Emergence and Genomic Characterization of a spa Type t4407 ST6-SCCmec Type IVa Methicillin-Resistant Staphylococcus aureus Strain Isolated from Al-Karak Hospital, Jordan

Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major concern in Jordanian hospitals in terms of infection control. The purpose of this study was to identify the resistance patterns of Staphylococcus aureus strains isolated from surfaces of critical locations within the Al-Karak Governmental Hospital in 2019. Additionally, the study aimed to conduct whole-genome sequencing on the isolates. Materials and Methods: In February 2019, fourteen S. aureus strains were isolated from surfaces in critical sites in the Al-Karak Governmental Hospital. These isolates underwent antibiogram testing to determine their resistance profile. Genome sequencing using the Illumina MiSeq platform was applied to the extracted DNA from these isolates. The genomic data, including coding sequences, were analyzed to identify lineage, resistance genes, and plasmids. Results: The antibiogram results revealed that 11 of the 14 isolates were resistant to oxacillin, 6 to linezolid, and 1 to rifampicin, while none showed resistance to chloramphenicol. Eleven isolates were identified as MRSA, with a novel spa type (t4407) not previously reported in Jordan. High-quality sequencing data were obtained for only one isolate, i.e., A29, the genome showed 2,789,641 bp with a 32.7% GC content and contained 2650 coding sequences. Genomic analysis indicated the ST6 lineage, mecA gene (SCCmec type IVa(2B)), and a hybrid plasmid (pJOR_blaZ) carrying the blaZ gene for β-lactam resistance. Genomic data were deposited in NCBI (CP104989). The A29 genome closely resembled an MRSA genome isolated from a Danish hospital in 2011. The SNP analysis revealed identical antimicrobial resistance genes in these two genomes. Conclusions: This study unveils the first genomic sequence of an MRSA isolate from Jordan, marked by distinctive genotypic traits. The findings enhance our understanding of the MRSA types circulating in Jordan and the region and substantiate the phenomenon of intercontinental MRSA transmission.

Antibacterial, antioxidant, and cytotoxic activities of Syzygium aromaticum (L.) Merr. & Perry essential oil with identification of its chemical constituents

Aromatic plants embrace volatile compounds with efficiency in treating different diseases. In Jordan, Syzygium aromaticum flower buds (clove) are extensively used as folk medicine without awareness of its bio-safe dosage. Herein, clove buds were hydrodistilled using the Clevenger apparatus, and the resulting essential oil (CEO) was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The antibacterial activity was evaluated against tested bacterial strains by agar diffusion test and micro-broth dilution assay. The antioxidant capacity was assessed using DPPH radical scavenging assay, while the cytotoxic potency was unraveled by determination of its anti-proliferative activity against MDA-MB-231 breast adenocarcinoma and normal Vero cell lines. CEO yield was 5.7 ± 1.3% (w/w); encompassed 24 volatile ingredients with eugenol as the principal compound (73.41%). The CEO inhibited the growth of both Gram-positive and Gram-negative bacterial test strains, causing the formation of 13.7 ± 1.5-17.3 ± 0.6 mm and 11.7 ± 1.5-20.7 ± 1.2 mm inhibition zones, respectively with MIC 1.25-5 μL/mL. Moreover, it showed antioxidant activity with IC₅₀ 0.0016 ± 0.0001 μL/mL (1.6 ± 0.1 μg/mL, 2.98 ± 0.4 µg Trolox^®/µg CEO). Intriguingly, the CEO was cytotoxic against both cancerous and noncancerous cell lines at IC₅₀ of 0.25 ± 0.02 μL/mL and 0.18 ± 0.01 μL/mL, respectively. Herein results unveil the potential application of CEO as a pharmaceutical remedy with considering its bio-safe dosage.

Green Synthesis of Silver Nanoparticles Using Hypericum perforatum L. Aqueous Extract with the Evaluation of Its Antibacterial Activity against Clinical and Food Pathogens

