Single-cell analysis identifies the interaction of altered renal tubules with basophils orchestrating kidney fibrosis.

Inflammation is an important component of fibrosis but immune processes that orchestrate kidney fibrosis are not well understood. Here we apply single-cell sequencing to a mouse model of kidney fibrosis. We identify a subset of kidney tubule cells with a profibrotic-inflammatory phenotype characterized by the expression of cytokines and chemokines associated with immune cell recruitment. Receptor-ligand interaction analysis and experimental validation indicate that CXCL1 secreted by profibrotic tubules recruits CXCR2+ basophils. In mice, these basophils are an important source of interleukin-6 and recruitment of the TH17 subset of helper T cells. Genetic deletion or antibody-based depletion of basophils results in reduced renal fibrosis. Human kidney single-cell, bulk gene expression and immunostaining validate a function for basophils in patients with kidney fibrosis. Collectively, these studies identify basophils as contributors to the development of renal fibrosis and suggest that targeting these cells might be a useful clinical strategy to manage chronic kidney disease.

Basophils prime group 2 innate lymphoid cells for neuropeptide-mediated inhibition.

Type 2 cytokine responses promote parasitic immunity and initiate tissue repair; however, they can also result in immunopathologies when not properly restricted. Although basophilia is recognized as a common feature of type 2 inflammation, the roles basophils play in regulating these responses are unknown. Here, we demonstrate that helminth-induced group 2 innate lymphoid cell (ILC2) responses are exaggerated in the absence of basophils, resulting in increased inflammation and diminished lung function. Additionally, we show that ILC2s from basophil-depleted mice express reduced amounts of the receptor for the neuropeptide neuromedin B (NMB). Critically, NMB stimulation inhibited ILC2 responses from control but not basophil-depleted mice, and basophils were sufficient to directly enhance NMB receptor expression on ILC2s. These studies suggest that basophils prime ILC2s to respond to neuron-derived signals necessary to maintain tissue integrity. Further, these data provide mechanistic insight into the functions of basophils and identify NMB as a potent inhibitor of type 2 inflammation.

Hookworms dynamically respond to loss of Type 2 immune pressure.

The impact of the host immune environment on parasite transcription and fitness is currently unknown. It is widely held that hookworm infections have an immunomodulatory impact on the host, but whether the converse is true remains unclear. Immunity against adult-stage hookworms is largely mediated by Type 2 immune responses driven by the transcription factor Signal Transducer and Activator of Transcription 6 (STAT6). This study investigated whether serial passage of the rodent hookworm Nippostrongylus brasiliensis in STAT6-deficient mice (STAT6 KO) caused changes in parasites over time. After adaptation to STAT6 KO hosts, N. brasiliensis increased their reproductive output, feeding capacity, energy content, and body size. Using an improved N. brasiliensis genome, we found that these physiological changes corresponded with a dramatic shift in the transcriptional landscape, including increased expression of gene pathways associated with egg production, but a decrease in genes encoding neuropeptides, proteases, SCP/TAPS proteins, and transthyretin-like proteins; the latter three categories have been repeatedly observed in hookworm excreted/secreted proteins (ESPs) implicated in immunosuppression. Although transcriptional changes started to appear in the first generation of passage in STAT6 KO hosts for both immature and mature adult stages, downregulation of the genes putatively involved in immunosuppression was only observed after multiple generations in this immunodeficient environment. When STAT6 KO-adapted N. brasiliensis were reintroduced to a naive WT host after up to 26 generations, this progressive change in host-adaptation corresponded to increased production of inflammatory cytokines by the WT host. Surprisingly, however, this single exposure of STAT6 KO-adapted N. brasiliensis to WT hosts resulted in worms that were morphologically and transcriptionally indistinguishable from WT-adapted parasites. This work uncovers remarkable plasticity in the ability of hookworms to adapt to their hosts, which may present a general feature of parasitic nematodes.

Monocytes maintain central nervous system homeostasis following helminth-induced inflammation.

