Background: Serratia marcescens (SM) is a Gram-negative pathogen discovered by Italian pharmacist, Bizio, in 1819. According to the literature, S. marcescens is resistant to a wide range of antibiotics, including penicillin, cephalosporin, tetracycline, macrolide, nitrofurantoin, and colistin. We conducted a systematic review of published reports, determined what invasive infections could cause SM, and established the most appropriate antibiotic therapy. Methods: We registered this systematic review on the PROSPERO registry of systematic reviews–meta-analyses before we started our research (registration number CRD42022323159). The online searches of published studies were implemented via MEDLINE, the Cochrane Central Register of Controlled Trials, EBSCO, Scopus, Google Scholar, SCIndex, and the registry of clinical studies of human participants (ClinicalTrials.gov). Results: Our study included 32 published articles (9 case series and 23 case reports). There were 57 individual cases, respectively. The oldest patient was 97 years and the youngest patient was a newborn. S. marcescens was, in most cases, isolated from blood followed by urine and cerebrospinal fluid. In most cases, sensitivity was tested to cotrimoxazole (from 27 isolates, 10 showed resistance) followed by gentamicin (from 26 isolates, 3 showed resistance) as well as amikacin (from 21 isolates, none showed resistance). Patients died from an infection in 21 cases (31%). Conclusions: Treatment of SM infections should include carbapenems or aminoglycosides in combination with third-generation (and eventually fourth-generation) cephalosporin. Cotrimoxazole should be considered in cases of uncomplicated urinary infections.

A serie of novel square pyramidal copper(II) complexes [Cu(L)₂H₂O] (3a–d) with O,O-bidentate ligands [L = ethyl-2-hydroxy-4-aryl-4-oxo-2-butenoate; aryl = 3-methoxyphenyl-2a, (E)-2-phenylvinyl-2b, (E)-2-(4′-hydroxy-3′-methoxyphenyl)vinyl-2c, 3-nitrophenyl-2d, 2-thienyl-2e] were synthesized and characterized by spectral (UV-Vis, IR, ESI-MS and EPR), elemental and X-ray analysis. The antimicrobial activity was estimated by the determination of the minimal inhibitory concentration (MIC) using the broth microdilution method. The most active antibacterial compounds were 3c and 3d, while the best antifungal activity was showed by complexes 3b and 3e. The lowest MIC value (0.048 mg mL⁻¹) was measured for 3c against Proteus mirabilis. The cytotoxic activity was tested using the MTT method on human epithelial carcinoma HeLa cells, human lung carcinoma A549 cells and human colon carcinoma LS174 cells. All complexes showed extremely better cytotoxic activity compared to cisplatin at all tested concentrations. Compound 3d expressed the best activity against all tested cell lines with IC₅₀ values ranging from 7.45 to 7.91 μg mL⁻¹. The type of cell death and the impact on the cell cycle for 3d and 3e were evaluated by flow cytometry. Both compounds induced apoptosis and S phase cell cycle arrest. The interactions between selected complexes (3d and 3e) and CT-DNA or bovine serum albumin (BSA) were investigated by the fluorescence spectroscopic method. Competitive experiments with ethidium bromide (EB) indicated that 3d and 3e have a propensity to displace EB from the EB–DNA complex through intercalation suggesting strong competition with EB [K_sv = (1.4 ± 0.2) and (2.9 ± 0.1) × 10⁴ M⁻¹, respectively]. K_sv values indicate that these complexes bind to DNA covalently and non-covalently. The achieved results in the fluorescence titration of BSA with 3d and 3e [K_a = (2.9 ± 0.2) × 10⁶ and (2.5 ± 0.2) × 10⁵ M, respectively] showed that the fluorescence quenching of BSA is a result of the formation of the 3d– and 3e–BSA complexes. The obtained K_a values are high enough to ensure that a significant amount of 3d and 3e gets transported and distributed through the cells.

The objective of this study was to synthesize seven novel thiourea derivatives of naproxen (8–14), examine the anti-inflammatory activity of the newly synthesized compounds, investigate the cytotoxic potential of both sets of synthesized compounds (1–7 and 8–14), and select the most promising anti-inflammatory and antitumor drug candidates. The results of the in vivo anti-inflammatory study clearly showed that compounds 8 and 9 were capable of decreasing paw edema, as evident from a high percentage of inhibition (44.83% and 49.29%, respectively). In addition, the results of in vitro enzyme inhibition assays demonstrated that neither of the newly synthesized compounds reached 50% inhibition of 5-LOX at concentrations lower than 100 µM. In terms of antitumor potential, derivatives 3 and 8 exhibited strong cytotoxic effects on the HeLa cell line, suggesting the involvement of the extrinsic pathway of apoptosis. According to the overall results obtained for both sets of synthesized molecules, derivatives 4 and 8 can be underlined as molecules with the strongest anti-inflammatory activity, while derivatives 3 and 8 are the most promising cytotoxic agents.