Antibiotics resistance occurs when microorganisms such as bacteria develop the ability to withstand the effects of an antibiotic either partially or totally. Bacteria can acquire this resistance to antibiotics directly through natural phenomena or indirectly through environmental stressors. One such stressor, the misuse of antibiotics by medical workers and patients, has especially lead to an increased prevalence of resistant bacteria.
Microorganisms exhibit resistance to antibiotics if they have acquired the ability through evolutionary means such as natural selection, specifically through a transfer between bacteria of the altered genes that are responsible for antibiotics resistance. Genetic variants that already exist in resistant bacteria can be transferred to the offspring of these mutated bacteria. Random genetic mutations can also be introduced through horizontal gene transfer, a gene action involving bacteria that are not the offspring of each other. Bacteria that carry more that one resistant gene are considered multi-resistant and are commonly referred to as superbugs. When bacteria are exposed to an antibiotic, the normal bacteria die off and leave behind antibiotic-resistant bacteria, which can then multiply rapidly and emerge as the dominant strain.
The extensive use of antibiotics in medicine has been linked to a growing number of cases of antibiotics resistance. Inappropriate or unnecessary prescriptions of antibiotics by physicians and misapplication of antibiotics by patients who do not use them as prescribed or who insist on taking antibiotics for a non-bacterial infection are the leading causes of antibiotics resistance. Patients who do not finish the full course of antibiotics as prescribed increase the chances that antibiotics resistance will occur. Antibiotics combat only bacterial infections, and physicians who misdiagnose a viral infection or other non-bacterial infection and prescribe antibiotics further promote the likelihood of the appearance of a resistant strain of bacteria. Such factors that fall under the scope of human medicine have contributed significantly to the emergence and persistence of resistant bacteria and life-threatening superbugs.
Antibiotics are not limited to human use and can be found in animals that are intended for human consumption or that come into contact with humans. Animal feeds might incorporate antibiotics for the purpose of promoting growth in the animals, and such practices increase the risk of human exposure to superbugs and other antibiotics resistance. Administering antibiotics to animals that lack disease further encourages the spread of resistant bacteria. The chances of the spread of a strain of bacteria with antibiotics resistance are elevated when humans consume affected meat, especially if it is raw or undercooked, or come into close contact with animals carrying resistant bacteria.