Hosana Dau Ferreira de Souza

Antimicrobial resistance is a global public health concern that requires an integrated approach including human, animal and environmental health. Agricultural environments, such as soil, animal waste and irrigation water, play crucial roles in the dynamics of antimicrobial resistance, as they act as reservoirs and pathways for disseminating resistance determinants. However, these agricultural environments are still often underestimated or neglected in many studies. This study aimed to address antimicrobial resistance in agricultural environments in Brazil and summarize the current state of knowledge about this issue in the country. Google Scholar, Google, ISI Web of Knowledge and Web of Science databases were searched for Portuguese, English and Spanish articles addressing antimicrobial resistance in agricultural environments in Brazil published through 2023. Different terms were used, and the findings were categorized according to the research questions posed. A total of 36 articles were found, 20 of which focused on antimicrobial resistance in animal waste from livestock production, 13 addressed antimicrobial resistance in agricultural soils, two considered both environments, and only one considered antimicrobial resistance associated with irrigation water in different agricultural environments. In all studies, diverse classes of resistant bacteria and antimicrobial resistance genes and mobile genetic elements were detected. However, the number of articles addressing this topic in Brazilian agricultural environments - in animal waste, followed by soils and, to a lesser degree, irrigation water - is still quite limited, revealing significant gaps to be filled. Therefore, it is essential to conduct more studies on antimicrobial resistance in these environments to elucidate their roles as reservoirs and sources of antimicrobial resistance and assess the risks to public health.

Escherichia coli is an essential bacteria as a human and animal pathogen, although this species can also be disseminated in the environment. The clinical laboratories use EMB agar (Eosin Methylene Blue) to identify E. coli from the observation of metallic green sheen. However, other bacterial species may show sheen when sown on EMB agar, or in some cases, the pH sample influences the presence of this sheen by E. coli. In this study, MALDI-TOF was used as the gold standard to detect E. coli from human, animal, and environmental samples by analyzing the presence of green glow on EMB agar. The positive predictive values (PPV) ​​were higher (above 85%) in human, animal, and environmental samples studied, and the negative predictive value (NPV) was variable between the samples. Specificity and sensitivity were also variables suggesting the influence of the pH of the samples in the presence of metallic green brightness. This work demonstrated that it is necessary to implement biochemical tests or, when possible, molecular assays to confirm E. coli since only the observation of the production of metallic green glow in EMB can generate false negative results in the identification of E. coli. Keywords: Biochemical tests; Escherichia coli; Laboratory Analysis; MALDI-TOF.

The development of biofilms is responsible for 80% of microbial infections, which are highly resistant to conventional antibiotics. The study aimed to assess the antimicrobial activity of essential oils of Mimosa verrucosa Benth. and Illicium verum Hook.f. against planktonic and sessile cells and evaluate toxicity. Thirty compounds were identified, the main ones being a-pinene (12.6%), b-pinene (16.7%) and (E)-caryophyllene (14.2%) for M. verrucosa, and estragole (4.2%) and anethole (86.8%) for I. verum. The minimum inhibitory concentrations of the EO of I. verum (29.40 µg/ml) and M. verrucosa (24.89 µg/ml) against planktonic cells showed 99% efficacy against all cells tested (sensitive and resistant Staphylococcus aureus and Escherichia coli). In sessile cells, essential oils of I. verum and M. verrucosa showed efficacy against sensitive S. aureus. The minimum bactericidal concentration (MBC) test revealed that I. verum caused cell death in sensitive S. aureus and E. coli. However, M. verrucosa only showed bactericidal activity against planktonic cells. Considering the expanding resistance to antimicrobials, the EOs tested represent an important therapeutic option, especially against S. aureus and E. coli, which can produce biofilms on various surfaces, becoming a serious public health problem.