Scoring personalized molecular portraits identify Systemic Lupus Erythematosus subtypes and predict individualized drug responses, symptomatology and disease progression.

OBJECTIVES: Systemic Lupus Erythematosus is a complex autoimmune disease that leads to significant worsening of quality of life and mortality. Flares appear unpredictably during the disease course and therapies used are often only partially effective. These challenges are mainly due to the molecular heterogeneity of the disease, and in this context, personalized medicine-based approaches offer major promise. With this work we intended to advance in that direction by developing MyPROSLE, an omic-based analytical workflow for measuring the molecular portrait of individual patients to support clinicians in their therapeutic decisions. METHODS: Immunological gene-modules were used to represent the transcriptome of the patients. A dysregulation score for each gene-module was calculated at the patient level based on averaged z-scores. Almost 6100 Lupus and 750 healthy samples were used to analyze the association among dysregulation scores, clinical manifestations, prognosis, flare and remission events and response to Tabalumab. Machine learning-based classification models were built to predict around 100 different clinical parameters based on personalized dysregulation scores. RESULTS: MyPROSLE allows to molecularly summarize patients in 206 gene-modules, clustered into nine main lupus signatures. The combination of these modules revealed highly differentiated pathological mechanisms. We found that the dysregulation of certain gene-modules is strongly associated with specific clinical manifestations, the occurrence of relapses or the presence of long-term remission and drug response. Therefore, MyPROSLE may be used to accurately predict these clinical outcomes. CONCLUSIONS: MyPROSLE (https://myprosle.genyo.es) allows molecular characterization of individual Lupus patients and it extracts key molecular information to support more precise therapeutic decisions.

Circular and L50-like leaderless enterocins share a common ABC-transporter immunity gene.

Microbes live within complex communities of interacting populations, either free-living in waters and soils or symbionts of animals and plants. Their interactions include the production of antimicrobial peptides (bacteriocins) to antagonize competitors, and these producers must carry their own immunity gene for self-protection. Whether other coexisting populations are sensitive or resistant to the bacteriocin producer will be key for the population dynamics within the microbial community. The immunity gene frequently consists of an ABC transporter to repel its own bacteriocin but rarely protects against a nonrelated bacteriocin. A case where this cross-resistance occurs mediated by a shared ABC transporter has been shown between enterocins MR10A/B and AS-48. The first is an L50-like leaderless enterocin, while AS-48 is a circular enterocin. In addition, L50-like enterocins such as MR10A/B have been found in E. faecalis and E. faecium, but AS-48 appears only in E. faecalis. Thus, using the ABC transporter of the enterocin MR10A/B gene cluster of Enterococcus faecalis MRR10-3 as a cross-resistance model, we aimed to unravel to what extent a particular ABC transporter can be shared across multiple bacteriocinogenic bacterial populations. To this end, we screened the MR10A/B-ABC transporters in available microbial genomes and analyzed their sequence homologies and distribution. Overall, our main findings are as follows: (i) the MR10A/B-ABC transporter is associated with multiple enterocin gene clusters; (ii) the different enterocins associated with this transporter have a saposin-like fold in common; (iii) the Mr10E component of the transporter is more conserved within its associated enterocin, while the Mr10FGH components are more conserved within the carrying species. This is the least known component of the transporter, but it has shown the greatest specificity to its corresponding enterocin. Bacteriocins are now being investigated as an alternative to antibiotics; hence, the wider or narrower distribution of the particular immunity gene should be taken into account for clinical applications to avoid the selection of resistant strains. Further research will be needed to investigate the mechanistic interactions between the Mr10E transporter component and the bacteriocin as well as the specific ecological and evolutionary mechanisms involved in the spread of the immunity transporter across multiple bacteriocins.

Incidence and Prognosis of Colorectal Cancer After Heart Transplantation: Data From the Spanish Post-Heart Transplant Tumor Registry.

In this observational and multicenter study, that included all patients who underwent a heart transplantation (HT) in Spain from 1984 to 2018, we analyzed the incidence, management, and prognosis of colorectal cancer (CRC) after HT. Of 6,244 patients with a HT and a median follow-up of 8.8 years since the procedure, 116 CRC cases (11.5% of noncutaneous solid cancers other than lymphoma registered) were diagnosed, mainly adenocarcinomas, after a mean of 9.3 years post-HT. The incidence of CRC increased with age at HT from 56.6 per 100,000 person-years among under 45 year olds to 436.4 per 100,000 person-years among over 64 year olds. The incidence rates for age-at-diagnosis groups were significantly greater than those estimated for the general Spanish population. Curative surgery, performed for 62 of 74 operable tumors, increased the probability of patient survival since a diagnosis of CRC, from 31.6% to 75.7% at 2 years, and from 15.8% to 48.6% at 5 years, compared to patients with inoperable tumors. Our results suggest that the incidence of CRC among HT patients is greater than in the general population, increasing with age at HT.

