MicrobiologyOpen最新文献

Fungal colonization is a known carcinogenic accomplice in lung and colon cancer but has not been implicated in breast cancer. Here, we attempt to explore the mechanism behind fungal colonization and carcinogenesis by Malassezia globosa in breast cancer. To begin with, we found an increased abundance of the fungus in tumor tissues of breast cancer patients and the fungal inhibitor Amphotericin-B impeded tumor growth in patient-derived breast cancer xenograft models. On the other hand, Malassezia globosa enhanced the proliferative, migratory, and invasive abilities of breast cancer cells, and facilitated tumor growth in vivo. The positive effect of Malassezia globosa on tumor growth occurred via M2 macrophage polarization resulting in the activation of the pro-inflammatory MBL-C3a-C3aR signaling cascade which was reversed with the knockout of MBL expression. The proliferative, migratory, and invasive capacities of breast cancer cells were enhanced by culture medium from Malassezia globosa-treated THP-1 cells, which were rescued by a C3aR antagonist. In conclusion, Malassezia globosa activates MBL-C3a-C3aR signaling to trigger M2 macrophage polarization, promoting breast cancer progression and this study unravels a novel paradigm for breast cancer treatment.

Pseudomonas aeruginosa is a model organism for biofilm formation research, as it forms biofilms under diverse environmental conditions. At the same time, numerous studies have reported impaired-biofilm formation in clinical isolates; however, the genetic basis of these impairments remains unexplored. In this study, we assessed the ability of P. aeruginosa clinical isolates from a laboratory collection to form biofilms. Among these isolates, three demonstrated biofilm formation impairment. A comparative genomic analysis revealed genetic determinants associated with biofilm formation impairment, including mutations in the pelA and fleQ genes, and psl operon deletion. Interestingly, the identified loss-of-function mutations in regulatory genes involved in biofilm formation did not appear to affect the ability to form biofilms.

Multi-Resistant Bacteria (MRB) is a threatening biomedical problem, whose solution is of paramount importance. Due to the antibiotics resistance there is an emerging need for novel treatment strategies and protocolls. As bacteria tolerance in modern chemotherapeytic agents expands, the introduction of alternative methods is fundamental. The use of High voltage Electric Pulses, through a process known as Irreversible Electroporation (IRE), is an effective alternative bacterial control method. This paper describes a new prototype high voltage nanosecond pulser and validates its effectiveness in the in-vitro growth inhibition of a clinical resistant Staphylococcus aureus strain. Radiofrequency (RF) pulses of 100 ns and 450 ns pulse width and 1 Hz and 1 kHz repetition rate respectively were tested for therapy time in the range of 20–200 s. Increasing the electric field strength up to 11.5 kV/cm and the duration of therapy time up to 200 s results in 3.5 log scale reduction in bacterial cells. Nanosecond electric pulsed fields from our prototype device inhibite S. aureus growth in in-vitro test. It is sugested to test our prototype device in ex-vivo studies and propose a therapeutic protocol for infected skin wounds.

Plasmids play an essential role in the spread of antimicrobial resistance (AMR) by facilitating the horizontal transfer of resistance genes between bacterial environments. However, large-scale investigations into the association between plasmid incompatibility groups (Inc groups) and specific resistance profiles remain limited. In this study, we analyzed 28,047 plasmid sequences from publicly available whole-genome sequencing data sets, identifying incompatibility groups in 11,288 plasmids using in silico replicon typing. Our results revealed that the majority of plasmids harbored a single replicon, while a substantial fraction carried multiple replicons, predominantly two. We evaluated the relationship between plasmid replicon spillovers and their role in the spread of resistance genes. Our results revealed that plasmids with five replicons have a significantly higher resistance potential (60%) compared to plasmids with fewer replicons, decreasing their adaptability and propensity for cointegration, which facilitates horizontal gene transfer. Among the resistance-associated plasmids, the IncF, IncI, and IncH families were predominant and acted as effective carriers of resistance genes. Comparative analyses between resistant and non-resistant plasmids did not reveal a clear visual pattern of association between the most prevalent Inc groups and specific antimicrobial classes, indicating that such relationships are shaped by contextual factors, including selective instructions, bacterial host diversity, and distribution. These findings highlight the complexity of the spread of plasmid-mediated AMR and highlight the need for integrated genomic and epidemiological approaches to better understand the ecological and evolutionary dynamics that influence the spread of resistance genes.

Tomatoes are produced worldwide, and in South Africa, they are cultivated in all provinces. The most destructive tomato diseases are bacterial spot, caused by Xanthomonas spp., and bacterial wilt caused by Ralstonia solanacearum. Over the years, different strategies have been employed to control tomato disease. The disadvantage of chemical pesticides is that they alter microbial communities and sometimes remain on food commodities. Recently, studies have been conducted on biological control agents in the hope of eventually replacing the use of chemical pesticides. Some studies have discovered potential biological control agents for bacterial diseases. Better insight into host-pathogen interaction will help develop better disease management strategies. This review provides insights into plant diseases caused by Ralstonia and Xanthomonas and how they are managed.

