Research Center for Food and Development A.C.

In November 2023, symptoms of leaf yellowing and wilting, as well as crown and root rot, were detected on raspberry plants in a commercial field located in Culiacán, Sinaloa, Mexico. Following the isolation of colonies displaying oomycete characteristics, two isolates were purified. Through a combination of morphological examinations, pathogenicity tests, and phylogenetic analysis using ITS and LSU sequence data, the causal agent was identified as Phytopythium helicoides Abad, De Cock, Bala, Robideau, Lodhi & Levesque. This is the first report of P. helicoides causing crown and root rot of raspberry worldwide.

Non-typhoidal Salmonella is responsible for gastrointestinal illnesses worldwide. Therefore, it is important to implement effective therapeutic interventions for preventing these diseases. Vaccines have proven highly efficacious in the treatment and prevention of several illnesses. Nevertheless, there is currently no authorized vaccine available for non-typhoidal salmonellosis. This study aimed to employ in silico techniques to develop a multi-epitope vaccine targeting non-typhoidal salmonellosis. Specifically, we focused on proteins associated with the starvation stress response (SSR) in Salmonella Oranienburg. The presence of these proteins is essential for the survival and disease of the host organism. The vaccine sequence was constructed utilizing B-cell and T-cell epitopes. Linkers, adjuvants and PADRE sequences were used to establish connections between epitopes. The vaccine exhibited no allergenicity, toxigenicity and a significantly high antigenicity score. Docking analysis conducted between the designed vaccine and the TLR-1, TLR-2 and TLR-4 receptors demonstrated favorable interactions and the potential to activate these receptors. In addition, it was found through immunological simulation testing that the vaccine elicits a robust immune response. The use of these proteins in the construction of a multi-epitope vaccine shows potential in terms of both safety and immunogenicity.

Frangipani (Plumeria spp.: Apocynaceae) is a small ornamental tree native to Mexico, susceptible to significant diseases such as anthracnose and foliar blight in hot, dry environments. Understanding the diversity of pathogens responsible for these diseases is crucial for developing effective disease management strategies. This study aimed to identify the pathogens responsible for these diseases. In February 2020 and 2021, symptoms of anthracnose and foliar blight were observed on frangipani plants in recreational areas of Morelos and Sinaloa, Mexico. Isolations from diseased leaf tissue resulted in the recovery of 12 Colletotrichum isolates from P. rubra and 18 Alternaria isolates from P. obtusa. After morphotype grouping, a representative isolate from each group was identified by morphology and phylogenetic reconstruction (ITS, act, gapdh, rpb2 and tef1) as Colletotrichum karstii, Colletotrichum siamense, Alternaria destruens and Alternaria burnsii. For pathogenicity testing, a conidial suspension was sprayed onto the leaves of 90-day-old plants, while control plants were sprayed with sterile distilled water. All inoculated fungi were pathogenic, reproducing the characteristic symptoms of the disease, while control plants remained symptomless. The fungi recovered from symptomatic plants were morphologically identical to the inoculated fungi, fulfilling Koch's postulates. This is the first report of A. burnsii and A. destruens causing foliar blight in P. obtusa, and C. siamense and C. karstii causing anthracnose in P. rubra. These findings contribute valuable insights for developing effective disease management strategies.

Resin from conifers is a sustainable material of human interest. Strategies to increase resin production, including chemical stimulation, are being implemented. This procedure is used in Brazil, India, and Indonesia, dominating countries in global resin production. China and Mexico are also recognized as crucial resin producers. The prime resin production zone in Mexico is Michoacan state, where nearly 90% of Mexican resin is produced, and the native Pinus devoniana var. cornuta and Pinus pringlei are included in the preferred species for this economic activity. Interestingly, chemical stimulation to improve the resin production of these species has not been applied. Consequently, this research aims to evaluate for the first time using chemical stimulation to increase the resin production from P. pringlei and P. devoniana var. cornuta. The stimulation was promoted by applying aqueous benzoic acid/H2SO4 directly on wounds. Analysis of Variance and Multiple Factor Analysis were performed to relate resin yield with chemical stimulation. Climatic factors were also involved in the study, including temperature, radiation, relative humidity, and wind. The influence of chemical stimulation on resin canals and the chemical composition of turpentine was boarded. Results provided exciting conclusions about the relationship between chemical stimulation, environmental impact, and anatomical changes in resin canals on the resination process in pines; in consequence, the chemical stimulation resulted in a potential strategy to increase resin production using P. pringlei and P. devoniana var. cornuta from Mexico.

