A longitudinal study of household water, sanitation, and hygiene characteristics and environmental enteropathy markers in children less than 24 months in Iquitos, Peru

Funding Information: Financial support: The MAL-ED is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center. While conducting this work, Natalie Exum was supported by The NSF IGERT Grant 1069213, The Osprey Foundation of Maryland Grant 1602030014, the Johns Hopkins Water Institute, Johns Hopkins Fisher Center Discovery Program Grant 010 KOS2015, The Kazuyoshi Kawata fund in Sanitary Engineering and Science, and the Dr. C. W. Kruse Memorial Fund Scholarship. Publisher Copyright: © 2018 by The American Society of Tropical Medicine and Hygiene.Peer reviewedPublisher PD

Gut microbiota features associated with Campylobacter burden and postnatal linear growth deficits in a Peruvian birth cohort

BACKGROUND: Campylobacter infection is associated with impaired growth of children, even in the absence of symptoms. To examine the underlying mechanisms, we evaluated associations between Campylobacter infection, linear growth, and fecal microbial community features in a prospective birth cohort of 271 children with a high burden of diarrhea and stunting in the Amazonian lowlands of Peru. METHODS: Campylobacter was identified using a broadly reactive, genus-specific enzyme-linked immunosorbent assay. 16S rRNA-based analyses were used to identify bacterial taxa in fecal samples at ages 6, 12, 18, and 24 months (N = 928). Associations between infection, growth, and gut microbial community composition were investigated using multiple linear regression adjusting for within-child correlations, age, and breastfeeding. Indicator species analyses identified taxa specifically associated with Campylobacter burden. RESULTS: Ninety-three percent (251) of children had Campylobacter present in asymptomatic fecal samples during the follow-up period. A 10% increase in the proportion of stools infected was associated with mean reductions of 0.02 length-for-age z scores (LAZ) at 3, 6, and 9 months thereafter (P \u3c .01). We identified 13 bacterial taxa indicative of cumulative Campylobacter burden and 14 taxa significantly associated with high or low burden of enteroaggregative Escherichia coli, norovirus, or Giardia. CONCLUSIONS: Campylobacter infection is common in this cohort and associated with changes in microbial community composition. These results support the notion that disruptions to the fecal microbiota may help explain the observed effects of asymptomatic infections on growth in early life

Diarrhea as a potential cause and consequence of reduced gut microbial diversity among undernourished children in Peru

BACKGROUND: Detrimental effects of diarrhea on child growth and survival are well documented, but details of the underlying mechanisms remain poorly understood. Recent evidence demonstrates that perturbations to normal development of the gut microbiota in early life may contribute to growth faltering and susceptibility to related childhood diseases. We assessed associations between diarrhea, gut microbiota configuration, and childhood growth in the Peruvian Amazon. METHODS: Growth, diarrhea incidence, illness, pathogen infection, and antibiotic exposure were assessed monthly in a birth cohort of 271 children aged 0-24 months. Gut bacterial diversity and abundances of specific bacterial taxa were quantified by sequencing 16S rRNA genes in fecal samples collected at 6, 12, 18, and 24 months. Linear and generalized linear models were used to determine whether diarrhea was associated with altered microbiota and, in turn, if features of the microbiota were associated with the subsequent risk of diarrhea. RESULTS: Diarrheal frequency, duration, and severity were negatively associated with bacterial diversity and richness (P \u3c .05). Children born stunted (length-for-age z-score [LAZ] ≤ -2) who were also severely stunted (LAZ ≤ -3) at the time of sampling exhibited the greatest degree of diarrhea-associated reductions in bacterial diversity and the slowest recovery of bacterial diversity after episodes of diarrhea. Increased bacterial diversity was predictive of reduced subsequent diarrhea from age 6 to 18 months. CONCLUSIONS: Persistent, severe growth faltering may reduce the gut microbiota\u27s resistance and resilience to diarrhea, leading to greater losses of diversity and longer recovery times. This phenotype, in turn, denotes an increased risk of future diarrheal disease and growth faltering

Determinants and Impact of Giardia Infection in the First 2 Years of Life in the MAL-ED Birth Cohort

