Exam 22: Nonfermenting Gram-Negative Rods

Which of the following oxidase-negative, non-motile, non-fermenting, gram-negative rods can mimic a late lactose fermenter due to the oxidation of lactose rather than fermentation?

Which of the following gram-negative rods is associated with individuals who have cystic fibrosis?

The isolation of an extremely mucoid, oxidase-positive, non-lactose fermenter from the lower respiratory tract usually correlates with the clinical diagnosis of

A tracheal aspirate, obtained from a comatose patient on a ventilator, grew an oxidase-positive non-lactose fermenter that produced a distinctive odor of sliced apples. It proved to be: Motile: positive Nitrate: red after addition of reagents A, B, and zinc OF medium: Open tubes: glucose: blue, maltose: blue, lactose: blue, sucrose: blue Closed tubes: glucose: green, maltose: green, lactose: green, sucrose: green This organism is

Respiratory cultures obtained from an individual with cystic fibrosis should include selective medium for the isolation of

A physician calls the microbiology department for the results of a lower respiratory culture of a 15-year-old female with cystic fibrosis. The culture grows an oxidase-negative, motile, lysine-positive, non-lactose fermenter that presents as K/NC on TSI and an oxidase-positive, lysine-positive, non-lactose fermenter. Based on these results, you tell the physician she can potentially treat both organisms with

Commercial identification systems may have problems with the identification of non-fermenting gram-negative rods because

A 23-year-old male develops folliculitis after spending the afternoon in the hot tub at a ski resort. The ski resort physician submits a swab of the pustular discharge for culture. The organism isolated grew as an oxidase-positive, non-lactose fermenter. It is beta-hemolytic on sheep blood agar with a cyan-colored pigment in the surrounding medium and emits a fruity odor. These culture results

Hugh-Leifson oxidation-fermentation (OF) medium differs from carbohydrate medium used to identify Enterobacteriaceae by all of the following characteristics except

Two blood cultures of a premature infant grow a yellow-pigmented colony that is a non-lactose fermenter. The colony provides the following reactions: Oxidase: purple Indole: pink Motility: negative The organism is probably

A 69-year-old retired army general develops pneumonia after his diagnosis of chronic lymphocytic leukemia. The organism isolated in his sputum culture is an oxidase-positive, wrinkled, non-lactose fermenter with a musty odor that is arginine positive. He probably acquired this organism from

A patient in the intensive care unit has developed pneumonia. A sputum culture grows an oxidase-negative, non-lactose fermenter. The organism is demonstrated in the Gram stain below. The microbiologist works up the organism as a member of the Enterobacteriaceae. The next day she realizes her error. The organism displays the following results: Source: CDC and Dr. W. A. Clark TSI: K/NC Motility: negative OF medium: Open tubes: glucose: yellow, lactose: yellow, maltose: green Closed tubes: glucose: green, lactose: green, maltose: green

The second- and third-degree burns of a firefighter become infected with Pseudomonas aeruginosa while she is hospitalized in the burn unit. What is the most likely environmental source for this organism?

A yellow-pigmented gram-negative rod is isolated from the tracheal aspirate of a 76-year-old female. She is comatose due to meningitis and on a ventilator. The organism proved to be: \begin{array}{ll} \text {MacConkey agar: clear colonies}& \text {Oxidase: no color change}\\ \text {Motility: positive}& \text {TSI: \mathrm{K} / \mathrm{NC} }\end{array} OF medium: Open tubes: glucose: yellow, lactose: yellow, maltose: yellow Closed tubes: glucose: green, lactose: green, maltose: green When assessing the organisms's clinical significance, it is probably

An anemic patient received a unit of blood. She develops fever and chills after infusion of the unit. Blood cultures of the patient and a sample of the blood unit grow the same organism. The non-lactose fermenter isolated displays the following reactions: \begin{array}{lrr}\text {Oxidase: purple}&\text {Growth at 42^{\circ} \mathrm{C} : negative}\\\text {Colony under UV light: yellow}&\text {Arginine: purple}\\\text {Motility: positive}&\text {Gelatin hydrolysis: liquified}\\\text {Acetamide: no color change}&\text {Nitrate after addition of zinc: red}\end{array} The organism is

An oxidase-negative, non-motile, non-lactose fermenter demonstrates K/NC on TSI and is considered a significant nosocomial pathogen due to its multiresistance. Which of the following antibiotics remains a viable treatment option for this organism?

The decarboxylase control tube inoculated with a suspected non-fermenting gram-negative rod is a turbid dirty gray color after incubation at 35°C in ambient air for 24 hours. This result

The deep or butt reaction of a TSI slant appears red-orange for non-fermenting gram-negative rods because the organisms

An oxidase-positive, wrinkled, non-lactose fermenting colony is suspicious for

Which of the following characteristics would lead you to suspect the presence of a nonfermenting gram-negative rod?