Pattern and causes of the establishment of the invasive bacterial potato pathogen Dickeya solani and of the maintenance of the resident pathogen D. dianthicola.

Invasive pathogens can be a threat when they affect human health, food production or ecosystem services, by displacing resident species, and we need to understand the cause of their establishment. We studied the patterns and causes of the establishment of the pathogen Dickeya solani that recently invaded potato agrosystems in Europe by assessing its invasion dynamics and its competitive ability against the closely related resident D. dianthicola species. Epidemiological records over one decade in France revealed the establishment of D. solani and the maintenance of the resident D. dianthicola in potato fields exhibiting blackleg symptoms. Using experimentations, we showed that D. dianthicola caused a higher symptom incidence on aerial parts of potato plants than D. solani, while D. solani was more aggressive on tubers (i.e. with more severe symptoms). In co-infection assays, D. dianthicola outcompeted D. solani in aerial parts, while the two species co-existed in tubers. A comparison of 76 D. solani genomes (56 of which have been sequenced here) revealed balanced frequencies of two previously uncharacterized alleles, VfmBPro and VfmBSer , at the vfmB virulence gene. Experimental inoculations showed that the VfmBSer population was more aggressive on tubers, while the VfmBPro population outcompeted the VfmBSer population in stem lesions, suggesting an important role of the vfmB virulence gene in the ecology of the pathogens. This study thus brings novel insights allowing a better understanding of the pattern and causes of the D.solani invasion into potato production agrosystems, and the reasons why the endemic D. dianthicola nevertheless persisted.

Elevation of Pectobacterium carotovorum subsp. odoriferum to species level as Pectobacterium odoriferum sp. nov., proposal of Pectobacterium brasiliense sp. nov. and Pectobacterium actinidiae sp. nov., emended description of Pectobacterium carotovorum and description of Pectobacterium versatile sp. nov., isolated from streams and symptoms on diverse plants.

The Pectobacteriumcarotovorum species corresponds to a complex, including two subspecies with validly published names, two proposed subspecies and two new species, Pectobacterium polaris and Pectobacterium aquaticum. Recent studies suggested that this complex needed revision. We examined the taxonomic status of 144 Pectobacterium strains isolated from a wide range of plant species, various geographical origins and waterways. Sequences of the leuS, dnaX and recA housekeeping genes clustered 114 of these Pectobacterium strains together within a not yet described clade. We sequenced eight strains of this clade and analysed them together with the 102 Pectobacterium genomes available in the NCBI database. Phylogenetic analysis, average nucleotide identity calculation and in silico DNA-DNA hybridization allowed us to differentiate seven clades. This led us to propose the elevation of Pectobacterium carotovorumsubsp. odoriferum to species level as Pectobacteriumodoriferum sp. nov. (type strain CFBP 1878T=LMG 5863T=NCPPB 3839T=ICMP 11533T), the proposal of Pectobacteriumactinidiae sp. nov. (type strain KKH3=LMG 26003 T=KCTC 23131T) and Pectobacteriumbrasiliense sp. nov. (type strain CFBP 6617T= LMG 21371T=NCPPB 4609T), to emend the description of Pectobacterium carotovorum (type strain CFBP 2046T=LMG 2404T=NCPPB 312T=ICMP 5702T), and to propose a novel species, Pectobacterium versatile sp. nov (type strain CFBP6051T= NCPPB 3387T=ICMP 9168T) which includes the strains previously described as 'Candidatus Pectobacterium maceratum'. Phenotypic analysis performed using Biolog GENIII plates on eight strains of P. versatile sp. nov. and related strains completed our analysis.

Biocontrol of the Potato Blackleg and Soft Rot Diseases Caused by Dickeya dianthicola.

Development of protection tools targeting Dickeya species is an important issue in the potato production. Here, we present the identification and the characterization of novel biocontrol agents. Successive screenings of 10,000 bacterial isolates led us to retain 58 strains that exhibited growth inhibition properties against several Dickeya sp. and/or Pectobacterium sp. pathogens. Most of them belonged to the Pseudomonas and Bacillus genera. In vitro assays revealed a fitness decrease of the tested Dickeya sp. and Pectobacterium sp. pathogens in the presence of the biocontrol agents. In addition, four independent greenhouse assays performed to evaluate the biocontrol bacteria effect on potato plants artificially contaminated with Dickeya dianthicola revealed that a mix of three biocontrol agents, namely, Pseudomonas putida PA14H7 and Pseudomonas fluorescens PA3G8 and PA4C2, repeatedly decreased the severity of blackleg symptoms as well as the transmission of D. dianthicola to the tuber progeny. This work highlights the use of a combination of biocontrol strains as a potential strategy to limit the soft rot and blackleg diseases caused by D. dianthicola on potato plants and tubers.

Transfer of the potato plant isolates of Pectobacterium wasabiae to Pectobacterium parmentieri sp. nov.

