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Some statistical analysis techniques may require complete data matrices, but a frequent problem in the construction of databases is the incomplete collection of information for different reasons. One option to tackle the problem is to estimate and impute the missing data. This paper describes a form of imputation that mixes regression with lower rank approximations. To improve the quality of the imputations, a generalisation is proposed that replaces the singular value decomposition (SVD) of the matrix with a regularised SVD in which the regularisation parameter is estimated by cross-validation. To evaluate the performance of the proposal, ten sets of real data from multienvironment trials were used. Missing values were created in each set at four percentages of missing not at random, and three criteria were then considered to investigate the effectiveness of the proposal. The results show that the regularised method proves very competitive when compared to the original method, beating it in several of the considered scenarios. As it is a very general system, its application can be extended to all multivariate data matrices. •The imputation method is modified through the inclusion of a stable and efficient computational algorithm that replaces the classical SVD least squares criterion by a penalised criterion. This penalty produces smoothed eigenvectors and eigenvalues that avoid overfitting problems, improving the performance of the method when the penalty is necessary. The size of the penalty can be determined by minimising one of the following criteria: the prediction errors, the Procrustes similarity statistic or the critical angles between subspaces of principal components.

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Mexico and Central America have a high incidence of acute lymphoblastic leukemia (ALL) in adolescents and young adults. Historically, this patient group has been treated using adult-based regimens, which entails a high rate of treatment-related mortality and a poor overall survival (OS). The use of the CALGB 10403, a pediatric-inspired regimen, has been proven effective in this patient subgroup. Nonetheless, low- and middle-income countries (LMICs) may present limited access to standard care treatments implemented elsewhere, warranting the need for further research to improve outcomes among vulnerable populations. In this study, we present the outcomes in terms of safety and effectiveness of using a modified CALGB 10403 regimen to reflect drug and resource availability in LMICs. Modifications included the use of Escherichia coli asparaginase,6-mercaptopurine instead of thioguanine and the use of rituximab among patients with CD20+. A total of 95 patients with a median age of 23 (range, 14-49) years treated with this modified scheme were prospectively assessed at 5 centers in Mexico and 1 in Guatemala. Among these, 87.8% achieved a complete response after induction. During follow-up, 28.3% of patients relapsed. Two-year OS rate was 72.1%. Factors associated with worse OS included hyperleukocytosis (hazard ratio [HR], 4.28; 95% confidence interval [CI], 1.81-10.10) and postinduction minimal residual disease (HR, 4.67; 95% CI, 1.75-12.44). Most patients presented hepatotoxicity (51.6% and 53.7% during induction and consolidation, respectively), and the treatment-related mortality was 9.5%. Overall, results highlight that implementing a modified CALGB 10403 regimen in Central America is feasible, and it is associated with improvements in clinical outcomes and a manageable safety profile.

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This paper describes strategies to reduce the possible effect of outliers on the quality of imputations produced by a method that uses a mixture of two least squares techniques: regression and lower rank approximation of a matrix. To avoid the influence of discrepant data and maintain the computational speed of the original scheme, pre-processing options were explored before applying the imputation method. The first proposal is to previously use a robust singular value decomposition, the second is to detect outliers and then treat the potential outliers as missing. To evaluate the proposed methods, a cross-validation study was carried out on ten complete matrices of real data from multi-environment trials. The imputations were compared with the original data using three statistics: a measure of goodness of fit, the squared cosine between matrices and the prediction error. The results show that the original method should be replaced by one of the options presented here because outliers can cause low quality imputations or convergence problems.•The imputation algorithm based on Gabriel's cross-validation method uses two least squares techniques that can be affected by the presence of outliers. The inclusion of a robust singular value decomposition allows both to robustify the procedure and to detect outliers and consider them later as missing. These forms of pre-processing ensure that the algorithm performs well on any dataset that has a matrix form with suspected contamination.

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Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.

