Question

Select which of the following were used by laboratory personnel to initially identify the bacteria in the knee fluid as F. tularensis?

1) Gram staining
2) Culture on selective media
3) Biochemical tests
4) PCR analysis

Answer 1

To identify bacteria such as F. tularensis in knee fluid, lab personnel would typically use Gram staining, culture on selective media, biochemical tests, and potentially PCR analysis to determine its presence and characteristics.

Step-by-step explanation:

To initially identify the bacteria in the knee fluid as F. tularensis, laboratory personnel would have likely used the following methods:

1. Gram staining: This is a common early step in the identification of bacteria, revealing the Gram stain reaction and providing insight into the bacterial cell wall structure.
2. Culture on selective media: Special media that allows for the growth of certain types of bacteria while inhibiting others could be used to isolate F. tularensis for further testing.
3. Biochemical tests: These tests assess various metabolic activities of the bacteria, providing a biochemical profile that helps in classification or identification.
4. PCR analysis: Although not as widely available, PCR can be used to detect the DNA of F. tularensis directly from patient samples.

All these methods contribute to the classification and identification of the bacterium, each giving different insights into its characteristics.

Answer 2

Laboratory personnel likely used Gram staining, culture on selective media, and biochemical tests for initial identification of F. tularensis in the knee fluid, with PCR analysis possibly employed for confirmation. Option 1,2 and 3 are the correct answers.

Step-by-step explanation:

The laboratory personnel likely used a combination of methods to identify the bacteria in the knee fluid as F. tularensis. Initially, a Gram staining method could be used to determine the Gram reaction of the bacteria, which is a crucial first step in bacterial identification. As indicated in Bergey's Manual and affirmed by clinical practice, this would be followed by culturing the bacteria on possibly selective media that supports the growth of F. tularensis while inhibiting other types. The growth pattern, color, shape, and other characteristics of the colonies would help in narrow-down identification.

Subsequently, the laboratory may perform biochemical tests to ascertain the metabolic profile of the bacteria, which offers a 'fingerprint' used for classification. Lastly, PCR analysis might be conducted for a more definitive identification, as it's a powerful molecular tool used to amplify and identify specific DNA sequences unique to F. tularensis. Though PCR is not widely available, when it is utilized it provides a high level of specificity for the identification of pathogens.

Considering these processes and the information provided, the most likely methods used by laboratory personnel for the initial identification of F. tularensis in knee fluid would include 1) Gram staining, 2) Culture on selective media, and 3) Biochemical tests. The option 4) PCR analysis may not be initially used given its limited availability, but it could be employed for confirmation after initial tests indicate the presence of F. tularensis. Thus, all four options have been used in various stages of identification but PCR might be used specifically for confirmation.