Pectobacterium wasabiae was originally isolated from Japanese horseradish (Eutrema wasabi), but recently some Pectobacterium isolates collected from potato plants and tubers displaying blackleg and soft rot symptoms were also assigned to P. wasabiae. Here, combining genomic and phenotypical data, we re-evaluated their taxonomic position. PacBio and Illumina technologies were used to complete the genome sequences of P. wasabiae CFBP 3304T and RNS 08-42-1A. Multi-locus sequence analysis showed that the P. wasabiae strains RNS 08-42-1A, SCC3193, CFIA1002 and WPP163, which were collected from potato plant environment, constituted a separate clade from the original Japanese horseradish P. wasabiae. The taxonomic position of these strains was also supported by calculation of the in-silico DNA-DNA hybridization, genome average nucleotide indentity, alignment fraction and average nucleotide indentity values. In addition, they were phenotypically distinguished from P. wasabiae strains by producing acids from (+)-raffinose, α-d(+)-α-lactose, d(+)-galactose and (+)-melibiose but not from methyl α-d-glycopyranoside, (+)-maltose or malonic acid. The name Pectobacterium parmentieri sp. nov. is proposed for this taxon; the type strain is RNS 08-42-1AT (=CFBP 8475T=LMG 29774T).

Genomic overview of the phytopathogen Pectobacterium wasabiae strain RNS 08.42.1A suggests horizontal acquisition of quorum-sensing genes.

The blackleg and soft-rot diseases caused by pectinolytic enterobacteria such as Pectobacterium and Dickeya are major causes of losses affecting potato crop in the field and upon storage. In this work, we report the isolation, characterization and genome analysis of the Pectobacterium wasabiae (formerly identified as Pectobacterium carotovorum subsp. carotovorum) strain RNS 08.42.1A, that has been isolated from a Solanum tuberosum host plant in France. Comparative genomics with 3 other P. wasabiae strains isolated from potato plants in different areas in North America and Europe, highlighted both a strong similarity at the whole genome level (ANI > 99 %) and a conserved synteny of the virulence genes. In addition, our analyses evidenced a robust separation between these four P. wasabiae strains and the type strain P. wasabiae CFBP 3304(T), isolated from horseradish in Japan. In P. wasabiae RNS 08.42.1A, the expI and expR nucleotidic sequences are more related to those of some Pectobacterium atrosepticum and P. carotovorum strains (90 % of identity) than to those of the other potato P. wasabiae strains (70 to 74 % of identity). This could suggest a recruitment of these genes in the P. wasabiae strain RNS 08.42.1A by an horizontal transfer between pathogens infecting the same potato host plant.

Family caregivers' perceptions of depression in patients with advanced cancer: a qualitative study.

OBJECTIVE: Depression is a serious issue for cancer patients, resulting in impaired quality of life and probably shorter survival. However, many cancer patients with depression are not treated because of the difficulties in identifying depression within this population. Our study aimed to examine caregivers' perceptions of depression among advanced cancer patients. METHOD: This qualitative study employed semistructured interviews, and we analyzed data using grounded theory and qualitative methods. We recruited caregivers from our palliative care unit (PCU) at an academic medical center. RESULTS: We interviewed a total of 15 caregivers. Cancer patients' caregivers had a good theoretical knowledge of depression but also acknowledged that, in the context of cancer and because of their relationship with the patient, identification of depressive symptoms could be challenging. They considered themselves as partners in the patient's care with a supportive role. However, by assuming the role of partner in patient care, caregivers exposed themselves to emotional difficulties and an increased need for support and information. SIGNIFICANCE OF RESULTS: Our results suggest a significant impact of depression in advanced cancer caregivers, and it is therefore crucial that healthcare professionals develop educational programs targeting cancer patients' families as well as specific interventions to minimize the impact of the burden of patient care on caregivers.

Do parent media habits contribute to child global development?

Background/objective: Parents of preschoolers' report using screen media frequently. More frequent screen use by parents may undermine child development by displacing time for foundational parent-child interactions. The objective of the present study is to examine the extent to which parent screen use contributes to child global development 1 year later. Methods: Data are from a cohort of 315 preschoolers from Nova Scotia, Canada and their parents during the COVID-19 pandemic. Parents reported the number of hours per day they spent using screens, as well as child screen time and sex, and parent educational attainment. Our outcome is child global development scores, which combine assessments of communication, cognitive, personal-social, and motor skills measured at 4.5 using the Ages and Stages Questionnaire (ASQ) (N = 249, 79% retained). Results: Parents in our sample spent on average 6.35 h per day using screen media outside of work (SD = 3.07) and children spent on average 3.43 h per/day using screens. Multivariate linear regression indicated that each 1-h increase in parents daily screen media use, corresponded to a 1.25 decrease in child global development scores, B = -1.25 p < 0.05, 95% CI between -2.37 and -0.13. Conclusion: Our results indicate that parent screen use may represent a key component of children's media ecology. Given the importance of global development in early childhood for later health and achievement, the present results suggest that interventions should include parent screen use habits in media wellness interventions.

