Bacterial disease of mink

摘要

Bacteria are present virtually everywhere in the environment. They are ubiquitous in the soil, water, on other living organisms, and also on dust and droplets in the air. They can even be found in such inhospitable places as boiling hot springs at the bottom of the ocean and on the surfaces of rocks in the middle of the desert. Researchers have estimated that as many as 4000 species of bacteria are commonly present in one gram of soil. The vast majority of bacteria do not cause disease in animals.Many species of bacteria (often referred to as "normal flora") are normally found in large numbers in healthy animals, primarily on the surface of the skin and throughout the mucosal surfaces of the digestive, upper respiratory, and urogenital tracts. Generally bacteria are beneficial in that they often prevent the growth of pathogenic (disease-causing) bacteria by competition for environmental nutrients. Some species are opportunistic pathogens, referring to the fact that they can potentially cause disease if the skin or mucosal surfaces are damaged, if the immune system of the animal is somehow compromised, or if a sudden imbalance in the composition of the normal flora develops. These situations can arise on mink farms if there are any management conditions that increase stress, compromise optimal nutrition, or involve the improper use of antibiotics.