HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication, thus indicating that the person infected with Hepatitis B can likely transmit the virus on to another person.

These viruses are pathogens for both humans and animals. They are pleiomorphic, coated, single positive strand RNA viruses. In the electron microscope, they have a doughnut shape.

The rotavirus non-structural protein NSP4 was the first viral enterotoxin discovered. It induces diarrhea and causes Ca²⁺dependent transepithelial secretion.

Herpesvirus is much larger than the DNA viruses having a genome size of 100 to 200 kilobases. These are often co-carcinogens. They may have a hit and run mechanism of oncogenesis.

Vpr is a human immunodeficieny viral gene and protein product. Vpr stands for Viral Protein R. It plays an important role in regulating nuclear import of the HIV-1 pre-integration complex and is required for virus replication in non-dividing cells, such as macrophages.

Bacteria can also be used in the place of pesticides in the biological pest control. This commonly uses Bacillus thuringiensis (also called BT), a Gram-positive, soil dwelling bacterium. This bacteria is used as a Lepidopteran-specific insecticide under trade names such as Dipel and Thuricide.

Arthrobacter sp H65-7 produces the enzyme inulase II that converts inulin into difructose anhydride (DFA). DFA is a promising nutrient for fighting osteoporis, because it helps absorption of calcium in the intestines.

The dinoflagellates causing red tides are known as Gonyaulax, which contain a neurotoxin and are poisonous to marine fauna.

The gram negative bacteria have an extra layer of lipid on the outside of the cell wall and appear pink during the gram staining procedure.

Candida dubliniensis has recently been recognised from the oral cavity of HIV-infected patients and are most frequently implicated in cases of recurrent infection following antifungal drug treatment.

Kawasaki disease is an acute febrile illness with inflammation of small and medium sized blood vessels throughout the body, in particular the coronary arteries (blood vessels around the heart).

Ectomycorrhiza forms between fungi and the roots of around 2% of plant species. These tend to be composed of woody plants, including species from the birch, dipterocarp, myrtle, beech, willow, pine and rose families. Most plants form with endomycorrhizae.

Zygomycosis, in a debilitated patient, is the most acute and fulminate fungal infection known. The disease typically involves the rhino-facial-cranial area, lungs, gastrointestinal tract and skin.

Folliculitis is the name given to a group of skin conditions in which there are inflamed hair follicles. The result is a tender red spot, often with a surface pustule. Acne and its variants are also types of folliculitis.

Pneumocystis pneumonia is a disease caused by the fungus Pneumocystis jirovecii. It is one of the most frequent and severe opportunistic infections in people with weakened immune systems, particularly people with HIV/AIDS.