45 research outputs found

    Comparative genomics of Pseudomonas fluorescens subclade III strains from human lungs

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    Abstract Background While the taxonomy and genomics of environmental strains from the P. fluorescens species-complex has been reported, little is known about P. fluorescens strains from clinical samples. In this report, we provide the first genomic analysis of P. fluorescens strains in which human vs. environmental isolates are compared. Results Seven P. fluorescens strains were isolated from respiratory samples from cystic fibrosis (CF) patients. The clinical strains could grow at a higher temperature (>34 °C) than has been reported for environmental strains. Draft genomes were generated for all of the clinical strains, and multi-locus sequence analysis placed them within subclade III of the P. fluorescens species-complex. All strains encoded type- II, −III, −IV, and -VI secretion systems, as well as the widespread colonization island (WCI). This is the first description of a WCI in P. fluorescens strains. All strains also encoded a complete I2/PfiT locus and showed evidence of horizontal gene transfer. The clinical strains were found to differ from the environmental strains in the number of genes involved in metal resistance, which may be a possible adaptation to chronic antibiotic exposure in the CF lung. Conclusions This is the largest comparative genomics analysis of P. fluorescens subclade III strains to date and includes the first clinical isolates. At a global level, the clinical P. fluorescens subclade III strains were largely indistinguishable from environmental P. fluorescens subclade III strains, supporting the idea that identifying strains as ‘environmental’ vs ‘clinical’ is not a phenotypic trait. Rather, strains within P. fluorescens subclade III will colonize and persist in any niche that provides the requirements necessary for growth.http://deepblue.lib.umich.edu/bitstream/2027.42/116129/1/12864_2015_Article_2261.pd

    Homeobox Transcription Factors Are Required for Conidiation and Appressorium Development in the Rice Blast Fungus Magnaporthe oryzae

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    The appropriate development of conidia and appressoria is critical in the disease cycle of many fungal pathogens, including Magnaporthe oryzae. A total of eight genes (MoHOX1 to MoHOX8) encoding putative homeobox transcription factors (TFs) were identified from the M. oryzae genome. Knockout mutants for each MoHOX gene were obtained via homology-dependent gene replacement. Two mutants, ΔMohox3 and ΔMohox5, exhibited no difference to wild-type in growth, conidiation, conidium size, conidial germination, appressorium formation, and pathogenicity. However, the ΔMohox1 showed a dramatic reduction in hyphal growth and increase in melanin pigmentation, compared to those in wild-type. ΔMohox4 and ΔMohox6 showed significantly reduced conidium size and hyphal growth, respectively. ΔMohox8 formed normal appressoria, but failed in pathogenicity, probably due to defects in the development of penetration peg and invasive growth. It is most notable that asexual reproduction was completely abolished in ΔMohox2, in which no conidia formed. ΔMohox2 was still pathogenic through hypha-driven appressoria in a manner similar to that of the wild-type. However, ΔMohox7 was unable to form appressoria either on conidial germ tubes, or at hyphal tips, being non-pathogenic. These factors indicate that M. oryzae is able to cause foliar disease via hyphal appressorium-mediated penetration, and MoHOX7 is mutually required to drive appressorium formation from hyphae and germ tubes. Transcriptional analyses suggest that the functioning of M. oryzae homeobox TFs is mediated through the regulation of gene expression and is affected by cAMP and Ca2+ signaling and/or MAPK pathways. The divergent roles of this gene set may help reveal how the genome and regulatory pathways evolved within the rice blast pathogen and close relatives

    Association between social support and place of delivery: a cross-sectional study in Kericho, Western Kenya

