Antimicrobial Resistance: Its Surveillance, Impact, and Alternative Management Strategies in Dairy Animals

Abstract

Antimicrobial resistance (AMR), one among the most common priority areas identified by both national and international agencies, is mushrooming as a silent pandemic. The advancement in public health care through introduction of antibiotics against infectious agents is now being threatened by global development of multidrug-resistant strains. These strains are product of both continuous evolution and un-checked antimicrobial usage (AMU). Though antibiotic application in livestock has largely contributed toward health and productivity, it has also played significant role in evolution of resistant strains. Although, a significant emphasis has been given to AMR in humans, trends in animals, on other hand, are not much emphasized. Dairy farming involves surplus use of antibiotics as prophylactic and growth promoting agents. This non-therapeutic application of antibiotics, their dosage, and withdrawal period needs to be re-evaluated and rationally defined. A dairy animal also poses a serious risk of transmission of resistant strains to humans and environment. Outlining the scope of the problem is necessary for formulating and monitoring an active response to AMR. Effective and commendably connected surveillance programs at multidisciplinary level can contribute to better understand and minimize the emergence of resistance. Besides, it requires a renewed emphasis on investments into research for finding alternate, safe, cost effective, and innovative strategies, parallel to discovery of new antibiotics. Nevertheless, numerous direct or indirect novel approaches based on host–microbial interaction and molecular mechanisms of pathogens are also being developed and corroborated by researchers to combat the threat of resistance. This review places a concerted effort to club the current outline of AMU and AMR in dairy animals; ongoing global surveillance and monitoring programs; its impact at animal human interface; and strategies for combating resistance with an extensive overview on possible alternates to current day antibiotics that could be implemented in livestock sector.

Antibiotic Consumption, Resistance Data, and Prevention Strategies

“…Since growth results were quite impressive, the use of high antibiotic concentrations (200 g/ton) in animal feeds was quickly adopted worldwide [73] . The selection of resistance genes due to widespread antibiotic use and the spread of these resistance genes among farm animals due to close captivity resulted in the emergence and spread of a resistant Salmonella typhimurium strain in the mid-1960s [74] . The matter was considered to be a public health issue due to infection transmission to farm workers who cared for infected cattle, to veterinarians, and even to individuals who consumed the milk of infected cattle during this period.…”

Efficient engineered probiotics using synthetic biology approaches: A review

“…The system efficiency is obstructed via innate mismatch repair method, which is used to correct mutations. CRISPR‐based synthetic regulation of genes is the most developed recombinant engineering technology for bacteria, yeast, and mammals . Different roles of CRISPR Cas systems are used to engineer probiotic strains via additive therapy (yeast or bacteria), subtractive therapy by eliminating the targeted bacterial through designer lytic phages, and modulatory therapies by modulating the composition and activity of bacteria as described in Fig.…”

Current trends of antimicrobials used in food animals and aquaculture

“…Both pathogenic and commensal microbes are exposed to antimicrobials and in response AMR develops. It has been detected that microbes develop resistance by any of the four mechanisms: through drug inactivation or its modification, alteration in the drug target site, modification in the metabolic pathways to overcome drug effects, and by minimizing entry and promoting active efflux of the drugs (Sharma et al, 2018). Microbes can develop antimicrobial resistance by mutating existing genes (vertical gene transfer) or by obtaining new genes from the environment, other spp., or strains (horizontal gene transfer) (Jeters et al, 2009).…”