Utility of the IMPACT score for predicting heart transplant mortality. Analysis on a contemporary cohort of the Spanish Heart Transplant Registry.

INTRODUCTION AND OBJECTIVES: The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score was derived and validated as a predictor of mortality after heart transplantation (HT). The primary objective of this work is to externally validate the IMPACT score in a contemporary Spanish cohort. METHODS: Spanish Heart Transplant Registry data were used to identify adult (>16 years) HT patients between January 2000 and December 2015. Retransplantation, multiorgan transplantation and patients in whom at least one of the variables required to calculate the IMPACT score was missing were excluded from the analysis (N = 2810). RESULTS: Median value of the IMPACT score was five points (IQR: 3, 8). Overall, 1-year survival rate was 79.1%. Kaplan-Meier 1-year survival rates by IMPACT score categories (0-2, 3-5, 6-9, 10-14, ≥15) were 84.4%, 81.5%, 79.3%, 77.3%, and 58.5%, respectively (Log-Rank test: p < .001). Performance analysis showed a good calibration (Hosmer-Lemeshow chi-square for 1 year was 7.56; p = .47) and poor discrimination ability (AUC-ROC .59) of the IMPACT score as a predictive model. CONCLUSIONS: In a contemporary Spanish cohort, the IMPACT score failed to accurately predict the risk of death after HT.

Antibacterial and Antiparasitic Activity of Propyl-Propane-Thiosulfinate (PTS) and Propyl-Propane-Thiosulfonate (PTSO) from Allium cepa against Gilthead Sea Bream Pathogens in In Vitro and In Vivo Studies.

The use of phytogenic extracts is considered a sustainable strategy for the prevention of fish diseases, including Alliaceae as a potential option due to their variety of bioactive compounds. In this study, we analyzed the antibacterial and antiparasitic potential of propyl-propane-thiosulfinate (PTS) and propyl-propane-thiosulfonate (PTSO) from onions. The in vitro activity against Pseudomonas anguilliseptica, Tenacibaculum maritimum, and Photobacterium damselae of both compounds was tested. In addition, the viability of Sparicotyle chrysophrii larvae was evaluated. Moreover, a diet that consisted of a blend of PTS/PTSO (ALLIUM) was used. A total of 90 gilthead sea bream juveniles were tested against P. damselae subsp. Piscicida after 12 weeks of dietary administration. Furthermore, 150 fish with a rate of 10-15 parasites/fish were fed for 21 days and the number of gill parasites was recorded. All strains were sensitive to both compounds. PTSO showed the highest inhibitory effect against all target strains, while PTS showed higher effectiveness against S. chrysophrii. Fish from ALLIUM group presented the highest probability of survival, increasing up to 91.1%, whereas in the control group, the probability of survival was 66.7%. The number of parasites in the gilthead sea bream decreased in the ALLIUM group over time. These results suggest the inclusion of PTS and PTSO in feed as a natural strategy to prevent antibacterial and antiparasitic fish diseases.

Spanish experience with heart transplants from controlled donation after the circulatory determination of death using thoraco-abdominal normothermic regional perfusion and cold storage.

Heart transplantation from controlled donation after the circulatory determination of death (cDCDD) may help to increase the availability of hearts for transplantation. During 2020, four heart transplants were performed at three different Spanish hospitals based on the use of thoraco-abdominal normothermic regional perfusion (TA-NRP) followed by cold storage (CS). All donors were young adults <45 years. The functional warms ischemic time ranged from 8 to 16 minutes. In all cases, the heart recovered sinus rhythm within 1 minute of TA-NRP. TA-NRP was weaned off or decreased <1L within 25 minutes. No recipient required mechanical support after transplantation and all were immediately extubated and discharged home (median hospital stay: 21 days) with an excellent outcome. Four livers, eight kidneys, and two pancreata were also recovered and transplanted. All abdominal grafts recipients experienced an excellent outcome. The use of TA-NRP makes heart transplantation feasible and allows assessing heart function before organ procurement without any negative impact on the preservation of abdominal organs. The use of TA-NRP in cDCDD heart donors in conjunction with cold storage following retrieval can eliminate the need to use ex situ machine perfusion devices, making cDCDD heart transplantation economically possible in other countries.