La leucemia mieloide aguda (LMA) comprende un grupo heterogéneo de neoplasias de células hematopoyéticas de linaje mieloide que surgen de la expansión clonal de sus precursores en la médula ósea, interfiriendo con la diferenciación celular, lo que conlleva a un síndrome de falla medular. La LMA es una consecuencia de cambios genéticos y epigenéticos (mutaciones puntuales, rearreglos de genes, deleciones, amplificaciones y arreglos en cambios epigenéticos que influyen en la expression del gen) en las células hematopoyéticas precursoras, la cual crea una clona de células anormales que son capaces de proliferar, pero no se pueden diferenciar en células hematopoyéticas maduras ni sufrir una muerte celular programada. El diagnostic requiere más del 20% de blastos mieloides en médula ósea y ciertas anormalidades citogénicas. El tratamiento dependerá de la edad, comorbilidades, riesgo citogenético entre las más frecuentes.

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BACKGROUND: Acute lymphoblastic leukemia (ALL) is a malignant clonal bone marrow disorder with a high mortality rate during the initial therapy. This retrospective study aimed to describe and analyze the risk factors and causes of induction-related mortality (IRM) in an adolescent and adult ALL population treated in a low- and middle-income country. METHODS: From 2009 to 2016, a total of 167 patients were included, of which 50.9% were male with a median age of 28 years. B-immunophenotype represented 97.6%, and high-risk cytogenetics were present in 23.3%. During induction therapy, 91% had at least 1 complication, most of which were infectious, with an IRM of 12%. RESULTS: Factors associated with increased mortality rate were central nervous system (CNS) status [CNS-3: hazard ratio (HR) 3.029; 95% confidence interval (CI), 0.79‒11.49; P =0.103 and CNS-2: HR, 9.98; 95% CI, 2.65‒37.65; P =0.001] and dialysis requirement (HR, 9.15; 95% CI, 2.44‒34.34; P =0.001). CONCLUSION: Our study confirms that ALL patients treated in resource-constrained settings have high rates of IRM, mainly attributed to advanced disease and high tumor burden at diagnosis.

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Objectives: Venetoclax combinations are a new standard for patients with acute myeloid leukemia (AML). We aimed to evaluate the safety and efficacy of these combinations in a period of accelerated approval in Latin-America.Methods: This observational study evaluated adults with acute myeloid leukemia who received venetoclax-based therapy in 11 public or private centers in Mexico and Peru for both newly diagnosed or relapsed and refractory AML.Results: Fifty patients were included; 28 with newly diagnosed (ND) AML and 22 with relapsed/refractory (RR) disease. ND patients were older (64 vs. 40 years; p < 0.001) with a lower functional capacity (ECOG ≥2 64.3% vs 9%; p < 0.001). Venetoclax was frequently combined with azacytidine (60%) and prophylactic azoles (82%) with a median maximum dose of 200 mg (range, 100-600 mg). Hematologic toxicities were common. Complete response rates including patients with incomplete hematopoietic recovery were 78.6% in ND and 45.5% in RR patients, with a median overall survival of 9.6 (95% CI 3.7-15.5) and 8 months (95% CI 4.8-11.2).Discussion: Our study showed a preferred use of venetoclax plus azacytidine over cyatrabine. Patients in the first-line setting were similar to those in the landmark studies, while most patients with relapsed disease had received prior intensive therapies. Responses were favorable, with a median survival in agreement to other reports, albeit shorter than that observed in the randomized phase-3 trials.Conclusion: Venetoclax-based therapy in AML was effective despite dose reductions and prophylactic antifungals in two middle-income countries outside of a clinical trial setting.

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AIMS: Fermented feed is an agricultural practice used in many regions of the world to improve the growth performance of farm animals. This study aimed to identify and evaluate the lactic acid bacteria and yeast involved in the production of fermented feed. METHODS AND RESULTS: We isolated and described two micro-organisms from autochthonous microbiota origin present in a regional feed product, Lactobacillus paracasei IBR07 (Lacticaseibacillus paracasei) and Kazachstania unispora IBR014 (Saccharomyces unisporum). Genome sequence analyses were performed to characterize both micro-organisms. Potential pathways involved in the acid response, tolerance and persistence were predicted in both genomes. Although L. paracasei and K. unispora are considered safe for animal feed, we analysed the presence of virulence factors, antibiotic resistance and pathogenicity islands. Furthermore, the Galleria mellonella model was used to support the safety of both isolates. CONCLUSIONS: We conclude that IBR07 and IBR014 strains are good candidates to be used as starter cultures for feed fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: The data presented here will be helpful to explore other biotechnological aspects and constitute a starting point for further studies to establish the consumption benefit of fermented feed in farm animal production.