Unraveling the effects of maternal breastfeeding duration and exclusive breast milk on children's cognitive abilities in early childhood.

Background: This study investigated the putative associations between mothers' use of exclusive breast milk and the duration of breastfeeding with child cognitive development. Methods: This study is based on 2,210 Canadian families with children assessed longitudinally from age 4 to 7 years on their memory-span and math skills. These cognitive abilities were measured with standardized tasks. Breastfeeding practices were collected via maternal reports. We applied propensity scores to control the social selection bias for breastfeeding. Results: Results adjusted for propensity scores and sample weight revealed no significant differences between non-breastfed children with those being non-exclusively breastfed for 5 months or less, and with children being exclusively breastfed for 9.2 months on average, on their early math skills and memory-span. We found that children who were non-exclusively breastfed for 6.8 months on average had a slightly higher levels of memory-span at age 4 than children who were never breastfed, and this small but significant difference lasted up to age 7. Conclusion: Our findings suggest no significant differences between children being exclusively breastfed and those fed with formula on their early math skills and memory-span. The encouragement of breastfeeding to promote child cognitive school readiness may, in some case (non-exclusive breastfeeding for more than 5 months), show a small but long-lasting advantage in early memory-span.

Is the Association Between Early Childhood Screen Media Use and Effortful Control Bidirectional? A Prospective Study During the COVID-19 Pandemic.

Individual differences in effortful control, a component of temperament, reflecting the ability to use attention and other cognitive processes to self-regulate emotion and behavior, contribute to child academic adjustment, social competence, and wellbeing. Research has linked excessive screen time in early childhood to reduced self-regulation ability. Furthermore, research suggests that parents are more likely to use screens with children who have more challenging temperaments, such as low levels of effortful control. Since screen time by children between the ages of 0 and 18 has increased during the COVID-19 pandemic, it remains timely to investigate the developmental pattern of association between child screen media use and effortful control. We hypothesize that higher levels of screen media intake at age 3.5 will be associated with lower effortful control at age 4.5 and that lower effortful control at 3.5 will contribute to more screen media intake at age 4.5. This study draws on participants followed longitudinally over the span of 2-years for an investigation of Canadian preschoolers' screen media use during the pandemic (N = 316, Wave 1). A follow-up with this sample was completed in 2021 (N = 265, Wave 2). Analyses using a cross-lagged panel model revealed stability in child screen time and effortful control between the ages of 3.5 and 4.5. Child screen time at age 3.5 significantly contributed to decreased effortful control scores at the age of 4.5, whereas effortful control at age 3.5 did not contribute to screen time at age 4.5. Our results partially confirmed our hypothesis and indicated that higher levels of screen time intake were detrimental to the development of effortful control. These results suggest that screen media use, an exceedingly frequent activity, may play an enduring role in development by shaping young children's temperaments.

European Population of Pectobacterium punjabense: Genomic Diversity, Tuber Maceration Capacity and a Detection Tool for This Rarely Occurring Potato Pathogen.

Enterobacteria belonging to the Pectobacterium and Dickeya genera are responsible for soft rot and blackleg diseases occurring in many crops around the world. Since 2016, the number of described species has more than doubled. However, some new species, such as Pectobacterium punjabense, are often poorly characterized, and little is known about their genomic and phenotypic variation. Here, we explored several European culture collections and identified seven strains of P. punjabense. All were collected from potato blackleg symptoms, sometimes from a long time ago, i.e., the IFB5596 strain isolated almost 25 years ago. We showed that this species remains rare, with less than 0.24% of P. punjabense strains identified among pectinolytic bacteria present in the surveyed collections. The analysis of the genomic diversity revealed the non-clonal character of P. punjabense species. Furthermore, the strains showed aggressiveness differences. Finally, a qPCR Taqman assay was developed for rapid and specific strain characterization and for use in diagnostic programs.

When knowing only one word for "car" leads to weak application of mutual exclusivity.

From a very young age, monolingual children assume their language has no synonyms, or use the principle of mutual exclusivity (only one label per object). In contrast, bilingual children often accept more novel synonyms than monolinguals. One possible explanation for this difference is the lexicon structure hypothesis: having synonyms (across languages) in the lexicon reduces adherence to mutual exclusivity. The purpose of this study is to test the lexicon structure hypothesis by comparing three- to five-year-old children who speak either Canadian French or English. Canadian French allows more synonyms than English. French-speaking children should therefore accept more novel synonyms than English-speaking children. The children did a disambiguation task, choosing whether a familiar or an unfamiliar object was the referent of a novel word (e.g., moli). Surprisingly, the French-speaking children accepted significantly fewer novel synonyms than English-speaking children. However, they accepted the most synonyms for objects that had synonyms in French but they did not know both synonyms. These results support a modified version of the lexicon structure hypothesis, one that accounts for children's weak access to synonyms.