Animal models are invaluable for studying biological processes and disease mechanisms. Fish, as vertebrates, share many conserved physiological, anatomical, and molecular features with humans, making them a valuable biological model. Their unique biological characteristics make them easy to manipulate and maintain in laboratory conditions. Also, fish diversity provides many options for choosing the most suitable model for a specific study. The increasing prevalence of microbiota-related diseases has heightened interest in gut microbiota and its impact on health, as gut microbiota is involved in several systems, such as digestive, endocrine, physiological, and immune systems; however, host-microorganism interaction mechanisms are far from being fully described. This review explores the potential of fish models in gut microbiota research, highlighting applications in biomedical and aquaculture sciences.

Lipopeptides are amphiphilic compounds since their molecular structure is formed by a fatty acid, which gives them hydrophobic characteristics. They are covalently linked to a hydrophilic peptide sequence that has between 7 and 10 amino acid residues. Lipopeptides are bioactive agents synthesized by the nonribosomal pathway in different species of bacteria and fungi. These biosurfactant compounds present a high biodiversity since they can present variations in the size and saturation of the fatty acid chain and the sequence, composition, and size of the peptide fraction. The high biodiversity of lipopeptides induces a wide range of properties such as surfactants, immunomodulators, antitumors, bioremediators, and mainly antimicrobials. The antimicrobial potential of lipopeptides is related to their ability to bind to the lipid molecules of cell membranes, where, depending on the concentration, they can cause alterations in the structure and permeability of the membranes, which can trigger cell death. The structural and functional diversity of lipopeptides has applications in different sectors, such as the food industry, where they can be used as emulsifiers and antimicrobials; in the recovery of crude oil from contaminated marine environments; in the agricultural sector as biocontrol products to reduce or eliminate diseases caused by plant pathogenic microorganisms, among others. Genetic engineering, metabolic engineering, and synthetic biology tools are used to increase the biodiversity, performance and effectiveness of lipopeptides to expand and improve their application in industrial activity.

The inclusion of by-products or discarded fruit in a second value chain can be a strategy to contribute to sustainable food production and consumption, with a focus on following a circular economy model, since certain by-products may be a source of nutrients and compounds with biological potential. The objective of this research was to evaluate the content of phenolic compounds and antioxidant capacity of by-products from five non-marketable grape varieties, as well as the bioaccessibility and absorption of their phenolic compounds during a simulated digestion, in order to support their potential use as sources of health-promoting compounds of interest. By-products of five grape varieties grown in northwest Mexico were evaluated. They were manually divided into two fractions, skin and pulp + seed, and subjected to a simulated digestion. Grape skin had the highest concentration of phenolic compounds and antioxidant capacity. Catechin exhibited the highest bioaccessibility and absorption, although 40% of this compound was compromised during simulated digestion. Catechin, quercetin, and protocatechuic acid contained in grape by-products make them attractive for insertion into a second value chain with potential uses, such as applications in the food and pharmaceutical industries. Additional research is required to evaluate potential applications, ensuring that these alternative uses are profitable and sustainable.

Background: Coffee is widely consumed worldwide and is rich in polyphenols with antioxidant properties linked to a reduced risk of metabolic and cardiovascular diseases. Olive pomace (OP), a by-product of olive oil production, contains phenolic compounds with cardioprotective effects but is often discarded. Combining it with coffee could enhance health benefits and promote sustainability. Methods: Soluble solids, total phenols, flavonoids, and antioxidant capacity (DPPH• scavenging activity) were analyzed in C-OP at 5%, 10%, 15%, and 20% OP concentrations. The C-OP 10% brew was selected for further evaluation with α-amylase inhibition and a 14-day pilot study in a murine model, evaluating weight, food and liquid intake, and behavior, compared to a control group. Results: Adding OP powder to ground coffee increased the total phenol content in the brews. The highest antioxidant activity (6.62–8.17 mmol TE/L) was found in those brewed from 10%, 15%, and 20% concentrations. The C-OP 10% brew had the highest acceptance in mice, with increased consumption, greater exploratory behavior, and reduced resting time. It also showed 30.5% α-amylase inhibition at 200 µg/mL. Conclusions: The incorporation of OP into coffee enhances its total phenol content and antioxidant capacity. The C-OP 10% brew showed optimal bioactivity, suggesting its potential as a functional beverage for metabolic health.

