Plasmid-mediated phenotypic noise leads to transient antibiotic resistance in bacteria.

The rise of antibiotic resistance is a critical public health concern, requiring an understanding of mechanisms that enable bacteria to tolerate antimicrobial agents. Bacteria use diverse strategies, including the amplification of drug-resistance genes. In this paper, we showed that multicopy plasmids, often carrying antibiotic resistance genes in clinical bacteria, can rapidly amplify genes, leading to plasmid-mediated phenotypic noise and transient antibiotic resistance. By combining stochastic simulations of a computational model with high-throughput single-cell measurements of blaTEM-1 expression in Escherichia coli MG1655, we showed that plasmid copy number variability stably maintains populations composed of cells with both low and high plasmid copy numbers. This diversity in plasmid copy number enhances the probability of bacterial survival in the presence of antibiotics, while also rapidly reducing the burden of carrying multiple plasmids in drug-free environments. Our results further support the tenet that multicopy plasmids not only act as vehicles for the horizontal transfer of genetic information between cells but also as drivers of bacterial adaptation, enabling rapid modulation of gene copy numbers. Understanding the role of multicopy plasmids in antibiotic resistance is critical, and our study provides insights into how bacteria can transiently survive lethal concentrations of antibiotics.

Sustainable cultivation of melon landraces: Effects of grafting on the accumulation of flavor-related compounds.

Melon landraces are highly appreciated by consumers who pay price premiums to compensate for lower yields, enabling on-farm conservation. However, they are highly susceptible to soilborne diseases. This study analyses the impact of Cucurbita and Cucumis rootstocks on the accumulation of flavor-related metabolites in Spanish landraces of the Ibericus melon group, as a strategy to promote their sustainable cultivation. Scion genotype was the main factor conditioning the accumulation of sugars and acids both under standard and saline organic farming conditions. The effects of grafting on organic acid accumulation were negligible, while the effects on sugar content were significant. The latter effects were dependent on specific scion-rootstock combinations, though wild Cucumis (e.g. Fian) rootstocks represent an alternative that should be further studied. The effect on the accumulation of volatiles was limited, and again depended on specific scion-rootstock combinations. The rootstock effect even differed between populations of the same landrace.

MGRN1 depletion promotes intercellular adhesion in melanoma by upregulation of E-cadherin and inhibition of CDC42.

Mahogunin Ring Finger 1 is an E3-ubiquitin ligase encoded by the color gene MGRN1. Our previous in vitro and in vivo studies demonstrated that Mgrn1 deletion in mouse melanoma cells induced cell differentiation and adhesion, and decreased cell motility and invasion on collagen I, and lung colonization in an in vivo model. Here, we investigated the role of MGRN1 on human melanoma cell morphology, adhesion and expression of genes/proteins involved in an EMT-like transition. We demonstrated that wild-type BRAF human melanoma cells adopted a clustering-like morphology on collagen I, with permanent MGRN1 abrogation resulting in bigger cell clusters. Enhanced intercellular adhesion was mostly mediated by induction of E-cadherin and higher co-localization with ß-catenin. Transcriptional upregulation of E-cadherin likely occurred through downregulation of the ZEB1 repressor. Finally, pulldown assays showed reduced activation of CDC42 in the absence of MGRN1, which was reverted after E-cadherin silencing. Overall, these findings highlight a new MGRN1-dependent pathway regulating melanoma cell shape, motility, and invasion potential.

Outcomes in patients managed with endovascular stent for malignant superior vena cava syndrome.

