When the switch of a flashlight is pushed into the ON position, it makes contact between two contact strips, which begin a flow of electricity, powered from the battery. The batteries are connected in such a way that electricity (flow of electrons) runs between the positive and negative electrodes of the battery.
Shigella infection (shigellosis) is an intestinal disease caused by a family of bacteria known as shigella. The main sign of shigella infection is diarrhea, which often is bloody. Shigella can be passed through direct contact with the bacteria in the stool.
Infectious diseases are the invasion of a host organism by a foreign replicator, generally microorganisms, often called microbes, that are invisible to the naked eye. Microbes that cause illness are also known as pathogens.The most common pathogens are various bacteria and viruses, though a number of other microorganisms, including some kinds of fungi and protozoa, also cause disease. An infectious disease is termed contagious if it is easily transmitted from one person to another.nfectious disease requires an agent and a mode of transmission (or vector). A good example is malaria, which is caused by Plasmodial parasites, chiefly Plasmodium falciparum but does not affect humans unless the vector, the Anopheles mosquito, is around to introduce the parasite into the human bloodstream.