1 Biological characteristics of Salmonella Salmonella is a large genus of serologically related Gram-negative bacilli. According to the first volume of the Berger's Bacterial Taxonomy Manual (1984), Salmonella is divided into five subgenus with a total of 2020 serotypes. About 200 serotypes have been found in China. Many serotypes of Salmonella produce toxins, especially Salmonella enterica, Salmonella typhimurium and Salmonella choleraesuis. Toxins have heat-resistance, and are still toxic at 75 ° C for 1 hour, which can cause food poisoning. Salmonella bacteria can be divided into two types: host-adapted serotypes and non-host-adapted serotypes, depending on their range of infections to the host. In addition to the pathogenicity of the host to which it is adapted, the former rarely causes other hosts to develop disease. For example, Salmonella in the abortion, Salmonella in the abortion, Salmonella choleraesuis, Salmonella typhimurium, Salmonella pullorum; the latter are pathogenic to a variety of hosts, such as Salmonella typhimurium, Salmonella Newport, Salmonella Tennessee, Salmonella typhimurium. Salmonella is mainly derived from diseased humans and animals and their carriers. Salmonella mainly consists of feces, urine, milk and aborted fetuses, fetal clothes and amniotic fluids, which discharge germs from polluted water sources, soils and feeds. In particular, the spread of germs caused by slaughtering sick and infected animals, and infection of healthy animals through the digestive tract, some people think that Rats can spread the disease. The pollution of feed and water sources is the main cause of the mutual infection of Salmonella. Salmonella can be found in various feeds, especially animal feeds (such as fishmeal). 2 Harm of feed Salmonella contamination Livestock and poultry eat a feed containing a certain number of Salmonella, which can cause disease or bacteria. Infection with Salmonella in poultry and livestock can cause corresponding infectious diseases such as pig cholera and chicken white mites. Under normal circumstances, the intestinal bacteria rate of livestock and poultry is relatively high. When the animal is debilitated due to illness, weakness, malnutrition, fatigue, the Salmonella in the intestine can enter the bloodstream through the mesenteric lymph nodes and lymphoid tissue to cause systemic infection and even death. For example, Salmonella choleraesuis can cause paratyphoid fever in piglets, and sepsis changes in acute cases with a high mortality rate. Chronic cases produce necrotic enteritis, affecting the growth and development of pigs. Some continue to squat and finally die, and adult pigs are mostly recessive carriers or piglets, and their resistance is reduced, followed by salmonella infection. Another example is Salmonella typhimurium, which mainly attacks chickens and causes sepsis, which can cause a large number of deaths. In adult hens, it mainly causes oophoritis, which can be transmitted to the young chicks in the yolk. Salmonellosis is a common disease in livestock and poultry, with a high incidence and great harm. In particular, Salmonella typhimurium has a host specificity that is detrimental to humans and various animals. This type accounts for the majority of Salmonella, such as Salmonella typhimurium, Salmonella choleraesuis, Salmonella enteritidis and the like. If people eat foods (meat, eggs, etc.) that contain a lot of such bacteria, they can cause food poisoning. For example, a farmer in a suburb is sick and misdiagnosed as influenza; if the treatment is ineffective, it will be slaughtered; more than 70 people will be poisoned by high-temperature processing of beef; it is confirmed by serological and bacteriological tests that it is caused by Salmonella enteritidis. It is also reported that in summer and autumn, residents often suffer from Salmonella food poisoning due to preserved eggs. A city has conducted on-site investigations on poisoning incidents, and the positive detection rate of Salmonella typhimurium is as high as 79.4%. Artificial contamination experiments have shown that Salmonella typhimurium can survive in the alkaline environment of preserved eggs, so be careful when eating preserved eggs. Among the various food poisonings in humans, bacterial food poisoning is the most common. The incidence of Salmonella food poisoning is the highest in bacterial food poisoning. Therefore, improving feed hygiene to prevent salmonella contamination is not only the need to develop animal husbandry, but also an important condition for reducing food poisoning in human salmonella. Guangdong Jishengke Industrial Co., Ltd. , https://www.suronart.com Core Tip: At present, China's feed market is still not standardized. Deteriorating feed and counterfeit goods are not uncommon. Private maps are slaughtered and sick animals are still being sold in some areas. The incidence of human and animal salmonellosis is increasing, so Salmonella is prevented. Pollution is also a noteworthy issue.