Antimicrobial resistance in wildlife and in the built environment in a wildlife rehabilitation center

Abstract

Injured and orphaned wildlife are often brought to Wildlife Rehabilitation Centers (WRC) to be cared for by professionals to ultimately be released back to their natural habitats. In these centers, animals may spend months and frequently receive prolonged antibiotic therapy. Therefore, WRC may play a role in the emergence and dissemination of antimicrobial resistance (AMR). The goal of this study was to investigate the presence and antibiotic resistance profiles of Gram-negative bacteria with reduced susceptibility to cephalosporins in both the wildlife admitted to a WRC and in the WRC built environment in Chile. A cross-sectional study was conducted sampling animals undergoing rehabilitation (n = 64) and the WRC environment (n = 160). Isolated bacterial species were identified with MALDI-TOF, and antimicrobial susceptibility determined using the disk diffusion method. Enterobacteriaceae and Pseudomonadaceae were the dominant bacterial families among the environmental (n = 78) and animal (n = 31) isolates. For Enterobacteriaceae, isolates of the most abundant species (E. coli) were classified into 20 antibiotic resistance profiles, with eight of those isolates being resistant to more than nine antibiotics, including imipenem. Isolates of the Pseudomonadaceae family identified 11 isolates with resistance to antibiotics such as carbapenems and quinolones. Even though a cluster analysis based on antibiotic resistance patterns did not show a clear overlap between environmental and animal isolates, it is important to highlight the identification of isolates resistant to carbapenems, which is very relevant from a public health perspective. Further, numerous antibiotic resistance profiles were observed in different bacterial species, indicating not only environmental contamination with a wide diversity of bacteria, but also a wide diversity of resistant bacteria in animals at the WRC. The approach taken by sampling animals and their hospital environment can be useful in understanding AMR dynamics in wildlife rehabilitation settings, as well as the potential dissemination of AMR into the natural environment.

Keywords: Antibiotic; Antimicrobial resistance; Chile; Cluster analysis; Latin America; Wildlife.

Fig. 1

Dendrogram for Enterobacteriales that resulted from the cluster analysis. The y-axis (height) represents how close together observations were when they were merged into clusters. gower_distR refers to Gower distance which was used to calculate the distance matrix, and Ward's refers to the method used as the hierarchical clustering algorithm. The rectangular boxes represent each one of the two clusters (I and II).

Fig. 2

Dendrogram for Pseudomonadaceae that resulted from the cluster analysis. The y-axis (height) represents how close together observations were when they were merged into clusters. gower_distR refers to Gower distance which was used to calculate the distance matrix, and Ward's refers to the method used as the hierarchical clustering algorithm. The rectangular boxes represent each one of the four clusters (I, II, III, and IV).