Neuroimmune interactions are crucial for regulating immunity and inflammation. Recent studies have revealed that the central nervous system (CNS) senses peripheral inflammation and responds by releasing molecules that limit immune cell activation, thereby promoting tolerance and tissue integrity. However, the extent to which this is a bidirectional process, and whether peripheral immune cells also promote tolerance mechanisms in the CNS remains poorly defined. Here we report that helminth-induced type 2 inflammation promotes monocyte responses in the brain that are required to inhibit excessive microglial activation and host death. Mechanistically, infection-induced monocytes express YM1 that is sufficient to inhibit tumor necrosis factor production from activated microglia. Importantly, neuroprotective monocytes persist in the brain, and infected mice are protected from subsequent lipopolysaccharide-induced neuroinflammation months after infection-induced inflammation has resolved. These studies demonstrate that infiltrating monocytes promote CNS homeostasis in response to inflammation in the periphery and demonstrate that a peripheral infection can alter the immunologic landscape of the host brain.

Can we lower the platelet threshold of ≥ 50 × 109/L for performing a lumbar puncture safely in patients with hematological malignancies?

Lumbar punctures (LP) are routinely used to administer intrathecal chemotherapy for children and adults with hematologic malignancies. The current guidelines suggest a platelet threshold of ≥ 50 × 109/L prior to LP for intrathecal chemotherapy (ITC). This can be challenging in patients with hematological malignancies who are thrombocytopenic. We conducted a retrospective chart review of 900 LPs for ITC and compared adverse events in patients with a platelet count of ≥ 50 × 109/L and < 50 × 109/L. Cohort 1 included 682 LPs (75.8%) with a pre-procedure platelet count ≥ 50 × 109/L, and cohort 2 included 218 LPs (24.2%) with a pre-procedure platelet count < 50 × 109/L. Cohort 2 was further subdivided into pre-procedure platelet counts of 41 × 109/L-49 × 109/L (n = 43), 31 × 109/L-40 × 109/L (n = 77), 21 × 109/L-30 × 109/L (n = 84), and 11 × 109/L-20 × 109/L (n = 14). Among 900 LP procedures, a pre-procedure platelet count < 50 × 109/L did not demonstrate a higher rate of post-procedure adverse events (6.5% vs 6.8%, p = 0.8237). When cohort 2 was further stratified, the cohort with a pre-procedure platelet count of 21 × 109/L-30 × 109/L had the highest percentage of complications from LP (9.5%) and the highest rates of traumatic taps with observed LP RBC count > 200 (35.7%, p = 0.0015). The rate of red blood cells (RBC) in the CSF was significantly higher in the group with platelets < 50 × 109/L with observed LP RBC count ≥ 200 (31.2% vs 20.5%, p = 0.0016), ≥ 500 (27.1% vs 14.6%, p < 0.0001), and ≥ 1000 (23% vs 11.6%, p < 0.0001). No instances of epidural hematomas were seen. We found no significant difference in bleeding complications between patients undergoing LPs for ITC with a platelet count above or below 50 × 109/L.

Trichinella spiralis-induced mastocytosis and erythropoiesis are simultaneously supported by a bipotent mast cell/erythrocyte precursor cell.

Anti-helminth responses require robust type 2 cytokine production that simultaneously promotes worm expulsion and initiates the resolution of helminth-induced wounds and hemorrhaging. However, how infection-induced changes in hematopoiesis contribute to these seemingly distinct processes remains unknown. Recent studies have suggested the existence of a hematopoietic progenitor with dual mast cell-erythrocyte potential. Nonetheless, whether and how these progenitors contribute to host protection during an active infection remains to be defined. Here, we employed single cell RNA-sequencing and identified that the metabolic enzyme, carbonic anhydrase (Car) 1 marks a predefined bone marrow-resident hematopoietic progenitor cell (HPC) population. Next, we generated a Car1-reporter mouse model and found that Car1-GFP positive progenitors represent bipotent mast cell/erythrocyte precursors. Finally, we show that Car1-expressing HPCs simultaneously support mast cell and erythrocyte responses during Trichinella spiralis infection. Collectively, these data suggest that mast cell/erythrocyte precursors are mobilized to promote type 2 cytokine responses and alleviate helminth-induced blood loss, developmentally linking these processes. Collectively, these studies reveal unappreciated hematopoietic events initiated by the host to combat helminth parasites and provide insight into the evolutionary pressure that may have shaped the developmental relationship between mast cells and erythrocytes.

Does the global activity limitation indicator measure participation restriction? Data from the European Health and Social Integration Survey in Spain.