Chagas disease is a neglected disease caused by the parasite Trypanosoma cruzi, a public health problem in both endemic and non-endemic countries. In Mexico, the southern region is considered endemic, and cases are frequently reported; however, in the northwestern region, only a few cases are confirmed annually. This study describes, for the first time, the Discrete Typing Unit (DTU) of Trypanosoma cruzi in a volunteer blood donor rejected for being reactive in the northwestern region of Mexico. Seroreactivity was confirmed using “in-house” ELISAs which employed three different antigens: total extract from Trypanosoma cruzi isolated from a vector (Triatoma rubida) from Sonora (strain T1), strain H1 and CL-Brener. The molecular characterization of Trypanosoma cruzi was conducted by amplifying satellite DNA by qPCR and posterior sequencing of the mini-exon gene, using Next Generation Sequencing (NGS) to enhance the accuracy of genetic characterization. The results show that the reactive status of this blood donor was confirmed using our in-house ELISAs, and the presence of Trypanosoma cruzi by detecting TcI DTU confirmed the infection status.

Emerging and re-emerging plant diseases continue to present multifarious threats to global food security. Considerable recent efforts are therefore being channeled towards understanding the nature of pathogen emergence, their spread and evolution. Xanthomonas euvesicatoria pv. perforans (Xep), one of the causal agents of bacterial spot of tomato, rapidly emerged and displaced other bacterial spot xanthomonads in many tomato production regions around the world. In less than three decades, it has become a dominant xanthomonad pathogen in tomato production systems across the world and presents a compelling example for understanding diversification of recently emerged bacterial plant pathogens. Although Xep has been continuously monitored in Florida since its discovery, the global population structure and evolution at the genome-scale is yet to be fully explored. The objectives of this work were to determine genetic diversity globally to ascertain if different tomato production regions contain genetically distinct Xep populations, to examine genetic relatedness of strains collected in tomato seed production areas in East Asia and other production regions, and to evaluate variation in type III secretion effectors, which are critical pathogenicity and virulence factors, in relationship to population structure. We used genome data from 270 strains from 13 countries for phylogenetic analysis and characterization of type III effector gene diversity among strains. Our results showed notable genetic diversity in the pathogen. We found genetically similar strains in distant tomato production regions, including seed production regions, and diversification over the past 100 years, which is consistent with intercontinental dissemination of the pathogen in hybrid tomato production chains. Evolution of the Xep pangenome, including the acquisition and loss of type III secreted effectors, is apparent within and among phylogenetic lineages. The apparent long-distance movement of the pathogen, together with variants that may not yet be widely distributed, poses risks of emergence of new variants in tomato production.

Food safety is a significant global and local concern due to the threat of foodborne pathogens to public health and food security. Bacterial biofilms are communities of bacteria adhered to surfaces and represent a persistent contamination source in food environments. Their resistance to conventional antimicrobials exacerbates the challenge of eradication, driving the search for alternative strategies to control biofilms. Unconventional or “green” antimicrobial agents have emerged as promising solutions due to their sustainability and effectiveness. These agents include bacteriophages, phage-derived enzymes, plant extracts, and combinations of natural antimicrobials, which offer novel mechanisms for targeting biofilms. This approach aligns with the “One Health” concept, which underscores the interconnectedness of human, animal, and environmental health and advocates for integrated strategies to address public health challenges. Employing unconventional antimicrobial agents to manage bacterial biofilms can enhance food safety, protect public health, and reduce environmental impacts by decreasing reliance on conventional antimicrobials and mitigating antimicrobial resistance. This review explores the use of unconventional antimicrobials to combat foodborne pathogen biofilms, highlighting their mechanisms of action, antibiofilm activities, and the challenges associated with their application in food safety. By addressing these issues from a “One Health” perspective, we aim to demonstrate how such strategies can promote sustainable food safety, improve public health outcomes, and support environmental health, ultimately fostering a more integrated approach to combating foodborne pathogen biofilms.