COVID-19 in transplant recipients: The Spanish experience.

We report the nationwide experience with solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients diagnosed with coronavirus disease 2019 (COVID-19) in Spain until 13 July 2020. We compiled information for 778 (423 kidney, 113 HSCT, 110 liver, 69 heart, 54 lung, 8 pancreas, 1 multivisceral) recipients. Median age at diagnosis was 61 years (interquartile range [IQR]: 52-70), and 66% were male. The incidence of COVID-19 in SOT recipients was two-fold higher compared to the Spanish general population. The median interval from transplantation was 59 months (IQR: 18-131). Infection was hospital-acquired in 13% of cases. No donor-derived COVID-19 was suspected. Most patients (89%) were admitted to the hospital. Therapies included hydroxychloroquine (84%), azithromycin (53%), protease inhibitors (37%), and interferon-ß (5%), whereas immunomodulation was based on corticosteroids (41%) and tocilizumab (21%). Adjustment of immunosuppression was performed in 85% of patients. At the time of analysis, complete follow-up was available from 652 patients. Acute respiratory distress syndrome occurred in 35% of patients. Ultimately, 174 (27%) patients died. In univariate analysis, risk factors for death were lung transplantation (odds ratio [OR]: 2.5; 95% CI: 1.4-4.6), age >60 years (OR: 3.7; 95% CI: 2.5-5.5), and hospital-acquired COVID-19 (OR: 3.0; 95% CI: 1.9-4.9).

Fluorizoline-induced apoptosis requires prohibitins in nematodes and human cells.

We previously showed that fluorizoline, a fluorinated thiazoline compound, binds to both subunits of the mitochondrial prohibitin (PHB) complex, PHB1 and PHB2, being the expression of these proteins required for fluorizoline-induced apoptosis in mouse embryonic fibroblasts. To investigate the conservation of this apoptotic mechanism, we studied the effect of PHB downregulation on fluorizoline activity on two human cell lines, HEK293T and U2OS. Then, we asked whether PHBs mediate the effect of fluorizoline in a multicellular organism. Interestingly, reduced levels of PHBs in the human cells impaired the induction of apoptosis by fluorizoline. We observed that fluorizoline has a detrimental dose-dependent effect on the development and survival of the nematode model Caenorhabditis elegans. Besides, such effects of fluorizoline treatment in living nematodes were absent in PHB mutants. Finally, we further explored the apoptotic pathway triggered by fluorizoline in human cell lines. We found that the BH3-only proteins NOXA, BIM and PUMA participate in fluorizoline-induced apoptosis and that the induction of NOXA and PUMA is dependent on PHB expression.

Cosmetic coloration of cross-fostered eggs affects paternal investment in the hoopoe (Upupa epops).

The signalling hypothesis suggests that avian eggshell coloration is a sexually selected female signal advertising her quality to its male partner, thereby stimulating his provisioning rate. This hypothesis has been tested for structural eggshell pigments, but not for cosmetic colorations, such as that produced by the uropygial secretion on eggshells. During the breeding season, female hoopoes (Upupa epops) host in their uropygial glands symbiotic bacteria. Females actively smear the eggshells with their secretion, protecting embryos from pathogenic trans-shell infections and changing eggshell coloration. Because the colour of the secretions is related to their antimicrobial potential, cosmetic eggshell coloration may act as a cue or even as a post-mating sexually selected signal if it affects male provisioning rates. To experimentally test this hypothesis, we cross-fostered already-smeared clutches between hoopoe nests, and quantified male feeding behaviour to females before and after the experiment. This approach allows disentanglement of the effects of female quality and of egg coloration on male investment. In accordance with the hypothesis, males adjusted their provisioning rate to the eggshell cosmetic coloration. This is, to our knowledge, the first experimental demonstration that egg colour stained with uropygial secretion could act as a post-mating sexual signal of female quality to males.

Malignancy following heart transplantation: differences in incidence and prognosis between sexes - a multicenter cohort study.