Background. Giardia are among the most common enteropathogens detected in children in low-resource settings. We describe here the epidemiology of infection with Giardia in the first 2 years of life in the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED), a multisite birth-cohort stu dy. Methods. From 2089 children, 34 916 stool samples collected during monthly surveillance and episodes of diarrhea were tested for Giardia using an enzyme immunoassay. We quantified the risk of Giardia detection, identified risk factors, and assessed the associations with micronutrients, markers of gut inflammation and permeability, diarrhea, and growth using multivariable linear regression. Results. The incidence of at least 1 Giardia detection varied according to site (range, 37.7%–96.4%) and was higher in the sec - ond year of life. Exclusive breastfeeding (HR for first Giardia detection in a monthly surveillance stool sample, 0.46 [95% confidence interval (CI), 0.28–0.75]), higher socioeconomic status (HR, 0.74 [95% CI, 0.56–0.97]), and recent metronidazole treatment (risk ratio for any surveillance stool detection, 0.69 [95% CI, 0.56–0.84]) were protective. Persistence of Giardia (consecutive detections) in the first 6 months of life was associated with reduced subsequent diarrheal rates in Naushahro Feroze, Pakistan but not at any other site. Giardia detection was also associated with an increased lactulose/mannitol ratio. Persistence of Giardia before 6 months of age was associated with a −0.29 (95% CI, −0.53 to −0.05) deficit in weight-for-age z score and −0.29 (95% CI, −0.64 to 0.07) deficit in length-for-age z score at 2 years. Conclusions. Infection with Giardia occurred across epidemiological contexts, and repeated detections in 40% of the children suggest that persistent infections were common. Early persistent infection with Giardia , independent of diarrhea, might contribute to intestinal permeability and stunted growth

Early Life Child Micronutrient Status, Maternal Reasoning, and a Nurturing Household Environment have Persistent Influences on Child Cognitive Development at Age 5 years : Results from MAL-ED

Funding Information: The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED) is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the NIH, and the National Institutes of Health/Fogarty International Center. This work was also supported by the Fogarty International Center, National Institutes of Health (D43-TW009359 to ETR). Author disclosures: BJJM, SAR, LEC, LLP, JCS, BK, RR, RS, ES, LB, ZR, AM, RS, BN, SH, MR, RO, ETR, and LEM-K, no conflicts of interest. Supplemental Tables 1–5 and Supplemental Figures 1–3 are available from the “Supplementary data” link in the online posting of the article and from the same link in the online table of contents at https://academic.oup.com/jn/. Address correspondence to LEM-K (e-mail: [email protected]). Abbreviations used: HOME, Home Observation for Measurement of the Environment inventory; MAL-ED, The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project; TfR, transferrin receptor; WPPSI, Wechsler Preschool Primary Scales of Intelligence.Peer reviewe

Early life child micronutrient status, maternal reasoning, and a nurturing household environment have persistent influences on child cognitive development at age 5 years: Results from MAL-ED

Background: Child cognitive development is influenced by early-life insults and protective factors. To what extent these factors have a long-term legacy on child development and hence fulfillment of cognitive potential is unknown. Objective: The aim of this study was to examine the relation between early-life factors (birth to 2 y) and cognitive development at 5 y. Methods: Observational follow-up visits were made of children at 5 y, previously enrolled in the community-based MAL-ED longitudinal cohort. The burden of enteropathogens, prevalence of illness, complementary diet intake, micronutrient status, and household and maternal factors from birth to 2 y were extensively measured and their relation with the Wechsler Preschool Primary Scales of Intelligence at 5 y was examined through use of linear regression. Results: Cognitive T-scores from 813 of 1198 (68%) children were examined and 5 variables had significant associations in multivariable models: mean child plasma transferrin receptor concentration (β: −1.81, 95% CI: −2.75, −0.86), number of years of maternal education (β: 0.27, 95% CI: 0.08, 0.45), maternal cognitive reasoning score (β: 0.09, 95% CI: 0.03, 0.15), household assets score (β: 0.64, 95% CI: 0.24, 1.04), and HOME child cleanliness factor (β: 0.60, 95% CI: 0.05, 1.15). In multivariable models, the mean rate of enteropathogen detections, burden of illness, and complementary food intakes between birth and 2 y were not significantly related to 5-y cognition. Conclusions: A nurturing home context in terms of a healthy/clean environment and household wealth, provision of adequate micronutrients, maternal education, and cognitive reasoning have a strong and persistent influence on child cognitive development. Efforts addressing aspects of poverty around micronutrient status, nurturing caregiving, and enabling home environments are likely to have lasting positive impacts on child cognitive development.publishedVersio

Marcadores Rapd ligados al sexo de Mauritia flexuosa l.f. “aguaje” (Arecaceae) en el distrito de San Juan Bautista, Loreto-Perú

