Global Impact Journal: Advances in Microbiology

Prevalence and Genotyping of Human Papillomavirus in Oral Squamous Cell Carcinoma, Oral Potentially Malignant Disorders, and Healthy Oral Mucosa: A Cross-Sectional Study

2026-08-27T08:15:30+00:00

Background and Objectives: This study aimed to detect and genotype human papillomavirus (HPV) in tissues from oral squamous cell carcinoma (OSCC), oral potentially malignant disorders (OPMD), and healthy individuals. Materials and Methods: The study included 60 patients (31 men and 29 women; median age 60 years, IQR 41.5–69.8) admitted to the Department of Dental, Oral and Maxillofacial Surgery, Medical University of Sofia. Patients were divided into three groups: healthy oral mucosa (n = 20), OPMD (n = 20), and OSCC (n = 20). HPV was tested using punch biopsies with nested PCR and chip technology. Results: Low-risk HPV was found in four (20%) healthy individuals (types 6/11, 43), seven (35%) OPMD patients (types 6/11, 42, 43), and eleven (55%) OSCC patients (types 6/11, 42, 43). Pairwise comparison showed a significant difference in HPV positivity between healthy individuals and OSCC patients (p = 0.022). Among all HPV-positive OPMDs, the virus was detected in two leukoplakia cases (28.6%), three lichen planus cases (42.9%), one lichenoid lesion case (14.3%), and one proliferative verrucous leukoplakia case (14.3%). According to binary logistic regression, OSCC patients were 4.9 times more likely to be HPV-positive compared to healthy individuals (p = 0.027). Conclusions: HPV infection may play a potential role in the pathogenesis of OPMD and OSCC.

Optimization of IAA Production by Halotolerant Vreelandella titanicae J113 Through Fermentation Process Engineering with Response Surface Methodology

2026-08-27T07:03:58+00:00

Soil salinization is a significant environmental factor limiting agricultural production. Developing salt–alkali-tolerant microbial resources is important for the improvement of saline–alkali land. Plant growth-promoting rhizobacteria stimulate crop growth by producing the plant growth hormone indole-3-acetic acid (IAA), but their fermentation process under salt stress still needs optimization. Single-factor experiments and response surface methodology (RSM) were used to systematically optimize the fermentation conditions of the salt–alkali-tolerant Vreelandella titanicae J113. Key influencing factors were screened using the single-factor experiment design, and optimal process parameters were determined using the Box–Behnken design. IAA production and cell biomass were used as evaluation indicators to study the interactions of carbon sources, nitrogen sources, inorganic salts, temperature, cultivation time, and inoculum size. The optimal fermentation process was obtained: starch concentration 17.5 g/L, NaCl concentration 32.5 g/L, yeast extract 5 g/L, cultivation temperature 30 ^◦C, inoculum size 3%, and cultivation time 144 h. After optimization, IAA production reached 23.02 μg/mL, an increase of 115% compared with before
optimization. Salt stress experiments showed that the strain could still maintain high IAA production under 3% NaCl, demonstrating good salt tolerance. Maize seed germination experiments demonstrated that the optimized fermentation broth significantly promoted seed germination and seedling growth under salt stress conditions, with root length, fibrous root number, and fresh weight increasing by 61–86%, 137–200%, and 25–57%, respectively, compared to the control group. This study established an efficient IAA fermentation process for the salt–alkali-tolerant Vreelandella titanicae J113, providing technical support for developing microbial plant growth regulators suitable for saline–alkali land. The optimized strain exhibits excellent growth-promoting potential under salt stress conditions, offering favorable application prospects.

Faecal Microbiota Transplantation in IL-10 Knockout Mice Reverses Increased Susceptibility to Pseudomonas aeruginosa Lung Infection

