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The species Salix alba L. and Salix purpurea L. are medicinal herbs, frequently used in the pharmaceutical industry. This study performs phytochemical and antibacterial analysis of ethanolic extracts from the bark of these two species. The qualitative and quantitative phytochemical analyses were performed by thin-layer chromatography identifying the salicin and salicylic acid; the salicin content was assessed by high performance liquid chromatography. The bark extracts yielded 4.300 μg/ml-1 salicin for Salix alba and 1.167 μg/ml-1 salicin for Salix purpurea. The plant extracts were tested on Gram negative and positive bacteria (Escherichia coli and Staphylococcus aureus). Both tested strains showed a mild resistance, but S. aureus showed slightly higher inhibition by all extract samples.

Hypericum perforatum, H. umbellatum, H. maculatum, and H. hircinum accessions originating from botanical gardens across Europe were examined by flow cytometry and molecular markers. 2C DNA content of 17 Hypericum perforatum accessions (Hp) and the H. perforatum cultivar Topaz amounted to between 1.56 pg and 1.62 pg. In four Hp accessions some individual plants were found with a DNA content corresponding to 6Cx (2.34 - 2.39 pg). All plants of accession Hp8 showed a DNA content of 6Cx (2.41 pg). In root tips of Hp plants with an average DNA amount of 1.58 pg, 32 chromosomes were detected, corresponding to 2n = 4x. This is the first ploidy and/or DNA content report for H. umbellatum, H. maculatum and H. hircinum. H. umbellatum and H. maculatum, each contained 0.76 pg DNA and 16 chromosomes were counted. The 2C DNA content of H. hircinum was 1.00 pg with the best metaphase plate revealing 32 chromosomes. Additionally, a combined marker analysis, based on inter-simple sequence repeats (ISSR) and sequence related amplified polymorphism (SRAP), was conducted to gain a better understanding of diversity especially within the accessions of H. perforatum. A total of 27 (11 ISSR and 16 SRAP) primer combinations were screened, showing 699 bands, of which 661 were polymorphic. UPGMA clustering revealed that accessions from the same geographic area tended to be more closely related, while H. maculatum was grouped separately from all H. perforatum accessions. Both methods have shown similar sensitivities in detecting the genetic diversity of the analyzed genotypes. Our results may be useful for Hypericum breeding programs and the development of effective conservation strategies.

As a consequence of global demographic challenges, both the artificial and the natural environment are increasingly impacted by contaminants of emerging concern, such as bacterial pathogens and their antibiotic resistance genes (ARGs). The aim of this study was to determine the extent to which anthropogenic contamination contributes to the spread of antibiotic resistant enterococci in aquatic compartments and to explore genetic relationships among Enterococcus strains. Antimicrobial susceptibility testing (ampicillin, imipenem, norfloxacin, gentamycin, vancomycin, erythromycin, tetracycline, trimethoprim-sulfamethoxazole) of 574 isolates showed different rates of phenotypic resistance in bacteria from wastewaters (91.9–94.4%), hospital effluents (73.9%), surface waters (8.2–55.3%) and groundwater (35.1–59.1%). The level of multidrug resistance reached 44.6% in enterococci from hospital effluents. In all samples, except for hospital sewage, the predominant species were E. faecium and E. faecalis. In addition, E. avium, E. durans, E. gallinarum, E. aquimarinus and E. casseliflavus were identified. Enterococcus faecium strains carried the greatest variety of ARGs (blaTEM-1, aac(6′)-Ie-aph(2″), aac(6′)-Im, vanA, vanB, ermB, mefA, tetB, tetC, tetL, tetM, sul1), while E. avium displayed the highest ARG frequency. Molecular typing using the ERIC2 primer revealed substantial genetic heterogeneity, but also clusters of enterococci from different aquatic compartments. Enterococcal migration under anthropogenic pressure leads to the dispersion of clinically relevant strains into the natural environment and water resources. In conclusion, ERIC-PCR fingerprinting in conjunction with ARG profiling is a useful tool for the molecular typing of clinical and environmental Enterococcus species. These results underline the need of safeguarding water quality as a strategy to limit the expansion and progression of the impending antibiotic-resistance crisis.

Being frequently exposed to foreign nucleic acids, bacteria and archaea have developed an ingenious adaptive defense system, called CRISPR-Cas. The system is composed of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) array, together with CRISPR (cas)-associated genes. This system consists of a complex machinery that integrates fragments of foreign nucleic acids from viruses and mobile genetic elements (MGEs), into CRISPR arrays. The inserted segments (spacers) are transcribed and then used by cas proteins as guide RNAs for recognition and inactivation of the targets. Different types and families of CRISPR-Cas systems consist of distinct adaptation and effector modules with evolutionary trajectories, partially independent. The origin of the effector modules and the mechanism of spacer integration/deletion is far less clear. A review of the most recent data regarding the structure, ecology, and evolution of CRISPR-Cas systems and their role in the modulation of accessory genomes in prokaryotes is proposed in this article. The CRISPR-Cas system's impact on the physiology and ecology of prokaryotes, modulation of horizontal gene transfer events, is also discussed here. This system gained popularity after it was proposed as a tool for plant and animal embryo editing, in cancer therapy, as antimicrobial against pathogenic bacteria, and even for combating the novel coronavirus – SARS-CoV-2; thus, the newest and promising applications are reviewed as well.