PURPOSE: The global activity limitation indicator (GALI) is the only internationally agreed and harmonised participation restriction measure. We examine if GALI, as intended, is a reflective measure of the domains of participation; furthermore, we determine the relative importance of these domains. Also, we investigated the consistency of response to GALI by age and gender and compared the performance of GALI with that of self-rated health (SRH). METHODS: We used Spanish data from the European Health and Social Integration Survey and selected adults aged 18 and over (N = 13,568). Data analysis, based on logistic regression models and Shapley value decomposition, were also stratified by age. The predictors of the models were demographic variables and restrictions in participation domains: studies, work, mobility, leisure and social activities, domestic life, and self-care. The GALI and SRH were the response variables. RESULTS: GALI was strongly associated with all participation domains (e.g. for domestic life, adjusted OR 24.34 (95% CI 18.53-31.97) in adult under 65) and performed differentially with age (e.g. for domestic life, adjusted OR 13.33 (95% CI 10.42-17.03) in adults over 64), but not with gender. The relative importance of domains varied with age (e.g. work was the most important domain for younger and domestic life for older adults). The results with SRH were parallel to those of GALI, but the association of SRH with participation domains was lowest. CONCLUSIONS: GALI reflects well restrictions in multiple participation domains and performs differently with age, probably because older people lower their standard of good functioning.

Information needs of parents of children with congenital anomalies across Europe: a EUROlinkCAT survey.

BACKGROUND: Parents of children who have a congenital anomaly can experience significant worry about their child's health. Access to clear, helpful, and trustworthy information can provide a valuable source of support. In this study the aim was to explore the information needs of parents/carers of children with congenital anomalies across Europe. METHOD: A cross-sectional online survey was developed in nine languages to measure parents' information needs, including: (1) the 'helpfulness'/'trustworthiness' of information received from eight relevant sources, and (2) overall satisfaction with information received. Parents/carers of children (0-10 years) with cleft lip, spina bifida, congenital heart defect [CHD] requiring surgery, and/or Down syndrome were recruited online via relevant organisations in 10 European countries from March-July 2021. Quantitative analyses using multivariable logistic regressions were performed. RESULTS: One thousand seventy parents/carers of children with a cleft lip (n = 247), spina bifida (n = 118), CHD (n = 366), Down syndrome (n = 281), and Down syndrome with CHD (n = 58) were recruited in Poland (n = 476), the UK (n = 120), Germany (n = 97), the Netherlands/Belgium (n = 74), Croatia (n = 68), Italy (n = 59), other European countries (n = 92), and not specified/non-European countries (n = 84). Most participants were mothers (92%) and aged 31-40 years (71%). Participants were most likely to rate support groups (63%), patient organisations (60%), specialist doctors/nurses (58%), and social media (57%) as 'very helpful' information sources. 'Very trustworthy' ratings remained high for specialist doctors/nurses (61%), however, they declined for support groups (47%), patient organisations (48%), and social media (35%). Germany had the highest proportion of participants who were 'very satisfied' (44%, 95% CI = 34%-54%) with information, whereas this percentage was lowest in Croatia (11%, 95% CI = 3%-19%) and Poland (15%, 95% CI = 11%-18%). Parents of children with Down syndrome had significantly lower satisfaction ratings than parents of children with CHD; 13% (95% CI = 8%-18%) reported being 'very satisfied' compared to 28% (95% CI = 23%-33%) in the CHD group. CONCLUSIONS: Findings suggest that informal sources of information (e.g. support groups) are of value to parents, however, they are not deemed as trustworthy as specialist medical sources. Satisfaction ratings differed across countries and by anomaly, and were particularly low in Croatia and Poland, as well as for parents of children with Down syndrome, which warrants further investigation.

Clinical Impact of Accelerate Pheno Rapid Blood Culture Detection System in Bacteremic Patients.

