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Crustaceans form the second largest subphylum on Earth, which includes Litopeneaus vannamei (Pacific whiteleg shrimp), one of the most cultured shrimp worldwide. Despite efforts to study the shrimp microbiota, little is known about it from shrimp obtained from the open sea and the role that aquaculture plays in microbiota remodeling. Here, the microbiota from the hepatopancreas and intestine of wild type (wt) and aquacultured whiteleg shrimp and pond sediment from hatcheries were characterized using sequencing of seven hypervariable regions of the 16S rRNA gene. Cultured shrimp with AHPND/EMS disease symptoms were also included. We found that (i) microbiota and their predicted metagenomic functions were different between wt and cultured shrimp; (ii) independent of the shrimp source, the microbiota of the hepatopancreas and intestine was different; (iii) the microbial diversity between the sediment and intestines of cultured shrimp was similar; and (iv) associated to an early development of AHPND/EMS disease, we found changes in the microbiome and the appearance of disease-specific bacteria. Notably, under cultured conditions, we identified bacterial taxa enriched in healthy shrimp, such as Faecalibacterium prausnitzii and Pantoea agglomerans , and communities enriched in diseased shrimp, such as Aeromonas taiwanensis , Simiduia agarivorans and Photobacterium angustum .

Phenolic compounds are known to have antioxidant capacity; however, there is little information about molecular interactions between particular phenolics found in fruits at different developmental stages. Therefore, the total antioxidant capacity of the phenolic compounds of a fruit may not correspond to the sum of individual antioxidant capacity given by antioxidants from that tissue. In this study, individual antioxidant capacity and the interactions of four major phenolic compounds (chlorogenic, gallic, protocatechuic and vanillic acid) found in ‘Ataulfo’ mango pulp were tested using the DPPH assay. Significant synergism was found in the majority of the all combinations, as well as the combination of the four phenolics. However, antagonism was also observed between some molecules. This work demonstrated particular interactions that may occur in a complex environment within the complex framework of a natural food. The present results may also assist in the future design of functional foods or ingredients based on their antioxidant activity and their synergistic or antagonist interactions.

Rocky Mountain spotted fever (RMSF), a severe and extraordinarily lethal infectious disease, has emerged as a widespread public health crisis among predominantly vulnerable populations in several countries of Latin America, particularly evident in northern Mexico. Historically, RMSF has gained less attention than many other tropical infectious diseases, resulting in insufficient allocations of resources and development of capabilities for its prevention and control in endemic regions. We argue that RMSF fulfills accepted criteria for a neglected tropical disease (NTD). The relative neglect of RMSF in most Latin American countries contributes to disparities in morbidity and mortality witnessed in this region. By recognizing RMSF as an NTD, an increased public policy interest, equitable and more appropriate allocation of resources, scientific interest, and social participation can ameliorate the impact of this potentially treatable disease, particularly in vulnerable populations.

Objective: To analyze determinants of KAP (knowledge, attitudes, practices) regarding tick exposure and their association with household characteristics in a region with high prevalence of rickettsiosis transmitted by the tick Rhipicephalus sanguineus. Methods: A cross-sectional study was conducted in Sonora, Mexico, using stratified random sampling of 228 households in high-incidence areas. A 30-item questionnaire assessed KAP on vector-borne diseases, employing dichotomous, categorical, and Likert scale responses. The chi-square test evaluated associations between variables (p<0.05 significance). Data analysis was performed using IBM® SPSS Statistics software. Results: The median age of household representatives was 36.9 years; 66.0% were women. Higher levels of knowledge about tick-borne diseases, preventive measures, symptoms, and greater motivation to avoid ticks correlated with educational level (p<0.001), occupation (p=0.001), attitudes and practices like the frequency of dogs entering households (p=0.005), prior tick findings on dogs (p=0.030), fumigation practices (p=0.017), and higher perceived risk of tick bites (p=0.023). Conclusion: A limited understanding of tick-related risks highlights gaps in KAP, reflecting insufficient individual awareness and systemic public health education failures. These gaps perpetuate risky behaviors and inadequate environmental practices, fostering conditions for vector proliferation and increasing zoonotic disease transmission risks. Objetivo: Analizar los determinantes del conocimiento, actitudes y prácticas (CAP) sobre la exposición a garrapatas y su asociación con las características de las viviendas en una región con alta prevalencia de rickettsiosis transmitida por la garrapata Rhipicephalus sanguineus. Métodos: Se realizó un estudio transversal en Sonora, México, mediante muestreo aleatorio estratificado en 228 viviendas ubicadas en áreas de alta incidencia. Se aplicó un cuestionario de 30 ítems para evaluar el CAP sobre enfermedades transmitidas por vectores, utilizando respuestas dicotómicas, categóricas y escalas de Likert. La prueba chi-cuadrada evaluó las asociaciones entre variables (significancia p<0.05). El análisis de datos fue realizado utilizando el software estadístico IBM® SPSS. Resultados: La media de edad de los representantes de las viviendas fue de 36.9 años; el 66.0% eran mujeres. Niveles más altos de conocimiento sobre enfermedades transmitidas por garrapatas, medidas preventivas, síntomas y mayor motivación para evitar las garrapatas se asociaron con el nivel educativo (p<0.001), ocupación (p=0.001), actitudes y prácticas como la frecuencia de entrada de perros al hogar (p=0.005), hallazgos previos de garrapatas en perros (p=0.030), prácticas de fumigación (p=0.017) y una mayor percepción del riesgo de picaduras de garrapatas (p=0.023). Conclusión: La comprensión limitada de los riesgos relacionados con las garrapatas pone de manifiesto las brechas en los CAP, reflejando insuficiencia tanto en la conciencia individual como en la educación en salud pública. Estas deficiencias perpetúan conductas de riesgo y prácticas ambientales inadecuadas, fomentando condiciones para la proliferación de vectores y aumentando los riesgos de transmisión de enfermedades zoonóticas.

