Which one is NOT included in the etiology of osteomyelitis

Correct Answer: B

Rationale: The correct answer is B: EBV. Osteomyelitis is primarily caused by bacteria, not viruses like Epstein-Barr virus (EBV). The main pathogens involved in osteomyelitis are typically Staphylococcus aureus, including Methicillin-resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, and Pseudomonas aeruginosa. EBV is not a causative agent of osteomyelitis. It is crucial to differentiate between bacterial and viral etiologies in infectious diseases to guide appropriate treatment.

Correct Answer: B

Rationale: The correct answer is B: Phage typing of the obtained culture. This method is used for typing Mycobacterium tuberculosis strains based on susceptibility to specific bacteriophages. If the culture shows susceptibility, it confirms the presence of M. tuberculosis. In this case, the absence of cord factor indicates that the bacteria are unlikely to be M. tuberculosis. Option A (Inoculation of laboratory animals) is unethical and not necessary when other methods are available. Option C (Allergy skin test) is not relevant for confirming a diagnosis of renal tuberculosis. Option D (Toxigenicity testing) is not specific for confirming or refuting a diagnosis of M. tuberculosis.

Correct Answer: A

Rationale: The correct answer is A: vectors. Vectors are animals that transmit infectious diseases from one host to another, typically through biting or contact. They do not cause the disease themselves but serve as intermediaries. Pathogens (B) are the microorganisms that cause diseases. Carriers (C) are individuals who harbor a pathogen without showing symptoms. Parasites (D) are organisms that live on or inside another organism and may or may not transmit diseases. Therefore, the term "vectors" specifically refers to animals that transmit infectious diseases, making it the correct choice in this context.

Correct Answer: D

Rationale: The correct answer is D because Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum are all known to cause non-gonococcal urethritis and cervicitis. These organisms can infect the urogenital tract and lead to inflammation and symptoms in both males and females. Each of these bacteria has been identified as a common cause of these conditions through research and clinical studies. Therefore, since all three organisms are capable of causing non-gonococcal urethritis and cervicitis, the correct answer is D. The other choices (A, B, and C) are incorrect because each of them alone can cause these conditions, making option D the most comprehensive and accurate choice.

Correct Answer: C

Rationale: The correct answer is C (100°C) because the Koch apparatus is used for sterilization, and the standard temperature for sterilization is 100°C. At this temperature, most microorganisms are killed, making it an effective method for sterilization. Choice A (90°C), B (95°C), and D (110°C) are incorrect because they are not commonly used temperatures for sterilization purposes. Choosing a temperature lower than 100°C may not effectively kill all microorganisms, while choosing a temperature higher than 100°C may lead to unnecessary energy consumption without providing additional sterilization benefits.

Correct Answer: B

Rationale: The correct answer is B because lysozyme, lactoferrin, interferon, and complement are all humoral factors involved in natural resistance. Lysozyme and lactoferrin are antimicrobial proteins that help defend against pathogens. Interferon is a signaling protein that inhibits viral replication, while complement is a group of proteins that enhance the immune response by promoting inflammation and opsonization. Choices A, C, and D are incorrect: - Choice A mentions only macrophages, which are not humoral factors but rather phagocytic cells. - Choice C lists immune cells involved in adaptive immunity (B and T lymphocytes, NK cells) rather than humoral factors of natural resistance. - Choice D includes immunoglobulins, which are part of adaptive immunity, not natural resistance.

Correct Answer: B

Rationale: The correct answer is B because collecting specimens from the surface of a wound does not provide adequate samples for anaerobic agent detection. Anaerobic agents thrive in deep tissue environments with low oxygen levels, making surface specimens unreliable. Tissue samples and aspirations (choice A) are superior for diagnosing skin infections. Excessive production of toxins, not skin rash (choice C), causes symptoms in some infections. While healthy skin provides some protection, it is not completely impenetrable to microorganisms (choice D).

Correct Answer: C

Rationale: The correct answer is C: Peptidoglycan. Bacterial cell walls are primarily composed of peptidoglycan, a unique molecule consisting of alternating sugar chains connected by peptide cross-links. This structure provides rigidity and shape to the cell wall, protecting the bacterial cell from osmotic pressure. Lipopolysaccharides (A) are found in the outer membrane of Gram-negative bacteria. Cellulose (B) is a component of plant cell walls, not bacterial cell walls. Chitin (D) is a polysaccharide found in the exoskeletons of arthropods and fungi, not in bacterial cell walls.

Correct Answer: A

Rationale: The correct answer is A: Anaerobic. Pulpitis is an inflammatory condition of the dental pulp, often caused by bacterial infection. Anaerobic bacteria are commonly associated with dental infections, making it likely to find them in the inoculated culture medium. Anaerobic bacteria thrive in the absence of oxygen, which is typical of the dental environment. Acid-resistant (B) and acidophilic (C) microorganisms are not specifically linked to pulpitis. Haemolytic (D) microorganisms typically lyse red blood cells, which is not a characteristic feature of bacteria causing pulpitis. Therefore, the most likely microorganisms to be found in the culture medium would be anaerobic bacteria.