24: The most preferable laboratory sample for diagnosis of Mycobacteria tuberculosis in microbiology

Here are the answers to the questions:

16. The most pathogenic Mycobacterium species which cause human infection are Mycobacterium tuberculosis (causing tuberculosis) and Mycobacterium leprae (causing leprosy).
The correct option is C.

• C) both A and B are correct

17. The most common methods for visualizing acid-fast bacilli as bright red against a blue background are the Ziehl-Neelsen stain and the modified Kinyoun stain.
The correct option is C.

• C) Ziehl-Neelsen stain and modified Kinyoun stain are correct

18. Staphylococcus and Streptococci are Gram-positive cocci. Clostridium species are Gram-positive rods. The question asks for the one that is not a Gram-positive coccus.
The correct option is D.

• D) Clostridium

19. E. coli, Shigella, and Salmonella are all members of the Enterobacteriaceae family. Staphylococcus is a Gram-positive coccus and not part of this family.
The correct option is C.

• C) Staphylococcus

20. Bacteria with cell walls containing thick layers of peptidoglycan are characteristic of Gram-positive bacteria.
The correct option is B.

• B) Gram Positive Bacteria

21. Fine-needle aspiration (FNA) is a technique used to collect cells or tissue samples from a mass or lesion, often from organs or deep-seated tissues.
The correct option is B.

• B) Cell and Tissue

22. Escherichia coli (E. coli) is the most common Gram-negative bacterium associated with Urinary Tract Infections (UTIs) and can also cause food poisoning.
The correct option is A.

• A) Escherichia coli

23. Bacteria that are "chain forming" and "round shaped" (cocci) are characteristic of Streptococcus species.
The correct option is B.

• B) Streptococcus

24. For the diagnosis of Mycobacterium tuberculosis, especially in cases of pulmonary tuberculosis, sputum is the most preferable laboratory sample.
The correct option is B.

• B) Sputum