Male patients are at increased risk for developing malignancy postheart transplantation (HT); however, real incidence and prognosis in both genders remain unknown. The aim of this study was to assess differences in incidence and mortality related to malignancy between genders in a large cohort of HT patients. Incidence and mortality rates were calculated for all tumors, skin cancers (SCs), lymphoma, and nonskin solid cancers (NSSCs) as well as survival since first diagnosis of neoplasia. 5865 patients (81.6% male) were included. Total incidence rates for all tumors, SCs, and NSSCs were lower in females [all tumors: 25.7 vs. 44.8 per 1000 person-years; rate ratio (RR) 0.68, (0.60-0.78), P < 0.001]. Mortality rates were also lower in females for all tumors [94.0 (77.3-114.3) vs. 129.6 (120.9-138.9) per 1000 person-years; RR 0.76, (0.62-0.94), P = 0.01] and for NSSCs [125.0 (95.2-164.0) vs 234.7 (214.0-257.5) per 1000 person-years; RR 0.60 (0.44-0.80), P = 0.001], albeit not for SCs or lymphoma. Female sex was associated with a better survival after diagnosis of malignancy [log-rank p test = 0.0037; HR 0.74 (0.60-0.91), P = 0.004]. In conclusion, incidence of malignancies post-HT is higher in males than in females, especially for SCs and NSSCs. Prognosis after cancer diagnosis is also worse in males.

Gender differences in heart transplantation: Twenty-five year trends in the nationwide Spanish heart transplant registry.

The study of gender differences may lead into improvement in patient care. We have aimed to identify the gender differences in heart transplantation (HT) of adult HT recipients in Spain and their evolution in a study covering the years 1993-2017 in which 6740 HT (20.6% in women) were performed. HT indication rate per million inhabitants was lower in women, remaining basically unchanged during the 25-year study period. HT rate was higher in men, although this decreased over the 25-year study period. Type of heart disease differed in men versus women (p < .001): ischemic heart disease 47.6% versus 22.5%, dilated cardiomyopathy 41.3% versus 34.6%, or other 36% versus 17.8%, respectively. Men were more frequently diabetics (18% vs. 13.1% p < .001), hypertensives (33.1% vs. 24% p < .001), and smokers (21.7% vs. 12.9% p < .001), respectively. Women had more pre-HT malignancies (7.1% vs. 2.8% p < .001), and their clinical status was worse at HT due to renal function and mechanical ventilation. Adjusted survival (p = .198) and most of the mortality-related variables were similar in men and women. Death occurred more frequently in women due to rejection (7.9% vs. 5.1% p < .001) and primary failure (18.2% vs. 12.5% p < .001) and in men due to malignancies (15.1% vs. 6.6% p < .001).

Left Ventricular Ejection Fraction Recovery in Patients with Heart Failure and Reduced Ejection Fraction Treated with Sacubitril/Valsartan.

BACKGROUND: A significant number of heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF) experience ventricular function recovery during follow-up. We studied the variables associated with LVEF recovery in patients treated with sacubitril/valsartan (SV) in clinical practice. METHODS: We analyzed data from a prospective and multicenter registry including 249 HF outpatients with reduced LVEF who started SV between October 2016 and March 2017. The patients were classified into 2 groups according to LVEF at the end of follow-up (>35%: group R, or ≤35%: group NR). RESULTS: After a mean follow-up of 7 ± 0.1 months, 62 patients (24.8%) had LVEF >35%. They were older (71.3 ± 10.8 vs. 67.5 ± 12.1 years, p = 0.025), and suffered more often from hypertension (83.9 vs. 73.8%, p = 0.096) and higher blood pressure before and after SV (both, p < 0.01). They took more often high doses of beta-blockers (30.6 vs. 27.8%, p = 0.002), with a smaller proportion undergoing cardiac resynchronization therapy (14.8 vs. 29.0%, p = 0.028) and fewer implanted cardioverter defibrillators (ICD; 32.8 vs. 67.9%, p < 0.001), this being the only predictive variable of NR in the multivariate analysis (OR 0.26, 95% CI 0.13-0.47, p < 0.0001). At the end of follow-up, the mean LVEF in group R was 41.9 ± 8.1% (vs. 26.3 ± 4.7% in group NR, p < 0.001), with an improvement compared with the initial LVEF of 14.6 ± 10.8% (vs. 0.8 ± 4.5% in group NR, p < 0.0001). Functional class improved in both groups, mainly in group R (p = 0.035), with fewer visits to the emergency department (11.5 vs. 21.6%, p = 0.07). CONCLUSIONS: In patients with LVEF ≤35% treated with SV, not carrying an ICD was independently associated with LVEF recovery, which was related to greater improvement in functional class.