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Abstract Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.

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Immune thrombocytopenia (ITP) has been widely reported as a complication of SARS-CoV-2 infection, but to our knowledge, there have been no reports on the association of the COVID-19 vaccine with thrombocytopenia. Here, we report a case of secondary ITP in a patient who was recently immunised with the messenger RNA COVID-19 vaccine BNT162b2 (Pfizer-BioNTech).

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To identify this increasingly common pathology, known as multiple myeloma (MM), it is necessary to refer to the specific factors that characterize it; to this end, the classic criteria known as CRAB (hyperkalemia, renal failure, anemia, and lytic lesions) are available, in which renal failure is one of the most frequent complications. Recently, three indisputable biomarkers have been described for the diagnostic support for MM, which are: more than 10% of clonal plasma cells in bone marrow or, a biopsy that corroborates the presence of a plasmacytoma, light chain ratio ≥ 100 mg/dL and more than one focal lesion on magnetic resonance imaging. A differential diagnosis for plasma cell leukemia, solitary bone plasmacytoma, and extramedullary plasmacytoma should always be considered. Being this an incurable disease, a lot of research has been done regarding its therapeutic management, whose main objective is the disappearance of plasma cells and the patient clinical improvement. Melphalan was the first drug that showed a benefit in 1958 and afterward, with the addition of a steroid as a second drug, it was possible to improve response rates. Subsequently, different molecules were studied, forming multiple combinations, and achieving better rates of overall survival and progression-free survival. Years later, with the arrival of proteasome inhibitors such as bortezomib, and immunomodulators such as thalidomide and lenalidomide, an important turnaround in the disease has been seen, as deeper responses, more prolonged remissions, and improvement in the quality of life of patients have been achieved. This consensus has the purpose of integrating a group of Mexican specialists and promoting the updating of this pathology.

Para identificar una patología cada vez más común, conocida como mieloma múltiple, es necesario hacer alusión de los factores específicos que la caracterizan. Para ello existen los clásicos criterios conocidos como CRAB (hipercalcemia, insuficiencia renal, anemia y lesiones líticas), siendo la insuficiencia renal una de sus complicaciones más frecuentes. Recientemente se han descrito tres biomarcadores indiscutibles para el apoyo diagnóstico del mieloma múltiple, que son: más del 10% de células plasmáticas clonales en medula ósea o biopsia que corrobora la presencia de un plasmocitoma, relación de cadenas ligeras ≥ 100 mg/dl y más de una lesión focal en resonancia magnética. Se debe tomar siempre en cuenta el diagnóstico diferencial con leucemia de células plasmáticas, plasmocitoma óseo solitario y plasmocitoma extramedular. Al ser una enfermedad incurable, se ha investigado mucho en cuanto al manejo terapéutico, el cual tiene como objetivo principal la desaparición de las células plasmáticas y la mejoría clínica del paciente. El primer fármaco que demostró algún beneficio fue el melfalán en el año 1958 y posteriormente al adicionar un esteroide como segundo fármaco se logró mejorar las tasas de respuesta. Después se fueron estudiando diferentes moléculas, con las que se han realizado múltiples combinaciones, alcanzando mejores tasas de supervivencia global y supervivencia libre de progresión. Años más tarde, con la llegada de los inhibidores de proteosoma como el bortezomib, así como de los agentes inmunomoduladores como la talidomida y la lenalidomida, se presenta un giro importante en la enfermedad, ya que se logran respuestas más profundas, periodo de remisiones más prolongadas y mejoría en la calidad de vida de los pacientes. Este consenso tiene la finalidad de integrar a un grupo de especialistas mexicanos y promover la actualización de esta patología.

