This research project delves into the multifaceted dynamics of Mycobacterium tuberculosis (M.tb) endocarditis, a significant yet uncommon manifestation of tuberculosis (TB). Beginning with an overview of M.tb and the global challenges posed by TB, we navigate through the bacterium's evolution, transmission modes, and the intricate host immune response. The pathology and pathophysiology of M.tb endocarditis are explored, emphasizing its complexities and the host's efforts to contain the pathogen. The study extends to atypical mycobacterial endocarditis, highlighting the emergence of species like M.chimaera, M.fortuitum, and M.chelonae, with a focus on their association with life-threatening mycobacterial endocarditis. Clinical presentations and complications of M.tb endocarditis are detailed, addressing challenges in diagnosis, drug-resistant, co-infections with Human Immunodeficiency Virus (HIV), and potential sepsis. The research underscores the need for a deeper understanding of M.tb endocarditis to enhance prevention, diagnosis, and treatment strategies. Examining the genetic and environmental factors influencing M.tb endocarditis, the study discusses the interplay of immune-related genes, environmental conditions, and predispositions contributing to infection susceptibility. Despite challenges in treatment due to its rarity, the research highlights current protocols, surgical interventions, and promising pharmaceutical developments. Lastly, unraveling these intricate factors is crucial for refining strategies and conducting large-scale trials to address this global health threat effectively.

Background: Urinary tract infections (UTIs) are among the most common infections and can cause numerous complications of the renal system. This study aimed to assess the prevalence of uropathogens and their antibiotic susceptibility patterns in Al-Madinah Al-Munawarah, Saudi Arabia.

Methods: Data was collected from patients with UTIs presented at King Fahad General Hospital in Al-Madinah Al-Munawarah, Saudi Arabia. In this retrospective cross-sectional study, UTI microbial-causing agents and antimicrobial resistance profiles identified using automated systems, Phoenix and VITEK2, were collected between July 2022 and June 2023. In addition, minimal demographic data, including date of collection and sex and age of patients were collected and analyzed using Chi-square test.

Results: The study included 1394 patients positive for UTI, comprising 50.57% males and 49.43% females (chi-square goodness-of-fit, p > 0.999). Microbial identification and antimicrobial susceptibility tests were performed on UTI-positive cultures. Among UTIs, mono-infection, caused by a single pathogen, was the most prevalent, accounting for 88.16% of cases, whereas poly-infection (caused by multiple pathogens) presented at 11.9%. The most prevalent UTIs' pathogens were E. coli (30.59%), followed by Klebsiella pneumoniae (21.40%), Enterococcus faecalis (8.46%), Pseudomonas aeruginosa (7.81%), Streptococcus agalactiae (6.35%), Enterococcus faecium (3.01%), Proteus mirabilis (3.01%), Enterobacter cloacae (2.52%), Candida sp. (2.44%), Acinetobacter calcoaceticus-baumannii (1.95%), Staphylococcus aureus (1.79%), and Enterobacter aerogenes (1.30%). The most dominant pathogens that coexisted with other uropathogens to cause UTIs were K. pneumoniae and P. mirabilis (9.32%, chi-square 5.550, p = 0.018), K. pneumoniae and P. aeruginosa (8.07%, chi-square 6.285, p = 0.012), K. pneumoniae and E. faecalis (7.45%, chi-square 5.785, p = 0.016), Candida sp. and Enterococcus faecium (4.97%, chi-square 9.176, p = 0.002, and Candida sp. and Acinetobacter calcoaceticus-baumannii (3.11%, chi-square 4.312, p=0.038)). Among the uropathogens, gram-negative pathogens showed resistance to most of the tested antimicrobials (ampicillins, cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, aztreonam, and nitrofurantoin). High rates of resistance were identified to cephalosporins, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole.

Conclusion: This study reported UT mono-infection and poly-infection in Al-Madinah Al-Munawarah, Saudi Arabia, with a predominant representation from gram-negative bacteria, Enterobacteriaceae. Most of the UT microbial strains showed a highly resistant profile.

Chitosan seems to be an innovative biological material potentially utilized as a nanoparticle carrier for drug delivery, which could be low toxic, biocompatible, and easy to prepare. Chitosan nanoparticles have been employed in gene delivery. As a type of multifunctional adjuvant, chitosan nanoparticles could activate the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway to induce cell protection and/or proliferation via the modulation of autophagy within dendritic cells. In general, adjuvants may improve the innate and/or adaptive immune responses to a vaccine antigen by facilitating the antigen presentation of antigen presenting cells such as dendritic cells. The choice of a suitable adjuvant has become vital for improved safety and/or expanded application of vaccines. Fortunately, chitosan nanoparticles could be designed to target the dendritic cells to be enhanced by its adjuvant effect and for stimulating robust immune responses. Therefore, chitosan nanoparticles may be a good immune stimulant with encouraging properties for the development of superior vaccine delivery. Indeed, vaccines could play a key role in human health. In this review, we summarize the concept and/or recent progress in the field of chitosan nanoparticles, providing a valuable resource for investigating the molecular mechanisms of chitosan for the development of a greater vaccine.