Community-acquired infections caused by Klebsiella pneumoniae (K. pneumoniae) have become a significant global health concern, particularly with the emergence of hypervirulent strains (hvKP). These strains are associated with severe infections, such as pyogenic liver abscesses, even in otherwise healthy individuals. Initially reported in Taiwan in the 1980s, hvKP has now spread worldwide. The pathogenicity of hvKP is attributed to an array of virulence factors that enhance its ability to colonize and evade host immune defenses. Additionally, the convergence of hypervirulence with antibiotic resistance has further complicated treatment strategies. As a member of the ESKAPE group of pathogens, K. pneumoniae exhibits high resistance to multiple antibiotics, posing a challenge for healthcare settings. This review provides a comprehensive overview of hvKP, highlighting its structural and pathogenic differences from classical K. pneumoniae strains, key virulence factors, mechanisms of antibiotic resistance, and the increasing threat of multidrug-resistant hvKP. Lastly, we discuss current treatment guidelines and emerging therapeutic strategies to combat this formidable pathogen.

Introduction: Venetoclax (VCX) is a selective BCL-2 inhibitor approved for the treatment of leukemia and lymphoma. However, the mechanisms of anti-cancer effect of VCX either as a monotherapy or in combination with other chemotherapeutic agents against breast cancer need investigation. Methods: Breast cancer cell lines with different molecular subtypes (MDA-MB-231, MCF-7, and SKBR-3) were treated with different concentrations of VCX for indicated time points. The expression of cell proliferative, apoptotic, and autophagy genes was determined by qRT-PCR and Western blot analyses. In addition, the percentage of MDA-MB-231 cells underwent apoptosis, expressed higher oxidative stress levels, and the changes in the cell cycle phases were determined by flow cytometry. Results: Treatment of human breast cancer cells with increasing concentrations of VCX caused a significant decrease in cells growth and proliferation. This effect was associated with a significant increase in the percentage of apoptotic MDA-MB-231 cells and in the expression of the apoptotic genes, caspase 3, caspase 7, and BAX, with inhibition of anti-apoptotic gene, BCL-2 levels. Induction of apoptosis by VCX treatment induced cell cycle arrest at G0/G1 phase with inhibition of cell proliferator genes, cyclin D1 and E2F1. Furthermore, VCX treatment increased the formation of reactive oxygen species and the expression level of autophagy markers, Beclin 1 and LC3-II. Importantly, these cellular changes by VCX increased the chemo-sensitivity of MDA-MB-231 cells to doxorubicin. Discussion: The present study explores the molecular mechanisms of VCX-mediated inhibitory effects on the growth and proliferation of TNBC MDA-MB-231 cells through the induction of apoptosis, cell cycle arrest, and autophagy. The study also explores the role of BCL-2 as a novel targeted therapy for breast cancer.

The rapid progress of antibiotic resistance among bacteria has prompted serious medical concerns regarding how to manage multidrug-resistant (MDR) bacterial infections. One emerging strategy to combat antibiotic resistance is the use of antimicrobial peptides (AMPs), which are amino acid chains that act as broad-spectrum antimicrobial molecules and are essential parts of the innate immune system in mammals, fungi, and plants. AMPs have unique antibacterial mechanisms that offer benefits over conventional antibiotics in combating drug-resistant bacterial infections. Currently, scientists have conducted multiple studies on AMPs for combating drug-resistant bacterial infections and found that AMPs are a promising alternative to conventional antibiotics. On the other hand, bacteria can develop several tactics to resist and bypass the effect of AMPs. Therefore, it is like a battle between the bacterial community and the AMPs, but who will win? This review provides thorough insights into the development of antibiotic resistance as well as detailed information about AMPs in terms of their history and classification. Furthermore, it addresses the unique antibacterial mechanisms of action of AMPs, how bacteria resist these mechanisms, and how to ensure AMPs win this battle. Finally, it provides updated information about FDA-approved AMPs and those that were still in clinical trials. This review provides vital information for researchers for the development and therapeutic application of novel AMPs for drug-resistant bacterial infections.

Background/Objectives: Drugs exhibiting poor aqueous solubility present a challenge to efficient delivery to the site of action. Spanlastics (a nano, surfactant-based drug delivery system) have emerged as a powerful tool to improve solubility, bioavailability, and delivery to the site of action. This study aimed to better understand factors affecting the physicochemical properties of spanlastics, quantify their effects, and use them to enhance the bioavailability of famotidine (FMT), a model histamine H2 receptor antagonist (BCS class IV). Methods: FMT was incorporated into nano-spanlastics drug delivery system. The ethanol injection method, Box–Behnken design, and mathematical modeling were utilized to fabricate famotidine-loaded nano-spanlastics and optimize the formula. Spanlastics were characterized for their particle size, polydispersity index, zeta potential, entrapment efficiency, drug loading, compatibility of the excipients (using DSC), in vitro drug release, and in vivo pharmacokinetics. Results: Span 60 (the non-ionic surfactant) and tween 60 (the edge activator) gave rise to spanlastics with the best characteristics. The optimal spanlastic formulation exhibited small particle size (<200 nm), appropriate polydispersity index (−30 mV). The entrapment efficiency and drug loading of the optimum formula assured its suitability for hydrophobic drug entrapment as well as practicability for use. DSC assured the compatibility of all formulation components. The drug release manifested a biphasic release pattern, resulting in a fast onset and sustained effect. Spanlastics also showed enhanced C_max, AUC_0–24, and bioavailability. Conclusions: Spanlastics manifested improved FMT dissolution, drug release characteristics, membrane permeation, and pharmacokinetic behavior.

The tyrosine kinase inhibitor sunitinib was recently approved for use against gastrointestinal stromal tumors and advanced renal cell carcinoma. Yet, the protective effect of sunitinib against breast cancer has been poorly investigated. In this study, we investigated the antiproliferative and apoptogenic effects of sunitinib and the possible mechanism involved against the MCF7 human breast cancer cell line. Treatment of MCF7 cells with sunitinib caused concentration-dependent cell growth suppression due to apoptosis. Apoptotic death induced by sunitinib in MCF7 cells was mediated by activation of caspase-3 and p53 mRNA and protein expression and an increase in the percentage of apoptotic cells (40%) as determined by flow cytometry. Apoptosis was associated with a significant inhibition of nuclear factor-kappa B mRNA and protein expression. Mechanistically, blocking of de novo RNA synthesis by actinomycin D significantly inhibited sunitinib-induced expression of p53 mRNA, but not that of caspase-3, indicating involvement of a transcriptional mechanism. This apoptosis-mediated inhibition of MCF7 cell growth was attributed to inhibition of cell cycle-related genes (cyclin D1 and cyclin E2) and arrest of MCF7 cells in the G₂/M phase in the cell cycle, allowing up-regulation of expression of DNA repair genes such as x-ray repair cross-complementing protein 1. In addition, sunitinib exhibited concentration-dependent induction of oxidative stress genes (heme oxygenase 1 and glutathione transferase A1) through the nuclear factor erythroid 2–related factor 2 pathway. These findings lead us to propose that sunitinib suppressed the proliferation of MCF7 cells via cell-cycle arrest and apoptotic- and oxidative stress-mediated pathways.