In this work we compared the most frequently used Klebsiella pneumoniae typing methods: PFGE, cgMLST and coreSNP. We evaluated the discriminatory power of the three methods to confirm or exclude nosocomial transmission on K. pneumoniae strains isolated from January to December 2017, in the framework of the routine surveillance for multidrug-resistant organisms at the San Raffaele Hospital, in Milan. We compared the results of the different methods to the results of epidemiological investigation. Our results showed that cgMLST and coreSNP are more discriminant than PFGE, and that both approaches are suitable for transmission analyses. cgMLST appeared to be inferior to coreSNP in the K. pneumoniae CG258 phylogenetic reconstruction. Indeed, we found that the phylogenetic reconstruction based on cgMLST genes wrongly clustered ST258 clade1 and clade2 strains, conversely properly assigned by coreSNP approach. In conclusion, this study provides evidences supporting the reliability of both cgMLST and coreSNP for hospital surveillance programs and highlights the limits of cgMLST scheme genes for phylogenetic reconstructions.

Antibiotic resistance is a public health problem with increasingly alarming data being reported. Gram-positive bacteria are among the protagonists of severe nosocomial and community infections. The objective of this review is to conduct an extensive examination of emerging treatments for Gram-positive infections including ceftobiprole, ceftaroline, dalbavancin, oritavancin, omadacycline, tedizolid, and delafloxacin. From a methodological standpoint, a comprehensive analysis on clinical trials, molecular structure, mechanism of action, microbiological targeting, clinical use, pharmacokinetic/pharmacodynamic features, and potential for therapeutic drug monitoring will be addressed. Each antibiotic paragraph is divided into specialized microbiological, clinical, and pharmacological sections, including detailed and appropriate tables. A better understanding of the latest promising advances in the field of therapeutic options could lead to the development of a better approach in managing antimicrobial therapy for multidrug-resistant Gram-positive pathogens, which increasingly needs to be better stratified and targeted.

The global spread of multidrug-resistant (MDR) Gram-negative bacteria, particularly extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii, presents a significant public health challenge by limiting effective antimicrobial treatment options. Cefepime, a fourth-generation cephalosporin with broad-spectrum activity, is increasingly compromised by β-lactamase production, efflux pumps, and porin loss. In response, novel cefepime-based β-lactam/β-lactamase inhibitor (BL/BLI) combinations have been developed to overcome these resistance mechanisms. This review examines preclinical and clinical studies on cefepime-based BL/BLI combinations, specifically cefepime/enmetazobactam, cefepime/taniborbactam, cefepime/zidebactam, and cefepime/nacubactam, as found in the PubMed database. Key findings include the restoration of activity against class A ESBLs with cefepime/enmetazobactam, while cefepime/taniborbactam and cefepime/zidebactam show broader inhibition of serine β-lactamases and selected metallo-β-lactamases. Additionally, zidebactam and nacubactam target penicillin-binding protein 2, enhancing bactericidal potency. Preclinical and early-phase clinical trial data indicate potent in vitro activity and favorable pharmacokinetic/pharmacodynamic (PK/PD) profiles. Specifically, the combination of cefepime with enmetazobactam has demonstrated an optimal Cmax/MIC ratio of 8–10, supporting its efficacy in treating MDR Gram-negative infections. Phase III studies are ongoing to confirm efficacy in complicated infections. Cefepime-based BL/BLI combinations are emerging as promising carbapenem-sparing agents, offering broad-spectrum activity, dual mechanisms of action, and encouraging clinical outcomes. These findings support their inclusion in antimicrobial stewardship strategies aimed at mitigating resistance.

In this work we present EasyPrimer, a user-friendly online tool developed to assist pan-PCR and High Resolution Melting (HRM) primer design. The tool finds the most suitable regions for primer design in a gene alignment and returns a clear graphical representation of their positions on the gene. EasyPrimer is particularly useful in difficult contexts, e.g. on gene alignments of hundreds of sequences and/or on highly variable genes. HRM analysis is an emerging method for fast and cost saving bacterial typing and an HRM scheme of six primer sets on five Multi-Locus Sequence Type (MLST) genes is already available for Klebsiella pneumoniae . We validated the tool designing a scheme of two HRM primer sets on the hypervariable gene wzi of Klebsiella pneumoniae and compared the two schemes. The wzi scheme resulted to have a discriminatory power comparable to the HRM MLST scheme, using only one third of primer sets. Then we successfully used the wzi HRM primer scheme to reconstruct a Klebsiella pneumoniae nosocomial outbreak in few hours. The use of hypervariable genes reduces the number of HRM primer sets required for bacterial typing allowing to perform cost saving, large-scale surveillance programs.

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