Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology最新文献

Water vending machines are widely utilised in various locations, including workplaces, universities and urban areas due to their convenience and accessibility. However, the microbial quality of the water dispensed from these machines, particularly in residential colleges, has not been thoroughly studied. This study aims to analyse the physicochemical and microbiological quality of drinking water collected from water vending machines located in 14 residential colleges around Universiti Malaya, Kuala Lumpur. Our study revealed that all drinking water samples met WHO acceptable limits for pH, TDS and electrical conductivity. However, dissolved oxygen and free chlorine levels were slightly below the acceptable range. No faecal contamination was detected in the drinking water samples, as indicated by the absence of enterococci and coliform bacteria, including faecal coliforms. Nevertheless, Gram-negative non-coliform bacteria were identified in water samples from 11 residential colleges. The identified bacteria included Pseudomonas spp., Acinetobacter spp., Bosea sp., Stenotrophomonas sp., Achromobacter sp., Roseatels sp. and Cupriavidus sp. Using CLSI guidelines as the standard, antibiotic sensitivity tests showed that all bacterial isolates were resistant to penicillin G (100%), while most were susceptible to ofloxacin (> 80%). Notably, Pseudomonas spp., Acinetobacter spp., Stenotrophomonas sp., Achromobacter sp. and Cupriavidus sp. were identified as multidrug-resistant bacteria, showing resistance to three or more categories of antimicrobial agents tested in this study. The biofilm assay confirmed that Bosea sp., Roseateles sp. and Acinetobacter sp. possess biofilm formation capacity. Overall, this study highlights that while the water from vending machines generally meets physicochemical standards and is free of faecal contamination, multidrug-resistant Gram-negative bacteria are still prevalent. Although these bacteria may not pose immediate health risks upon consumption, their presence poses long-term risks due to biofilm accumulation, resistance gene transfer and poor maintenance. This underscores the need for proper maintenance measures of water vending machines, including regular cleaning and effective disinfection, to ensure the microbial safety of drinking water.

Enset (Ensete ventricosum) serves as a staple or co-staple food crop for over 20 million people in Southern, Southwestern, and Central Ethiopia, significantly contributing to regional food security. Despite its importance, food safety concerns surrounding its fermented product, kocho, remain largely unaddressed. This study aimed to evaluate the food safety of traditionally fermented kocho samples collected from districts in the Gamo Zone using a cross-sectional study design. The microbial community composition was analyzed through both culture-based methods and PacBio sequencing. The physicochemical properties exhibited slight variations in acidity, fermentation stage, and moisture content among samples from different districts. Culture-based microbiological analysis indicated total viable aerobic counts ranging from 5.76 to 7.13 log CFU/g, yeast and mold counts between 5.20 to 8.53 log CFU/g, and Enterobacteriaceae counts ranging from 5.03 to 6.13 log CFU/g. Metagenomic analysis revealed that Proteobacteria and Firmicutes were the predominant phyla, with Acetobacter and Lactobacillus as the most prevalent genera. Notably, potential pathogenic bacteria, including Klebsiella pneumoniae, Klebsiella terrigena, Dysgonomonas capnocytophagoides, and Clostridium paraputrificum, were identified. The coexistence of beneficial microorganisms and potential pathogens underscores the urgent need for enhanced food safety measures in the traditional production of kocho.

This study focused on the synthesis of silver nanoparticles (AgNPs) using the aqueous extract of Dioscorea alata leaves, followed by their detailed characterisation using ultraviolet–visible (UV–Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), zeta potential analysis, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The AgNPs exhibited spherical shapes with sizes ranging from 50 to 106 nm, as confirmed by TEM and DLS, and a crystalline face-centred cubic structure as revealed by XRD analysis. The applicability of the synthesised nanoparticles for controlling bacteria of high interest in tropical agricultural environments (Xanthomonas citri subsp. citri, Paracidovorax citrulli, and Pectobacterium brasiliense) was evaluated in vitro, revealing that AgNPs inhibited the growth of the three bacterial pathogens in a dose-dependent manner. Our findings demonstrate that AgNPs synthesised from D. alata leaves extract offer a promising, sustainable alternative for managing bacterial diseases affecting important crops, fostering the prospect of green synthesis as an environmentally friendly approach to support agricultural productivity and disease control.

