Microbiology and Biotechnology Research: An Overview Vol. 9

Targeted Delivery of Atractylodin via PLGA Nanoparticles Enhances Therapeutic Efficacy in Cholangiocarcinoma

2026-07-15T09:43:37+00:00

Cholangiocarcinoma (CCA) is a major health challenge in the Greater Mekong subregion, particularly in north-eastern Thailand, where chronic infection with the liver fluke Opisthorchis viverrini is a principal cause. Limited treatment options and the absence of reliable early diagnostic tools impede effective CCA management. This study investigated Atractylodes lancea (Thunb.) DC., a plant traditionally used in Thai and East Asian medicine. Atractylodin (ATD)-loaded poly(lactic-co-glycolic acid) nanoparticles (ATD-PLGA NPs) were developed to improve anticancer activity against CCA. The nanoparticles were prepared using a modified nanoprecipitation method and characterised for particle size, surface charge, morphology, encapsulation efficiency, loading capacity, and in vitro drug-release profile. Anticancer activity was evaluated in CL-6 and HuCCT-1 CCA cell lines using MTT cytotoxicity, real-time migration and invasion, and caspase-3/7-mediated apoptosis assays. A CCA xenograft model was established by implanting CL-6 cells into nude mice, and tumour-related gene expression was assessed using quantitative real-time PCR. The nanoparticles had a mean diameter of 229.8 nm and an encapsulation efficiency of 83%, with a biphasic release profile reaching 92% cumulative release over seven days. They selectively reduced CL-6 and HuCCT-1 cell viability, with selectivity indices of 3.53 and 2.61, inhibited migration and invasion by up to 90% within 12 hours, and induced apoptosis in 83% of cells. Micronucleus assays indicated lower mutagenic potential than the positive control. In vivo, ATD-PLGA NPs inhibited tumour growth in a dose-dependent manner and prolonged survival. Gene-expression analysis showed downregulation of pro-tumorigenic and pro-inflammatory factors and upregulation of IL-10. These findings support further evaluation of ATD-PLGA NPs as a targeted nanotherapeutic platform for CCA.

Epidemiology and Associated Risk Factors of Tuberculosis (TB)

2026-07-15T09:49:47+00:00

Worldwide, tuberculosis (TB) remains a major cause of death resulting from infection with Mycobacterium tuberculosis. During the past decade, despite several effective treatment options and preventive strategies, the incidence of TB has increased. The epidemiology of tuberculosis is shaped by dynamic interactions among the bacterium Mycobacterium tuberculosis, host behavioural vulnerabilities, comorbid conditions, environmental determinants, and socioeconomic status. The infectious agent has several critical characteristics, including efficient airborne transmission, the ability to survive within host immune cells, slow replication, latent persistence, and the capacity to develop drug resistance. Collectively, these attributes enable Mycobacterium tuberculosis to infect and persist successfully within human populations. A detailed understanding of TB epidemiology is necessary for the effective implementation of prevention and treatment strategies. Several demographic, medical, behavioural, occupational, and socioeconomic risk factors play important roles in the initiation of infection and the development of active TB disease. Comprehensive knowledge of TB epidemiology and its risk factors can link early diagnosis with effective treatment, help prevent recurrence, and support the development of context-specific policies based on population characteristics. This chapter provides updated TB statistics and a broad overview of associated risk factors. Tobacco use should be rigorously controlled among both healthy individuals and patients with existing medical conditions, as smoking significantly increases the risk of TB infection, disease progression, and poor treatment outcomes. Consequently, public health policies and clinical management strategies should be regularly reviewed and strengthened to improve TB prevention, control, and treatment outcomes. In addition, individuals undergoing immunosuppressive therapy should be systematically evaluated for a history of active or latent TB before treatment is initiated. Early identification and appropriate management of latent or previous TB infection may substantially reduce the risk of TB reactivation and associated complications in immunocompromised patients.