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    Background: An estimated 358,000 maternal deaths still occur worldwide each year. The place of delivery is of great significance to the reduction of maternal mortality. Moreover, socio-economic factors, cultural traits, and local customs are associated with health-seeking behavior. This study aimed to explore determinants of association between social support and place of delivery. Methods: This cross-sectional study was conducted from September to November 2011 at Sosiot Health Center, Kericho West District, Kenya. Participants were 303 mothers who brought their babies to the health center for immunization within their first year of life. Women underwent a structured interview using a questionnaire on demographic characteristics and their experiences of delivery including place of delivery and social support. Results: The proportion of deliveries at health facilities was significantly higher in unmarried than married women (93% and 78%, respectively; P = 0.008). Unmarried women whose mothers supported them in housework and whose sisters helped them fetch water were more likely to deliver at health facilities (P = 0.002 and 0.042, respectively) than those without this support. However, married women whose husbands supported them in farming and whose neighbors helped them fetch water were less likely to deliver at health facilities (P = 0.003 and 0.021, respectively) than those without this support. Married women who were advised to deliver at a health facility by their mother-in-law or health staff were more likely to deliver at health facilities (P = 0.015 and 0.022, respectively) than those who did not receive this advice. Multivariate analysis revealed that married women were more likely to deliver at health facilities if they were highly educated (odds ratio [OR] = 2.5); had financial capability (OR = 4.3); had medical insurance (OR = 4.2); were primiparous (OR = 3.5); did not have the support of sisters-in-law for fetching water (OR = 2.2); or were advised to deliver at a health facility by family or neighbors (OR = 2.5).Conclusions: Promotion of delivery at health facilities requires approaches that consider women\u27s social situation, since factors influencing place of delivery differ for married and unmarried women

    Consanguinity and reproductive health among Arabs

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    Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Lay health workers in primary and community health care.

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    BACKGROUND: Lay health workers (LHWs) are widely used to provide care for a broad range of health issues. However, little is known about the effectiveness of LHW interventions. OBJECTIVES: To assess the effects of LHW interventions in primary and community health care on health care behaviours, patients' health and wellbeing, and patients' satisfaction with care. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care and Consumers and Communication specialised registers (to August 2001); the Cochrane Central Register of Controlled Trials (to August 2001); MEDLINE (1966- August 2001); EMBASE (1966-August 2001); Science Citations (to August 2001); CINAHL (1966-June 2001); Healthstar (1975-2000); AMED (1966-August 2001); the Leeds Health Education Effectiveness Database and the reference lists of articles. SELECTION CRITERIA: Randomised controlled trials of any intervention delivered by LHWs (paid or voluntary) in primary or community health care and intended to promote health, manage illness or provide support to patients. A 'lay health worker' was defined as any health worker carrying out functions related to health care delivery; trained in some way in the context of the intervention; and having no formal professional or paraprofessional certificated or degreed tertiary education. There were no restrictions on the types of consumers. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data onto a standard form and assessed study quality. Studies that compared broadly similar types of interventions were grouped together. Where feasible, the results of included studies were combined and an estimate of effect obtained. MAIN RESULTS: Forty three studies met the inclusion criteria, involving more than 210,110 consumers. These showed considerable diversity in the targeted health issue and the aims, content and outcomes of interventions. Most were conducted in high income countries (n=35), but nearly half of these focused on low income and minority populations (n=15). Study diversity limited meta-analysis to outcomes for five subgroups (n=15 studies) (LHW interventions to promote the uptake of breast cancer screening, immunisation and breastfeeding promotion [before two weeks and between two weeks and six months post partum] and to improve diagnosis and treatment for selected infectious diseases). Promising benefits in comparison with usual care were shown for LHW interventions to promote immunisation uptake in children and adults (RR=1.30 [95% CI 1.14, 1.48] p=0.0001) and LHW interventions to improve outcomes for selected infectious diseases (RR=0.74 [95% CI 0.58, 0.93) p=0.01). LHWs also appear promising for breastfeeding promotion. They appear to have a small effect in promoting breast cancer screening uptake when compared with usual care. For the remaining subgroups (n=29 studies), the outcomes were too diverse to allow statistical pooling. We can therefore draw no general conclusions on the effectiveness of these subgroups of interventions. AUTHORS' CONCLUSIONS: LHWs show promising benefits in promoting immunisation uptake and improving outcomes for acute respiratory infections and malaria, when compared to usual care. For other health issues, evidence is insufficient to justify recommendations for policy and practice. There is also insufficient evidence to assess which LHW training or intervention strategies are likely to be most effective. Further research is needed in these areas
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