This study aimed to characterize the biofilm-forming microbial communities on clinically used dental elevators to assess their potential risks of cross-contamination and nosocomial infections resulting from percutaneous injuries in dental healthcare settings. Over a period of 3 consecutive weeks starting on August 1, 2024, biofilm samples were collected from the tips of 15 dental elevators used on the first five wisdom teeth extraction patients daily. Total DNA was extracted, and specific barcoded primers were synthesized to construct SMRTbell sequencing libraries, which were subsequently sequenced using the PacBio Sequel II platform. The sequencing generated 923,990 circular consensus sequences (CCS), with an average of 61,599 CCS per sample. Taxonomic annotation revealed a diverse microbial community dominated by genera such as Prevotella, Fusobacterium, Streptococcus, and Lactobacillus, alongside unclassified taxa from the Candidatus Saccharibacteria (TM7) group. Alpha and beta diversity analyses demonstrated significant variations in microbial composition across samples, highlighting the heterogeneity of biofilm formation, while strong positive correlations observed between specific bacterial genera, such as Bacillus and Paenibacillus, suggested potential co-colonization patterns. These findings underscore the complexity of microbial contamination on dental instruments and emphasize the need for improved sterilization protocols to mitigate infection risks. Consequently, this study provides valuable insights into the microbiological safety of dental practices and highlights the utility of third-generation sequencing in advancing infection control strategies.

The objective of this study was to evaluate the temporal stability and object-to-skin transferability of the skin virome in a Korean population. Skin virus metagenomes were collected from the anatomical locations (forehead, left hand, and right hand) of eight healthy adults and monitored over 3 months at intervals of 6 weeks. To assess the potential transfer of virome between skin and objects, subjects were instructed to contact four types of objects (cell phones, door handles, fabric, and plastic). Virome samples were then collected from the surfaces of these objects. Viruses were identified using databases and viral annotation bioinformatics tools. Fifteen viral families were consistently found to be stable and well-transmissible across anatomical locations and four types of objects. Furthermore, the presence/absence profiles of 54 viral species belonging to these 15 viral families exhibited significant individual specificity on both the skin (p < 0.01) and the objects handled by each subject (p < 0.05). We confirmed that these 54 viral markers remain stable over time within individuals and are transferable to contacted surfaces. Additionally, we explored the potential of using the virome as an individual identification marker, which may suggest new approaches for forensic applications.

Accumulation of synthetic plastics in the biosphere has led to global pollution, provoking serious consequences for the environment and human health. Uncontrolled agricultural plastic landfills have the risk of becoming a source of agrochemicals and microplastics. Biotechnological approaches to solve plastic pollution include the removal of these polymers through biological degradation, which is a friendly environmental method. The microbial communities colonizing plastic debris (plastisphere) are considered as a potential source of plastic-degrading microorganisms. In this study, a bacterial biodiversity analysis, based on 16S rRNA gene-targeted metagenomic sequencing, was achieved in the plastisphere of low-density polyethylene (LDPE) and polypropylene (PP) polymers from an agricultural landfill. The α-diversity analysis did not show significant differences between LDPE and PP plastispheres and the plastic-free bulk soil, while LDPE and PP bacterial communities clustered close, but separately from the bulk soil in a β-diversity analysis. Although the taxonomic composition of both plastispheres was different, they shared a significantly higher proportion of Cyanobacteria and Deinococcota than the bulk soil. Additional analyses showed different indicator families, genera and species that can be associated with plastispheres. A predictive functional analysis suggests that degradation of plastic additives in both plastispheres is probably occurring. In addition, the existence of degradation processes for specific herbicides in each plastisphere is highlighted, and the possible exposure of LDPE to both physical and biological degradation processes is also described. These results will contribute to characterize the soil plastisphere exposed to different environmental conditions, and to understand the specific biological niches where plastic-degrading microorganisms could survive.

The complexities of microbial detection and conventional enumeration necessitates the adoption of pragmatic alternatives. This review expands the boundaries of knowledge for microbial detection and sensing, particularly within the field of water quality analysis. Observed alternatives to conventional techniques for microbial analyses in recent studies include Microarray, Fluorescent in situ hybridization (FISH), loop-mediated isothermal amplification (LAMP), matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and flow cytometry, while nanosensors stood out as an alternative for microbial detection in real-time. This study presents the limitation of conventional methods of detection in water and presents nanoparticles as a detection agent with possibility of incorporation into point-of-use detection. It is notable that nanosensors are currently emerging in the detection of bacteria, viruses and other pathogens in water and have been used in the detection of bacterial pathogens than viral. Nanosensors are established as good choice for rapid water analysis with application in point-of-use and analytical devices. In the use of nanozymes, the choice over natural enzymes can be linked to their unique and excellent catalytic activities, cost-effectiveness and ease of mass production.