Effect of Propionic Acid and Bee–Carnauba Wax on Purple Passion Fruit Quality and Stability During Ambient Storage

2026-07-15T09:53:15+00:00

This study aimed to determine the effects of different concentrations of propionic acid combined with mixed wax (beeswax and carnauba wax; MW) on the quality and storage life of postharvest purple passion fruit under ambient conditions (25 ± 2 °C and 70%–80% relative humidity). After washing and air-drying, the fruits were dipped for 1 min in propionic acid solutions at concentrations of 0.15%, 0.25%, or 0.35% (v/v), or in 0.2% carbendazim, and were then manually coated with 2.5% MW. After drying, the fruits were stored under the stated ambient conditions for 18 days. Untreated and uncoated fruits served as controls. The assessed parameters included the isolation and identification of microorganisms, total microorganism counts, fruit decay, weight loss, total soluble solids (TSS), total sugars, titratable acidity, and ascorbic acid content, measured at 3-day intervals. Two microorganisms, Fusarium moniliforme var. subglutinans and Fusarium oxysporum Schlecht., were identified. Treatment with 0.25% propionic acid followed by MW coating reduced total microorganism counts, fruit decay, and weight loss during 18 days of storage. This treatment also maintained TSS, total sugars, titratable acidity, and ascorbic acid content throughout the storage period.

Immune Tuberculous Anergy: A Brief Mechanistic Overview

2026-07-21T09:20:42+00:00

Immune tuberculous anergy represents a state of reduced immune responsiveness, expressed clinically by negative delayed-type hypersensitivity responses and functionally by impaired lymphocyte proliferation and altered cytokine production. This chapter provides a mechanistic overview of immune anergy, with emphasis on tuberculosis and related chronic intracellular microbial infections. It summarises immune anergy as a cellular and molecular process involving T- and B-lymphocyte dysfunction, defective co-stimulatory signaling, altered T-cell receptor signaling, reduced interleukin-2 production, increased regulatory influences, and possible impairment of lymphocyte immunometabolism. The chapter also compares anergic B cells, anergic T cells, exhausted T cells, immune tolerance, and immune resilience, noting shared features such as hyporesponsiveness and reduced effector function while recognising differences in induction pathways, transcriptional patterns, and cell fate. A possible protective role of immune anergy in graft acceptance and prevention of autoimmune responses is also described. The manuscript further summarize a local clinical program involving 125 human subjects, including 25 normal controls, 50 tuberculin-positive pulmonary tuberculosis patients, and 50 tuberculin-negative tuberculosis patients aged 25 to 65 years. The evaluated cellular immune parameters included nitro-blue tetrazolium reduction, leukocyte inhibitory factor response, and total T-cell E-rosette counts. In the summarized observations, tuberculin-negative tuberculosis patients showed clinical and cellular evidence of anergy, with reduced adaptive cellular immune activity and preserved innate cellular function compared with tuberculin-positive tuberculosis patients. Overall, the chapter frames immune tuberculous anergy as a clinically relevant form of immune hypo-responsiveness linked to chronic infection, immune tolerance, lymphocyte signalling, and immune-metabolic disturbance.

Antibacterial Activity of African and Asian Zingiberaceae Plant Species against Salmonella typhi

2026-07-21T09:26:43+00:00

Typhoid fever remains an important public health concern in many low- and middle-income settings, and increasing antimicrobial resistance has encouraged further investigation of plant-derived antibacterial agents. This preliminary in vitro study evaluated the antibacterial activity of ethanolic extracts of two Zingiberaceae species in Uganda, the introduced Zingiber officinale and the indigenous Aframomum angustifolium, against Salmonella typhimurium ATCC/3076, a close relative of Salmonella typhi. Rhizomes were extracted using ethanol. The crude extracts were tested using agar well diffusion, while minimum inhibitory concentration and minimum bactericidal concentration were assessed using serially diluted extracts. Ciprofloxacin was used as the positive control. A. angustifolium produced the highest mean inhibition zone of 33.0 ± 0.5 mm, compared with 30.3 ± 2.08 mm for ciprofloxacin and 17.0 ± 3.8 mm for the combined extract, while no bacterial inhibition was observed with Z. officinale. The lowest inhibitory concentrations observed for A. angustifolium and the combined extract were 0.125 g/ml and 0.250 g/ml, respectively. The minimum bactericidal concentration reported for A. angustifolium was 0.5 g/ml. These findings indicate that the ethanolic rhizome extract of A. angustifolium showed measurable in vitro antibacterial activity against the tested Salmonella strain, whereas Z. officinale did not show activity in this assay. Further studies are required to confirm the active constituents, reproducibility, and relevance against clinically confirmed S. Typhi isolates.