Impact of mechanical circulatory support on survival in pediatric heart transplantation.

Evidence on the impact of MCS on pediatric heart transplant survival is still scarce related to congenital heart disease patients including univentricular physiology as well as the risk factors for complications. We performed a retrospective review of all urgent pediatric (aged ≤16 years) HT from 2004 to 2014 in the Spanish Pediatric Heart Transplant Registry Group. Patients were stratified into two groups: urgent 0 (MCS at HT) and urgent 1 (non-MCS at HT). The primary outcome measure was post-transplant survival; secondary outcome measures were complications and absence of infections and rejection during the first post-transplant year. One hundred twenty-one pediatric patients underwent urgent HT, 58 (47.9%) urgent 0 and 63 (52%) urgent 1. There were 30 (24.8%) deaths: 12 in the urgent 0 group and 18 in the urgent 1 group, P = n.s. Regarding the type of MCS, patients on ECMO had the highest rate of complications (80%) and mortality (40%). Patients in the urgent 1 group showed a higher risk of hospital re-admission for infection during the first year after transplantation (OR 2.31 [1.1-4.82]), P = .025. We did not identify a risk factor for mortality. MCS does not impact negatively on survival after HT. However, there is a significant increase in 30-day and 1-year mortality and complications in ECMO patients compared with VAD patients. Infants, congenital heart disease, and PediMACS were not found to be risk factors for mortality.

An update on the genetics of systemic lupus erythematosus.

PURPOSE OF REVIEW: The aim of this study is to update on the most recent findings on the genetics of systemic lupus erythematosus. RECENT FINDINGS: Our overview focuses particularly on results from expression quantitative trait loci, exome sequencing, and rare variants and their impact on disease. SUMMARY: Systemic lupus erythematosus is a systemic autoimmune disease for which a significant number of susceptibility genes have been identified. Several genome-wide association studies were recently published in different populations that provide a better picture of the molecular mechanisms. It is becoming clear that the genetic architecture of lupus is quite well established but more information is required on the role of rare variants.

Polymorphisms at phase I-metabolizing enzyme and hormone receptor loci influence the response to anti-TNF therapy in rheumatoid arthritis patients.

The aim of this case-control study was to evaluate whether 47 single-nucleotide polymorphisms (SNPs) in steroid hormone-related genes are associated with the risk of RA and anti-TNF drug response. We conducted a case-control study in 3 European populations including 2936 RA patients and 2197 healthy controls. Of those, a total of 1985 RA patients were treated with anti-TNF blockers. The association of potentially interesting markers in the discovery population was validated through meta-analysis with data from DREAM and DANBIO registries. Although none of the selected variants had a relevant role in modulating RA risk, the meta-analysis of the linear regression data with those from the DREAM and DANBIO registries showed a significant correlation of the CYP3A4rs11773597 and CYP2C9rs1799853 variants with changes in DAS28 after the administration of anti-TNF drugs (P = 0.00074 and P = 0.006, respectively). An overall haplotype analysis also showed that the ESR2GGG haplotype significantly associated with a reduced chance of having poor response to anti-TNF drugs (P = 0.0009). Finally, a ROC curve analysis confirmed that a model built with eight steroid hormone-related variants significantly improved the ability to predict drug response compared with the reference model including demographic and clinical variables (AUC = 0.633 vs. AUC = 0.556; PLR_test = 1.52 × 10-6). These data together with those reporting that the CYP3A4 and ESR2 SNPs correlate with the expression of TRIM4 and ESR2 mRNAs in PBMCs (ranging from P = 1.98 × 10-6 to P = 2.0 × 10-35), and that the CYP2C9rs1799853 SNP modulates the efficiency of multiple drugs, suggest that steroid hormone-related genes may have a role in determining the response to anti-TNF drugs.KEY POINTS• Polymorphisms within the CYP3A4 and CYP2C9 loci correlate with changes in DAS28 after treatment with anti-TNF drugs.• A haplotype including eQTL SNPs within the ESR2 gene associates with better response to anti-TNF drugs.• A genetic model built with eight steroid hormone-related variants significantly improved the ability to predict drug response.

Correction: Polymorphisms at phase I-metabolizing enzyme and hormone receptor loci influence the response to anti-TNF therapy in rheumatoid arthritis patients.

The original version of this Article contained an error in the spelling of the author Ana Rodríguez-Ramos, which was incorrectly given as Ana Rodríguez Ramos. This has now been corrected in both the PDF and HTML versions of the Article.