Background: Malignant Superior Vena Cava Syndrome (SVCS) corresponds to the clinical manifestations due to the restriction of venous return to the right atrium secondary to obstruction of the superior vena cava and/or its main tributaries for a tumor. Endovascular management has proven to be safe, effective and cause a fast symptomatic relief in patients with SVCS. There is limited evidence in factors associated with outcomes in malignant setting for this procedure. Materials and methods: An analytical retrospective study was conducted and included patients that underwent endovascular management for malignant SVCS at the National Cancer Institute of Colombia between May 2016 and May 2021. Clinical and technical variables were analyzed to found associations with outcomes in these patients. Results: 54 patients were analyzed. Successful procedure rate was 94.4 %. At 10 months, the OS of the entire cohort of patients was 25 %. Patients with breast or lung cancer (P = 0.031), unsuccessful procedure (P = 0.011), and also with short time of symptoms to the date of the endovascular procedure (P = 0.027) had worse OS. Multivariate analysis showed that lung cancer [HR = 2.55, 95%IC:(1.21-5.36)] and left internal jugular vein or left Innominate vein distal stent attachment [HR = 3.27, 95%IC:(1.31-8.15)] were independent factors for worst OS. Conclusions: Based in the high success rate of the endovascular management and the better outcome in patients with early and successful procedure, this procedure should be considered as part of the multimodal treatment in patients with SVCS independent of the clinical scenario and the oncological diagnosis.

Toothpaste use in Peruvian children during COVID-19 pandemic: results from a National Demographic and Health Survey.

PURPOSE: To determine the impact of COVID-19 pandemic on use of toothpaste in Peruvian children. METHODS: A national database of Peruvian children from 0 to 11 years old was used to develop a cross-sectional study, with a final sample of 51, 013 subjects. Data were obtained of results of the Demographic and Family Health Survey (ENDES); the questionnaire was self-reported. The use of toothpaste and fluoride concentration in toothpaste were dependent variables, and for the independent variable, the year was considered; in addition, other covariates were included. The statistical analyses applied were descriptive, bivariate, and multivariate tests. RESULTS: Use of toothpaste was 98.99% (n = 50,134), while fluoride toothpaste with < 1000 ppm was used by 77.29% (n = 27,366). For bivariate analysis, use of toothpaste was associated with place and area of residence, altitude, natural region, and age; for use of fluoride toothpaste with minimum 1000 ppm, there was an association with place and area of residence, natural region, wealth index, and age. In a multivariate manner, year only presented a positive association with use of fluoride toothpaste < 1000 ppm (RPa:1.04; 95%CI 1.01-1.07). CONCLUSIONS: Year 2020 of COVID-19 pandemic had a positive impact on the use of < 1000 ppm fluoride toothpaste in Peruvian children.

ATP increases head volume in capacitated human sperm via a purinergic channel.

Scanning ion-conductance microscopy allowed us to document an external Ca2+ dependent ATP driven volume increase (ATPVI) in capacitated human sperm heads. We examined the involvement of purinergic receptors (PRs) P2X2R and P2X4R in ATPVI using their co-agonists progesterone and Ivermectin (Iver), and Cu2+, which co-activates P2X2Rs and inhibits P2X4Rs. Iver enhanced ATPVI and Cu2+ and 5BDBD inhibited it, indicating P2X4Rs contributed to this response. Moreover, Cu2+ and 5BDBD inhibited the ATP-induced acrosome reaction (AR) which was enhanced by Iver. ATP increased the concentration of intracellular Ca2+ ([Ca2+]i) in >45% of individual sperm, most of which underwent AR monitored using FM4-64. Our findings suggest that human sperm P2X4R activation by ATP increases [Ca2+]i mainly due to Ca2+ influx which leads to a sperm head volume increase, likely involving acrosomal swelling, and resulting in AR.

Segregational instability of multicopy plasmids: A population genetics approach.

Plasmids are extra-chromosomal genetic elements that encode a wide variety of phenotypes and can be maintained in bacterial populations through vertical and horizontal transmission, thus increasing bacterial adaptation to hostile environmental conditions like those imposed by antimicrobial substances. To circumvent the segregational instability resulting from randomly distributing plasmids between daughter cells upon division, nontransmissible plasmids tend to be carried in multiple copies per cell, with the added benefit of exhibiting increased gene dosage and resistance levels. But carrying multiple copies also results in a high metabolic burden to the bacterial host, therefore reducing the overall fitness of the population. This trade-off poses an existential question for plasmids: What is the optimal plasmid copy number? In this manuscript, we address this question by postulating and analyzing a population genetics model to evaluate the interaction between selective pressure, the number of plasmid copies carried by each cell, and the metabolic burden associated with plasmid bearing in the absence of selection for plasmid-encoded traits. Parameter values of the model were estimated experimentally using Escherichia coli K12 carrying a multicopy plasmid encoding for a fluorescent protein and bla TEM-1, a gene conferring resistance to ß-lactam antibiotics. By numerically determining the optimal plasmid copy number for constant and fluctuating selection regimes, we show that plasmid copy number is a highly optimized evolutionary trait that depends on the rate of environmental fluctuation and balances the benefit between increased stability in the absence of selection with the burden associated with carrying multiple copies of the plasmid.

