Editorial: Exploiting Novel Combined Host- and Pathogen-Directed Therapies for Combating Bacterial Multidrug Resistance

The golden age of antibiotic therapy started in 1928 with the discovery of penicillin and reached a peak at the mid-1950s. Thereafter, antibiotic discovery and development of new molecules gradually declined with the parallel emergence of drug resistance of many human bacterial pathogens. These circumstances led to the current therapeutical crisis due to antimicrobial resistance (1). Today, the frequency and spectrum of antibiotic resistance in specific bacterial pathogens continues to increase worryingly, with particular concerns on Mycobacterium tuberculosis and on several Gram-positive (e.g., Streptococcus pneumoniae, Staphylococcus aureus, and enterococci) as well as Gram-negative bacteria (e.g., Klebsiella pneumoniae, Escherichia coli, Enterobacter spp, Acinetobacter baumannii, and Pseudomonas aeruginosa). The slow-pace of discovery of novel antimicrobial agents, the dearth of new antibiotics already in the drug development pipeline, and the emergence and rapid diffusion of strains resistant to last resort antibiotics, make novel therapeutic approaches an urgent need to reduce the burden of infectious diseases. It is estimated that deaths due to antibiotic resistant bacterial pathogens may pass from the actual 700,000 cases to about 10 million per year by 2050, if adequate countermeasures are not undertaken.