Sacubitril/Valsartan in Daily Clinical Practice: Data From a Prospective Registry.

Sacubitril/valsartan (SV) is a new therapy in heart failure with reduced ejection fraction. Our aim was to determine the efficacy and safety of this drug daily clinical practice. We performed a multicenter registry in 10 hospitals. All patients who started SV from October 2016 to March 2017 on an outpatient basis were included. A total of 427 patients started treatment with SV. Mean follow-up was 7.0 ± 0.1 months. Forty-nine patients (11.5%) discontinued SV, and 12 (2.8%) died. SV discontinuation was associated with higher cardiovascular (hazard ratio 13.22, 95% confidence interval, 6.71-15.73, P < 0.001) and all-cause mortality (hazard ratio 13.51, 95% confidence interval 3.22-56.13, P < 0.001). Symptomatic hypotension occurred in 71 patients (16.6%). Baseline N-terminal pro-B-type natriuretic peptide levels, functional class, and left ventricular ejection fraction improved at the end of follow-up in patients who continued with SV (all P values ≤0.001). This improvement was not significant in patients with SV discontinuation. SV has a good tolerability in patients from daily clinical practice. SV withdrawal in patients with heart failure and reduced ejection fraction was independently associated with increased all-cause mortality. Patients who continued with SV presented an improvement in functional class left ventricular ejection fraction and N-terminal pro-B-type natriuretic peptide levels.

Sex Influence on the Efficacy and Safety of Sacubitril/Valsartan.

BACKGROUND: Women are underrepresented in sacubitril/valsartan (SV) clinical trials. The aim of this study was to assess sex-specific differences in efficacy, tolerability, and safety of SV in real-world heart failure with reduced ejection fraction (HFrEF) patients. METHODS: A prospective registry in 10 centers including all patients who started SV during the last 6 months was analyzed in this study. RESULTS: A total of 427 patients were included, 126 (29.5%) were women. There were no substantial differences in HFrEF treatment before SV initiation, although fewer women than men carried an implantable cardioverter defibrillator (57 [45.2%] vs. 173 [58.1%], p = 0.02). SV starting dose was 24/26 mg b.i.d. in 206 patients (48.2%), 49/51 mg b.i.d. in 184 (43.1%), and 97/103 mg b.i.d. in 34 (8.2%), without relevant differences associated to sex. There were no losses during a mean follow-up of 7.0 ± 0.1 months. The proportion of patients who discontinued the drug (16 [12.7%] women vs. 33 [11.0%] men, p = 0.66) or presented SV-related adverse effects (31 [24.6%] women vs. 79 [26.5%] men, p = 0.72) was also similar in both sexes. However, female sex was an independent predictor of functional class improvement in the multivariate analysis (odds ratio 2.33, 95% confidence interval: 1.24-4.38, p = 0.04). CONCLUSIONS: SV in women with HFrEF has a similar tolerability as in men. Females seem to have a more frequent functional class improvement than males.

Effects of Enterococcus faecalis UGRA10 and the enterocin AS-48 against the fish pathogen Lactococcus garvieae. Studies in vitro and in vivo.

The aim of this study was to evaluate the effects of Enterococcus faecalis UGRA10 and its enterocin AS-48 against the fish pathogen Lactococcus garvieae. The minimum bactericidal concentrations of AS-48 against L. garvieae CECT 5807, 5806, and 5274 were 15.62, 15.62, and 7.81 µg/ml respectively. In broth cultures, enterocin at 100, 50, and 25 µg/ml reduced 108 CFU/ml lactococci after 2, 5, and 10 h, respectively. In co-cultures of UGRA10/L. garvieae at a 1/10 CFU/ml ratio, lactococci were eliminated after 24 h. Studies on UGRA10 biosafety and AS-48 toxicity in R1 cells and in rainbow trout have shown a lack of adverse effects from both the strain and bacteriocin. Trout challenged with L. garvieae and UGRA10 administered in diet 30 days before infection had a cumulative survival rate of 50% compared with 0% for control fish. Trout inoculated with the pathogen and treated by regular dipping in AS-48 baths had a survival rate of 60% after 20 days compared with that of untreated fish (0%). These results indicate the protective effect of the UGRA10 strain and the bacteriocin AS-48 against L. garvieae and the potential of these natural products as alternatives to antibiotics for controlling diseases in aquaculture.