ESKAPE is an acronym comprising the scientific names of six highly virulent and antibiotic resistant bacterial pathogens including: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.[1] The acronym is sometimes extended to ESKAPEE to include Escherichia coli.[2] This group of Gram-positive and Gram-negative bacteria can evade or 'escape' commonly used antibiotics due to their increasing multi-drug resistance (MDR).[1] As a result, throughout the world, they are the major cause of life-threatening nosocomial or hospital-acquired infections in immunocompromised and critically ill patients who are most at risk.[3] P. aeruginosa and S. aureus are some of the most ubiquitous pathogens in biofilms found in healthcare.[4] P. aeruginosa is a Gram-negative, rod-shaped bacterium, commonly found in the gut flora, soil, and water that can be spread directly or indirectly to patients in healthcare settings.[5][6] The pathogen can also be spread in other locations through contamination, including surfaces, equipment, and hands. The opportunistic pathogen can cause hospitalized patients to have infections in the lungs (as pneumonia), blood, urinary tract, and in other body regions after surgery.[6] S. aureus is a Gram-positive, cocci-shaped bacterium, residing in the environment and on the skin and nose of many healthy individuals.[7] The bacterium can cause skin and bone infections, pneumonia, and other types of potentially serious infections if it enters the body. S. aureus has also gained resistance to many antibiotic treatments, making healing difficult.[7] Because of natural and unnatural selective pressures and factors, antibiotic resistance in bacteria usually emerges through genetic mutation or acquires antibiotic-resistant genes (ARGs) through horizontal gene transfer - a genetic exchange process by which antibiotic resistance can spread.[8]
One of the main reasons for the rise in the selection for antibiotic resistance (ABR) and MDR which led to the emergence of the ESKAPE bacteria is from the rash overuse of antibiotics not only in healthcare, but also in the animal, and agricultural sector.[9] Other key factors include misuse and inadequate adherence to treatment guidelines.[10] Due to these factors, fewer and fewer antibiotic treatments are effective in eradicating ABR and MDR bacterial infections, while at the same time there are now no new antibiotics being created due to lack of funding.[10] These ESKAPE pathogens, along with other antibiotic-resistant bacteria, are an interweaved global health threat and are being addressed from a more holistic and One Health perspective.[6][9]