Enzymes from Fish-Processing By-products: Recovery, Properties and Commercial Applications

2026-07-23T11:30:56+00:00

Global fish processing generates enormous volumes of by-products, including heads, viscera, skin, bones, scales and trimmings, that historically have been discarded or reduced to low-value fishmeal despite constituting a rich reservoir of catalytically active proteins. This review critically synthesises recent literature on the recovery, biochemical characterisation and commercial exploitation of enzymes derived from fish-processing residues, with particular attention to proteases, lipases, chitinolytic enzymes and collagen-modifying biocatalysts. The composition and enzymatic potential of major by-product fractions are examined alongside conventional and emerging recovery strategies, ranging from salting-out and chromatographic purification to aqueous two-phase partitioning and membrane-based fractionation. Particular emphasis is placed on the cold-adapted kinetic and structural properties that distinguish fish-derived enzymes from their mammalian and microbial counterparts, and on how these properties translate into practical advantages for low-temperature food processing, detergent formulation, leather manufacture and nutraceutical peptide production. The review further considers the use of fish by-products as low-cost fermentation substrates for microbial enzyme production and evaluates techno-economic and environmental assessments of enzymatic valorisation relative to chemical alternatives. Across the literature examined, enzymatic bioconversion consistently emerges as a milder, more selective and more sustainable route to recovering protein hydrolysates, collagen peptides, chitin derivatives and lipid fractions than acid or alkaline hydrolysis, although industrial uptake remains constrained by raw-material variability, enzyme cost and regulatory heterogeneity. The review concludes by identifying priority research directions, summarising the principal contributions of the field, and outlining the methodological limitations inherent to a narrative synthesis of a rapidly evolving literature.

Mycoflora of the Phylloplane and Rhizosphere of Aloe vera: Implications for Plant Growth

2026-07-31T10:16:55+00:00

Plant health is greatly influenced by the presence of various microorganisms in the rhizosphere and phylloplane. The present investigation was conducted to study the spectrum of mycoflora associated with the phylloplane and rhizosphere of Aloe vera and to assess their effects on plant growth parameters and their antagonistic activity against C. gloeosporioides, which causes black spot disease in Aloe vera. For the isolation of phylloplane mycoflora, both healthy and diseased leaves were randomly collected from different plants. During the study, a total of 15 fungal isolates belonging to ten genera were isolated from Aloe vera using the leaf-washing technique for the phylloplane and serial dilution for rhizosphere soil. Among these, fungal species belonging to the genera Aspergillus, Trichoderma, and Penicillium were more abundant. Rhizosphere isolates were further evaluated under pot conditions in a greenhouse to determine their plant-growth-promoting potential. The results revealed significant variation among the isolates in their effects on plant growth. Isolates of Fusarium, Cladosporium, Curvularia, and Alternaria exhibited negative effects, leading to reduced plant height, fresh and dry leaf weights, and root biomass after 15 days of inoculation. The antagonistic potential of beneficial mycoflora from both the phylloplane and rhizosphere was assessed using the dual-culture technique. All beneficial isolates demonstrated strong inhibition (>65%) of pathogen growth on PDA medium. Overall, the study indicates that certain mycoflora associated with the phylloplane and rhizosphere of Aloe vera can promote plant growth and exhibit substantial antagonistic activity against Colletotrichum gloeosporioides.