Antimicrobial resistance in Acinetobacter baumannii poses a significant global health challenge. Phage therapy, particularly through phage-antibiotic synergy (PAS), offers a promising strategy to combat this pathogen. This study demonstrated significant PAS, where the combination of phage Indie and ceftazidime achieved a bacterial reduction of more than 85% of A. baumannii strain AbAK03 at 17 h using low doses. Notably, this combination overcame phage resistance observed at 4 h when the phage was used alone, extending bacterial eradication by 13 h. Furthermore, phage Indie restored bacterial susceptibility to ceftazidime, supporting its role in improving interventional treatments against multidrug-resistant A. baumannii. To explore this interaction, phage Indie was isolated and characterized from multidrug-resistant clinical strains. An in vitro PAS experiment was performed using ceftazidime and piperacillin-tazobactam. The combination of phage Indie with ceftazidime consistently showed superior bactericidal effects compared to either agent alone, while the combination of phage Indie with piperacillin-tazobactam exhibited an antagonistic effect. These findings provide clear evidence supporting the application of phage-antibiotic combinations as an effective intervention strategy and lay the groundwork for future in vivo trials in a mouse model to combat antimicrobial resistance.

Transition state regulators from Bacillus can control diverse physiological responses such as growth, metabolism, motility, virulence, and sporulation. The AbrB protein is a transcriptional regulator involved in multiple functions during exponential phase and intricated regulatory pathways that control adaptive states differentially. Despite its importance, the AbrB role has not been well characterized during the growth cycle, and its implication in metabolic functions remains elusive, especially in the Bacillus cereus group. In this work, we characterized the role of AbrB on phenotypes such as spreading motility, growth profiles, sporulation, and on activity of core metabolic pathways of Bacillus thuringiensis. For this, a strain with inducible abrB expression was generated in the wild type Bt HD73 background. In vitro evaluations of phenotypic traits demonstrated differences in sporulation and motility, where induction of abrB presumably affected these functions under nutrient-limited media. In addition, AbrB induction during bioreactor fermentations led to higher biomass production and changes dissolved oxygen (DO) profile, which was also accompanied with a delay in sporulation. Based on these results, metabolic pathways such as glycolysis and the Krebs cycle were explored to address the effect of AbrB overproduction on transcription of genes coding for pyruvate dehydrogenase (pdHA), lactate dehydrogenase (ldH), citrate synthase (citZ) and aconitase (citB). Our findings suggest variations in the carbon-flux in the central carbon metabolism due to abrB overexpression. This work contributes to the elucidation of AbrB involvement in regulatory networks of B. thuringiensis, to develop engineering-based strategies to use these bacteria in other biotechnological applications besides as biological control agent. Graphical Abstract

Rhizoctonia is among the most important soilborne pathogens responsible for causing lettuce diseases worldwide. In this study, a total of 59 Rhizoctonia isolates obtained from lettuce plants with bottom rot symptoms in seven states producers in Brazil were studied using phylogenetic analysis of the internal transcribed spacer (ITS) region of rDNA as well as pathogenicity tests. Fifty-five isolates were identified as R. solani and four isolates as binucleate Rhizoctonia (BNR). Thirty-nine isolates (66.1%) belonged to anastomosis group AG-1 IB, nine (15.3%) to AG-4 HGI, four (6.8%) to AG-2–2 IIIB, three (5.1%) to AG-4 HGIII, two (3.4%) to AG-A, one (1.7%) to AG-L and one (1.7%) to AG–P. AG-1 IB isolates were widely distributed and recovered from six out of seven Brazilian states, including 10 lettuce-growing fields. Only two isolates were not pathogenic to lettuce. Significant differences in aggressiveness were observed among different isolates and AGs, with AG-1 IB showing higher aggressiveness to lettuce leaves compared to other AGs. This study represents the first detailed report on the AG composition of Rhizoctonia populations causing bottom rot of lettuce in different Brazilian regions. Additionally, this is the first time that AG-2–2 IIIB, AG-A, AG-L, and AG–P have been associated with this disease worldwide.

