Threats across boundaries: the spread of ESBL-positive bacteria and its challenge to the "one health" concept.

-lactam antibiotics are essential medications for treating human diseases. The spread of extended-spectrum β-lactamase-producing (ESBL-PE) exists globally in multiple reservoirs and the natural environment and poses an immense threat to public health. Plasmid incompatibility groups, such as IncFIA, IncI1, IncY, IncFIB, IncN, IncFIC, IncX4, IncB/O/K/Z, IncHI1/2, and IncA/C, which exist in humans, animals, and the environment, carrying , , and genes. The IS upstream and orf477 downstream of genes, as well as other mobile genetic elements (MGEs) such as IS and IS, are involved in capturing and mobilizing antibiotic-resistant genes (ARGs). The gene is the most common among all discussed reservoirs. The environmental reservoir and propagation mode of ESBL-PE are increasing and difficult to control. The reasons include but are not limited to bacterial adaptability and horizontal gene transfer (HGT) mediated by MGEs and plasmids. Conjugation is a pathway of HGT that is almost uncontrollable. MGEs and plasmids such as Tn, IS families, IncI1, IncK, and IncN are facilitating HGT of genes. This review highlights the need to monitor trends in antimicrobial resistance (AMR) in the natural environment. Therefore, policies such as antibiotic management plans, training for healthcare providers and/or patients, cautious use of antibiotics, the need for epidemiological networks, pre-travel consultations, World Health Organization (WHO) infection control and biosafety guidelines, and other intervention measures are considered desirable.