Breaking news! AMR IS ON THE LOOSE! What is it?
How does it happen?
Antimicrobial resistance (AMR) is the ability of microbes to resist the effect of antimicrobials previously used to treat them; this broader term covers bacterial antibiotic resistance. AMR rates have dramatically escalated in the past few decades, due to the extensive use of antibiotics.
Whenever antibiotics are administered to either humans or animals, a selective pressure is set. The susceptible bacteria are inhibited or killed, whereas resistant bacteria can propagate. Antibiotics do not differentiate between pathogenic and commensal (microbiota) bacteria. Antibiotic resistance is based on resistance-mediating mutations or transferable resistance genes.
Resistance genes can be disseminated between different bacteria within the same host. Resistant bacteria can be transferred between humans or between animals and they can also exchange their resistance genes.
Accordingly, microbiome composition can be rapidly altered by high exposure to antibiotics The proportion of resistant bacteria increases versus susceptible bacteria. Resistant microbiota bacteria can be persisted for a long time period. Thus, the microbiota, e.g. in the gastrointestinal tract, may be an important reservoir of resistant bacteria and transferable resistance genes.
How does it spread? AMR is a complex phenomenon driven by many interconnected factors, such as the interaction of human, animal & environmental sources for AMR.
❖ 80% of antimicrobials used in the U.S.A. are in farm animals ❖ Nearly 210,000 tons of antibiotics are used in China per year, almost half of them on food producing animals
Overuse or misuse of antibiotics for therapeutic & prophylactic purposes in farm animals
❖ According to Animal Health Institute, 13% of total amount of antimicrobials are used as growth factors
Overuse or misuse of antibiotics for treatment in companion animals
Veterinary medicine
Animal waste, farm runoff & use of manure
Estimated deaths due to AMR bacteria per year: 25,000 in E.U. 100,000 in U.S.A. 80,000 in China According to ECDC, infections caused by AMR bacteria result in an increase of €1,500,000,000 in medical bills annually in E.U.
Animal waste & domestic environment
Reservoirs for development and distribution of AMR bacteria Antibioticresistant bacteria remain in edible animal products
Recent studies have shown that 75-90% of antibiotics used in food animals get excreted unmetabolized, becoming a source of AMR development in the environmental bacteria.
Direct contact
Human waste Close contact (petting, licking)
According to World Health Organization antibiotics are categorized into 3 groups: Important Highly Important Critically Important Nowadays, there are concerns that AMR has been developed against the Critically Important Antibiotics
Undercooked food
Interpersonal contact & inappropriate use of antibiotics in the community
Overuse and misuse of antibiotics in the hospitals an excellent compartment for the selection of multi-drug resistant (MDR) bacteria
Human medicine
How to deal with it? Rapid diagnostic and antimicrobial susceptibility testing • In order to select the most efficient antibiotic • To minimize the use of broad spectrum antibiotics Antibiotics are important tools for the therapy of infectious bacterial diseases in both human and animals. The aims of combating AMR and preserving the efficacy of the currently available antibiotics in human and veterinary medicine, as well as in different ecological systems, must be addressed in an interdisciplinary effort within a “One Health” approach.
Prudent and rational use of antibiotics • Only for therapeutic purposes; the non-therapeutic use of antibiotics, as growth promoters, must be discontinued worldwide • In proper dosage schemes • Antimicrobial agents in humans and animals should be made available by prescription only • Rule out the critically important ones in animals • Within hospitals, the restriction of antimicrobials, cycling and mixing strategies and the use of combination therapies have been used to avoid resistance
Alexandra Palaiologou Theocharis Pappas Paraskevi Pilidi Christos Politis Tryfon Chatzimanou School of Veterinary Medicine Faculty of Health Sciences Aristotle University of Thessaloniki