SEARCH · Search PubMed

Results for “biocidal effect”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

6 recordsLinked to original sources

PubMed2026

Prophage Activation as an Overlooked Mechanism Underlying the Biocidal Effect of Free Nitrous Acid in Sewers.

Biogenic hydrogen sulfide produced in sewer systems causes odor nuisance and concrete corrosion, necessitating effective biocidal control. Free nitrous acid (FNA) has emerged as a promising biocide, but its unclear mechanisms complicate dosage optimization and risk assessment. Here, using Desulfovibrio vulgaris as a model lysogenic bacterium, we demonstrate that low-dose FNA (0.2-4.0 mg N/L) induces bacterial inactivation via prophage activation-associated lysis in addition to chemical oxidation. Reactive nitrogen species (RNS) scavenging tests revealed that RNS-mediated oxidative stress was closely associated with prophage activation. Activated phages further infected new hosts, reducing the viability of freshly cultured D. vulgaris cells by 25.7% and increasing total phage production 15.2-fold. The phenomenon was further validated in real sewage biofilms, where increased phage production and decreased bacterial viability were observed at a low FNA dose of 0.2 mg N/L, below the dose required for cell destruction by chemical oxidation. Furthermore, metagenomic analysis of 896 sewage samples worldwide revealed that 71.9% of recovered sewage-derived microbial genomes harbor prophages, indicating a widespread genomic basis for prophage activation-mediated bacterial inactivation. Overall, this study expands current understanding of the biocidal mechanisms of FNA and contributes to the development of environmentally sustainable biocidal strategies.

Nitrous Acid↗

PubMed2026

Environmentally relevant concentrations of DCOIT impaired lifespan and healthspan in Caenorhabditis elegans.

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is an antifouling biocide widely used as an alternative to organotin compounds. While previous studies had focused on its effects on energy production, endocrine disruption, and lipid metabolism, its impact on aging and underlying mechanisms remained unclear. Here, we demonstrated that environmentally relevant concentrations of DCOIT (37, 370 and 3700 ng/L) significantly impaired both lifespan and healthspan in Caenorhabditis elegans. RNA-seq and validation assays revealed that DCOIT upregulated comt-4, a key gene in dopamine metabolism, leading to dopamine depletion and subsequent induction of oxidative stress. This redox imbalance critically contributed to accelerated aging phenotypes. Importantly, both genetic (comt-4 RNAi) and pharmacological (opicapone) interventions restored dopamine levels, alleviated oxidative stress, and reversed DCOIT-induced aging deficits. Our study established the comt-4/dopamine/oxidative stress axis as a central mechanism in DCOIT toxicity, suggesting dopamine modulation as a potential countermeasure against environmental toxicant-induced aging.

Animals↗

PubMed2025

The efficacy of a filtered handheld far-ultraviolet disinfection device for decontamination of high-touch surfaces in healthcare settings: a genomic bacterial analysis.

BACKGROUND AND OBJECTIVES: Enhanced environmental disinfection is linked to reduced hospital-acquired infection rates. In this study, we aimed to evaluate the efficacy of an emerging disinfection technology, a filtered far-UV-C handheld (FFUHH) device, for reducing bacterial loads on high-touch surfaces in shared clinical workrooms, and to isolate, identify and characterize clinically significant environmental pathogens. METHODS: We compared samples from high-touch items (dictation device, mouse, armchair, desk, and keyboard) before and after FFUHH treatment. Samples were collected weekly: contact plates for colony counts and swabs before and after intervention on standardized adjacent areas for each surface, respectively. The swabs were enriched and cultured on selective media to isolate pathogens. Environmental samples, as well as clinical samples collected from patients during the study period, were validated using MALDI-TOF and whole genome sequencing. RESULTS: Among the 440 collected plates (220 before and 220 after treatment), the highest mean colony count pre-treatment was detected from armchairs, and the lowest from keyboards. The mean reduction of colony-forming units ranged 53% and 83% and was statistically significant (P < 0.05) across all surfaces except for the keyboard. We characterized multidrug-resistant Staphylococcus epidermidis ST5 and ST16 strains, a carbapenem-resistant Acinetobacter baumannii, and a Klebsiella pneumoniae genetically related to a clinical isolate with a rare sequence type not previously detected in our institution. CONCLUSION: The FFUHH effectively reduced the microbial burden on high-touch surfaces. It can offer an advantage for surface disinfection and an alternative to routinely used biocides.

Humans↗

PubMed2025

Universal versus targeted chlorhexidine and mupirocin decolonisation and clinical and molecular epidemiology of Staphylococcus epidermidis bloodstream infections in patients in intensive care in Scotland, UK: a controlled time-series and longitudinal genotypic study.

