Background: Klebsiella pneumoniae is an opportunistic pathogen that causes a wide range of infections worldwide. The emergence and spread of multidrug-resistant clones requires the implementation of novel therapeutics, and phages are a promising approach. Results: In this study, two Klebsiella phages, KpTDp1 and KpTDp2, were isolated from wastewater samples in Tunisia. These phages had a narrow host range and specifically targeted the hypervirulent K2 and K28 capsular types of K. pneumoniae. Both phages have double-stranded linear DNA genomes of 49,311 and 49,084 bp, respectively. Comparative genomic and phylogenetic analyses placed phage KpTDp2 in the genus Webervirus, while phage KpTDp1 showed some homology with members of the genus Jedunavirus, although its placement in a new undescribed genus may be reconsidered. The replication efficiency and lytic ability of these phages, combined with their high stability at temperatures up to 70 °C and pH values ranging from 3.5 to 8.2, highlight the potential of these phages as good candidates for the control of hypervirulent multidrug-resistant K. pneumoniae. Methods: Phage isolation, titration and multiplicity of infection were performed. The stability of KpTDp1 and KpTDp2 was tested at different pH and temperatures. Genomic characterization was done by genome sequencing, annotation and phylogenetic analysis. Conclusions: The ability of KpTDp1 and KpTDp2 to lyse one of the most virulent serotypes of K. pneumoniae, as well as the stability of their lytic activities to pH and temperature variations, make these phages promising candidates for antibacterial control.

Objectives: This study examined the impact of various abiotic factors, specifically temperature and precipitation, on the yield and composition (volatile profile) of essential oils (EO) from four Eucalyptus species, including Eucalyptus salmonophloia , Eucalyptus torquata, Eucalyptus lesouefii and Eucalyptus astringens . Additionally, the antimicrobial properties of these EO were assessed. Methods: The species were collected from five arboreta in Tunisia belonging to two climatic conditions (arid and semi-arid). EOs were extracted from the leaves using the hydrodistillation technique and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The antimicrobial activity was evaluated by measuring the diameters of inhibition zones using the agar well diffusion method and by determining the minimum inhibitory concentrations (MICs). Results: The yield of Eucalyptus EOs varied from 0.12% to 4.63% (w/w, dry weight) depending on the species and the plant's growing location. 1,8-cineole (29.71% to 67.16%) was by far the major compounds in EOs of E. salmonophloia, E. lesouefii and E. astringens , however E. torquata was torquatone chemotype (33.41% to 44.78%). In general, the aridity increased the extraction yield of EO. Higher temperature and lower rainfall conditions enhanced the production of key compounds such as, 1,8-cineole and ɑ-pinene, however, it decreases others compounds like spathulenol and viridiflorol. A notable antimicrobial activity was observed against all microbial strains tested, demonstrating both microbicidal and microbiostatic effects, particularly against Escherichia coli , Serratia marcescens , and Candida tropicalis . The EOs derived from the studied Eucalyptus species represent a valuable source of bioactive compounds, including 1,8-cineole, ɑ-pinene, spathulenol, and β-eudesmol. These compounds contribute to the oils’ significant antimicrobial efficacy, offering the additional advantage of being a natural product. Conclusion: Our findings reinforce the notion that environmental factors may serve as a limiting factor in the production and availability of Eucalyptus EO for medicinal and industrial applications.

Chronic myeloid leukemia (CML) is a hematological malignancy driven by the BCR:ABL1 fusion gene. Oxidative stress is implicated in CML progression and treatment resistance. Glutathione peroxidase (GPX1), a key antioxidant enzyme, helps modulate oxidative stress. Genetic variations in the GPX1 gene may alter enzyme function and affect disease risk or treatment response. The o bjective of this article is to investigate the association of GPX1 single nucleotide polymorphisms (SNPs) rs2107819200, and rs1575633487 with CML altering susceptibility and response to tyrosine kinase inhibitor (TKI) treatment in Iraqi patients. A case-control study was conducted including 120 CML patients (20 newly diagnosed and 100 under TKI treatments), who were diagnosed based on detection of the BCR:ABL1 fusion gene by reverse transcription polymerase chain reaction (RT-PCR), and 60 healthy controls. Genomic DNA was extracted from peripheral blood and genotyped for the two SNPs rs2107819200 and rs1575633487 using conventional PCR followed by Sanger sequencing. Statistical analyses were performed, by calculating the odds ratio (OR) with a 95% confidence interval (CI) and P-value, to assess genotype frequencies and the associations with susceptibility of CML and treatment status. In the overall analysis, no significant association was found between both SNP and general CML susceptibility. However, subgroup analysis revealed a strong association between the rs1575633487 TG genotype and newly diagnosed disease (45%) compared to treated patients (8%) (OR = 11.3; 95% CI: 2.54–50.5; P = 0.001). Similarly, for rs2107819200, the CG genotype was significantly more frequent in newly diagnosed patients (25%) versus treated patients (11%) (OR = 3.00; 95% CI: 1.66–13.8; P = 0.001). The CC genotype, while most prev a lent overall, appeared more commonly in treated patients (79%) than in newly diagnosed patients (55%), suggesting possible genotype shifts with therapy. While no associations were found between these two GPX1 polymorphisms and general CML risk, both rs1575633487 TG and rs2107819200 CG genotypes were significantly associated with newly diagnosed disease, suggesting a potential role in early-phase pathogenesis or oxidative stress regulation. These findings support their utility as candidate biomarkers for early disease status or therapeutic monitoring and warrant further validation through large-scale, ethnically diverse studies and functional analyses.