ARAV Antimicrobial Stewardship Policy

Abstract

Antimicrobial drugs (AMDs) are frequently used and misused in the treatment of reptiles and amphibians. Although the general reliance on advanced broad-spectrum antimicrobials implies a low level of skill and expertise on the part of the clinician, the continued use of large-volume antibiotic baths for treating amphibians presents obvious concerns regarding disposal and environmental contamination. Unfortunately, there are very few studies that have fulfilled Koch’s postulates and confirmed the pathogenicity of isolated bacteria through transmission studies. Those studies that are available have often recommended advanced antimicrobials over more basic drugs. For example, Devriesea agamarum is a bacterium that is known to cause dermatitis in lizards; however, despite demonstrable sensitivity to clindamycin, erythromycin, penicillin, potentiated sulfonamides, and tylosin, ceftiofur (a third generation cephalosporin) was still the primary recommendation (Hellebuyck et al., 2009). There continues to be a bias in the herpetological pharmacokinetic research with a persistent focus on the newer more advanced drugs than on more basic drug classes. Consequently, practitioners are often compelled to use these more advanced drugs for which pharmacokinetic data are known (Hedley et al., 2021). Finally, there are issues of antimicrobial availability, outside of the veterinary profession, and owners may be tempted to obtain (legally or illegally) antimicrobials without veterinary prescription. Veterinarians should restrict prescription volumes to those required to treat a particular case and not provide a stock volume for clients with multiple animals or larger collections. Typically, such prescribing restrictions are governed by veterinary licensing bodies to which veterinary professionals should adhere. Importantly, there is a need to appreciate that more could be done to prevent infections and the need for antimicrobials through improved biosecurity and quarantine, improved husbandry, and nutrition (Divers and Stahl, 2019). Antimicrobial resistance (AMR) is an emerging problem that can affect the ability to treat individual patients as well as control infectious diseases in animal populations, and many healthcare-associated infections (HAIs; infections not present on hospital admission but associated with the delivery of healthcare) can be attributed to bacteria and fungi resistant to antimicrobials (Sidhu et al., 2007; Portner and Johnson, 2010). AMR can evolve through the acquisition of chromosomal mutations and resistance genes and can be transferred between bacteria from different taxonomic and ecologic groups through mobile genetic elements (e.g., plasmids, transposons, or bacteriophages). Acquired resistance genes can confer resistance to a single antimicrobial, a single antimicrobial class, or a broad group of antimicrobials. Theoretically, all uses of AMDs have the potential to promote the evolution of resistance in bacterial populations by providing a survival advantage for resistant bacteria. Genes associated with AMR to one antimicrobial can be linked to resistance genes for other antimicrobials as well as to disinfectants, thereby promoting the development of multidrug-resistant strains that may be more difficult to treat and eliminate from the hospital environment (Sidhu et al., 2002; Levy and Marshall, 2004; Rajamohan et al., 2010). When needed, AMDs should be used to treat patients with bacterial infections; however, they should be used judiciously, taking into account the following eight factors (AVMA, 2008):