Liver transplant with controlled donors after circulatory death with normothermic regional perfusion and brain dead donors: A multicenter cohort study of transfusion, one-year graft survival and mortality.

BACKGROUND: Controlled donation after circulatory death (cDCD) has expanded the donor pool for liver transplantation (LT). However, transfusion requirements and perioperative outcomes should be elucidated. The aim of this multicenter study was to assess red blood cell (RBC) transfusions, one-year graft and patient survival after LT after cDCD with normothermic regional perfusion (NRP) compared with donors after brain death (DBD). METHODS: 591 LT carried out in ten centers during 2019 were reviewed. Thromboelastometry was used to manage coagulation and blood product transfusion in all centers. Normothermic regional perfusion was the standard technique for organ recovery. RESULTS: 447 patients received DBD and 144 cDCD with NRP. Baseline MCF Extem was lower in the cDCD group There were no differences in the percentage of patients (63% vs. 61% p = 0.69), nor in the number of RBC units transfused (4.7 (0.2) vs 5.5 (0.4) in DBD vs cDCD, p = 0.11. Twenty-six patients (6%) died during admission for LT in the DBD group compared with 3 patients (2%) in the cDCD group (p = 0.15). To overcome the bias due to a worse coagulation profile in cDCD recipients, matched samples were compared. No differences in baseline laboratory data, or in intraoperative use of RBC or one-year outcome data were observed between DBD and cDCD recipients. CONCLUSIONS: cDCD with NRP is not associated with increased RBC transfusion. No differences in graft and patient survival between cDCD and DBD were found. Donors after controlled circulatory death with NRP can increasingly be utilized with safety, improving the imbalance between organ donors and the ever-growing demand.

Vitrification of Iberian wolf (Canis lupus signatus) sperm: A possible alternative to conventional cryopreservation.

Sperm vitrification is a simple, inexpensive method that allows the cryopreservation of sperm in the field and for endangered species is a useful alternative to conventional freezing. The study, therefore, is focused on the suitability of vitrification for cryopreserving Iberian wolf sperm and utilizing plasma testosterone concentration as a marker for procedure efficacy. Sperm and blood samples were collected from 17 wolves. There were 14 samples suitable for cryopreservation (12 ejaculated and two epididymal). Immediately after collection, these samples were proportioned into two aliquots for conventional freezing using a Tris-citric acid-glucose based extender (TCG) or vitrification utilizing an animal protein free extender (HTF®). Vitrification occurred by directly plunging a sperm suspension into liquid nitrogen. Sperm were assessed for motility, membrane integrity, acrosomal status and DNA integrity before and after cryopreservation. With both techniques, there were similar post-thaw/warming results (P > 0.05) with respect to progressive motility, kinetic variables VCL, VSL, VAP and BCF, DNA fragmentation, sperm membrane functionality and morphological abnormalities. Total motile sperm, progression ratios LIN, STR, and WOB, the ALH, sperm viability and sperm with intact membrane and acrosome were greater (P < 0.05) in the conventional frozen-thawed sperm than vitrified-warmed sperm. Plasma testosterone concentrations varied from 0.0 ng/mL to 7.7 ng/mL. For epididymal sperm, sperm motility and viability following thawing were greater in vitrified-warmed samples than conventionally-frozen samples; however, small sample numbers precluded statistical analysis. When considered together, these results indicate vitrification may be a possible alternative for wolf sperm cryopreservation.

Evolutionary Pathways and Trajectories in Antibiotic Resistance.