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• Isolated EMR is defined as the presence of clonal blasts in any tissue other than the medullary compartment with a bone marrow evaluation with less than 5% clonal blasts and a full donor chimerism. • Patients with iEMR have shown better survival outcomes when compared to BMR and EMR and in most cases it heralds a systemic relapse. • Risk factors for iEMR include: younger age, history of EMD, poor risk cytogenetics, advanced disease at HSCT, development of GVHD, and non-TBI based conditioning regimens. • Combination therapy, local and systemic, can achieve better remission rates in this subgroup of patients.

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Enterococcus faecium is frequently isolated from fermented food; in particular, they positively contribute to the aroma compound generation in traditional cheese. Citrate fermentation is a desirable property in these bacteria, but this feature is not uniformly distributed among E. faecium strains. In the present study, three selected E. faecium strains, IQ110 (cit-), GM70 (cit+ type I), and Com12 (cit+ type II), were analyzed in their production of aroma compounds in milk. End products and volatile organic compounds (VOCs) were determined by solid-phase micro-extraction combined with gas chromatography mass spectrometry (SPME-GC-MS). Principal component analysis (PCA) of aroma compound profiles revealed a different VOC composition for the three strains. In addition, resting cell experiments of E. faecium performed in the presence of leucine, citrate, or pyruvate as aroma compound precursors allowed us to determine metabolic differences between the studied strains. GM70 (cit+ type I) showed an active citrate metabolism, with increased levels of diacetyl and acetoin generation relative to Com12 or to citrate defective IQ110 strains. In addition, in the experimental conditions tested, a defective citrate-fermenting phenotype for the Com12 strain was found, while its leucine degradation and pyruvate metabolism were conserved. In conclusion, rational selection of E. faecium strains could be performed based on genotypic and phenotypic analyses. This would result in a performing strain, such as GM70, that could positively contribute to flavor, with typical notes of diacetyl, acetoin, 3-methyl butanal, and 3-methyl butanol in an adjuvant culture.

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PURPOSE OF REVIEW: The purpose of this review is to discuss the potential role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for Philadelphia-negative (Ph-) adult acute lymphoblastic leukemia (ALL) in first complete remission (CR1) in the era of minimal residual disease (MRD). RECENT FINDINGS: Allo-HSCT continues to have a role in the therapy of a selected group of high-risk adult patients with ALL in CR1. Although the clinical significance of MRD has been studied less extensively in adults with ALL than in children, recent studies support its role as the strongest prognostic factor that can identify patients that are unlikely to be cured by standard chemotherapy and benefit from undergoing allo-HSCT. In addition, MRD status both pre- and post-HSCT has been found to correlate directly with the risk of relapse. Currently, the clinical challenge consists on applying MRD and molecular failure to integrate novel agents and immunotherapy to lower MRD before allo-HSCT and to modulate the graft versus leukemia (GVL) effect after transplant.

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Pseudolymphomatous folliculitis is a rare entity included among the cutaneous pseudolymphomas. A 32-year-old man, with an unremarkable medical history, presented with a two-month history of an asymptomatic solitary nodule on his left cheek. Histopathological examination demonstrated a dense nodular and diffuse dermal lymphocytic infiltrate with numerous histiocytes and dendritic cells that surrounded hypertrophic hair follicles. Pseudolymphomatous folliculitis commonly presents in the fourth decade of life, with no sex predominance, as an asymptomatic, rapidly growing and solitary red dome-shaped nodule on the face. It has a benign clinical course as the lesions usually resolve with surgical excision or regress spontaneously after incisional biopsy. Although there is no report of pseudolymphomatous folliculitis progressing into lymphoma in the literature, follow-up of these patients is recommended.

