Antibiotics are life-saving tools for both humans and animals. Recently, concerns over antibiotic resistance have intensified the calls for a more judicious approach to antibiotic use. To help you brush up on the history of antibiotics, the current dynamic surrounding shared-use or medically important antibiotics and the future of preventing bacterial infection in the United States, the Corporate Affairs team at Charleston|Orwig has tapped many sources to pull together the following questions and answers about antibiotics and resistance.

1) What is the difference between human-grade and animal-grade antibiotics?

Antibiotics are grouped into “classes” based on their mode of action against bacteria, fungi or viruses. Only a few classes are specific to either humans or animals—the majority of antibiotics are used in both, though many of the antibiotics approved for human medicine are not approved for animal use or are simply too expensive to use for treating animals. Additionally, some classes are specific for animal use only.

The FDA closely regulates the antibiotics that are acceptable for use in food-producing animals. In human medicine, doctors determine treatment for their patients based on what they think is best—in animal medicine, treatment plans follow specific label directions or federal regulations that explicitly outline dosage, use and duration.

[Source: Animal Health Institute]

2) How will changes in the law affect how livestock are treated with antibiotics?

Over a span of several years, the FDA has moved to eliminate the use of medically important drugs (those important in human medicine) as growth and feed efficiency promotants in production animals, and to ensure that all other use of these drugs is under close supervision of veterinarians. With the final implementation of the FDA’s Veterinary Feed Directive (VFD) regulation in January 2017, there will be changes in the process for obtaining and treating animals with antibiotics as part of an overall strategy to ensure judicious use of medically important drugs.

The final rule requires veterinarians to authorize use of VFD drugs only within an active veterinarian-client-patient relationship (see accompanying article)—in other words, one where the veterinarian regularly visits the operation, conducts rigorous examinations and follow-ups, and is able to appropriately make clinical judgments regarding an animal’s care. This gives veterinarians the flexibility to meet circumstantial needs of their clients while abiding by a set of consistent, sustainable national principles as they prescribe drugs for animals’ treatment. The rule ensures that medically important antimicrobial drugs will continue to be used only in a judicious, responsible manner, only when medically necessary, and according to label directions to meet specific animal health needs, thus significantly reducing the likelihood of antibiotic overuse and abuse.

[Source: U.S. Food and Drug Administration]

3) Does human use contribute to antibiotic resistance?

According to the Centers for Disease Control and Prevention (CDC), simply using antibiotics is the most important factor contributing to antibiotic resistance worldwide, whether in human or animal medicine. In addition to antibiotic use in animals, the spread of resistant strains from person to person is a major factor in the growth of antibiotic resistance. The CDC estimates that up to 50 percent of all antibiotics prescribed for human use are not done so optimally, whether drugs are prescribed when not truly needed or are prescribed with incorrect doses or durations. In addition, the CDC maintains that most deaths attributed to antibiotic resistance happen in hospital settings.

[Source: Centers for Disease Control and Prevention]

Historically, some doctors have prescribed antibiotics when not medically necessary, often to appease a patient seeking immediate relief or as a precautionary measure before test results have actually come in. Similarly, others have prescribed antibiotics inappropriately, like when a patient is suffering from a virus—antibiotics are meant to treat bacterial infections, not viral ones. Other contributing factors include purchasing antibiotics without a prescription and using antibiotics that are left over from a previous prescription.

[Source: Mayo Clinic]

Many antibiotic-resistant bacteria are not linked to animals at all. Staphylococcus, Streptococcus and strains of drug-resistant tuberculosis are all among the list of prevalent bacterial pathogens that do not possess a known connection to food producing animals, as identified by the Centers for Disease Control and Prevention and the Infectious Disease Society of America.

[Source: Animal Health Institute]

4) When did antibiotics first come into use for treating human or animal health problems?

Before the discovery of antibiotics, diseases from bacterial meningitis, pneumonia and whooping cough to everyday infections like strep throat and ear infections killed or seriously disabled thousands of people every year, particularly children. In 1928, British scientist Alexander Fleming discovered a naturally growing mold that could dissolve Staphylococcus aureus bacteria. Fleming and other researchers across Europe and the United States continued conducting experiments demonstrating the substance’s ability to destroy certain bacteria. By 1941, it was clear that even low doses of this mold—now called penicillin—could eliminate infections in humans and save many lives. It became widely used over the following decade, first in WWII battlefields and then by the general public.