The aim of this study was to investigate the extent of heavy metal (HM) pollution and its effect on microorganisms from rhizosphere soil in Baia Mare area (Maramures County, Romania). Two sites wit...

Antibiotic resistance has increased significantly in the recent years, and has become a global problem for human health and the environment. As a result, several technologies for the controlling of health-care associated infections have been developed over the years. Thus, the most recent findings in hydrogel fabrication, particularly antimicrobial hydrogels, could offer valuable solutions for these biomedical challenges. In this review, we discuss the most promising strategies in the development of antimicrobial hydrogels and the application of hydrogels in the treatment of microbial infections. The latest advances in the development of inherently and composite antimicrobial hydrogels will be discussed, as well as hydrogels as carriers of antimicrobials, with a focus on antibiotics, metal nanoparticles, antimicrobial peptides, and biological extracts. The emergence of CRISR-Cas9 technology for removing the antimicrobial resistance has led the necessity of new and performant carriers for delivery of the CRISPR-Cas9 system. Different delivery systems, such as composite hydrogels and many types of nanoparticles, attracted a great deal of attention and will be also discussed in this review.

CRISPR-Cas is an adaptive immunity system of prokaryotes, composed of CRISPR arrays and the associated proteins. The successive addition of spacer sequences in the CRISPR array has made the system a valuable molecular marker, with multiple applications. Due to the high degree of polymorphism of the CRISPR loci, their comparison in bacteria from various sources may provide insights into the evolution and spread of the CRISPR-Cas systems. The aim of this study was to establish a correlation between the enterobacterial CRISPR loci, the sequence of direct repeats (DR), and the number of spacer units, along with the geographical origin and collection source. For this purpose, 3474 genomes containing CRISPR loci from the CRISPRCasdb of Salmonella enterica, Escherichia coli, and Klebsiella pneumoniae were analyzed, and the information regarding the isolates was recorded from the NCBI database. The most prevalent was the I-E CRISPR-Cas system in all three studied taxa. E. coli also presents the I-F type, but in a much lesser percentage. The systems found in K. pneumoniae can be classified into I-E and I-E*. The I-E and I-F systems have two CRISPR loci, while I-E* has only one locus upstream of the Cas cluster. PCR primers have been developed in this study for each CRISPR locus. Distinct clustering was not evident, but statistically significant relationships occurred between the different CRISPR loci and the number of spacer units. For each of the queried taxa, the number of spacers was significantly different (p < 0.01) by origin (Africa, Asia, Australia and Oceania, Europe, North America, and South America) but was not linked to the isolation source type (human, animal, plant, food, or laboratory strains).

COVID-19 offers ideal premises for bacteria to develop antimicrobial resistance. In this study, we evaluated the presence of several antimicrobial resistance genes (ARG) in vancomycin-resistant Enterococcus (VRE) isolated from rectal swabs from patients at a hospital in Cluj-Napoca, Romania. Rectal swabs were cultivated on CHROMID® VRE (bioMérieux, Marcy—l’ Étoile, France) and positive isolates were identified using MALDI-TOF Mass Spectrometry (Bruker Daltonics, Bremen, Germany) and further analyzed using the PCR technique for the presence of the following ARGs: van A, van B, tet(M), tet(L), ermB, msrA, mefA, aac(6′)-Im, aph(2)-Ib, ant(4′)-Ia, sul1, sul2, sul3, and NDM1. We isolated and identified 68 isolates of Enterococcus faecium and 11 isolates of Enterococcus faecalis. The molecular analysis showed 66 isolates positive for the vanA gene and eight positive for vanB. The most frequent association of ARG in VRE was vanA-tet(M)-ermB. There was no statistically significant difference between Enterococcus faecium and Enterococcus faecalis regarding ARGs. Our work proves that during the COVID-19 pandemic, highly resistant isolates of Enterococcus were present in patients in the intensive care unit; thus, better healthcare policies should be implemented for the management and control of these highly resistant isolates in the future.

In Romania, Prunus species have great economic and social importance. With the introduction of new cultivars arises the need to preserve and characterize the local Prunus germplasm. Thus, a set of 24 polymorphic SSRs were selected for the overall characterization, including 10 peach, 11 apricot and 5 nectarine cultivars. The average number of alleles per locus (Na = 1.958), in addition to overall observed (Ho = 0.299) and expected heterozygosity (He = 0.286) were lower or comparable to those reported in similar studies, probably explained by the smaller number of analyzed cultivars restricted to a smaller geographic area. Among 26 genotypes a total of 101 alleles were identified, of which 46 alleles were in peach, 55 in apricot and 40 in nectarine, respectively. Six alleles from six loci (CPPCT-030, Pchgms-003, Pchgms-004, Pchgms-010, UDP97-401, UDP98-405) were common to all taxonomic groups. The most informative loci were BPPCT-025, Pchgms-021 and UDP96-001 in peach; BPPCT-025, BPPCT-001 and UDP96-001 in nectarine; and BPPCT-002, BPPCT-025, Pchgms-004, Pchgms-020 and Pchgms-021 in apricot. Clustering and genetic similarity analysis indicated that the degree of interspecific divergence in peach and nectarine cultivars was less than that in peach and apricot. These results will be useful to prevent confusion between cultivars, to improve breeding strategies and to benefit the management of Prunus cultivars bred in Romania.