2026-05-20T04:42:42+00:00

Differences in the gut microbiota are directly reflected in lung–gut axis crosstalk, which may increase susceptibility to pulmonary infections, such as those caused by the bacterium Pseudomonas aeruginosa. Deficiency of the cytokine IL-10 leads to gut inflammation, and this pro-inflammatory environment is partly due to changes in the gut microbiota. To better understand the effects of IL-10 deficiency on the gut microbiota, the intestinal microbial composition of IL-10 KO mice was assessed, and an increase in the phyla Bacteroidetes and Proteobacteria and a decrease in the phylum Firmicutes were observed in the faeces compared with the wild-type group (WT). Additionally, IL-10 KO mice had a higher pro-inflammatory immunostimulatory caecal content. Furthermore, it was found that heterologous faecal microbiota transplantation (FMT) between groups reversed this gut imbalance. IL-10 KO mice showed greater susceptibility to acute pulmonary infection by P. aeruginosa, with a higher recovery of viable bacteria in the lung and spleen, greater tissue damage and increased expression of genes encoding pro-inflammatory cytokines in the lungs. This greater susceptibility was reversed after FMT. Taken together, these results demonstrate the role of endogenous IL-10 in the gut microbiota constitution and its importance in the pulmonary immune response against P. aeruginosa infection.

Bioactivity of Pod and Seed Extracts from Leucaena leucocephala, Prosopis laevigata, and Pithecellobium dulce Collected in Oaxaca, Mexico

2026-08-27T07:25:33+00:00

Guaje (Leucaena leucocephala), mezquite (Prosopis laevigata), and guamuchil (Pithecellobium dulce) are leguminous trees distributed throughout southeastern Mexico. Their pods and seeds constitute the main agroecological residues and represent a natural source of secondary metabolites with high biotechnological potential. The aim of this study was to determine the chemical composition, antimicrobial and antioxidant activities, and toxicity of the pods and seeds of L. leucocephala, P. laevigata, and P. dulce. It was found that pod extracts contained higher concentrations of phenolic compounds, flavonoids, and terpenes than seed extracts. Antimicrobial assays showed inhibition zones ranging from 8.1–14.7 mm (E. coli), 8.8–15.1 mm (S. aureus), 11.3–15.4 mm (E. faecalis), 8.9–24.1 mm (C. albicans), and 8.5–22.6 mm (C. krusei). The ethyl acetate (AVPD) and ethanolic (EVPD) extracts from P. dulce pods showed the highest antimicrobial activity, with MIC values ranging from 0.03 to 0.15 mg/mL, MBC values of 0.07 mg/mL (S. aureus and E. faecalis), and MFC values of 1.25 mg/mL (C. albicans) and 0.62 mg/mL (C. krusei). Antioxidant activity was higher in pod extracts, with AVPD and EVPD showing IC₅₀ values of 0.257 and 0.320 mg/mL, respectively. Consistently, EVPD exhibited the highest phenolic content (133.24 mg GAE/g) and flavonoid content (50.90 mg QE/g), followed by AVPD (87.29 mg GAE/g and 42.40 mg QE/g, respectively). The results indicate that pod extracts of L. leucocephala and P. dulce contain secondary metabolites with broad antimicrobial and antioxidant potential and low toxicity.

Engineering Escherichia coli for Aromatic Compound Biosynthesis: Integrating Metabolic Engineering and Synthetic Biology

2026-08-27T06:42:47+00:00

Aromatic compounds derived from the shikimate (SHK) pathway constitute a diverse class of high-value molecules with applications in the pharmaceutical, food, cosmetic, and chemical industries. In microbial systems, particularly Escherichia coli, this pathway links central carbon metabolism (CCM) to the biosynthesis of L-tyrosine (L-Tyr), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp), which serve as key precursors for structurally diverse metabolites. Over the past decades, metabolic engineering strategies have focused on increasing precursor availability, relieving feedback inhibition, and eliminating competing pathways. More recently, advances in synthetic biology have enabled dynamic control of metabolic flux through pathway modularization, genome-scale interventions, and regulatory circuit design. In this review, we provide a comprehensive overview of the engineering of E. coli for aromatic compound biosynthesis, highlighting key developments in the optimization of the SHK pathway and its major metabolic nodes chorismate, L-Tyr, L-Phe, and L-Trp. We examine emerging approaches, including CRISPR-based regulation, biosensor-driven dynamic control, membrane engineering, and synthetic microbial consortia. Despite significant progress, challenges related to pathway regulation, cofactor balance, metabolic burden, and product toxicity remain critical bottlenecks. Integrating metabolic engineering with synthetic biology is driving the development of programmable, scalable microbial platforms for the efficient bioproduction of aromatic compounds.