RESUMEN
Many of the world's most devastating crop diseases are caused by fungal pathogens that elaborate specialized infection structures to invade plant tissue. Here, we present a quantitative mass-spectrometry-based phosphoproteomic analysis of infection-related development by the rice blast fungus Magnaporthe oryzae, which threatens global food security. We mapped 8,005 phosphosites on 2,062 fungal proteins following germination on a hydrophobic surface, revealing major re-wiring of phosphorylation-based signaling cascades during appressorium development. Comparing phosphosite conservation across 41 fungal species reveals phosphorylation signatures specifically associated with biotrophic and hemibiotrophic fungal infection. We then used parallel reaction monitoring (PRM) to identify phosphoproteins regulated by the fungal Pmk1 MAPK that controls plant infection by M. oryzae. We define 32 substrates of Pmk1 and show that Pmk1-dependent phosphorylation of regulator Vts1 is required for rice blast disease. Defining the phosphorylation landscape of infection therefore identifies potential therapeutic interventions for the control of plant diseases.
Asunto(s)
Proteínas Fúngicas , Oryza , Enfermedades de las Plantas , Fosforilación , Oryza/microbiología , Oryza/metabolismo , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/metabolismo , Fosfoproteínas/metabolismo , Ascomicetos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteómica , Transducción de SeñalRESUMEN
Bioengineering of plant immune receptors has emerged as a key strategy for generating novel disease resistance traits to counteract the expanding threat of plant pathogens to global food security. However, current approaches are limited by rapid evolution of plant pathogens in the field and may lack durability when deployed. Here, we show that the rice nucleotide-binding, leucine-rich repeat (NLR) immune receptor Pik-1 can be engineered to respond to a conserved family of effectors from the multihost blast fungus pathogen Magnaporthe oryzae. We switched the effector binding and response profile of the Pik NLR from its cognate rice blast effector AVR-Pik to the host-determining factor pathogenicity toward weeping lovegrass 2 (Pwl2) by installing a putative host target, OsHIPP43, in place of the native integrated heavy metal-associated domain (generating Pikm-1OsHIPP43). This chimeric receptor also responded to other PWL alleles from diverse blast isolates. The crystal structure of the Pwl2/OsHIPP43 complex revealed a multifaceted, robust interface that cannot be easily disrupted by mutagenesis, and may therefore provide durable, broad resistance to blast isolates carrying PWL effectors in the field. Our findings highlight how the host targets of pathogen effectors can be used to bioengineer recognition specificities that have more robust properties compared to naturally evolved disease resistance genes.
Asunto(s)
Proteínas Fúngicas , Proteínas NLR , Oryza , Enfermedades de las Plantas , Proteínas de Plantas , Oryza/microbiología , Oryza/inmunología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Proteínas NLR/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/inmunología , Proteínas de Plantas/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/inmunología , Interacciones Huésped-Patógeno/inmunología , Resistencia a la Enfermedad/inmunología , Inmunidad de la Planta , Bioingeniería/métodos , Magnaporthe/inmunología , Magnaporthe/genética , Magnaporthe/metabolismo , Unión Proteica , Receptores Inmunológicos/metabolismo , AscomicetosRESUMEN
Filamentous plant pathogens deliver effector proteins into host cells to suppress host defence responses and manipulate metabolic processes to support colonization. Understanding the evolution and molecular function of these effectors provides knowledge about pathogenesis and can suggest novel strategies to reduce damage caused by pathogens. However, effector proteins are highly variable, share weak sequence similarity and, although they can be grouped according to their structure, only a few structurally conserved effector families have been functionally characterized to date. Here, we demonstrate that Zinc-finger fold (ZiF) secreted proteins form a functionally diverse effector family in the blast fungus Magnaporthe oryzae. This family relies on the Zinc-finger motif for protein stability and is ubiquitously present in blast fungus lineages infecting 13 different host species, forming different effector tribes. Homologs of the canonical ZiF effector, AVR-Pii, from rice infecting isolates are present in multiple M. oryzae lineages. Wheat infecting strains of the fungus also possess an AVR-Pii like allele that binds host Exo70 proteins and activates the immune receptor Pii. Furthermore, ZiF tribes may vary in the proteins they bind to, indicating functional diversification and an intricate effector/host interactome. Altogether, we uncovered a new effector family with a common protein fold that has functionally diversified in lineages of M. oryzae. This work expands our understanding of the diversity of M. oryzae effectors, the molecular basis of plant pathogenesis and may ultimately facilitate the development of new sources for pathogen resistance.