Bovine mastitis is an important economic and public health issue of the milk sector which leads to reduction in milk-production, quality, and increased culling rates. The main causative is Staphylococcus aureus because this microorganism has ability to produce the virulence factors like hemolysins. However, these factors enhance defense against host immune system and produce antibiotic resistance because the antibiotic agents are frequently used and also the antibiotic residues may be remained in the milk which is a major publish health concern. This issue can be counteracted by alternative such as probiotics. Therefore, this review focuses on the utilization of probiotics against Staphylococcus aureus virulence factors and product the mammary glands from commensal and colonizing to disease. it highlights how probiotics interfere against pathogenesis such as; biofilm production, hemolysins, adhesion, invasion into mammary epithelial cells, and quorum-sensing signaling, all of which are pivotal for colonization. Ultimately, probiotics proves advantageous in treating and preventing bovine mastitis, potentially contributing to an extended disease-free period and reduce the frequent use of antibiotics. The aims of this study are to systematically summarize the mechanisms by which probiotics counteract Staphylococcus aureus virulence factors, evaluate the efficacy of probiotics in the prevention and treatment of bovine mastitis and provide a theoretical basis for the practical application of probiotics as an alternative to antibiotics in the dairy industry.

Graphical Abstract

Lumpy skin disease (LSD) is a transboundary viral infection of cattle caused by the lumpy skin disease virus (LSDV), a member of the Poxviridae family in genus Capripox. In Pakistan, after its first outbreak in 2021, the disease caused significant financial damage to the livestock sector. The current study was designed to investigate LSDV and its histopathological lesions in the LSDV infected cattle population of the Lower Chitral district of Khyber Pakhtunkhwa, Pakistan. Overall, 384 samples were collected, including nasal swabs, blood, and skin nodules from LSDV suspected cattle. These samples were subjected to Polymerase Chain Reaction (PCR) by targeting the p32 and ORF036 coding regions in the virus. Out of 384 samples, 71 were positive for both coding regions. The phylogenetic analysis revealed that virus strains from neighboring countries shared a common cluster with PQ067260 from Chitral, indicating the close genetic relationship between them. Seasonal analysis showed the highest prevalence of LSDV in summer (23%). Additionally, our research identified that the virus is more likely to infect females (32%) than males, animals younger than one year (25%) than older than one year, and cross cattle breeds (22%) than other breeds. Our results also found variations in disease prevalence across different regions of Chitral. Subsequent SPSS analysis demonstrated that gender (< 0.0001), age (0.0002), season (0.0004), and breed (< 0.0001) had a significant impact on the prevalence of the disease. Histopathology indicated presence of eosinophils, vacuolar degeneration, necrosis, and leukocytic infiltration, in diseased tissues. Further research needs to be conducted on the isolation of the field virus and local vaccine development to control this highly contagious and economically important viral disease in the country.

Biofortification of plants using Plant Growth-Promoting Bacteria (PGPB) represents a promising strategy in sustainable agriculture. This paper discusses the PGPB action in the context of their impact on phenolic compounds biosynthesis and the prospects for their application in agriculture. So far, no review article has summarized the significance of PGPB in increasing phenolic compounds in plants. PGPB, such as Pseudomonas, Bacillus, and Azospirillum, promote plant growth by producing phytohormones, enhancing nutrient availability, and stimulating the biosynthesis of secondary metabolites through the activation of Induced Systemic Resistance (ISR). The activation of ISR (Induced Systemic Resistance) by PGPB stimulates the phenylpropanoid pathway, which is the primary biosynthetic route for polyphenolic compounds, including phenolic acids and flavonoids, in plants. Studies indicate that PGPB may increase phenolic compounds content from 9% to over 200%, while simultaneously improving antioxidant activity. Through the secretion of phenolic compounds, PGPB also can mitigate abiotic stresses such as drought, salinity and heavy metal contamination. Among the phenolic compounds whose production in various plant parts can be stimulated by PGPB are flavonoids, such as quercetin, procyanidin B1, EGCG, and catechin, and phenolic acids, including caffeic acid, ferulic acid, and chlorogenic acid. Advancements in omics research will enable a more precise investigation of the impact of PGPB, including endophytic bacteria, on the biosynthetic pathways of phenolic compounds. In the future, this will translate into improved efficiency in stimulating the production of these compounds. Nevertheless, even now, the use of PGPB offers a sustainable alternative to genetic engineering, reducing reliance on chemical inputs in agriculture.

Soil microbes play a crucial role in biogeochemical cycling and are a valuable resource for discovering novel taxa with environmental applications. This study aimed to explore rhizospheric microbial diversity for potential biotechnological and ecological relevance. The taxonomic placement of strain NCCP-28^T was determined through polyphasic characterization. Isolated from the rhizospheric soil of a legume, strain NCCP-28^T exhibited Gram-positive, motile, aerobic, and rod-shaped cells that produced endospores. Additionally, it tested negative for oxidase but positive for catalase. The cells were grown at a pH range of 6‒10 (optimum of 7.0) or over a 20‒45 °C range (optimum of 30 °C) and could thrive in 0‒10% NaCl (optimum of 1% w/v). Strain NCCP-28^T also tolerated heavy metals, including chromium (450 ppm), copper (300 ppm), and zinc (550 ppm). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain NCCP-28^T is closely related to Niallia nealsonii DSM 15077^T, exhibiting 97.79% sequence similarity. However, strain NCCP-28^T formed a distinct and well-supported clade in the phylogenomic tree, clearly separating it from its nearest relatives. This distinction was further substantiated by whole-genome comparisons, including digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values, which collectively support the classification of strain NCCP-28^T as a novel species within the genus Niallia. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and unknown amino phospholipids were included in the polar lipid profile of the strain. The predominant fatty acids (> 10%) included anteiso-C_15:0, iso-C_15:0, and C_16:0. However, MK-7 and MK-8 are respiratory quinones. Strain NCCP-28^T classified as a distinct species within the genus Niallia based on its phylogenetic, phenotypic, chemotaxonomic and genotypic traits and was designated the type strain NCCP-28^T (CGMCC1.62018^T = GDMCC1.4390^T), which was named Niallia pakistanensis sp. nov. These findings emphasize microbial systematics, environmental microbiology, and functional genomics. The ecological origin, genomic insights, and adaptive traits of strain NCCP-28^T support its potential application in environmental sustainability and microbial biotechnology.