Evolution is the hallmark of life. Descriptions of the evolution of microorganisms have provided a wealth of information, but knowledge regarding "what happened" has precluded a deeper understanding of "how" evolution has proceeded, as in the case of antimicrobial resistance. The difficulty in answering the "how" question lies in the multihierarchical dimensions of evolutionary processes, nested in complex networks, encompassing all units of selection, from genes to communities and ecosystems. At the simplest ontological level (as resistance genes), evolution proceeds by random (mutation and drift) and directional (natural selection) processes; however, sequential pathways of adaptive variation can occasionally be observed, and under fixed circumstances (particular fitness landscapes), evolution is predictable. At the highest level (such as that of plasmids, clones, species, microbiotas), the systems' degrees of freedom increase dramatically, related to the variable dispersal, fragmentation, relatedness, or coalescence of bacterial populations, depending on heterogeneous and changing niches and selective gradients in complex environments. Evolutionary trajectories of antibiotic resistance find their way in these changing landscapes subjected to random variations, becoming highly entropic and therefore unpredictable. However, experimental, phylogenetic, and ecogenetic analyses reveal preferential frequented paths (highways) where antibiotic resistance flows and propagates, allowing some understanding of evolutionary dynamics, modeling and designing interventions. Studies on antibiotic resistance have an applied aspect in improving individual health, One Health, and Global Health, as well as an academic value for understanding evolution. Most importantly, they have a heuristic significance as a model to reduce the negative influence of anthropogenic effects on the environment.

Quantifying plasmid dynamics using single-cell microfluidics and image bioinformatics.

Multicopy plasmids play an important role in bacterial ecology and evolution by accelerating the rate of adaptation and providing a platform for rapid gene amplification and evolutionary rescue. Despite the relevance of plasmids in bacterial evolutionary dynamics, evaluating the population-level consequences of randomly segregating and replicating plasmids in individual cells remains a challenging problem, both in theory and experimentally. In recent years, technological advances in fluorescence microscopy and microfluidics have allowed studying temporal changes in gene expression by quantifying the fluorescent intensity of individual cells under controlled environmental conditions. In this paper, we will describe the manufacture, experimental setup, and data analysis pipeline of different microfluidic systems that can be used to study plasmid dynamics, both in single-cells and in populations. To illustrate the benefits and limitations of microfluidics to study multicopy plasmid dynamics, we will use an experimental model system consisting on Escherichia coli K12 carrying non-conjugative, multicopy plasmids (19 copies per cell, in average) encoding different fluorescent markers and ß-lactam resistance genes. First, we will use an image-based flow cytometer to estimate changes in the allele distribution of a heterogeneous population under different selection regimes. Then we will use a mothermachine microfluidic device to obtain time-series of fluorescent intensity of individual cells to argue that plasmid segregation and replication dynamics are inherently stochastic processes. Finally, using a microchemostat, we track thousands of cells in time to reconstruct bacterial lineages and evaluate the allele frequency distributions that emerge in response to a range of selective pressures.

Transglutaminase Type 2 is Involved in the Hematopoietic Stem Cells Homeostasis.

Type 2 transglutaminase (TG2) is a multifunctional protein involved in various biological processes playing a key regulatory role in cell homeostasis such as cell death and autophagy. New evidence is emerging that support an important role of autophagy in regulating normal hematopoiesis. Prompted by these findings, in this study we investigated in vivo involvement of TG2 in mouse hematopoiesis under normal or nutrient deprivation conditions. We found that the number and rate of differentiation of bone marrow hematopoietic stem cell was decreased in the TG2 knockout mice. We present evidence showing that these effects on hematopoietic system are very likely due to the TG2-dependent impairment of autophagy. In fact, stimulation of autophagy by starvation is able to rescue the block of the differentiation of stem cells progenitors in the TG2 KO mice. It was also shown that the RhoA/ERK½ pathway, known to be essential for regulation of the bone marrow progenitor cells homeostasis, was significantly impaired in the absence of TG2. Hence, this study expanded our knowledge about TG2 discovering a role of this enzyme in regulation of hematopoiesis.

Factors Associated with Prolonged Recipient Hepatectomy Time During Liver Transplantation: A Single-Centre Experience.

