Recently, the public has focused on the use of antibiotics as growth promotants in the livestock industry. Use as a growth promotant usually means feeding the antibiotics to livestock at low levels for long periods. High levels of antibiotics used for short periods will kill more bacteria, including the slightly resistant ones. Low levels of antibiotics are believed to promote the survival of resistant bacteria, especially when fed to animals for long periods. Some bacteria found in livestock that do not cause disease in humans can pass their resistant genes onto bacteria that do which allows the problem to spread more rapidly.
Some people believe food passes resistant bacteria to humans.
Residues Testing shows that antibiotic residues in meat are very rare and at very low levels. Disinfectants and antibacterial products may also contribute to the problem. Also, many of the resistant bacteria causing problems in humans are only found in humans and not in livestock. This article has looked at the major causes of antibiotic resistance. Next month, a follow-up will look at ways to deal with the problem in the livestock industry.