BACKGROUND: Accelerate Pheno blood culture detection system (AXDX) provides rapid identification and antimicrobial susceptibility testing results. Limited data exist regarding its clinical impact. Other rapid platforms coupled with antimicrobial stewardship program (ASP) real-time notification (RTN) have shown improved length of stay (LOS) in bacteremia. METHODS: A single-center, quasi-experimental study of bacteremic inpatients before and after AXDX implementation was conducted comparing clinical outcomes from 1 historical and 2 intervention cohorts (AXDX and AXDX + RTN). RESULTS: Of 830 bacteremic episodes, 188 of 245 (77%) historical and 308 (155 AXDX, 153 AXDX + RTN) of 585 (65%) intervention episodes were included. Median LOS was shorter with AXDX (6.3 days) and AXDX + RTN (6.7 days) compared to historical (8.1 days) (P = .001). In the AXDX and AXDX + RTN cohorts, achievement of optimal therapy (AOT) was more frequent (93.6% and 95.4%, respectively) and median time to optimal therapy (TTOT) was faster (1.3 days and 1.4 days, respectively) compared to historical (84.6%, P ≤ .001 and 2.4 days, P ≤ .001, respectively). Median antimicrobial days of therapy (DOT) was shorter in both intervention arms compared to historical (6 days each vs 7 days; P = .011). Median LOS benefit during intervention was most pronounced in coagulase-negative Staphylococcus bacteremia (P = .003). CONCLUSIONS: LOS, AOT, TTOT, and total DOT significantly improved after AXDX implementation. Addition of RTN did not show further improvement over AXDX and an already active ASP. These results suggest that AXDX can be integrated into healthcare systems with an active ASP even without the resources to include RTN.

Do high MICs predict the outcome in invasive fusariosis?

BACKGROUND: Invasive fusariosis (IF) affects mostly severely immunocompromised hosts and is associated with poor outcome. Since Fusarium species exhibit high MICs for most antifungal agents, this could explain the poor prognosis. However, a clear-cut correlation between MIC and outcome has not been established. OBJECTIVE: To evaluate the correlation between MIC and outcome (6 week death rate) in patients with IF. METHODS: We performed a multicentre retrospective study of patients with IF who received treatment and had MIC levels determined by EUCAST or CLSI for the drug(s) used during treatment. We compared the MIC50 and MIC distribution among survivors and patients who died within 6 weeks from the diagnosis of IF. RESULTS: Among 88 patients with IF, 74 had haematological diseases. Primary treatment was monotherapy in 52 patients (voriconazole in 27) and combination therapy in 36 patients (liposomal amphotericin B + voriconazole in 23). The MIC50 and range for the five most frequent agents tested were: voriconazole 8 mg/L (range 0.5-64), amphotericin B 2 mg/L (range 0.25-64), posaconazole 16 mg/L (range 0.5-64), itraconazole 32 mg/L (range 4-64), and isavuconazole 32 mg/L (range 8-64). There was no difference in MIC50 and MIC distribution among survivors and patients who died. By contrast, persistent neutropenia and receipt of corticosteroids were strong predictors of 6 week mortality. CONCLUSIONS: Our study did not show any correlation between MIC and mortality at 6 weeks in patients with IF.

Uterus procurement from deceased donor for transplantation.

Women with absolute uterine factor infertility cannot get pregnant. The current experience in uterine transplantation is limited and the use of a deceased donor uterus in this area is incipient after some initial unsuccessful attempts. The birth of healthy babies through this modality in four different centers has given a new impetus to the use of this transplantation technique. We aimed to develop a technique for uterus procurement and preparation for transplantation from a brain dead donor. Fifteen uteri were retrieved from multi-organ donor patients, 10 of these were used in bench surgeries with the proposed technique. All procedures were performed after obtaining family's consent. This study allowed the clinical use of two of the 15 organs that were procured for transplantation. One of these organs resulted in the first live birth worldwide using a uterus transplanted from a deceased donor, a landmark in reproductive medicine. Another outcome was the optimization of the surgical technique involving less manipulation of the uterine vascular pedicles. The success of this novel technique suggests that the proposed model can be replicated and optimized further to facilitate the transplantation of uterus from deceased donors.

Cancer pain management in the emergency department: a multicenter prospective observational trial of the Comprehensive Oncologic Emergencies Research Network (CONCERN).

PURPOSE: Many patients with cancer seek care for pain in the emergency department (ED). Prospective research on cancer pain in this setting has historically been insufficient. We conducted this study to describe the reported pain among cancer patients presenting to the ED, how pain is managed, and how pain may be associated with clinical outcomes. METHODS: We conducted a multicenter cohort study on adult patients with active cancer presenting to 18 EDs in the USA. We reported pain scores, response to medication, and analgesic utilization. We estimated the associations between pain severity, medication utilization, and the following outcomes: 30-day mortality, 30-day hospital readmission, and ED disposition. RESULTS: The study population included 1075 participants. Those who received an opioid in the ED were more likely to be admitted to the hospital and were more likely to be readmitted within 30 days (OR 1.4 (95% CI: 1.11, 1.88) and OR 1.56 (95% CI: 1.17, 2.07)), respectively. Severe pain at ED presentation was associated with increased 30-day mortality (OR 2.30, 95% CI: 1.05, 5.02), though this risk was attenuated when adjusting for clinical factors (most notably functional status). CONCLUSIONS: Patients with severe pain had a higher risk of mortality, which was attenuated when correcting for clinical characteristics. Those patients who required opioid analgesics in the ED were more likely to require admission and were more at risk of 30-day hospital readmission. Future efforts should focus on these at-risk groups, who may benefit from additional services including palliative care, hospice, or home-health services.

