Biology subjects

Fusco, S.

Publications and source records attributed to Fusco, S..

7 recordsLinked to original sources

bioRxiv2026

Dynamic Exchange of Bacteria and Carbapenem Resistance Genes between Sewer Biofilms and Wastewater

Sewer biofilms represent dynamic interfaces for exchange of bacteria and antibiotic resistance genes between biofilms and the overlying wastewater. Using inline, biofilm reactors, the movement of bacteria and 16S rRNA and carbapenemase genes (blaKPC, blaVIM, blaNDM, blaOXA-48-like, and blaIMP) between wastewater and sewer biofilms was investigated. Established, complex biofilms without these {beta}-lactamase (bla) genes, absorbed resistant bacteria within two minutes of exposure to high concentrations of resistant cultures in lab settings. Carbapenem-resistant organisms from these high-concentration source biofilms transferred to downstream biofilms over 60 minutes of representative sewer shear flows. Mass balances of bacteria and genes in biofilms versus wastewater under representative shear flow showed that biofilms exposed to resistant cultures contributed more to the wastewater than to the downstream biofilms. In field studies, established, complex biofilms without target carbapenem-resistant bacteria and genes from wastewater within hours and then stabilized between 2 to 15 days, not varying by more than 0.5 MPN/cm2 or 0.5 log gene copies (GC)/cm2. In contrast, metagenomic profiles of the bacterial community species continued to change up to 21 days. Established biofilms with resistant bacteria and genes exposed to tertiary-treated wastewater without target carbapenemase genes or meropenem antibiotics did not lose resistant genes or bacteria over nine days of exposure (i.e., < 1 log GC/cm2 reduction). Results show that sewer biofilms contribute to the resistance-gene signal found in sewer wastewater by absorbing and releasing bacteria and genes. Consideration of sewer biofilm dynamics is essential for more accurately interpreting wastewater bacterial concentrations in wastewater-based epidemiology studies. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/726639v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@19f6ce0org.highwire.dtl.DTLVardef@1a507c8org.highwire.dtl.DTLVardef@1a2013dorg.highwire.dtl.DTLVardef@ff8613_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Evaluation of Detection Methods for Wastewater Surveillance of Antimicrobial-Resistant Bacteria from Healthcare Facilities

Carbapenem resistance is an urgent public health threat. Wastewater surveillance could support antimicrobial resistance monitoring at long-term care facilities (LTCFs). Feasibility of wastewater sampling (via composite or passive sampler, and sewer biofilm swabs) for carbapenemase genes (blaKPC, blaVIM, blaOXA-48-like, blaNDM, and blaIMP) detected by qPCR or GeneXpert(R) Carba-R from a LTCF was assessed over 16 months and compared to clinical infections. blaKPC, blaOXA-48-like, and blaVIM were routinely detected in composite wastewater samples (6.4{+/-}0.8 log10 gene copy (GC)/ml (100% of 61 samples), 5.5{+/-}0.8 (98%), and 5.9{+/-}1.3 (34%), respectively), passive samples (8.2{+/-}0.5 log10 GC/g (31% of 55), 6.6{+/-}0.5 (96%), and 6.6{+/-}0.7 (31%)) and sewer biofilm (6.0{+/-}0.7 log10 GC/cm2 of pipe (100% of 17), 5.0{+/-}0.7 (100%), and 5.8{+/-}2.7 (24%)). Resistomes of wastewater and sewer biofilms differed, but both contained blaKPC, blaVIM, and blaIMP. Passive sampling may be a suitable alternative to composite sampling. Wastewater surveillance is a promising addition to carbapenemase monitoring.

microbiology↗

bioRxiv2025

Synergistic Action of Commercial Lipase, Lipoxygenases and Proteinase towards PLA Depolymerization

Polylactic acid (PLA) is a biobased aliphatic polyester produced from renewable resources. Its building block is lactic acid (LA), which is mainly produced through fermentation processes rather than chemical synthesis, as fermentation enables the production of optically pure D-LA or L-LA, instead of a racemic mixture. In this work, three commercial enzymes Proteinase K (PrK) from Tritirachium album, Candida rugosa lipase (CrLip), and Glycine max lipoxygenase (LOX I-B) were investigated for their synergistic action for the degradation of solvent-cast as well as EoL-PLA films. While Lip and LOX I-B alone did not promote PLA hydrolysis, they significantly enhanced PrK-mediated hydrolysis by 5.7-fold and 2.5-fold, respectively. Lip, and to a lesser extent LOX I-B, increased PrKs productive binding to the polymer, thus accelerating catalysis. These findings underline the potential of synergistic enzymes for PLA degradation and provide the first evidence of lipoxygenase activity in this process.

biochemistry↗

bioRxiv2024

Surfactin accelerates Bacillus subtilis pellicle biofilm development

Surfactin is a biosurfactant produced by many B. subtilis strains with a wide variety of functions from lowering surface tension to allowing motility of bacterial swarms, acting as a signaling molecule, and even exhibiting antimicrobial activities. However, the impact of surfactin during biofilm formation has been debated with variable findings between studies depending on the experimental conditions. B. subtilis is known to form biofilms at the solid-air, the solid-medium, and the liquid-air interfaces, the latter of which is known as a pellicle biofilm. Pellicle formation is a complex process requiring coordinated movement to the liquid-air interface and subsequent cooperative production of biofilm matrix components to allow robust pellicle biofilm formation. This makes pellicle formation a promising model system for assaying factors in biofilm formation and regulation. Here, we assayed the influence of surfactin and additional metabolites on the timing of pellicle biofilm formation. Using of time-lapse imaging, we assayed pellicle formation timing in 12 B. subtilis isolates and found that one, MB9_B4, was significantly delayed in pellicle formation by approximately 10 hours. MB9_B4 was previously noted to lack robust surfactin production. Indeed, deletion of surfactin synthesis in the other isolates delayed pellicle formation. Further, pellicle delay was rescued by addition of exogeneous surfactin and spent media from mature pellicles. Testing reporters of biofilm-related gene expression revealed that induction of pellicle formation was caused by a combination of increased gene expression of one of the biofilm components and promotion of growth. Intriguingly, spent media of surfactin mutant strains were also able to stimulate pellicle formation, indicating possible additional metabolites also influence the timing of pellicle development.

