**9. Resistant salmonella**

Salmonella is still a topical; it is in any way, a rearguard battle. They are among the first known causes of food borne illness. It is a collective and a real public health problem. Economically, they are crucial, given the casualties they cause. In recent years, problems related to Salmonella have increased significantly, both in terms of the incidence of salmonellosis, that the severity of human cases. While some countries have managed to reverse the upward trend in the incidence of human salmonellosis, new problems were identified. Since the late 90s, Salmonella strains resistant to a range of antimicrobials including major therapeutic agents in human medicine have emerged and are threatening to cause serious public health problem (Mermin et al., 1999). After a very long incubation period, between 7 and 21 days (sometimes up to six weeks), the disease can take many forms (Hu and Kopecko, 2003). The infection may be asymptomatic or cause very mild symptoms in the case of S. Paratyphi or, conversely, cause typhoid fever, severe disease, with fever and sepsis. It mainly affects young children and teenagers (Bäumler et al., 1998). This resistance results from the use of antimicrobials in both human medicine and animal husbandry.