Phosphate-Solubilising Fungi in Sustainable Agriculture: A Critical Narrative Review of Mechanisms, Agronomic Efficacy, and Evidentiary Limitations

2026-07-31T10:20:33+00:00

Phosphorus is a non-substitutable macronutrient that is frequently unavailable to plants because it becomes fixed in soil as sparingly soluble calcium, iron, and aluminium compounds or is retained within organic matter. Phosphate-solubilising fungi (PSF) have been proposed as an economical and environmentally compatible complement to inorganic phosphorus fertiliser, converting fixed phosphorus into forms that plant roots can absorb through organic acid excretion, proton extrusion, and the enzymatic mineralisation of organic phosphorus. This review critically synthesises the peer-reviewed evidence on the taxonomic diversity, biochemical mechanisms, environmental determinants, and agronomic performance of PSF, moving beyond descriptive cataloguing to evaluate the strength, consistency, and methodological quality of the supporting literature. The evidence indicates that solubilisation capacity is taxonomically concentrated within a small number of genera, most consistently Aspergillus and Penicillium, and that in vitro solubilisation assays reliably demonstrate organic acid production and phosphate release under acidic, carbon-rich culture conditions. Translation of this laboratory capacity into consistent field-scale yield benefit is considerably less certain: multi-year field trials of the most commercially advanced fungal inoculant, Penicillium bilaiae, report modest and variable yield increases that depend strongly on baseline soil phosphorus status, while a formal critical assessment of the wider phosphate-solubilising microorganism literature has questioned whether solubilisation capacity measured in culture reliably predicts plant-available phosphorus release in structured, competitive soil environments. Additional applications in salinity amelioration and heavy-metal immobilisation show mechanistic promise but remain supported chiefly by short-term, single-site, or laboratory-scale studies. Persistent limitations across the literature include correlational rather than causal inference regarding the relationship between medium pH and organic acid production, restricted geographic and taxonomic sampling, and inconsistent reporting of strain identity, formulation, and application rate. Future research priorities include standardised and comparable solubilisation assays, mechanistically linked field trials that measure organic acid production alongside yield outcomes, and genomic characterisation of solubilisation pathways, so as to clarify which fungal traits translate reliably into agronomic benefit rather than remaining confined to laboratory demonstration.

Beyond Virus Elimination: Unveiling Immunity to Hepatitis C Virus and the Immunological Landscape in Coinfection

2026-08-03T09:36:39+00:00

Hepatitis C virus (HCV) establishes chronic infection in most exposed adults, yet a substantial minority resolve infection spontaneously, and this divergence is governed largely by the quality and coordination of the host immune response. The advent of direct-acting antiviral (DAA) therapy has made virological cure achievable for the majority of treated individuals, and in doing so it has reframed the central immunological questions of the field: which responses determine clearance, whether the immune dysfunction of chronic infection is reversible, and how the frequent coinfections of HCV rseshape antiviral immunity. This critical narrative review synthesises evidence on innate sensing and interferon responses, natural killer (NK) cell behaviour, CD4+ and CD8+ T cell immunity, T cell exhaustion, and neutralising antibody responses, and integrates that evidence with the immunology of the principal HCV coinfections, namely human immunodeficiency virus (HIV), hepatitis B virus (HBV) and Schistosoma species. Literature was identified through structured searches of biomedical databases and citation tracking, appraised for methodological quality and consistency, and organised thematically rather than as a study-by-study catalogue. The available evidence indicates that early, broad and sustained CD4+ and CD8+ T cell responses, supported by timely neutralising antibodies and effective innate control, are the most reliable correlates of spontaneous clearance, whereas persistence is characterised by viral escape, failure of CD4+ helper responses and progressive CD8+ T cell exhaustion. Antiviral cure restores innate and several humoral compartments more completely than it reverses established T cell exhaustion, which appears only partially and slowly reversible. Coinfections act predominantly by degrading HCV-specific CD4+ helper responses and by amplifying hepatic inflammation and fibrosis, although the magnitude and mechanisms differ between pathogens and remain incompletely defined. Priorities include longitudinal study of immune reconstitution after cure, mechanistic investigation of coinfection, and the immunological insight required to support a prophylactic vaccine, which remains an unmet global need.