For rain and very light snow, 2WD will likely work fine, and for most vehicles, front-wheel drive is the preferred setup. (For performance cars, RWD is preferred, but AWD, if available, can increase traction. AWD is fine for most normal snow conditions or for light-duty, off-pavement excursions.
Microorganisms that cause diseases are called pathogens. They are specialised to infect body tissues where they reproduce and cause damage that gives rise to the symptoms of the infection. The body fights back by mobilising its immune system to fight off the infection.
The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, and some are beneficial. However, several species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy, and bubonic plague.f bacteria form a parasitic association with other organisms, they are classed as pathogens. Pathogenic bacteria are a major cause of human death and disease and cause infections such as tetanus, typhoid fever, diphtheria, syphilis, cholera, foodborne illness, leprosy and tuberculosis.