Exploring natural biodiversity to expand access to microbial terpene synthesis.

BACKGROUND: Terpenes are industrially relevant natural compounds the biosynthesis of which relies on two well-established-mevalonic acid (MVA) and methyl erythritol phosphate (MEP)-pathways. Both pathways are widely distributed in all domains of life, the former is predominantly found in eukaryotes and archaea and the latter in eubacteria and chloroplasts. These two pathways supply isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), the universal building blocks of terpenes. RESULTS: The potential to establish a semisynthetic third pathway to access these precursors has been investigated in the present work. We have tested the ability of a collection of 93 isopentenyl phosphate kinases (IPK) from the biodiversity to catalyse the double phosphorylation of isopentenol and dimethylallyl alcohol to give, respectively IPP and DMAPP. Five IPKs selected from a preliminary in vitro screening were evaluated in vivo in an engineered chassis E. coli strain producing carotenoids. The recombinant pathway leading to the synthesis of neurosporene and lycopene, allows a simple colorimetric assay to test the potential of IPKs for the synthesis of IPP and DMAPP starting from the corresponding alcohols. The best candidate identified was the IPK from Methanococcoides burtonii (UniProt ID: Q12TH9) which improved carotenoid and neurosporene yields ~ 18-fold and > 45-fold, respectively. In our lab scale conditions, titres of neurosporene reached up to 702.1 ± 44.7 µg/g DCW and 966.2 ± 61.6 µg/L. A scale up to 4 L in-batch cultures reached to 604.8 ± 68.3 µg/g DCW and 430.5 ± 48.6 µg/L without any optimisation shown its potential for future applications. Neurosporene was almost the only carotenoid produced under these conditions, reaching ~ 90% of total carotenoids both at lab and batch scales thus offering an easy access to this sophisticated molecule. CONCLUSION: IPK biodiversity was screened in order to identify IPKs that optimize the final carotenoid content of engineered E. coli cells expressing the lycopene biosynthesis pathway. By simply changing the IPK and without any other metabolic engineering we improved the neurosporene content by more than 45 fold offering a new biosynthetic access to this molecule of upmost importance.

Outcomes of patients with invasive fusariosis who undergo further immunosuppressive treatments, is there a role for secondary prophylaxis?

BACKGROUND: Patients treated for invasive aspergillosis may relapse during subsequent periods of immunosuppression and should receive secondary prophylaxis. Little is known about the frequency of relapse and practices of secondary prophylaxis for invasive fusariosis (IF). OBJECTIVES: Evaluate practices of secondary prophylaxis and the frequency of relapse in patients who survived IF and were exposed to subsequent periods of immunosuppression. METHODS: Multicentre retrospective study of patients with haematological malignancies who developed IF, survived the initial fungal disease period, and were exposed to subsequent periods of immunosuppression. RESULTS: Among 40 patients, 35 received additional chemotherapy and developed neutropenia (median, 24 days; range, 4-104), and five received glucocorticoids for the treatment of graft-vs-host disease. Overall, 32 patients received secondary prophylaxis (voriconazole in 24) for a median of 112 days (range, 12-468). IF relapsed in five patients (12.5%): 2/8 (25%) not on prophylaxis and 3/32 (9.4%) receiving prophylaxis. Among 28 patients with disseminated IF, relapse occurred in 2/2 (100%) not on prophylaxis and in 3/26 (11.5%) on prophylaxis (P = 0.03). All patients who relapsed IF died. CONCLUSIONS: Patients with IF who survive the initial disease may relapse if exposed to subsequent episodes of immunosuppressive therapies. Secondary prophylaxis should be considered, especially if IF was disseminated.

Validation of the Emergency Severity Index (Version 4) for the Triage of Adult Emergency Department Patients With Active Cancer.

