3.6 Analysis of keywords
Keywords in a publication provide a detailed picture of a publication’s theme, reflecting the research hotspots in the discipline fields, therefore helping researchers to explore dominant research topics. The keyword analysis helps recognizing which are the most applied keywords: AMR, E. coli , genes, prevalence, bacteria, Salmonella spp. and wild birds. This emphasizes that studies have focused in determining the antimicrobial susceptibility of specific indicator bacteria such asEscherichia coli and Salmonella spp. The choice of these bacterial species is mostly linked to their relevance as human foodborne pathogens. E. coli is also part of the mammals’ gut microbiota and can easily be disseminated in different ecosystems, facilitating the direct comparison of resistance phenotypes in distinct environments and host animals (Radhouani et al., 2014). Most studies have focused on searching for specific bacteria rather than search for the whole bacterial community. This is obviously a limitation and future research should concentrate on a wider range of bacteria groups. It also stresses a taxonomic bias, as mostly wild birds have been used as model species to determine antimicrobial resistance profiles, probably due to their wide migration routes but also their suitability to explore anthropogenic gradients, from natural to humanized (e.g. landfills) environments. In fact, migratory birds can acquire antibiotic resistance during their migratory stop-overs and can therefore act as a reservoir and long-distance disperser of antibiotic resistant bacteria. However, as humans transform landscapes the contact with wildlife concomitant increases, and circa of 70% of the majority of emerging infectious diseases in humans arise from wildlife reservoirs (Jones et al., 2008). Several mammals species due to their ecology (omnivorous, synantropic) or to their close association with humans (are hunted, consumed, wide distribution ranges, etc) could serve as key epidemiological and be
defined as priority species for surveillance and used for target monitoring and designing proactive management programs, such as the wild boar (Torres et al., 2020).