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Abstract Pseudolymphomatous folliculitis is a rare entity included among the cutaneous pseudolymphomas. A 32-year-old man, with an unremarkable medical history, presented with a two-month history of an asymptomatic solitary nodule on his left cheek. Histopathological examination demonstrated a dense nodular and diffuse dermal lymphocytic infiltrate with numerous histiocytes and dendritic cells that surrounded hypertrophic hair follicles. Pseudolymphomatous folliculitis commonly presents in the fourth decade of life, with no sex predominance, as an asymptomatic, rapidly growing and solitary red dome-shaped nodule on the face. It has a benign clinical course as the lesions usually resolve with surgical excision or regress spontaneously after incisional biopsy. Although there is no report of pseudolymphomatous folliculitis progressing into lymphoma in the literature, follow-up of these patients is recommended.

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Introducción: los casos de pacientes con procesos infecciosos al final de la vida muestran la necesidad de contar con alternativas que garanticen el cuidado y el manejo terapéutico instaurado. Las vías clásicas intravenosa, intramuscular y oral se ven limitadas, mientras que la vía subcutánea demuestra ser una alternativa prometedora; sin embargo, la escasa evidencia científica reflejada en el bajo número de investigaciones, devela la necesidad de explorar y generar productos científicos que respalden esta práctica. Metodología: estudio documental, con base en un proceso de revisión sistemática, en el cual se realiza la búsqueda de 10 acciones descritas en un protocolo. Fueron seleccionados 34 artículos en idioma inglés y español, excluyendo 17. Los artículos fueron clasificados a partir de la escala del Centre for Evidence-Based Medicine, Oxford, consultando las bases: Nursing Skills, Clinicalkey, Pubmed, Springerlink, Science Direct, ProQuest y Cochrane. Se utilizaron como descriptores: antibacterianos, cuidados paliativos, protocolos, catéter, subcutáneo, signos, tiempo, antibiótico, enfermería, registros, consentimiento informado, valoración. Resultados: el 60% de las acciones propuestas en el protocolo no tuvo artículos que respaldaran su práctica, solamente el 40% fue clasificado. Conclusión: el protocolo no se recomienda, puesto que más del 50% de las actividades no cuentan con evidencia científica que las respalde.

Introduction: the cases of patients with infectious processes at the end of life show the necessity to count with alternatives that guarantee the care and the established therapeutic management. The classic intravenous, intramuscular and oral routes are limited, while the subcutaneous route demonstrates to be a promising alternative; however, the scarce scientific evidence reflected in the low number of research, unveils the necessity to explore and generate scientific products to endorse this practice. Methodology: a documental study, based on a systematic review process, in which the search of 10 actions described in a protocol is performed. 34 articles in English and Spanish were selected, excluding 17. The articles were classified based on the scale from Centre for Evidence-Based Medicine, Oxford, consulting the databases: Nursing Skills, Clinicalkey, Pubmed, Springerlink, ScienceDirect, ProQuest and Cochrane. The used descriptors: antibacterials, palliative care, protocols, subcutaneous catheter, signs, time, antibiotic, nursing, records, informed consent, and valuation. Results: 60% of the actions proposed in the protocol did not have articles to endorse their practice, only 40% was classified. Conclusion: the protocol is not recommended, since more than 50% of the activities do not have scientific evidence to endorse them.

Introdução: os casos de pacientes com processos infecciosos ao final da vida mostram a necessidade de contar com alternativas que garantam o cuidado e o manejo terapêutico estabelecido. As vias clássicas intravenosa, intramuscular e oral estão limitadas, enquanto que a via subcutânea demostra ser uma alternativa prometedora; porém, a escassa evidencia científica refletida no baixo número de pesquisas, revela a necessidade de explorar e gerar produtos científicos que respaldem esta prática. Metodologia: estudo documental, baseado num processo de revisão sistemática, no qual se realizou a busca de 10 ações descritas num protocolo. Foram selecionados 34 artigos em idioma inglês e espanhol, excluindo 17. Os artigos foram classificados a partir da escala do Centre for Evidence-Based Medicine, Oxford, consultando as bases: Nursing Skills, Clinicalkey, Pubmed, Springerlink, Science Direct, ProQuest e Cochrane. Utilizaram-se como descritores: antibacterianos, cuidados paliativos, protocolos, cateter, subcutâneo, signos, tempo, antibiótico, enfermagem, registros, consentimento informado, valoração. Resultados: o 60% das ações propostas no protocolo não teve artigos que respaldaram sua prática, somente o 40% foi classificado. Conclusão: o protocolo não se recomenda, já que mais do 50% das atividades não têm evidencia científica para apoiá-lo.

