Search Results (4)

Background: Culture-negative vertebral osteomyelitis presents a significant diagnostic challenge. Neisseria sicca (N. sicca) is a typically benign commensal organism of the upper respiratory tract that rarely causes invasive infections, warranting cautious interpretation if isolated in a single positive culture. This case study details a 62-year-old male diagnosed with vertebral osteomyelitis caused by N. sicca, examining diagnostic challenges, treatment, and outcomes. Methods: We conducted a comprehensive search on MEDLINE using the keywords “Neisseria sicca”, “osteomyelitis”, and “diskitis”. An additional search excluding N. gonorrhea and N. meningitidis was also performed, revealing a total of four cases of N. sicca osteomyelitis in the literature. Results: A 62-year-old male with a history of hypertension, type 2 diabetes, atrial fibrillation, and previous L5-S1 spinal fusion presented with fever and back pain in May 2023. Initial imaging revealed T8-T9 vertebral osteomyelitis. Despite a six-week course of IV daptomycin, his symptoms worsened, prompting further evaluation. A CT-guided biopsy with comprehensive testing, including histopathology and microbial cultures, initially identified N. sicca. Due to its rarity, additional biopsies were conducted, confirming the infection. IV ceftriaxone was initiated, leading to significant pain improvement, and a subsequent MRI showed near resolution. The patient transitioned to oral cefuroxime, with follow-up confirming complete infection resolution by December 2023. Conclusions: This case underscores the importance of a structured diagnostic approach in culture-negative vertebral osteomyelitis to differentiate between commensal contamination and true infection. Repeated positive cultures of N. sicca from a sterile site confirmed its role as the causative agent. Early identification and targeted antibiotic therapy are critical to improving outcomes in rare cases of N. sicca vertebral osteomyelitis. Full article

Metal-based nanoparticles with antimicrobial activity are gaining a lot of attention in recent years due to the increased antibiotics resistance. The development and the pathogenesis of oral diseases are usually associated with the formation of bacteria biofilms on the surfaces; therefore, it is crucial to investigate the materials and their properties that would reduce bacterial attachment and biofilm formation. This work provides a systematic investigation of the physical-chemical properties and the antibacterial activity of TiO₂ thin films decorated by Ag and Au nanoparticles (NP) against Veillonella parvula and Neisseria sicca species associated with oral diseases. TiO₂ thin films were formed using reactive magnetron sputtering by obtaining as-deposited amorphous and crystalline TiO₂ thin films after annealing. Au and Ag NP were formed using a two-step process: magnetron sputtering of thin metal films and solid-state dewetting. The surface properties and crystallographic nature of TiO₂/NP structures were investigated by SEM, XPS, XRD, and optical microscopy. It was found that the higher thickness of Au and Ag thin films results in the formation of the enlarged NPs and increased distance between them, influencing the antibacterial activity of the formed structures. TiO₂ surface with AgNP exhibited higher antibacterial efficiency than Au nanostructured titania surfaces and effectively reduced the concentration of the bacteria. The process of the observation and identification of the presence of bacteria using the deep learning technique was realized. Full article

Bacteria of the Neisseria genus are Gram-negative diplococci including both pathogenic and commensal species. We focused on pathogenic Neisseria gonorrhoeae and commensal Neisseria sicca. We have demonstrated that not only N. gonorrhoeae, but also N. sicca induce the secretion of pro-inflammatory cytokines IL-6, TNF-α, and chemokines CXCL8 and CCL20 by infected epithelial cells. However, N. sicca triggers a lesser effect than does N. gonorrhoeae. Furthermore, N. gonorrhoeae and N. sicca invoke distinct effects on the expression of genes (JUNB, FOSB, NFKB1, NFKBIA) encoding protein components of AP-1 and NF-κB transcription factors. We have also shown that the infection of epithelial cells by N. gonorrhoeae leads to significant overexpression of the long non-coding RNAs (lncRNAs), including MALAT1, ERICD, and RP11-510N19.5. This effect was not identified for N. sicca. In conclusion, data on the expression of lncRNAs and cytokine secretion in response to Neisseria spp. exposure indicate new directions for research on Neisseria-host interactions and can provide further insights into virulence of not only pathogenic, but also commensal Neisseria spp. Full article

Gonorrhea is one of the most common, but still hidden and insidious, sexually transmitted diseases caused by Neisseria gonorrhoeae (gonococci). However, the diagnosis and treatment of gonorrhea are hampered by antigenic variability among gonococci, the lack of acquired immunity, and antimicrobial resistance. Further, strains resistant to cephalosporins, including ceftriaxone, the last line of defense, represent a growing threat, which prompted us to develop gonococci-specific diagnostic antibodies with broad-spectrum binding to gonococci strains to generate gonorrhea-detecting reagents. This study reports the identification of gonococci antibodies via bio-panning on gonococci cells using scFv-phage libraries. Reformatting the lead scFv-phage Clones 1 and 4 to a multivalent scFv1-Fc-scFv4 maxibody increased the sensitivity by up to 20-fold compared to the single scFv-Fc (maxibody) alone. Moreover, the multivalent maxibody showed broader cross-reactivity with clinical isolates and the ceftriaxone antibiotic-resistant World Health Organization (WHO) reference strain L. In contrast, the selected antibodies in the scFv-phage, maxibody, and multivalent maxibody did not bind to N. sicca, N. meningitides, and N. lactamica, suggesting the clinical and pharmaceutical diagnostic value of these selected antibodies for gonorrheal infections. The present study illustrates the advantages and potential application of multivalent maxibodies to develop rapid and sensitive diagnostic reagents for infectious diseases and cancer. Full article