Nokea
When cultured on solid growth media, bacteria with long O-specific chains form:
- A. Smooth S colonies
- B. Rough R colonies
- C. Mucoid -M colonies
- D. H colonies
Correct Answer: A
Rationale: The correct answer is A: Smooth S colonies. Bacteria with long O-specific chains are known as smooth strains, and when cultured on solid growth media, they form smooth colonies due to the presence of the O antigen. This gives them a glossy appearance. Rough R colonies (Choice B) lack O antigen and appear rough. Mucoid -M colonies (Choice C) are associated with capsules, not O-specific chains. H colonies (Choice D) are not relevant to the O-specific chains. Smooth S colonies are the characteristic phenotype of bacteria with long O-specific chains when cultured on solid media.
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On the 8th day since the patient was inoculated with antitetanic serum because of dirty wound of his foot he has developed rising temperature up to 380% , pains in the joints, rash and itch. The blood tests revealed leukopenia and thrombocytopenia. Allergic reaction of what type has developed in this case?
- A. Anaphylactic
- B. Cytotoxic
- C. Delayed type of hypersensitivity
- D. Immunocomplex
Correct Answer: D
Rationale: The correct answer is D: Immunocomplex. In this case, the patient's symptoms of fever, joint pains, rash, and itch along with leukopenia and thrombocytopenia indicate a serum sickness reaction. This is a type III hypersensitivity reaction where antigen-antibody complexes deposit in tissues, leading to inflammation and tissue damage. The symptoms typically occur 1-2 weeks after exposure to the antigen. Anaphylactic reaction (choice A) is immediate and involves IgE antibodies. Cytotoxic reaction (choice B) involves destruction of cells by antibodies. Delayed hypersensitivity (choice C) usually takes 48-72 hours to develop and involves T-cells. Therefore, the correct answer is D as it aligns with the symptoms and timeline of a type III hypersensitivity reaction.
Media that contain complex organic substances such as blood for the growth of specific bacteria are referred to as:
- A. enriched media
- B. general-purpose media
- C. reducing media
- D. differential media
Correct Answer: A
Rationale: The correct answer is A: enriched media. Enriched media contain additional nutrients such as blood to support the growth of fastidious bacteria. This allows for the cultivation of a wider range of microorganisms. General-purpose media (B) contain basic nutrients for a variety of bacteria. Reducing media (C) create anaerobic conditions, not necessarily rich in organic substances. Differential media (D) contain indicators to distinguish between different types of microorganisms, not necessarily enriched with organic substances.
Which one is true for the bacterial cell?
- A. The oxidative phosphorylation takes place in the mitochondria
- B. Capsules are essential organelles
- C. Has only DNA but not RNA
- D. Multiplies by binary fission
Correct Answer: D
Rationale: The correct answer is D: Multiplies by binary fission. Bacterial cells reproduce through binary fission, where a single cell divides into two identical daughter cells. This process is essential for bacterial growth and multiplication.
A: The oxidative phosphorylation does not take place in the mitochondria of bacterial cells but in the cell membrane.
B: Capsules are not organelles but outer protective layers found in some bacterial cells.
C: Bacterial cells contain both DNA and RNA, essential for their genetic information and protein synthesis.
Impression smear of mucosa biopsy material has been obtained from a patient with peptic ulcer disease of the stomach. Gram-negative arcuate bent microorganisms were detected, urease activity test was positive. What microorganisms were detected in the patient?
- A. Helicobacter
- B. Spirochete
- C. Spirilla
- D. Leptospira
Correct Answer: A
Rationale: The correct answer is A: Helicobacter. Helicobacter pylori is the main causative agent of peptic ulcer disease and is characterized by its gram-negative arcuate bent shape and positive urease activity. Helicobacter pylori specifically colonizes the stomach mucosa and is associated with various gastrointestinal disorders. Spirochetes (choice B), spirilla (choice C), and Leptospira (choice D) are not typically associated with peptic ulcer disease or stomach mucosa infections, making them incorrect choices in this context.
Examination of duodenal contents revealed some pyriform protozoa with twin nuclei and four pairs of flagella. There were two supporting filaments between the nuclei and a suctorial disc on the ventral side. What representative of protozoa was revealed in this patient?
- A. Lamblia
- B. Toxoplasma
- C. Leishmania
- D. Intestinal trichomonad
Correct Answer: D
Rationale: The correct answer is D: Intestinal trichomonad. This protozoan matches the description provided, with pyriform shape, twin nuclei, four pairs of flagella, supporting filaments, and a suctorial disc. Lamblia (A) lacks flagella and supporting filaments. Toxoplasma (B) is an intracellular parasite with different morphology. Leishmania (C) belongs to a different class with no flagella or supporting filaments. In summary, the unique combination of features described in the question points to an intestinal trichomonad, making it the correct answer.