Serious infections caused by bacteria that have become
resistant to commonly used antibiotics have become a
major global healthcare problem in the 21st century. They not only are more severe and require longer and more complex
treatments, but they are also significantly more expensive
to diagnose and to treat (Alfonso, 2005). In recent
years, there has been increasing concern that the use of antibiotics
in food-producing animals, particularly their long
term use for growth promotion, contributes to the emergence
of antibiotic-resistant bacteria in animals. In the recent
years, incidence of multidrug resistance in pathogenic and
opportunistic bacteria has been increasingly documented
(Jones et al., 2004). Great attention has been paid to foodproducing
animals as one of several potential sources of
antibiotic-resistant bacteria in humans (Janet et al., 2002).