of gastric cancer in persons with chronic infections?

A 60-year-old man suffered from fever, watery diarrhea, abdominal pain, and nausea. Three weeks later, he was admitted to the hospital unable to speak but coherent and oriented. Neurological examination revealed bilateral muscle weakness in his legs. Within hours, the muscle weakness extended to his arms and chest. He was diagnosed with Guillain–Barré syndrome. With which organism was he most likely infected?

An outbreak of gastroenteritis occurred in a youth group camp. Water at the camp, which was not chlorinated or filtered, was obtained from a spring on the premises. The farmland near the camp was grazed by cattle and sheep. Run-off from the pasture entered the camp spring. The isolated microorganism required an atmosphere containing reduced oxygen and increased carbon dioxide for its growth. In most cases, the gastroenteritis was self-limiting. Those requiring antibiotic treatment responded to erythromycin. Which is the most likely causative agent?

A 60-year-old male in the intensive care unit recovering from back surgery required intubation for respiratory support. Forty-eight hours after intubation, he developed ventilator-associated pneumonia. The microorganism isolated from tracheal secretions aspirated from the patient is a gram-negative, oxidase positive, obligate aerobe that produces a multitude of virulence factors including proteases, toxins, and rhamnolipid. The patient was treated with broad-spectrum antibiotics for several weeks, but the treatment was unsuccessful and he died. Which is the most likely causative agent of this patient’s infection?

Four weeks after hurricane Rita, a 50-year-old man and his wife from southeastern Louisiana developed diarrhea. The man had mild diarrhea. However, his wife had severe watery diarrhea, fever, muscle cramps, and vomiting, which quickly progressed in to a loss of renal function and respiratory and cardiac failure. She responded very well to antibiotic and aggressive rehydration therapy. Stool samples from both patients contained gram-negative comma-shaped bacteria. Which is the most likely causative agent?