Prebiotics and probiotics have shown a number of beneficial impacts preventing diseases in cultured shrimps. Complex soluble carbohydrates are considered ideal for fostering microbiota biodiversity by fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPS). Here we evaluated the growth performance and microbiota composition of the white shrimp Litopenaeus vannamei after dietary intervention using agavin as a FODMAP prebiotic under farming conditions. Adult L. vannamei were raised at a shrimp farm and the effect of agavin supplemented at 2% (AG2) or 10% (AG10) levels were compared to an agavin-free basal diet (BD). After 28 days-trial, the feed conversion ratio, total feed ingested, and protein efficiency ratio was significantly improved on animals fed with AG2. At the same time, no effect on growth performance was observed in AG10. Surprisingly, after sequencing the V3–V4 regions of the 16S rRNA gene a higher microbial richness and diversity in the hepatopancreas and intestine was found only in those animals receiving the AG10 diet, while those receiving the AG2 diet had a decreased richness and diversity, both diets compared to the BD. The beta diversity analysis showed a clear significant microbiota clustering by agavin diets only in the hepatopancreas, suggesting that agavin supplementation had a more substantial deterministic effect on the microbiota of hepatopancreas than on the intestine. We analyzed the literature to search beneficial microbes for shrimp’s health and found sequences for 42 species in our 16S data, being significantly increased Lactobacillus pentosus, Pseudomonas putida and Pseudomonas synxantha in the hepatopancreas of the AG10 and Rodopseudomonas palustris and Streptococcus thermophiles th1435 in the hepatopancreas of the AG2, both compared to BD. Interestingly, when we analyzed the abundance of 42 beneficial microbes as a single microbial community \"meta-community,\" found an increase in their abundance as agavin concentration increases in the hepatopancreas. In addition, we also sequenced the DNA of agavin and found 9 of the 42 beneficial microbes. From those, Lactobacillus lactis and Lactobacillus delbrueckii were found in shrimps fed with agavin (both AG2 and AG10), and Lysinibacillus fusiformis in AG10 and they were absent the BD diet, suggesting these three species could be introduced with the agavin to the diet. Our work provides evidence that agavin supplementation is associated with an increase of beneficial microbes for the shrimp microbiota at farming conditions. Our study provides the first evidence that a shrimp prebiotic may selectively modify the microbiota in an organ-dependent effect.

The shrimp has become the most valuable traded marine product in the world, and its microbiota plays an essential role in its development and overall health status. Massive high-throughput sequencing techniques using several hypervariable regions of the 16S rRNA gene are broadly applied in shrimp microbiota studies. However, it is essential to consider that the use of different hypervariable regions can influence the obtained data and the interpretation of the results. The present study compares the shrimp microbiota structure and composition obtained by three types of amplicons: one spanning both the V3 and V4 hypervariable regions (V3V4), one for the V3 region only (V3), and one for the V4 region only (V4) using the same experimental and bioinformatics protocols. Twenty-four samples from hepatopancreas and intestine were sequenced and evaluated using the GreenGenes and silva reference databases for clustering and taxonomic classification. In general, the V3V4 regions resulted in higher richness and diversity, followed by V3 and V4. All three regions establish an apparent clustering effect that discriminates between the two analyzed organs and describe a higher richness for the intestine and a higher diversity for the hepatopancreas samples. Proteobacteria was the most abundant phyla overall, and Cyanobacteria was more common in the intestine, whereas Firmicutes and Actinobacteria were more prevalent in hepatopancreas samples. Also, the genus Vibrio was significantly abundant in the intestine, as well as Acinetobacter and Pseudomonas in the hepatopancreas suggesting these taxa as markers for their respective organs independently of the sequenced region. The use of a single hypervariable region such as V3 may be a low-cost alternative that enables an adequate description of the shrimp microbiota, allowing for the development of strategies to continually monitor the microbial communities and detect changes that could indicate susceptibility to pathogens under real aquaculture conditions while the use of the full V3V4 regions can contribute to a more in-depth characterization of the microbial composition.