BACKGROUND: Recipient hepatectomy during liver transplantation can be a challenging operation and can increase cold ischaemic time. The aim of this study is to assess factors associated with prolonged recipient hepatectomy. METHODS: From 2005 to 2015, 930 patients were submitted to liver transplantation in our hospital. Prolonged hepatectomy time was defined as operative time >180 min (from knife on skin to total hepatectomy). Patients undergoing early liver retransplantation and living donation were excluded. RESULTS: A total of 715 patients were included in our study. Median age at transplantation was 53 (18-70) years, and median BMI was 26.2 (16-40). Median hepatectomy time was 131 min. Prolonged hepatectomy time occurred in 89 (12.4%) patients. At univariate analysis, previous decompensated cirrhosis with variceal bleeding and/or ascites, higher BMI and previous abdominal surgery were associated with prolonged operating time. Higher surgeon experience and acute liver failure were associated with shorter hepatectomy time. At multivariate analysis, previous episodes of variceal bleeding (p = 0.027, OR 1.78), BMI > 27 (p = 0.01, OR 1.75), previous abdominal surgery (p = 0.04, OR 1.68) and surgeon experience (p = 0.007, OR 2.04) were independently associated with operating time. Prolonged hepatectomy time was significantly associated with cold and total ischaemic time and intraoperative bleeding (p < 0.001, p = 0.002 and p = 0.002, respectively). CONCLUSIONS: Recipient BMI, previous episodes of variceal bleeding, previous abdominal surgery and surgeon experience are independently associated with hepatectomy duration. These factors can be helpful to identify those patients with potentially prolonged hepatectomy time, and therefore, strategies can be put in place to optimize outcomes in this group of patients.

Mucoepidermoid carcinoma. An update and review of the literature.

OBJECTIVE: Mucoepidermoid Carcinoma (MEC) is the most common malignant salivary gland neoplasm, representing 10 to 15% of all salivary neoplasms. A review of the literature was conducted in order to determine trends in presentation, diagnostic features, treatment, and outcomes. METHODS: A PubMed, Embase, and Scopus search was carried out. The search process was performed by 2 independent reviewing authors and inclusion criteria included systematic reviews, meta-analyses, case-controls studies, cohort studies, comparative studies, clinical trials, cross-sectional studies, descriptive studies, experimental studies, case reports, case series studies, and human studies evaluating MEC. RESULTS: Females were more affected (54.5%) and the average age was 48.8 years. The most common location of MEC was the parotid glands (56.8%) followed by hard palate (18%). The most frequent clinical presentation was mass (65.2%) followed by ulcer (29.4%) with pressure as their main symptom (64.4%). The most frequent histologic presentation was Low grade (46.7%) followed by Intermediate grade (27.3%) and the most used treatment was surgery (76.2%). The average follow up was 138.5months, and recurrence was reported at 8.5%. CONCLUSION: MEC showed a strong predilection for the parotid glands is frequently painful, most frequently presents as a mass and most commonly has a low-grade histologic presentation.

Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling.

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

El comienzo de la OFIL o un sueño hecho realidad / The beginning of OFIL or a dream come true

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Olive oil quality classification and measurement of its organoleptic attributes by untargeted GC-MS and multivariate statistical-based approach.

The capabilities of dynamic headspace entrainment followed by thermal desorption in combination with gas chromatography (GC) coupled to single quadrupole mass spectrometry (MS) have been tested for the determination of volatile components of olive oil. This technique has shown a great potential for olive oil quality classification by using an untargeted approach. The data processing strategy consisted of three different steps: component detection from GC-MS data using novel data treatment software PARADISe, a multivariate analysis using EZ-Info, and the creation of the statistical models. The great number of compounds determined enabled not only the development of a quality classification method as a complementary tool to the official established method "PANEL TEST" but also a correlation between these compounds and different types of defect. Classification method was finally validated using blind samples. An accuracy of 85% in oil classification was obtained, with 100% of extra virgin samples correctly classified.

