Which organism is likely identified from a gram-negative S-shaped rod grown at 42°C with positive oxidase and catalase tests?

Which organism is likely identified from a gram-negative S-shaped rod grown at 42°C with positive oxidase and catalase tests?

• A. Pseudomonas aeruginosa
• B. Campylobacter jejuni
• C. Campylobacter fetus
• D. Pseudomonas putida

Answer: (B)

The organism identified as Campylobacter jejuni fits the description of a gram-negative S-shaped rod that can grow optimally at 42°C, which is a distinctive characteristic of this bacterium. Campylobacter jejuni is known for its microaerophilic nature and its requirement for elevated temperatures, as it commonly colonizes the intestines of birds, particularly poultry, which thrive at these higher temperatures. Additionally, the positive oxidase and catalase tests further support the identification of this organism. Campylobacter species, including jejuni, typically produce the enzyme oxidase, which is involved in electron transport in aerobic respiration, and they are also catalase positive, indicating their ability to break down hydrogen peroxide, a byproduct of metabolism that can be harmful to them. This combination of morphological, growth, and biochemical characteristics distinctly aligns with Campylobacter jejuni, making it the likely organism in this scenario.

The organism identified as Campylobacter jejuni fits the description of a gram-negative S-shaped rod that can grow optimally at 42°C, which is a distinctive characteristic of this bacterium. Campylobacter jejuni is known for its microaerophilic nature and its requirement for elevated temperatures, as it commonly colonizes the intestines of birds, particularly poultry, which thrive at these higher temperatures.

Additionally, the positive oxidase and catalase tests further support the identification of this organism. Campylobacter species, including jejuni, typically produce the enzyme oxidase, which is involved in electron transport in aerobic respiration, and they are also catalase positive, indicating their ability to break down hydrogen peroxide, a byproduct of metabolism that can be harmful to them.

This combination of morphological, growth, and biochemical characteristics distinctly aligns with Campylobacter jejuni, making it the likely organism in this scenario.