**4. Antimicrobial resistance in wild environments**

Antibiotic resistance is a health threat for humans, animals, and the environment [72]. Regarding microorganisms, this resistance initially occurred in the absence of anthropogenic factors and without the clinical application of antibiotics [73]. Thus, this resistance can develop naturally from the ecological evolution of microorganisms, such as gene mutation, due to environmental pressure [74]. However, human factors have contributed to greater antimicrobial resistance with a direct impact on ecosystems [75].

The anthropization of forest areas favors the contact of wildlife with domestic animals and humans [76]. In this regard, resistance can be acquired through the consumption of water or food and can also occur through direct contact with human waste and sewage [77]. Another factor that favors the spread of resistant microorganisms is the displacement capacity of the carrier [78]. However, although wildlife has not had direct access to antibiotics, natural habitats altered by demographic expansion can enhance the sharing of resistance across different ecological niches [79]. According to Jechalke et al. [80], free-living wild animals that have not been exposed to antibiotics exhibit high drug resistance rates due to environmental contamination. Gilliver et al. [81] identified a marked prevalence of antibiotic-resistant wild rodents that were not exposed to antimicrobials.

Residues from antibiotics applied in human and veterinary medicine enable the spread of resistant agents to wild species through environmental contamination, especially among those that share the same habitat [82, 83]. Therefore, antimicrobial resistance can be greater in forest areas close to rural properties due to the inappropriate use of antibiotics to prevent and control diseases or due to their use as animal performance enhancers [84]. These conditions increase contamination of the environment, water resources, the food chain, and, finally, human and animal health. Sub-doses of antibiotics may select multiresistant plasmids [85]. It should be noted that resistance plasmids are highly associated with cases of resistance to beta-lactam antibiotics in gram-negative bacteria from extended-spectrum β-lactamases (ESBLs) [86].

Antimicrobial residues that accumulate in sediments can determine changes in the microbiome of soils in aquatic and terrestrial environments [87]. These effects are intensified by erosion, surface runoff, and displacement of soil minerals [88]. When these elements reach the springs or are used for irrigation, or when the sediment is used as decomposed organic matter for agriculture, cyclic, rotational maintenance of this contamination occurs in the environment [89].
