The chromosome-scale genome and the genetic resistance machinery against insect herbivores of the Mexican toloache, Datura stramonium

Plant resistance refers to the heritable ability of plants to reduce damage caused by natural enemies, such as herbivores and pathogens, either through constitutive or induced traits like chemical compounds or trichomes. However, the genetic architecture-the number and genome location of genes that affect plant defense and the magnitude of their effects-of plant resistance to arthropod herbivores in natural populations remains poorly understood. In this study, we aimed to unveil the genetic architecture of plant resistance to insect herbivores in the annual herb Datura stramonium (Solanaceae) through quantitative trait loci mapping. We achieved this by assembling the species' genome and constructing a linkage map using an F2 progeny transplanted into natural habitats. Furthermore, we conducted differential gene expression analysis between undamaged and damaged plants caused by the primary folivore, Lema daturaphila larvae. Our genome assembly resulted in 6,109 scaffolds distributed across 12 haploid chromosomes. A single quantitative trait loci region on chromosome 3 was associated with plant resistance, spanning 0 to 5.17 cM. The explained variance by the quantitative trait loci was 8.44%. Our findings imply that the resistance mechanisms of D. stramonium are shaped by the complex interplay of multiple genes with minor effects. Protein-protein interaction networks involving genes within the quantitative trait loci region and overexpressed genes uncovered the key role of receptor-like cytoplasmic kinases in signaling and regulating tropane alkaloids and terpenoids, which serve as powerful chemical defenses against D. stramonium herbivores. The data generated in our study constitute important resources for delving into the evolution and ecology of secondary compounds mediating plant-insect interactions.

Psychobiotics: Mechanisms of Action, Evaluation Methods and Effectiveness in Applications with Food Products

The gut-brain-microbiota axis consists of a bilateral communication system that enables gut microbes to interact with the brain, and the latter with the gut. Gut bacteria influence behavior, and both depression and anxiety symptoms are directly associated with alterations in the microbiota. Psychobiotics are defined as probiotics that confer mental health benefits to the host when ingested in a particular quantity through interaction with commensal gut bacteria. The action mechanisms by which bacteria exert their psychobiotic potential has not been completely elucidated. However, it has been found that these bacteria provide their benefits mostly through the hypothalamic-pituitary-adrenal (HPA) axis, the immune response and inflammation, and through the production of neurohormones and neurotransmitters. This review aims to explore the different approaches to evaluate the psychobiotic potential of several bacterial strains and fermented products. The reviewed literature suggests that the consumption of psychobiotics could be considered as a viable option to both look after and restore mental health, without undesired secondary effects, and presenting a lower risk of allergies and less dependence compared to psychotropic drugs.

Socioeconomic gradients of adverse birth outcomes and related maternal factors in rural and urban Alberta, Canada: a concentration index approach

OBJECTIVE

Using a summary measure of health inequalities, this study evaluated the distribution of adverse birth outcomes (ABO) and related maternal risk factors across area-level socioeconomic status (SES) gradients in urban and rural Alberta, Canada.

DESIGN

Cross-sectional study using a validated perinatal clinical registry and an area-level SES.

SETTING

The study was conducted in Alberta, Canada. Data about ABO and related maternal risk factors were obtained from the Alberta Perinatal Health Program between 2006 and 2012. An area-level SES index derived from census data (2006) was linked to the postal code at delivery.

PARTICIPANTS

Women (n=3 30 957) having singleton live births with gestational age ≥22 weeks.

PRIMARY AND SECONDARY OUTCOME MEASURES

We estimated concentration indexes to assess inequalities across SES gradients in both rural and urban areas (CIdx_R and CIdx_U, respectively) for spontaneous preterm birth (PTB), small for gestational age (SGA), large for gestational age (LGA), gestational hypertension, gestational diabetes, smoking and substance use during pregnancy and pre-pregnancy weight >91 kg.

RESULTS

The highest health inequalities disfavouring low SES groups were identified for substance abuse and smoking in rural areas (CIdx_R-0.38 and -0.23, respectively). Medium inequalities were identified for LGA (CIdx_R-0.08), pre-pregnancy weight >91 kg (CIdx_R-0.07), substance use (CIdx_U-0.15), smoking (CIdx_U-0.14), gestational diabetes (CIdx_U-0.10) and SGA (CIdx_U-0.07). Low inequalities were identified for PTB (CIdx_R-0.05; CIdx_U-0.05) and gestational diabetes (CIdx_R-0.04). Inequalities disfavouring high SES groups were identified for gestational hypertension (CIdx_R+0.04), SGA (CIdx_R+0.03) and LGA (CIdx_U+0.03).

CONCLUSIONS

ABO and related maternal risk factors were unequally distributed across the socioeconomic gradient in urban-rural settings, with the greatest concentrations in lower SES groups of rural areas. Future research is needed on underlying mechanisms driving SES gradients in perinatal health across the rural-urban spectrum.

Virulence profiles and innate immune responses against highly lethal, multidrug-resistant nosocomial isolates of Acinetobacter baumannii from a tertiary care hospital in Mexico

Virulence profiles and innate immune responses were studied in Acinetobacter baumannii from nosocomial infections collected over one year in a tertiary care hospital in Mexico. A. baumannii were identified by VITEK 2 System followed by susceptibility tests. Carbapenemase genes, active efflux mechanism to imipenem and meropenem and outer membrane proteins profile were analyzed to evaluate their role on the activity of carbapenem resistance. All isolates were genotyped by pulsed field gel electrophoresis. The ability to form biofilm was determined on a polystyrene surface. The resistance to complement was determined with a pooled human normal serum and TNFα release by infected macrophages was determined by ELISA. The 112 isolates from this study were associated with a 52% of mortality. All were resistance to β-lactams, fluoroquinolones, and trimethroprim-sulfamethoxal, 96 and 90% were resistant to meropenem and imipenem, respectively, but with high susceptibility to polymyxin B, colistin and tigecyclin. Isolates were classified in 11 different clones. Most isolates, 88% (99/112), were metallo-β-lactamases and carbapenemases producers, associated in 95% with the presence of bla_OXA-72 gene. Only 4/99 and 1/99 of the carbapenem-resistant isolates were related to efflux mechanism to meropenem or imipenem resistance, respectively. The loss of expression of 22, 29, and/or 33-36-kDa proteins was detected in 8/11 of the clinical isolates with resistance to carbapenem. More than 96% (108/112) of the isolates were high producers of biofilms on biotic surfaces. Finally, all isolates showed variable resistance to normal human serum activity and were high inductors of TNFα release by macrophages. In summary, these results suggest that multidrug-resistant A. baumannii can persist in the hospital environment through its ability to form biofilms. The high mortality observed was due to their ability to survive normal human serum activity and capability to induce potent inflammatory immune response making this nosocomial pathogen a serious threat to hospitalized patients.