[Source: American Academy of Pediatrics]

5) Are there natural sources for antibiotics?

Many foods have natural antibiotic properties, helping to boost immune function, fight infection and attack pathogens. Examples of bacteria-fighting foods include fruits and vegetables high in vitamin C (such as pineapples, citrus fruits, broccoli, kale and cauliflower), garlic and onions, oregano, cinnamon and probiotics (found commonly in dairy foods like yogurt and kefir), among many others.

[Source: Livestrong]

6) What is antibiotic resistance and how common is it?

Antibiotic resistance occurs when a microorganism that was previously susceptible to an antibiotic treatment develops the ability to resist the treatment. The bacteria survive exposure to the antibiotic and continue to grow and spread, potentially causing harm and spreading to other animals or people.

[Source: Centers for Disease Control and Prevention]

The CDC cautions that it is difficult to precisely estimate the impact of diseases and fatalities caused by antibiotic resistance for a variety of reasons. However, they estimate that every year, more than 2 million people in the United States develop infections caused by antibiotic-resistant bacteria, and over 23,000 people die every year due to antibiotic-resistant bacteria strains.

[Source: CDC Antibiotic Resistance Threats report, 2013]

7) Are probiotics becoming a replacement for antibiotics?

Probiotics are “good for you” bacteria that help strengthen the immune systems of humans and animals. As pressure to reduce antibiotic use continues to rise, many alternatives have been considered. The use of probiotics to help promote immune health, improve digestion, spur feed and growth efficiency and increase ability to resist disease continues to be studied in production animals. A probiotic feed additive for poultry was launched in the U.S. this year as an alternative to antibiotic growth promoters. Although probiotics are not a replacement for antibiotics, they have the potential to reduce the need to use antibiotics to fight infection, given the positive impact they have so far demonstrated on immune health.

[Source: American Association of Swine Veterinarians, Novozymes]

8) If antibiotics are becoming ineffective, why aren’t scientists developing new ones?

Scientists are working on the development of new antibiotics. But the discovery and development process for new drugs takes enormous time and research. Adding to the challenge is that antibiotic-resistant strains of bacteria develop at a much faster rate than researchers are able to develop, test and secure approval of new antibiotics.

[Source: The New York Times]

9) Should I be concerned about antibiotic resistance?

The CDC assesses antibiotic threats based on a number of factors, categorizing them as urgent, serious or concerning. Factors used in the assessment include clinical and economic impact, incidence, 10-year incidence projection, transmissibility, availability of effective antibiotics and barriers to prevention. The CDC warns that antibiotic resistance is a rapidly evolving issue in the United States, and plans to reassess threat levels for critical bacteria strains every five years. For current threat level assessments, click here.

[Source: Source: CDC Antibiotic Resistance Threats report, 2013]

10) Is it true that 80 percent of antibiotics are used in food animals? How do I know that an animal treated with antibiotics is really safe to eat?

This number has frequently been used to generalize the amount of antibiotics used in food animals. Though 80 percent of the total volume of all antibiotics sold in the United States are given to farm animals, nearly one-half of that amount belong to antibiotic classes that are used only in animal medicine.

[Source: National Chicken Council]

In 2013, the FDA released a report summarizing data regarding antimicrobial drug use and distribution in food-producing animals in the year 2011. As part of the release of this data, the FDA cautioned that a number of variables make it difficult to compare this data with that collected regarding antimicrobial use in human medicine. These include differences in physical characteristics of humans and animals, variations in the number of humans versus food-producing animals within a data collection period and differences in usage conditions.

[Source: U.S. Food and Drug Administration]

Antibiotics given to animals are metabolized so they can be readily used or removed from the body. Farmers are required to abide by a “withdrawal time” after treating animals, which is a waiting period that allows animals’ bodies ample time to either use or eliminate the medication. Within that period, animals cannot be slaughtered or used for eggs or milk to ensure that animal products are not consumed while containing medication.

[Source: South Dakota State University Extension]

Charleston|Orwig strives to further knowledge and understanding across the food system. Comments welcome via info@co-nxt.com