Microbiology Knowledge MCQ Quiz!

All of the bacteria listed (Salmonella, E. coli, Yersinia entercolitica, and Citrobacter) can be transmitted through the intestinal tract. These bacteria are known to cause gastrointestinal infections and are commonly spread through contaminated food or water, poor hygiene practices, or contact with infected individuals or animals. Therefore, all of the options given are correct in terms of being bacteria that can be transmitted via the intestinal tract.

The statement is true because the Phylum Firmicutes are indeed gram-positive organisms. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall, which retains the crystal violet stain during the Gram staining process. Additionally, it is also true that Firmicutes have a low Guanine + Cytosine (GC) DNA content. The GC content is the percentage of guanine and cytosine bases in the DNA molecule. Firmicutes typically have a lower GC content compared to other bacterial phyla.

Rickettsia rickettsii is the organism responsible for Rocky Mountain Spotted Fever. This bacterium is transmitted to humans through the bite of infected ticks. It causes a serious illness characterized by fever, headache, rash, and sometimes organ damage. Prompt treatment with antibiotics is necessary to prevent complications and severe outcomes.

All of the organisms/diseases listed in the options, namely Treponema pallidum, Trichomoniasis, Chlamydia trachomatis, and Chancroid, are transmitted by way of sexually transmitted diseases (STDs). This means that these organisms/diseases can be spread through sexual contact, including vaginal, oral, and anal sex. Therefore, the correct answer is "All of the above."

Antibiotic therapy can contribute to the transmission of Clostridium difficile and Candida albicans. Antibiotics can disrupt the balance of microorganisms in the body, allowing these pathogens to overgrow and cause infections. Clostridium difficile is a bacterium that can cause severe diarrhea and colitis, while Candida albicans is a yeast that can cause fungal infections, particularly in immunocompromised individuals. Therefore, it is true that antibiotic therapy can be a means of transmission for these pathogens.

Shigella is not typically associated with nosocomial infections. Nosocomial infections are infections that are acquired in a hospital or healthcare setting. Acinetobacter, E. aerogenes, Klebsiella pneumoniae, and Pseudomonas are all known to cause nosocomial infections. Shigella, on the other hand, is primarily transmitted through contaminated food or water and is associated with gastrointestinal infections, such as dysentery.

Neisseria gonorrhoeae is the correct answer because it is a bacterium that is known to be a diplococcus, meaning it forms pairs of spherical cells. Vibrio cholerae and Salmonella enterica typhi are both rod-shaped bacteria, while Desulfovibrio is a curved or spiral-shaped bacterium. Therefore, only Neisseria gonorrhoeae fits the description of being a diplococcus.

Yersinia pestis is the organism responsible for the bubonic plague. It is transmitted through rat fleas.

This would be true but S. pyogenes doesn't cause neonatal meningitis, S. agalactiae does.

Bacillariophyta, also known as diatoms, are a type of algae that have unique cell walls made of silica, which gives them a glass-like appearance. These cell walls are called frustules and are composed of two overlapping halves. This characteristic distinguishes them from other types of algae and allows them to have a variety of intricate shapes and patterns. Therefore, the statement that Bacillariophyta have glass cell walls is true.

The correct answer is Francisella tularensis; swollen lymph nodes, malaise, pneumonia. Tularemia is a bacterial infection caused by Francisella tularensis. Common symptoms include swollen lymph nodes, malaise, and pneumonia.

Diarrhea is a common symptom caused by various organisms, including Salmonella, Giardia lamblia, Shigella, and Bacillariophyta. However, Toxoplasma gondii is not known to cause diarrhea. This parasite primarily affects the central nervous system and can cause flu-like symptoms, but diarrhea is not typically associated with Toxoplasma gondii infection.

Haemophilus ducreyi is not considered an obligate intracellular parasite because it is a gram-negative bacterium that primarily causes the sexually transmitted infection known as chancroid. Unlike obligate intracellular parasites, which rely on host cells for replication and survival, Haemophilus ducreyi can survive and replicate both inside and outside of host cells.

Microsporum is not spread through the air. Microsporum is a type of fungus that causes skin infections, particularly ringworm. It is primarily spread through direct contact with infected individuals or contaminated objects, such as clothing or surfaces. Unlike the other organisms listed, which are all bacteria, Microsporum does not have the ability to be transmitted through respiratory droplets in the air.