Editorial: Special Issue “Molecular Epidemiology of Antimicrobial Resistance”

Antimicrobial resistance and multidrug-resistant organisms currently constitute a severe public health problem. Multidrug-resistant organisms are resistant to multiple antibiotic classes, resulting in limited therapeutic options and difficult-to-treat health-care-associated and community infections, with high morbidity and mortality rates. In particular, carbapenem-resistant (CR) Acinetobacter baumannii, CR Pseudomonas aeruginosa, CR Enterobacterales, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus spp. are recognized by the World Health Organization as global priority pathogens of critical or high priority [1].

This Special Issue was dedicated to updates on the “Molecular Epidemiology of Antimicrobial Resistance”. Two manuscripts investigated new patterns in the epidemiology of infections caused by isolates belonging to the A. baumannii-calcoaceticus complex. The epidemics of A. baumannii are characterized by the spread of multidrug-resistant clonal lineages [2]. Monnheimer et al. [3] analyzed the phenotypic and genotypic features of carbapenem-resistant A. baumannii isolates responsible for wound infections in Ghana. Chopjitt et al. [4] investigated the genomic epidemiology of extensively drug-resistant Acinetobacter pittii isolates from Taiwan and China.

The molecular determinants, genetic and genomic elements of antimicrobial resistance in Enterobacterales, have been the subject of four studies. The research paper by Bilal et al. [5] reported the occurrence of bla_NDM-1 bearing IncX3 plasmid in clinically isolated ST11 Klebsiella pneumoniae from Pakistan. A new resistance-mediating plasmid chimera was detected in bla_OXA-48-positive Klebsiella pneumoniae strain at a German university hospital [6]. HI2 plasmids mobilising the carbapenemase gene bla_IMP-4 were identified both in Escherichia coli Australian clinical samples and in multiple sublineages of E. coli ST216 colonising silver gulls [7]. Edowik et al. [8] demonstrated that the amino acid changes T55A, A273P and R277C in the beta-Lactamase CTX-M-14 render E. coli resistant to the antibiotic nitrofurantoin, which is used as first-line treatment of urinary tract infections. Lin et al. [9] showed that the dissemination of multidrug-resistant composite transposons MESPM1 or MES6272 between Enterococcus and ST59 S. aureus was mediated by insertion sequence IS1216V.

One manuscript focussed on diagnostics of antimicrobial resistances. Vasilakopoulou et al. [10] reported the evaluation of the NG-Test CARBA 5 immunochromatographic assay for detecting KPC, NDM and VIM-producing carbapenemases organisms directly from rectal swabs.

Therapeutics and management for the prevention and control of infections caused by multidrug-resistant organisms were investigated in three manuscripts. Yang et al. [11] analyzed the in vitro and in vivo efficacies of ceftazidime–avibactam and aztreonam–avibactam against carbapenem-nonsusceptible Enterobacteriaceae isolates collected in Taiwan. Siméon et al. [12] reported the use of cefiderocol to treat a case of prosthetic joint infection due to extensively drug-resistant Enterobacter hormaechei. Karruli et al. [13] identified the use of central venous catheters and length of hospitalization as risk factors of multidrug-resistant infections after heart transplants in a single-center study.

In conclusion, the genomic epidemiology of multidrug-resistant organisms, the analysis of molecular determinants of antimicrobial resistance, the identification of innovative diagnostic and therapeutic approaches are important to prevent and control antimicrobial resistance.