Asunto(s)
Proteínas Fúngicas , Enfermedades de las Plantas , Dedos de Zinc , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Interacciones Huésped-Patógeno , Oryza/microbiología , Ascomicetos/genética , Ascomicetos/metabolismo , Magnaporthe/genética , Magnaporthe/metabolismo , FilogeniaRESUMEN
BACKGROUND: Improving access to family planning (FP) is associated with positive health benefits that includes averting nearly a third of all maternal deaths and 10% of childhood deaths. Kenya has made great strides in improving access to family planning services. However, amid this considerable progress, regional variation has been noted which begs the need for a clearer understanding of the the patterns and determinants that drive these inconsistencies. METHODS: We conducted a cross-sectional study that involved 663 Muslim women of reproductive age (15-49 years) from Wajir and Lamu counties in Kenya between March and October 2018.The objective of this study was to understand patterns and determinants of contraceptive use in two predominantly Muslim settings of Lamu and Wajir counties that have varying contraceptive uptake. Eligible women were interviewed using a semi-structured questionnaire containing socio-demographic information and history of family planning use. Simple and multiple logistic regression were used to identify determinants of family planning use. The results were presented as Crude Odds Ratio (COR) and Adjusted Odds Ratio (AOR) ratios at 95% confidence interval. A p-value of 0.05 was considered statistically significant. RESULTS: Of the 663 Muslim women of reproductive age consenting to participate in the study, 51.5%, n = 342 and 48.5%, n = 321 were from Lamu and Wajir County, respectively. The prevalence of women currently using contraceptive was 18.6% (n = 123). In Lamu, the prevalence was 32.8%, while in Wajir, it was 3.4%. The determinants of current contraceptive use in Lamu include; marital status, age at marriage, employment status, discussion with a partner on FP, acceptability of FP in culture, and willingness to obtain information on FP. While in Wajir, determinants of current contraceptive use were education, and the belief that family planning is allowed in Islam. CONCLUSIONS: Our study found moderately high use of contraceptives among Muslim women of reproductive age in Lamu county and very low contraceptive use among women in Wajir. Given the role of men in decision making, it is critical to design male involvement strategy particularly in Wajir where the male influence is very prominent. It is critical for the government to invest in women and girls' education to enhance their ability to make informed decisions; particularly in Wajir where FP uptake is low with low education attainment. Further, our findings highlight the need for culturally appropriate messages and involvement of religious leaders to demystify the myths and misconception around family planning and Islam particularly in Wajir.
Asunto(s)
Anticoncepción , Anticonceptivos , Masculino , Femenino , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Islamismo , Estudios Transversales , Kenia , Servicios de Planificación Familiar , Encuestas y Cuestionarios , Conducta AnticonceptivaRESUMEN
Vaccination is crucial in reducing child mortality and the prevalence of Vaccine-Preventable-Diseases (VPD), especially in low-and-middle-income countries like Kenya. However, non-vaccination, under-vaccination, and missed opportunities for vaccination (MOV) pose significant challenges to these efforts. This study aimed to analyze the impact of demographic and socio-economic factors on non-vaccination, under-vaccination, and MOV among children aged 0-23 months in Kenya from 2003 to 2014. A secondary data analysis of data from the Kenya Demographic Health Surveys (KDHS) conducted during this period was conducted, with a total of 11,997 participants, using a two-stage, multi-stage, and stratified sampling technique. The study examined factors such as child's sex, residence, mother's age, marital status, religion, birth order, maternal education, wealth quintile, province, child's birth order, parity, number of children in the household, place of delivery, and mother's occupation. Binary logistic regression was employed to identify the determinants of non-vaccination, under-vaccination, and MOV, and multivariable logistic regression analysis to report odds ratios (OR) and their corresponding 95% confidence intervals (CI). In 2003, the likelihood of non-vaccination decreased with higher maternal education levels: mothers who did not complete primary education (AOR = 0.55, 95% CI = 0.37-0.81), completed primary education (AOR = 0.34, 95% CI = 0.21-0.56), and had secondary education or higher (AOR = 0.26, 95% CI = 0.14-0.50) exhibited decreasing probabilities. In 2008/09, divorced/separated/widowed mothers (AOR = 0.22, 95% CI = 0.07-0.65) and those with no religion (AOR = 0.37, 95% CI = 0.17-0.81) showed lower odds of non-vaccination, while lower wealth quintiles were associated with higher odds. In 2014, non-vaccination was higher among younger mothers aged 15-19 years (AOR = 12.53, 95% CI = 1.59-98.73), in North Eastern Province (AOR = 7.15, 95% CI = 2.02-25.30), in families with more than 5 children (AOR = 4.19, 95% CI = 1.09-16.18), and in children born at home (AOR = 4.47, 95% CI = 1.32-15.17). Similar patterns were observed for under-vaccination and MOV. This information can inform strategies for bridging the gaps in immunization coverage and promoting equitable vaccination practices in Kenya.