Optimización de la elección de talla para el segundo ojo basándose en el vault obtenido en el primero en la cirugía bilateral de lentes fáquicas de cámara posterior / Optimization of the lens sizing for the second eye based on the vault obtained in the first eye in bilateral myopic collamer phakic intraocular lens surgery

OBJETIVO: Evaluar el vault y la toma de decisiones en la selección del tamaño de la lente del segundo ojo en una serie de pacientes que recibieron implantes bilaterales de una lente fáquica de cámara posterior (pIOL) con puerto central para la corrección de la miopía. MÉTODOS: La muestra del estudio incluyó los pacientes a los que se implantó una pIOL de diferente tamaño entre ambos ojos de una serie total de 269 pacientes intervenidos mediante inserción bilateral secuencial en nuestra institución entre marzo de 2012 y mayo de 2015. Los procedimientos en cada paciente fueron separados en el tiempo para seleccionar el tamaño de la pIOL en los segundos ojos. El vault fue analizado objetivamente mediante tomografía de coherencia óptica. RESULTADOS: La decisión de modificar el tamaño de la pIOL se tomó en 25 pacientes. En 9 pacientes se implantó una pIOL más pequeña en el segundo ojo, mientras que en 16 pacientes se necesitó una talla más grande. La implantación de una talla más grande condujo a un aumento medio del vault de 251 ± 180 micras, mientras que una lente de menor tamaño se tradujo en una disminución media del vault de 542 ± 187 micras. En 5 pacientes, la pIOL implantada en el primer ojo se rotó verticalmente para reducir el vault. No fue necesario explantar ninguna lente. CONCLUSIONES: El vault en los ojos adelfos de pacientes intervenidos bilateralmente con una pIOL miópica puede ser optimizado valorando la talla a implantar en el segundo ojo en función del vault obtenido en el primer ojo

PURPOSE: To assess vault and the decision-making process involved in selecting the size of the lens for the fellow eye in a series of patients who received bilateral phakic collamer intraocular lens (pIOL) implants with central hole for correction of myopia. METHODS: The study sample included all patients who underwent bilateral insertion of a different size pIOL from a pool of 269 patients who underwent sequential bilateral insertion of a pIOL from March 2012 to May 2015 in our institution. Procedures were separated in time to assess the value of the vault and select the pIOL size in second eyes. Vault was analysed objectively using optical coherence tomography. RESULTS: The decision to change the size of the pIOL in the fellow eye was taken in 25 patients. A smaller pIOL was implanted in the second eye in 9 patients, whereas a lens that was 1 size larger was necessary in 16 patients. Implantation of a larger lens led to a mean increase in vault of 251 ± 180 microns; implantation of a smaller size lens led to a mean decrease in vault of 542 ± 187 microns. In 5 patients, the pIOL implanted in first eye was rotated vertically to reduce lens vault. No lenses had to be explanted. CONCLUSIONS: Vault in fellow eyes can be improved in patients receiving bilateral myopic pIOL implants by modifying the pIOL size based on the vault value obtained in the first eyes

Use of microbial models to evaluate the effect of UV-C light and trans-cinnamaldehyde on the native microbial load of grapefruit (Citrus × paradisi) juice.

The aim of this research was to evaluate the storage stability (5 °C), and microbial modeling, of Rubi red grapefruit (Citrus × paradisi) juice treated with ultraviolet-C (UV-C) light (0, 10 and 20 min), alone or in combination with trans-cinnamaldehyde (trans-CAH) (0, 25 and 50 µg/mL). A 32 factorial design was used and data modeled with the Weibull, Modified Gompertz and Logistic models. A response surface model was used to evaluate the effect of modeling parameters for suggesting the optimum treatment conditions. Treated and some untreated juice lasted up to 9 days without physicochemical and microbial changes. At the higher combination of UV-C light and trans-CAH, the microbial load of grapefruit juice was maintained below 100 CFU/mL up to 15 days. For mesophiles, the three predictive models indicated that the parameters n and Nmax decreased and the parameters λ and tc increased as the combination of UV-C light and trans-CAH increased. The response surface modeling of the parameters obtained by the predictive models showed acceptable correlation for mesophiles (R2 = 0.815-0.977) but not for yeasts (R2 = 0.618-0.815). The three predictive models showed that, the concentration of trans-CAH had more effect on stopping the microbial growth than the UV-C light treatment.