Yellow head virus (YHV) is a pathogen which causes high mortality in penaeid shrimp. Previous studies suggested that YHV enters shrimp cells via clathrin-mediated endocytosis. This research investigated the roles of clathrin adaptor protein 2 subunit β (AP-2β) from Penaeus monodon during YHV infection. Pm AP2-β was continuously up-regulated more than twofold during 6–36 hpi. Suppression of Pm AP2-β significantly reduced YHV copy numbers and delayed shrimp mortality. Quantitative RT-PCR revealed that knockdown of Pm AP2-β significantly enhanced the expression level of Pm Spätzle, a signaling ligand in the Toll pathway, by 30-fold at 6 and 12 hpi. Moreover, the expression levels of gene components in the Imd and JAK/STAT signaling pathways under the suppression of Pm AP2-β during YHV infection were also investigated. Interestingly, anti-lipopolysaccharide factor isoform 3 (ALF Pm 3) was up-regulated by 40-fold in Pm AP2-β knockdown shrimp upon YHV infection. In addition, silencing of Pm AP2-β dramatically enhanced crustin Pm 1 expression in YHV-infected shrimp. Knockdown of ALF Pm 3 and crustin Pm 1 significantly reduced shrimp survival rate. Taken together, this work suggested that Pm AP2-β-deficiency promoted the Toll pathway signalings, resulting in elevated levels of ALF Pm 3 and crustin Pm 1, the crucial antimicrobial peptides in defence against YHV.

Background Pacific Whiteleg shrimp ( Litopenaeus vannamei ) is an important model for breeding programs to improve global aquaculture productivity. However, the interaction between host genetics and microbiota in enhancing productivity remains poorly understood. We investigated the effect of two shrimp genetic lines, Fast-Growth (Gen1) and Disease-Resistant (Gen2), on the microbiota of L. vannamei . Results Using genome-wide SNP microarray analysis, we confirmed that Gen1 and Gen2 represented distinct genetic populations. After confirming that the rearing pond did not significantly influence the microbiota composition, we determined that genetic differences explained 15.8% of the microbiota variability, with a stronger selective pressure in the hepatopancreas than in the intestine. Gen1, which exhibited better farm productivity, fostered a microbiota with greater richness, diversity, and resilience than Gen2, along with a higher abundance of beneficial microbes. Further, we demonstrated that a higher abundance of beneficial microbes was associated with healthier shrimp vs. diseased specimens, suggesting that Gen1 could improve shrimp's health and productivity by promoting beneficial microbes. Finally, we determined that the microbiota of both genetic lines was significantly different from their wild-type counterparts, suggesting farm environments and selective breeding programs strongly alter the natural microbiome. Conclusions This study highlights the importance of exploring the hologenome perspective, where integrating host genetics and microbiome composition can enhance breeding programs and farming practices.

The benefits of phenolic acids on human health are very often ascribed to their potential to counteract free radicals to provide antioxidant protection. This potential has been attributed to their acidic chemical structure, which possesses hydroxyl groups in different positions. Phenolic acids can interact between themselves and exhibit an additive, antagonistic or synergistic effect. In this paper, we used 1H NMR to analyze the interactions and mechanisms that are present in major phenolic acids found in mango (gallic, protocatechuic, chlorogenic and vanillic acids) and papaya (caffeic, ferulic and p-coumaric acids), and the DPPH radical was used to evaluate the effect of the antioxidant mixtures. The interactions were found to occur via hydrogen bonds between the -OH and -COOH groups. Moreover, the phenolic acids exhibit two types of mechanisms for the neutralization of the DPPH radical. According to the results, these two mechanisms are Hydrogen Atom Transfer (HAT) and Single Electron Transfer (SET). The ability of the phenolic acid to neutralize the DPPH radical decreases in the following order in mango: gallic > chlorogenic > protocatechuic > vanillic. Moreover, within the acids found in papaya, the order was as follows: caffeic > p-coumaric > ferulic.

Recombinase polymerase amplification (RPA) facilitates rapid, exponential, isothermal nucleic acid amplification without the need for specialized equipment. Since its development in 2006, RPA has been widely applied to detect hundreds of RNA and DNA targets, spanning point-of-care diagnostics and agricultural uses. However, its reliance on pre-assembled commercial kits limits flexibility for customization. In this study, we introduce an open-source alternative to commercial RPA kits, utilizing purified, heterologously expressed proteins to circumvent the fixed molar ratios of proprietary systems. Our method incorporates enzymes from the bacteriophage T4 homologous recombination pathway—single-stranded binding protein (gp32), recombinase (UvsX), and mediator (UvsY)—along with Moloney murine leukemia virus (MMLV) reverse transcriptase with enhanced thermal stability, and Bst and Bsu DNA polymerases. We assessed the impact of buffer composition, reagent concentrations, and reaction temperature using synthetic SARS-CoV-2 genes. Notably, gp32 concentration and buffer composition emerged as critical factors in optimizing RPA performance. Using this tailored system, we demonstrated successful detection of the SARS-CoV-2 N gene on lateral flow devices (LFDs) with cDNA from eight clinical samples, achieving results consistent with RT-PCR. This open-source RPA platform provides an adaptable and cost-effective alternative for researchers, enabling the exploration of diverse experimental conditions and offering a viable solution for those without access to commercial kits.