The rapid development of nanotechnology and its applications in medicine has provided the perfect solution against a wide range of different microbes, especially antibiotic-resistant ones. In this study, a one-step approach was used in preparing silver nanoparticles (AgNPs) by mixing silver nitrate with hot Hypericum perforatum (St. John’s wort) aqueous extract under high stirring to prevent agglomeration. The formation of silver nanoparticles was monitored by continuous measurement of the surface plasma resonance spectra (UV-VIS). The effect of St. John’s wort aqueous extract on the formation of silver nanoparticles was evaluated and fully characterized by using different physicochemical techniques. The obtained silver nanoparticles were spherical, monodisperse, face-centered cubic (fcc) crystal structures, and the size ranges between 20 to 40 nm. They were covered with a capping layer of organic compounds considered as a nano dimension protective layer that prevents agglomeration and sedimentation. AgNPs revealed antibacterial activity against both tested Gram-positive and Gram-negative bacterial strains causing the formation of 13–32 mm inhibition zones with MIC 6.25–12.5 µg/mL; Escherichia coli strains were resistant to tested AgNPs. The specific growth rate of S. aureus was significantly reduced due to tested AgNPs at concentrations ≥½ MIC. AgNPs did not affect wound migration in fibroblast cell lines compared to control. Our results highlighted the potential use of AgNPs capped with plant extracts in the pharmaceutical and food industries to control bacterial pathogens’ growth; however, further studies are required to confirm their wound healing capability and their health impact must be critically evaluated.

Essential oils from Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks: Chemical examination and bioactivity studies

Context: Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks are immensely consumed by Jordanian population as food flavoring and remedies in treating different disorders without awareness of their effect or dose toxicity. Aims: To evaluate the antibacterial, antioxidant and cytotoxic effects of essential oils (EOs) hydro-distilled from E. cardamomum grains and C. verum barks. Methods: Hydro-distillation was carried out using Clevenger apparatus; the EOs were analyzed using GC/MS, and their constituents were quantified using GC/FID. The antibacterial activity was determined by agar diffusion test and micro-broth dilution assay, while the antioxidant activity was evaluated by DPPH and ABTS scavenging assays. The cytotoxic activity was evaluated against the MDA-MB-231 breast cancer cell line. Results: E. cardamomum EO was most effective against Bacillus subtilis with MIC 3.75 µL/mL and exhibited antioxidant activity in DPPH assay with IC50 0.057 ±0.013 µL/mL (0.076 ±0.017 µL EO/µg Trolox®) but was ineffective in the ABTS test up to 5 µL/mL; 86.22% of its EO constituent are oxygenated monoterpenes with α-terpinyl acetate as the major component. Whilst C. verum EO was active against both tested Gram-positive and negative bacterial strains with MIC 1.25-5.00 µL/mL but was devoid of significant antioxidant activity up to 5 µL/mL; phenylpropanoids constituted 69.48% of its EO with E-cinnamaldehyde as the major component. Both EOs showed cytotoxic activity against the breast cancer cell line withIC50 0.14-0.46 µL/mL. Conclusions: The current results unveil the potential application of C. verum and E. cardamomum in complementary and alternative medicine as biosafe remedies besides their usage as flavoring and seasoning sources.

A convenient one-pot approach to the synthesis of novel pyrazino[1,2-a]indoles fused to heterocyclic systems and evaluation of their biological activity as acetylcholinesterase inhibitors

Pyrazino[1,2-a]indoles fused with various heterocycles, such as oxazolidine, oxazinane, imidazolidine, hexahydropyrimidine and benzimidazole, were synthesized transition metal-free by domino reactions which involved the condensation of 1-(2-bromoethyl)-3-chloro-1H-indole-2-carbaldehydes 28–31 with various nucleophilic amines, resulting in the formation of two new interesting fused heterocycles. The anticholinesterase, antioxidant and antibacterial activities of the compounds were evaluated. Acetylcholinesterase (AChE) inhibitory activities were tested by Ellman’s assay, antioxidant activities were detected using the 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS•+) free-radical scavenging method and antibacterial activities were determined by agar diffusion tests. The oxazolo-pyrazino[1,2-a]indoles (8, 10), the oxazino-pyrazino[1,2-a]indoles (16, 18, 19), the pyrimido-pyrazino[1,2-a]indole (22), and the benzoimidazo-pyrazino[1,2-a]indole (27) possessed the highest inhibitory activity against AChE with IC50 values in the range 20–40 μg mL−1. The oxazolo-pyrazino[1,2-a]indoles (8, 9), the imidazo-pyrazino[1,2-a]indoles (12, 13), and the benzoimidazo-pyrazino[1,2-a]indole (24) revealed the highest antioxidant values with IC50 values less than 300 μg mL−1. However, the oxazolo-pyrazino[1,2-a]indole (11) and imidazo-pyrazino[1,2-a]indoles (12, 13) exhibited weak to moderate bioactivities against all tested Gram-positive bacteria, namely Staphylococcus aureus, Bacillus subtilis and Bacillus cereus.