RESUMEN
Unlike praziquantel, artemisinin derivatives are effective against juvenile schistosome worms. We assessed the efficacy and safety of a single oral dose of artesunate plus sulfalene-pyrimethamine versus praziquantel in the treatment of Schistosoma mansoni. Seventy-three schoolchildren (aged 9-15 years) with confirmed S. mansoni infection in Rarieda, western Kenya, were randomly assigned to receive either a single oral dose of artesunate plus sulfalene-pyrimethamine (n = 39) or a single dose of praziquantel (n = 34). The cure and egg reduction rates at 4 weeks posttreatment were 69.4% (25/36) versus 80.6% (25/31) (P = 0.297) and 99.1% versus 97.5% (P = 0.607) in the artesunate plus sulfalene-pyrimethamine group versus praziquantel group, respectively. Fourteen children developed adverse events, and there were no serious adverse events. A single oral dose of artesunate plus sulfalene-pyrimethamine has efficacy comparable to that of praziquantel in the treatment of S. mansoni, but these results should be confirmed in larger randomized controlled trials.
Asunto(s)
Antihelmínticos , Artemisininas , Esquistosomiasis mansoni , Sulfaleno , Adolescente , Animales , Niño , Humanos , Antihelmínticos/uso terapéutico , Artemisininas/efectos adversos , Artesunato/uso terapéutico , Quimioterapia Combinada , Pueblo de África Oriental , Kenia , Praziquantel/efectos adversos , Pirimetamina/uso terapéutico , Schistosoma mansoni , Esquistosomiasis mansoni/tratamiento farmacológico , Sulfaleno/farmacología , Sulfaleno/uso terapéutico , Resultado del TratamientoRESUMEN
Vaccines are effective and cost-effective. Non-vaccination, under-vaccination, and missed opportunities for vaccination (MOV), have contributed to incomplete vaccination coverage in Kenya. Analyzing their trends is essential for targeting interventions and improvement strategies. This study aimed to assess trends of non-vaccination, under-vaccination, and MOV among children aged 0-23 months in Kenya using data obtained from the Kenya Demographic and Health Surveys (KDHS) conducted in 2003, 2008/09, and 2014. A two-stage, multi-stage, and stratified sampling technique was used. Weighted analysis was conducted to ensure generalizability to the full population. Using the KDHS sample size estimation process, the sample size was estimated for each indicator, with varying standard error estimates, level of coverage and estimated response rates. Final sample size was 2380 (2003), 2237 (2008/09) and 7380 (2014). To determine the level of non-vaccination, under-vaccination and MOV among children aged 0-23 months, a weighted descriptive analysis was used to estimate their prevalence, with 95% confidence intervals (CI) for each year. MOV was defined using an algorithm as a binary variable. Data coding and recoding were done using Stata (version 14; College Station, TX: StataCorp LP). Trends in proportions of non-vaccination, under-vaccination and MOV were compared between 2003, 2008/09, and 2014 using the Cochrane-Armitage trend test. All results with P≤0.05 were considered statistically significant. Trends in proportion of non-vaccination among children aged 0-23 months in Kenya was 13.2%, 6.1% and 3.2% in 2003, 2008/09 and 2014, respectively (P = 0.0001). Trends in proportion of under-vaccination among children aged 0-23 months in Kenya was 54.3%, 50% and 51.3% in 2003, 2008/09 and 2014, respectively (P = 0.0109). The trends in proportion of children who experienced MOV was 22.7% in 2003, 31.9% in 2008/09 and 37.6% in 2014 (P = 0.0001). In the study duration, non-vaccination decreased by 10%, under-vaccination remained relatively stable, and MOV increased by ~15%. There is need for the Government and partners to implement initiatives that improve vaccine access and coverage, particularly in regions with low coverage rates, and to address missed opportunities for vaccination.
RESUMEN
Background: Non-typhoidal Salmonella infection (NTS) is an important foodborne zoonosis with underappreciated health and economic burdens, and low case fatality. It has global prevalence, with more burdens in under-resourced countries with poor health infrastructures. Using a cohort study, we determined the cost-effectiveness of NTS in humans in Nigeria for the year 2020. Methods: Using a customized Excel-based cost-effectiveness analysis tool, structured (One Health) and unstructured (episodic intervention against NTS) in Nigeria were evaluated. Input data on the disease burdens, costs surveillance, response and control of NTS were obtained from validated sources and the public health system. Results: The non-complicated and complicated cases were 309,444 (95%) and 16,287 (5%) respectively, and the overall programme cost was US$ 31,375,434.38. The current non-systematic episodic intervention costed US$ 14,913,480.36, indicating an additional US$ 16,461,954 to introduce the proposed intervention. The intervention will avert 4036.98 NTS DALYs in a single year. The non-complicated NTS case was US$ 60/person with significant rise in complicated cases. The cumulative costs of NTS with and without complications far outweighed the program cost for One Health intervention with an incremental cost-effectiveness ratio (ICER) of -US$ 221.30). Conclusions: Utilising structured One Health intervention is cost-effective against NTS in Nigeria, it carries additional mitigative benefits for other diseases and is less costly and more effective, indicative of a superior health system approach. Identified limitations must be improved to optimize benefits associated and facilitate policy discussions and resource allocation.