BACKGROUND: Patients with active cancer account for a growing percentage of all emergency department (ED) visits and have a unique set of risks related to their disease and its treatments. Effective triage for this population is fundamental to facilitating their emergency care. OBJECTIVES: We evaluated the validity of the Emergency Severity Index (ESI; version 4) triage tool to predict ED-relevant outcomes among adult patients with active cancer. METHODS: We conducted a prespecified analysis of the observational cohort established by the National Cancer Institute-supported Comprehensive Oncologic Emergencies Research Network's multicenter (18 sites) study of ED visits by patients with active cancer (N = 1075). We used a series of χ2 tests for independence to relate ESI scores with 1) disposition, 2) ED resource use, 3) hospital length of stay, and 4) 30-day mortality. RESULTS: Among the 1008 subjects included in this analysis, the ESI distribution skewed heavily toward high acuity (>95% of subjects had an ESI level of 1, 2, or 3). ESI was significantly associated with patient disposition and ED resource use (p values < 0.05). No significant associations were observed between ESI and the non-ED based outcomes of hospital length of stay or 30-day mortality. CONCLUSION: ESI scores among ED patients with active cancer indicate higher acuity than the general ED population and are predictive of disposition and ED resource use. These findings show that the ESI is a valid triage tool for use in this population for outcomes directly relevant to ED care.

Possible Transfusion-Transmitted Babesia divergens-like/MO-1 Infection in an Arkansas Patient.

A patient with asplenia and multiple red blood cell transfusions acquired babesiosis infection with Babesia divergens-like/MO-1 organisms and not Babesia microti, the common United States species. He had no known tick exposure. This is believed to be the first transfusion-transmitted case and the fifth documented case of B. divergens-like/MO-1 infection.

Establishing Chlamydomonas reinhardtii as an industrial biotechnology host.

Microalgae constitute a diverse group of eukaryotic unicellular organisms that are of interest for pure and applied research. Owing to their natural synthesis of value-added natural products microalgae are emerging as a source of sustainable chemical compounds, proteins and metabolites, including but not limited to those that could replace compounds currently made from fossil fuels. For the model microalga, Chlamydomonas reinhardtii, this has prompted a period of rapid development so that this organism is poised for exploitation as an industrial biotechnology platform. The question now is how best to achieve this? Highly advanced industrial biotechnology systems using bacteria and yeasts were established in a classical metabolic engineering manner over several decades. However, the advent of advanced molecular tools and the rise of synthetic biology provide an opportunity to expedite the development of C. reinhardtii as an industrial biotechnology platform, avoiding the process of incremental improvement. In this review we describe the current status of genetic manipulation of C. reinhardtii for metabolic engineering. We then introduce several concepts that underpin synthetic biology, and show how generic parts are identified and used in a standard manner to achieve predictable outputs. Based on this we suggest that the development of C. reinhardtii as an industrial biotechnology platform can be achieved more efficiently through adoption of a synthetic biology approach.

De novo production of six key grape aroma monoterpenes by a geraniol synthase-engineered S. cerevisiae wine strain.

BACKGROUND: Monoterpenes are important contributors to grape and wine aroma. Moreover, certain monoterpenes have been shown to display health benefits with antimicrobial, anti-inflammatory, anticancer or hypotensive properties amongst others. The aim of this study was to construct self-aromatizing wine yeasts to overproduce de novo these plant metabolites in wines. RESULTS: Expression of the Ocimum basilicum (sweet basil) geraniol synthase (GES) gene in a Saccharomyces cerevisiae wine strain substantially changed the terpene profile of wine produced from a non-aromatic grape variety. Under microvinification conditions, and without compromising other fermentative traits, the recombinant yeast excreted geraniol de novo at an amount (~750 µg/L) well exceeding (>10-fold) its threshold for olfactory perception and also exceeding the quantities present in wines obtained from highly aromatic Muscat grapes. Interestingly, geraniol was further metabolized by yeast enzymes to additional monoterpenes and esters: citronellol, linalool, nerol, citronellyl acetate and geranyl acetate, resulting in a total monoterpene concentration (~1,558 µg/L) 230-fold greater than that of the control. We also found that monoterpene profiles of wines derived from mixed fermentations were found to be determined by the composition of the initial yeast inocula suggesting the feasibility of producing 'à la carte' wines having predetermined monoterpene contents. CONCLUSIONS: Geraniol synthase-engineered yeasts demonstrate potential in the development of monoterpene enhanced wines.