A novel Enterococcus faecium phage EF-M80: unveiling the effects of hydrogel-encapsulated phage on wound infection healing.

Background: Enterococcus faecium is one of the members of ESKAPE pathogens. Due to its resistance to antimicrobial agents, treating this bacterium has become challenging. The development of innovative approaches to combat antibiotic resistance is necessary. Phage therapy has emerged as a promising method for curing antibiotic-resistant bacteria. Methods: In this study, E. faecium phages were isolated from wastewater. Phage properties were characterized through in vitro assays (e.g. morphological studies, and physicochemical properties). In addition, whole genome sequencing was performed. A hydrogel-based encapsulated phage was obtained and its structure characteristics were evaluated. Wound healing activity of the hydrogel-based phage was assessed in a wound mice model. Results: The purified phage showed remarkable properties including broad host range, tolerance to high temperature and pH and biofilm degradation feature as a stable and reliable therapeutic agent. Whole genome sequencing revealed that the genome of the EF-M80 phage had a length of 40,434 bp and harbored 65 open reading frames (ORFs) with a GC content of 34.9% (GenBank accession number is OR767211). Hydrogel-based encapsulated phage represented an optimized structure. Phage-loaded hydrogel-treated mice showed that the counting of neutrophils, fibroblasts, blood vessels, hair follicles and percentage of collagen growth were in favor of the wound healing process in the mice model. Conclusion: These findings collectively suggest the promising capability of this phage-based therapeutic strategy for the treatment of infections associated with the antibiotic-resistant E. faecium. In the near future, we hope to expect the presence of bacteriophages in the list of antibacterial compounds used in the clinical settings.

Insights into the novel Enterococcus faecalis phage: A comprehensive genome analysis.

Enterococcus faecalis, a Gram-positive bacterium, poses a significant clinical challenge owing to its intrinsic resistance to a broad spectrum of antibiotics, warranting urgent exploration of innovative therapeutic strategies. This study investigated the viability of phage therapy as an alternative intervention for antibiotic-resistant E. faecalis, with a specific emphasis on the comprehensive genomic analysis of bacteriophage SAM-E.f 12. The investigation involved whole-genome sequencing of SAM-E.f 12 using Illumina technology, resulting in a robust dataset for detailed genomic characterization. Bioinformatics analyses were employed to predict genes and assign functional annotations. The bacteriophage SAM-E.f 12, which belongs to the Siphoviridae family, exhibited substantial potential, with a burst size of 5.7 PFU/infected cells and a latent period of 20 min. Host range determination experiments demonstrated its effectiveness against clinical E. faecalis strains, positioning SAM-E.f 12 as a precise therapeutic agent. Stability assays underscore resilience across diverse environmental conditions. This study provides a comprehensive understanding of SAM-E.f 12 genomic composition, lytic lifecycle parameters, and practical applications, particularly its efficacy in murine wound models. These results emphasize the promising role of phage therapy, specifically its targeted approach against antibiotic-resistant E. faecalis strains. The nuanced insights derived from this research will contribute to the ongoing pursuit of efficacious phage therapies and offer valuable implications for addressing the clinical challenges associated with E. faecalis infections.

Decoding the genetic structure of conjugative plasmids in international clones of Klebsiella pneumoniae: A deep dive into blaKPC, blaNDM, blaOXA-48, and blaGES genes.

Carbapanem-resistant Klebsiella pneumoniae is a globally healthcare crisis. The distribution of plasmids carrying carbapenemase genes among K. pneumoniae poses a serious threat in clinical settings. Here, we characterized the genetic structure of plasmids harboring major carbapenemases (e.g. blaKPC, blaNDM, blaOXA-48-like, and blaGES) from K. pneumoniae using bioinformatics tools. The plasmids carrying at least one major carbapenemase gene were retrieved from the GenBank database. The DNA length, Inc type, and conjugal apparatus of these plasmids were detected. Additionally, allele types, co-existence, co-occurrence of carbapenemase genes, gene repetition, and sequence types of isolates, were characterized. There were 2254 plasmids harboring carbapenemase genes in the database. This study revealed that blaKPC-2, blaNDM-1, blaOXA-48, and blaGES-5 were the most prevalent allele types. Out of 1140 (50%) plasmids were potentially conjugative. IncFII, IncR, IncX3, and IncL replicon types were predominant. The co-existence analysis revealed that the most prevalent of other resistance genes were blaTEM-1 (related to blaKPC), blaOXA-232 (related to blaOXA-48), bleMBL (related to blaNDM), and aac (6')-Ib4 (related to blaGES). The co-occurrence of carbapenemases was detected in 42 plasmids while 15 plasmids contained carbapenemase gene repetitions. Sequence alignments highlighted that plasmids carrying blaKPC and blaOXA-48-like were more homogeneous whereas the plasmids carrying blaNDM were divergent. It seems that K. pneumoniae utilizes diversity of genetic flexibility and recombination for resistance against carbapenems. The genetic structure of the plasmids showed that class I and III, Tn3 family, Tn5403 family derivatives, and Tn7-like elements were strongly associated with carbapenemases. The mobilizable plasmids carrying carbapenemases play an important role in the spread of these genes. In addition, gene repetition maybe is related to carbapenem heteroresistance. According to MST (minimum spanning tree) results, the majority of plasmids belonged to sequence type (ST) 11, ST14, and ST12. These international clones have a high capacity to acquire the carbapenemase-containing plasmids.