The present work's objective was to identify RAPD markers linked to sex of “aguaje” Mauritia flexuosa L. f. from DNA mixtures of male and female plants. The sampling area were the community of Quistococha (latitude 03°49'28.66 " S length 73° 19'18.98" W, with 96 msnm) and Santa Clara (latitude 03°46'50.5" S, longitude 73 °18'25.3" W, with 118 msnm); 10 male and 10 female sexually differentiated plants were selected, Collecting leaves, roots and / or pneumatophores and transported to the Research Laboratory of the Biological Sciences School and the Research Laboratory of Natural Antiparasitic Products of the Amazon (LIPNAA) of the National University of the Peruvian Amazon (UNAP), DNA was extracted and mixed by sex , performing RAPD PCR tests with 38 random primers; of Which, 11 primers (E -36, E -37, D1, UNAP1, F1, F5xFa, R5xFma, UNR, PLF, FAR' and EXT5) generated 31 polymorphic amplification products (21 differential bands on female plants and 10 male) with sizes between 182 to 1.552bp; six bands presented better resolution (502bp, 513bp, 610bp, 762bp, 871bp and 975bp) and the F5xFa primer revealed a greater number of differential bands with the female sex. Therefore; the female sex plants are more polymorphic than the male sex and probably can identify sex with RAPD PCR technique early in M. flexuosa.TesisEl objetivo del presente trabajo fue identificar marcadores RAPD ligados al sexo de Mauritia flexuosa L. f. “aguaje” empleando mezclas de ADN de plantas masculinas y femeninas. Los muestreos se realizaron en los caseríos de Quistococha (latitud 03°49’28.66” S longitud 73°19’18.98” O, con 96 msnm) y Santa Clara (latitud 03°46’50.5” S, longitud 73°18’25.3” O, con 118 msnm), se seleccionaron 10 plantas masculinas y 10 femeninas sexualmente diferenciadas y se colectaron hojas, raíces y neumatóforos. Posteriormente fueron transportadas al Laboratorio de Investigación de la Facultad de Ciencias Biológicas y el Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonía (LIPNAA) de la Universidad Nacional de la Amazonía Peruana (UNAP), se extrajo el ADN, se hizo la mezcla por sexo y se realizaron las pruebas del RAPD PCR con 38 cebadores aleatorios; de las cuales, 11 (E-36, E-37, D1, UNAP1, F1, F5xFa, R5xFma, UNR, PLF, FAR y EXT5’) generaron 31 productos polimórficos (21 bandas diferenciales en plantas femeninas y 10 en masculino), con tamaños entre 182 a 1,552pb; seis bandas presentaron mejor resolución (502pb, 513pb, 610pb, 762pb, 871pb y 975pb) y el cebador F5xFa reveló mayor número de bandas diferenciales con el sexo femenino. Por lo tanto; las plantas del sexo femenino son más polimórficas que las de sexo masculino y probablemente se pueda identificar el sexo con la técnica del RAPD PCR a temprana edad en M. flexuosa

LINEAMIENTOS GENERALES PARA EL REPOBLAMIENTO DE PECES AMAZÓNICOS EN AMBIENTES NATURALES

El aumento de la ocupación territorial y la mayor efectividad en actividades de pesca, ha ocasionado una mayor presión sobre las especies de peces de elevado valor económico en la Amazonía. Como consecuencia de esto, especies como el paiche Arapaima gigas, la gamitana Colossoma macropomum y el paco Piaractus brachypomus entre otros, presentan drásticas reducciones en sus poblaciones naturales. Tratando de revertir esta situación diversas instituciones vienen promoviendo el repoblamiento de diferentes cuerpos de agua con estos peces Amazónicos. Es importante considerar que el repoblamiento es una actividad cuyo objetivo es contribuir al restablecimiento de una especie en un área geográfica, y que está tenga éxito a través del tiempo en su expansión demográfica

Diversidad genética y filogenia molecular de poblaciones de Mauritia flexuosa L.f. “aguaje” de la Amazonía Peruana

Mauritia flexuosa es una especie vegetal amazónica que forma extensas poblaciones denominadas “aguajales”. Como los pobladores amazónicos emplean varios órganos de M. flexuosa para suplir sus necesidades y con fines comerciales, se está ejerciendo un gran impacto negativo sobre esta especie. A pesar de ello, a la fecha no se conoce la diversidad genética de esta especie en la Amazonía peruana. Consecuentemente, los planes de manejo para la especie serían limitados sin este tipo de información. Por tanto, el objetivo de esta investigación fue determinar la diversidad genética y filogenia molecular de poblaciones de M. flexuosa aledañas a la carretera Iquitos-Nauta. Las hojas se colectaron en seis zonas contiguas a la carretera Iquitos–Nauta. El ADN purificado con protocolos estándares fue amplificado mediante la técnica de ADN Polimórfico Amplificado al Azar (RAPD) con dos cebadores aleatorios.  En total se generaron 28 amplicones RAPD (26 polimórficos y 2 monomórficos). Dentro de los aguajales la diversidad genética fue tres veces mayor (75±19 %) que la diversidad genética entre las seis poblaciones de M. flexuosa (25±19 %). La diferenciación genética entre las poblaciones varió de 0,0 a 0,6. Los aguajales que se agruparon en clados en el dendrograma por su mayor similitud genética tuvieron proximidad geográfica. La similitud genética entre las poblaciones de M. flexuosa depende de la distancia geográfica, de tal manera que las poblaciones con más similitud genética están más próximas entre sí que las que tienen menos similitud genética