Pure mycelium materials (PMMs) are a sustainable alternative for a range of non-sustainable products such as textile, leather and meat. So far, properties of PMMs of different fungi have not been systematically assessed. Here, 11 mushroom-forming fungi, of which 10 isolated from nature, were grown in liquid shaken cultures. Schizophyllum commune, Ganoderma resinaceum, and Trametes betulina produced the highest biomass (8.62, 7.58, and 6.94 g L⁻¹, respectively) when grown as mono-cultures in malt extract broth. Therefore, PMM properties were determined of mono-cultures, mixed-cultures, and co-cultures of these three fungi. The maximum tensile strength of the PMMs of the mono-cultures, mixed-cultures, and co-cultures of S. commune, G. resinaceum, and T. betulina did not show significant differences and ranged between 4.5 to 6.3 MPa. The elongation at break of the different PMMs was generally low and ranged between 0.8 and 1.6%. The Young’s modulus of the PMMs also showed relatively small differences ranging between 408 and 710 MPa. The G. resinaceum PMMs showed the lowest water uptake, while the S. commune mono-, mixed- and co-culture PMMs showed the highest water contact angle. Together, it is concluded that the properties of the mono-, mixed-, and co-cultures of S. commune, G. resinaceum, and T. betulina are not very different. These data suggest that the species of mushroom forming fungi does not have a major impact on PMM properties of biomass from liquid shaken cultures.

Although rhizosphere microbiota play pivotal roles in the adaptation of blueberry to acidic soils, their adaptation to contrasting soil types remains unexplored. Herein, rhizosphere soils from modified paddy and red soil plantations were analysed via 16S sequencing, core microbiome identification and KEGG pathway mapping. These analyses revealed that modified paddy soil exhibited higher α-diversity (Shannon index: p = 0.037) than red soil. The analysis of β-diversity confirmed significant divergence between the red soil rhizosphere communities and their bulk soil counterparts (p < 0.05), whereas the modified paddy soil communities remained structurally stable. Core OTU analysis identified 96 shared taxa (18.2% of total OTUs) across soils. The red soil rhizosphere microbes prioritised energy-yielding pathways (e.g. glucose-1-phosphate and sucrose degradation) that are critical for fruit cell wall synthesis. The modified paddy soil communities favoured glycogen degradation, reflecting the existence of resource competition under acidic stress. This study aimed to characterize the rhizosphere microbiota of blueberries cultivated in two distinct acidic soil types (modified paddy soil and red soil), identify core microbiome members, and elucidate their functional adaptations, thereby emphasising the importance of tailored microbial management during soil modification strategies (e.g. paddy soil acidification) to meet plant growth requirements.

Paenibacillus peoriae, a member of the genus Paenibacillus, is a gram-positive, spore-forming bacterium closely related to Paenibacillus polymyxa. This species exhibits a wide range of metabolic capabilities, enabling it to thrive in diverse environments and produce bioactive compounds with potential applications in agriculture and biotechnology. Recent studies reveal its capacity to produce biocontrol agents, such as fusaricidins, polymyxins, and tridecaptins, along with hydrolytic enzymes that inhibit phytopathogens including Fusarium, Rhizoctonia, Alternaria, Botrytis, Phytophthora (Oomycota phylum). Additionally, this species was capable of directly promoting plant growth through various mechanisms, such as the production of indole-3-acetic acid (IAA), nitrogen fixation, phosphorus solubilization, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. P. peoriae strains also produce enzymes like cellulase and protease, essential for various industrial applications, and extracellular polysaccharides (EPS) demonstrating potential in bioremediation and heavy metal removal. Recent studies highlight its ability to synthesize 2,3-butanediol, a valuable industrial compound, further establishing its biotechnological significance. This review consolidates current knowledge on the genome, metabolites, and applications of P. peoriae while identifying research gaps and future directions for maximizing its potential in sustainable agriculture and biotechnology.