In the face of a microbe's inherent ability to develop antibiotic resistance, many societal. medical and agricultural practices contribute to this process, foremost of which are discussed below.
Antibiotics in food and water
Prescription drugs are not the only source of antibiotics in the environment. In the United States, antibiotics can be found in beef cattle, pigs and poultry. The same antibiotics then find their way into municipal water systems when the runoff from housing facilities and feedlots contaminates streams and groundwater. So it's a double hit: we get antibiotics in our food and drinking water, and we meanwhile promote bacterial resistance. Routine feeding of antibiotics to animals is banned in the European Union and many other industrialized countries. Maybe they know something we don't.
Indiscriminate use of antibiotics in agriculture and veterinary practice
The non-therapeutic use of antibiotics in livestock production makes up at least 60 percent of the total antimicrobial production in the United States. Irresponsible use of antibiotics in farm animals can lead to the development of resistance in bacteria associated with the animal or with people who eat the animal. Such resistance can then be passed on to human pathogens by mechanisms of HGT.
Of major concern is the use of antibiotics as feed additives given to farm animals to promote animal growth and to prevent infections (rather than cure infections). The use of an antibiotic in this way contributes to the emergence of antibiotic-resistant pathogens and reduces the effectiveness of the antibiotic to combat human infections.
Antibiotic resistance in genetically modified crops
Antibiotic-resistance genes are used as "markers" in genetically modified crops. The genes are inserted into the plant in early stages of development to in order to detect specific genes of interest . e.g. herbicide-resistant genes or insecticidal toxin genes. The antibiotic-resistance genes have no further role to play, but they are not removed from the final product. This practice has met with criticism because of the potential that the antibiotic-resistance genes could be acquired by microbes in the environment. In some cases these marker genes confer resistance to front-line antibiotics such as the beta-lactams and aminoglycosides.
Inappropriate use of antibiotics in the medical environment
One problem is the casual use of antibiotics in medical situations where they are of no value. This is the fault of both health care workers and patients. Prescribers sometimes thoughtlessly prescribe 'informed' demanding patients with antibiotics. This leads to use of antibiotics in circumstances where they are of not needed, e.g. viral upper respiratory infections such as cold and flu, except when there is serious threat of secondary bacterial infection. Another problem is patient failure to adhere to regimens for prescribed antibiotics.
Patients and doctors need to realize their responsibility when they begin an antibiotic regimen to combat an infectious disease. There are several measures that should be considered.
- Patients should not take antibiotics for which there is no medical value (corollary: doctors should not prescribe antibiotics for which there is no medical value).
- Patients should adhere to appropriate prescribing guidelines and take antibiotics until they have finished.
- Patients should be give combinations of antibiotics, when necessary, to minimize the development of resistance to a single antibiotic (as in the case of TB).
- Patients need to be given another antibiotic or combination of antibiotics if the first is not working.