1.
In the lab the examination of wet preparation is mainly used to examine:-
Correct Answer
C. All above
Explanation
The examination of wet preparation in the lab is used to examine both motile pathogens and C.f.s encapsulated yeasts. Therefore, the correct answer is "All above".
2.
Most of these organisms are motile EXCEPT:
Correct Answer
B. Shigella spp
Explanation
Shigella spp is the correct answer because unlike Salmonella spp and Vibrio spp, Shigella spp are non-motile organisms. Salmonella spp and Vibrio spp are both known to be motile, meaning they have the ability to move on their own. However, Shigella spp lack this motility and are unable to move independently.
3.
Gram technique is used to identify pathogens by their:
Correct Answer
C. A and B
Explanation
The Gram technique is used to identify pathogens by their Gram reaction (whether positive or negative) and their morphology (such as cocci or rods). This technique involves staining the bacteria with crystal violet and iodine, followed by decolorization with alcohol and counterstaining with safranin. Gram-positive bacteria retain the crystal violet stain and appear purple, while Gram-negative bacteria do not retain the stain and appear pink. Additionally, the Gram technique allows for the observation of the shape and arrangement of the bacteria, aiding in their identification.
4.
All these species are gram +ve EXCEPT:
Correct Answer
A. Vibrio cholera
Explanation
Vibrio cholerae is the correct answer because it is a gram-negative bacterium, while Actinomyces and Clostridium are both gram-positive bacteria. Gram staining is a common technique used to differentiate bacteria based on their cell wall composition. Gram-positive bacteria retain the crystal violet stain and appear purple under a microscope, whereas gram-negative bacteria do not retain the stain and appear pink or red. Vibrio cholerae, which causes cholera, is a gram-negative bacterium with a curved shape.
5.
Zeihl-Nelson technique is used to identify:
Correct Answer
D. All above
Explanation
The Zeihl-Nelson technique is a staining method used in microbiology to identify acid-fast bacteria, including M. tuberculosis, M. leprae, and M. ulcerans. Acid-fast bacteria have a unique cell wall composition that allows them to retain the red dye used in this technique, making them easily distinguishable under a microscope. Therefore, the correct answer is that the Zeihl-Nelson technique is used to identify all of the above mentioned bacteria.
6.
There's acid fast differences between mycobacterium spp. Which species react weakly to acid fast stain:
Correct Answer
A. M.leprea
Explanation
When we are applying acid-fast stain mycobacterium spp act differently.
7.
The methylene blue technique can be used to show basic morphology of bacteria, e.g polychromed methylene blue is required to stain the capsules of :-
Correct Answer
B. Bacillus anthracis
Explanation
The methylene blue technique is a staining method that can be used to visualize the basic morphology of bacteria. In this case, polychromed methylene blue is specifically required to stain the capsules of Bacillus anthracis. This staining technique helps to highlight the presence of capsules, which are protective structures surrounding some bacteria. This information is important in identifying and studying the characteristics of Bacillus anthracis, the causative agent of anthrax.
8.
Giemsa is a stain that is used to identify:-
Correct Answer
A. Blood parasites e.g malaria
Explanation
Giemsa stain is commonly used in the laboratory to identify blood parasites such as malaria. This stain helps to visualize the parasites under a microscope by binding to their DNA and other cellular components, making them easily distinguishable from the surrounding blood cells. By using Giemsa stain, healthcare professionals can accurately diagnose and monitor the presence of blood parasites, enabling prompt treatment and prevention of complications. Intestine and liver parasites are not typically identified using Giemsa stain, making the correct answer "Blood parasites e.g malaria."