BACKGROUND: There are concerns that biocide skin and mucous membrane decolonisation, which is widely used to prevent health-care-associated infections in intensive care units (ICUs), might select for multidrug-resistant pathogens. We aimed to evaluate the effects of de-escalating from universal to targeted skin and nasal decolonisation on Staphylococcus epidermidis bloodstream infections (SE-BSI). METHODS: We did a retrospective, before-after-control-impact time-series analysis and longitudinal genotypic study in two ICUs with divergent decolonisation practice in tertiary care hospitals of adjacent health boards in Scotland, UK. Participants were aged at least 16 years and admitted between July 1, 2009, and Feb 28, 2022. There were no exclusion criteria for the study. In ICU one (intervention site) universal decolonisation in all admissions was de-escalated to targeted decolonisation of meticillin-resistant Staphylococcus aureus (MRSA) carriers on Feb 1, 2019, while in ICU two (control site) targeted decolonisation was applied throughout. We collected bloodstream infection data from all causes, including clinically significant SE-BSI. Antimicrobial susceptibility testing was used to define meticillin-resistant S epidermidis (MRSE) and chlorhexidine susceptibility. We used multilocus sequence typing to identify sequence types from archived SE-BSI isolates. Whole-genome sequencing was applied to a sample from ICU one. The primary outcomes were incidence densities of all bloodstream infections, SE-BSI, and meticillin-resistant S epidermidis bloodstream infections (MRSE-BSI), and the percentage probability that SE-BSI were MRSE-BSI. The effects of de-escalation on primary outcomes were estimated by differences between the intervention and control sites, before and after de-escalation, using a before-after-control-impact time-series design. Secondary outcomes included the proportion of multidrug resistant sequence types, carriage of mobile genetic elements and genes for multidrug resistance and biofilm production. FINDINGS: Between July 1, 2009, and Feb 28, 2022, S epidermidis was identified in 334 (45%) of 735 bloodstream infections in ICU one, of which 197 occurred before the de-escalation intervention in Feb 1, 2019, and S epidermidis was identified in 167 (60%) of 278 bloodstream infections in ICU two. There was no increase in all bloodstream infection incidence coinciding with de-escalation in ICU one, whereas MRSE-BSI incidence declined significantly from 10·4 cases per 1000 occupied bed days (OBDs; 95% credible interval [CrI] 7·2-15·4) to 4·3 cases per 1000 OBDs (2·5-6·7), as did the percentage probability of MRSE (from 89·2%, 95% CrI 77·8-96·5 to 56·7%, 34·3-77·5%). No significant changes in the primary outcomes were seen in ICU two. MRSE-BSI incidence density was positively associated with chlorhexidine use, but not mupirocin use. De-escalation was associated with a reduced proportion of SE-BSI due to multidrug-resistant sequence types and reduced carriage of mobile genetic elements and genes for multidrug resistance and biofilm production, as observed by multi-locus sequence typing and whole genome sequencing. INTERPRETATION: In ICU settings with low MRSA incidence, the benefits of universal decolonisation should be balanced against the risks of selecting MRSE sequence types adapted for invasive and device-associated infection. FUNDING: National Health Service Grampian Charity.

Humans↗

PubMed2026

Amplicon and metagenomic sequencing reveal thifluzamide drive rhizosphere microbial structural shifts and functional adaption.

Thifluzamide (TF) is a widely used phenyl urea fungicide in rice production; however, its impacts on the structural composition and functional dynamics of the rhizosphere microbiome remain poorly understood. Here, we systematically investigated the effects of TF on the structure, interactions, and functional potential of the rice (Oryza sativa L.) rhizosphere microbiome using integrated amplicon sequencing and metagenomic approaches. TF application significantly altered both bacterial and fungal community composition, bacterial diversity was markedly reduced, whereas fungal diversity increased. With bacterial diversity markedly reduced while fungal diversity increased. Beta-diversity analyses revealed strong treatment-driven community separation, indicating pronounced TF-induced microbial restructuring. Co-occurrence network analysis demonstrated reduced complexity and connectivity in bacterial networks but increased negative co-occurrence patterns within fungal communities, suggesting contrasting stability responses between microbial kingdoms. Metagenomic profiling further revealed substantial functional shifts, including the differential enrichment of KEGG and COG pathways associated with xenobiotic metabolism. Notably, while total ARG abundance remained stable, TF exposure altered the resistome profile by selectively enriching specific classes of antibiotic resistance genes (ARGs), biocide resistance genes (BRGs), and mobile genetic elements (MGEs). Strong positive correlations between MGEs and ARGs highlighted an elevated potential for horizontal gene transfer. Metagenome-assembled genome (MAG) analysis identified specific TF-enriched bacterial taxa, including Methylophilus, Sulfurospirillum, and Azospirillum, which harbored genes involved in pesticide degradation and xenobiotic transformation. Collectively, these findings demonstrate that TF profoundly reshapes the rice rhizosphere microbiome by altering microbial diversity, interaction networks, resistance gene profiles, and functional capacities. This study provides genomic insights into fungicide-microbiome interactions, underscoring the potential ecological implications associated with TF application, while identifying candidate microbial taxa that may contribute to pesticide degradation and rhizosphere microecology resilience.

Rhizosphere↗

PubMed2026

Soil management practices shape the abundance, diversity, and spread of antimicrobial resistance.

Agricultural soils are critical hotspots of antimicrobial resistance genes (ARGs). Yet, the environmental factors shaping these reservoirs and the hazards they pose to humans and livestock remain poorly understood. Because management practices introduce antibiotics, heavy metals, and nonantibiotic biocides, they can rapidly select for resistance. Most studies have examined components of management practices in isolation, overlooking the multiple stressors of modern industrial agriculture. Here, we used a large-scale field experiment to examine how multiple stressors from soil and crop management interact to shape antimicrobial resistance. We combined shotgun metagenomics, phylogenomics, and risk-score analyses to quantify the diversity of ARGs, mobile genetic elements (MGEs), and the transmission potential of drug-resistant pathogens. Relative to other management systems, intensive, chemically reliant monoculture systems, typical of the US Corn Belt, create strong selective pressures promoting more abundant and diverse ARGs and MGEs. These systems therefore carry greater potential to transmit ARGs, including those with relevance to both livestock and public health such as tetA and blaPAM, likely mediated by integration and excision. In contrast, less-intensive, lower-input systems with diverse crop rotations maintained resistomes with lower abundance, diversity, and transmission potential. Our results suggest that these patterns could arise due to the divergent effects of management practices on overall soil microbial diversity, an ecological barrier that can suppress ARGs. This study highlights the need to understand the combined stressors of agricultural practices, beyond antimicrobial use, to design effective strategies to mitigate antimicrobial resistance.

Soil Microbiology↗