Porcine respiratory and reproductive syndrome is a viral disease that impacts the health and profitability of swine farms, largely due to significant variation in the vaccination response. The objective was to identify and validate molecular markers associated with the antibody response in gilts following vaccination against the PRRSV. The study included one hundred (n = 100) 6-month-old Yorkshire gilts that were negative for the PRRSV. Gilts were randomly assigned to one of two treatments, PRRS-vaccinated (n = 75) and control (n = 25) groups. Blood samples collected on day 21 were analyzed to evaluate the antibody response, as indicated by the sample-to-positive (S/P) ratio, to the PRRSV following vaccination. DNA was extracted and genotyped using a low-density chip containing 10,000 single nucleotide polymorphisms (SNPs). A genome-wide association study (GWAS) was conducted to identify candidate SNPs associated with the S/P ratio, which were validated in two independent gilt populations (n = 226). The SNPs rs707264998, rs708860811, and rs81358818 in the genes RNF144B, XKR9, and BMAL1, respectively, were significantly associated (p < 0.01) with the S/P ratio and demonstrated an additive effect. In conclusion, three SNPs are proposed as candidate markers for an enhanced immune response to vaccination against the PRRSV and may be beneficial in genetic selection programs.

Bacteriophage therapy is a promising approach for targeting antibiotic-resistant bacteria and modulating gut microbiota in metabolic diseases such as obesity. This study evaluated the impact of a two-phage cocktail on an ex vivo colonic simulation model of gut microbiota derived from obese individuals, both in its normalized state and after enrichment with Enterobacter cloacae, an obesity-related bacteria. Microbiological analyses confirmed that the phage cocktail remained active throughout the colonic regions over three digestion cycles and effectively reduced enterobacterial populations in the enriched microbiota. Metabarcoding of the 16S rRNA gene revealed that phage therapy did not significantly alter the abundance of dominant genera, but selectively reduced E. cloacae across all colonic regions. Alpha diversity was significantly affected only in the enriched microbiota, while beta diversity analysis indicated significant compositional shifts during therapy, with reduced dispersion in the final treatment stage. Short-chain fatty acid profiling demonstrated region- and group-specific metabolic responses, with increased lactic and butyric acid concentrations in the ascending colon of the enriched microbiota following phage treatment. This study provides the first ex vivo evidence that a two-phage cocktail can selectively eliminate E. cloacae while preserving overall microbiota structure and functionality. These findings establish a foundation for future in vivo studies exploring the role of phage therapy in reshaping gut microbial communities and metabolic profiles, highlighting its potential as a precision tool for managing gut dysbiosis in metabolic disorders.

The present study evaluated the effect of ice storage on the freshness and quality of bullfrog (Lithobates catesbeianus) leg muscle. Biochemical, chemical, physical, and microbiological changes during 24 days of storage were analyzed. A rapid degradation of ATP into its intermediates (AMP, IMP, inosine, and hypoxanthine) was observed, with a significant increase in K-index (6.78% to 79.33%) and hypoxanthine concentration (3.93 ± 0.87 µmol/g), indicating a progressive reduction in freshness. The pH initially decreased due to post-mortem glycolysis but subsequently increased due to microbial activity and protein degradation. Volatile basic nitrogen (TVB-N) content increased significantly, reaching 27.36 mg/100 g, reflecting protein breakdown. A loss of texture was recorded, with a reduction in muscle firmness from 21.93 ± 1.36 Nw to 10.87 ± 1.08 Nw. Microbiological analyses showed an increase in bacterial load, with mesophiles and psychrophiles reaching 6.75 and 6.45 log CFU/g, respectively. These results indicate that the freshness and quality of bullfrog leg under ice storage remain within acceptable limits until day 18, but its quality and freshness decrease significantly toward the end of the study period.