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Dairy production plants produce highly polluted wastewaters rich in organic molecules such as lactose, proteins and fats. Fats generally lead to low overall performance of the treatment system. In this study, a wastewater dairy lagoon was used as microbial source and different screening strategies were conducted to select 58 lipolytic microorganisms. Exoenzymes and RAPD analyses revealed genetic and phenotypic diversity among isolates. Bacillus safensis, Pseudomonas alcaliphila and the potential pathogens, B. cereus, Aeromonas and Acinetobacter were identified by 16S-rRNA, gyrA, oprI and/or oprL sequence analyses. Five out of 10 selected isolates produced lipolytic enzymes and grew in dairy wastewater. Based on these abilities and their safety, B. safensis S9 and P. alcaliphila ED1 were selected and their genome sequences determined. The genome of strain S9 and ED1 consisted of 3,794,315 and 5,239,535 bp and encoded for 3990 and 4844 genes, respectively. Putative extracellular enzymes with lipolytic (12 and 16), proteolytic (20) or hydrolytic (10 and 15) activity were identified for S9 and ED1 strains, respectively. These bacteria also encoded other technological relevant proteins such as amylases, proteases, glucanases, xylanases and pectate lyases.

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El escrito que se presenta a continuación es el resultado de un trabajo indagativo relacionado con las actividades en contacto con la naturaleza (ACN) y personas con necesidades educativas especiales (NEE). El objetivo de este estudio ha sido identificar la influencia que este tipo de actividades ejerce sobre los estudiantes con NEE y de qué forma afecta su entorno cercano y las relaciones sociales que sostiene en su diario vivir. La investigación se enmarca en la metodología cualitativa toda vez que lo central es conocer el sentido que se le otorga a esta línea de trabajo desde la perspectiva de la actividad física. Los resultados permiten concluir que el acercamiento y relación de los estudiantes con NEE a los espacios naturales tiene una influencia positiva y colabora asimismo en su autoconocimiento, autoestima, mejora de las relaciones sociales, con su entorno y familia.

The article that follows is the result of a investigative work related outdoor activities and people with special educatives needs (SEN). The aim of this study was to identify the influence that these activities have on students with SEN and how it affects their immediate environment and social relations holding. The research is part of the qualitative methodology given that the core is known the sense that gives this line of work from the perspective of physical activity. Results show that the approach and relationship of students with SEN to natural areas, has a positive influence and also works in his self-knowledge, self-esteem and improved social relationships with their immediate surroundings and family.

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In Enterococcus faecalis, the mae locus is constituted by two putative divergent operons, maePE and maeKR. The first operon encodes a putative H(+)/malate symporter (MaeP) and a malic enzyme (MaeE) previously shown to be essential for malate utilization in this bacterium. The maeKR operon encodes two putative proteins with significant similarity to two-component systems involved in sensing malate and activating its assimilation in bacteria. Our transcriptional and genetic assays showed that maePE and maeKR are induced in response to malate by the response regulator MaeR. In addition, we observed that both operons were partially repressed in the presence of glucose. Accordingly, the cometabolism of this sugar and malate was detected. The binding of the complex formed by CcpA and its corepressor P-Ser-HPr to a cre site located in the mae region was demonstrated in vitro and explains the carbon catabolite repression (CCR) observed for the maePE operon. However, our results also provide evidence for a CcpA-independent CCR mechanism regulating the expression of both operons. Finally, a biomass increment of 40 or 75% was observed compared to the biomass of cells grown only on glucose or malate, respectively. Cells cometabolizing both carbon sources exhibit a higher rate of glucose consumption and a lower rate of malate utilization. The growth improvement achieved by E. faecalis during glucose-malate cometabolism might explain why this microorganism employs different regulatory systems to tightly control the assimilation of both carbon sources.

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