microbiology↗

bioRxiv2024

Recovery after human bone marrow mesenchymal stem cells (hBM-MSCs)-derived extracellular vesicles (EVs) treatment in post-MCAO rats requires handling associated with repeated behavioral testing.

Rehabilitation is the only current intervention that improves sensorimotor function in ischemic stroke patients, similar to task-specific intensive training in animal models of stroke. Bone marrow mesenchymal stem cells (BM-MSCs)-derived extracellular vesicles (EVs) are promising in restoring brain damage and function in stroke models. Additionally, the non-invasive intranasal route allows EVs to reach the brain and target specific ischemic regions. Yet unclear is how handling might enhance recovery or influence other therapies such as EVs after stroke. We used the transient middle cerebral artery occlusion (MCAO) model of stroke in rats to assess how intensive handling alone, in the form of sensorimotor behavioral tests, or in combination with an intranasal multidose or single dose of EVs restored neurological function and ischemic damage. Handled rats were exposed to a battery of sensorimotor tests, including the modified Neurological Severity Score (mNSS), beam balance, corner, grid walking, forelimb placement, and cylinder tests, together with Magnetic Resonance Imaging (MRI) at 2, 7, 14, 21, and 28 days post-stroke (dps). Handled MCAO rats were also exposed to an intranasal multidose of EVs (8 doses in total across four weeks, each dose containing 0.8 x 109 EVs in 120 {micro}l) or a single dose of EVs (2.4 x 109 EVs in 200 {micro}l) at 2 dps. Non-handled rats were evaluated only by mNSS and MRI at 2, 28, and 56 dps and were treated with a single intranasal dose of EVs. Our results showed that handling animals after MCAO is necessary for EVs to work and that a single cumulative dose of EVs further improves the neurological function recovered during handling without affecting ischemic damage. These results show the importance of rehabilitation in combination with other treatments and highlight how intensive behavioral testing might influence functional recovery after stroke, especially when other treatments are also given.

neuroscience↗

bioRxiv2022

Therapy-induced senescence upregulates antigen presentation machinery and triggers anti-tumor immunity in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive hematological malignancy often curable only by using intensive chemotherapy. Nonetheless, resistance/early relapses are frequent, underscoring the need to investigate the molecular events occurring shortly after chemotherapy. Therapy-induced senescence (TIS) is a fail-safe tumor suppressive mechanism that may elicit immune-mediated responses contributing to senescent cell clearance. Yet, TIS functional role in AML eradication and immune surveillance early post-chemotherapy remains ill-defined. By combining transcriptional and cellular-based evaluation of senescence markers in AML patient samples, we found upregulation of senescence-associated genes and interferon gene categories with concomitant induction of HLA class I and class II molecules, pointing to a causal link between TIS and leukemia immunogenicity. Consistently, senescence-competent AML samples activated autologous CD4+ and CD8+ T cells and improved leukemia recognition by both T-cell subsets. Lastly, the anti-leukemic activity of Immune Checkpoint Blockades (ICBs) was enhanced upon senescence engagement in AML. Altogether, our results identify senescence as a potent immune-related anti-leukemic mechanism that may rapidly translate into innovative senescence-based strategies to prevent AML relapse. STATEMENT OF SIGNIFICANCEOur findings uncover a novel link between senescence induction and leukemia immune recognition by T cells via upregulation of antigen presentation machinery components, providing the basis for conceptually novel senescence-based targeted immunotherapeutic regimens for AML patients.

cancer biology↗

bioRxiv2022

PIP4K2B is a mechanosensor and induces heterochromatin-driven nuclear softening through UHRF1.

Phosphatidylinositol-5-phosphate (PtdIns5P)-4-kinases (PIP4Ks) are stress-regulated phosphoinositide kinases able to phosphorylate PtdIns5P to PtdIns(4, 5)P2. In cancer patients their expression is typically associated with bad prognosis. Among the three PIP4K isoforms expressed in mammalian cells, PIP4K2B is the one with more prominent nuclear localization. Here, we unveil the role for PIP4K2B as mechanosensor. PIP4K2B protein level, indeed, strongly decreases in cells growing on soft substrates. Its direct silencing or pharmacological inhibition, mimicking cell response to soft, triggers a concomitant reduction of the epigenetic regulator UHRF1 and induces changes in nuclear polarity, nuclear envelope tension and chromatin compaction. This substantial rewiring of the nucleus mechanical state drives YAP cytoplasmic retention and impairment of its activity as transcriptional regulator, finally leading to defects in cell spreading and motility. Since YAP signalling is essential for initiation and growth of human malignancies, our data suggest that potential therapeutic approaches targeting PIP4K2B could be beneficial in the control of the altered mechanical properties of cancer cells.

cell biology↗