From suckling up to slaughter, pigs experience frequently enteritis outbreaks caused by various pathogens, most of them from bacterial origin. Preliminary epidemiological studies have shown that Escherichia coli are the most often isolated bacteria during diarrhoeas. Quinolones and penicillins are the most frequently used treatments when colibacillosis is suspected. Many reports have shown these bacteria became frequently resistant when these antibiotics were massively used. Moreover, many cross resistances were demonstrated in these antibiotic families, leading to a major zootechnical and zoonotic concern.