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1.
Clin Infect Dis ; 75(8): 1334-1341, 2022 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-36094137

RESUMEN

BACKGROUND: Sapovirus is one of the principal agents of acute viral enteritis in children. Because it has not been routinely included in diagnostic evaluations, the epidemiology and natural history remain poorly described. METHODS: A birth cohort of 1715 children from 8 countries contributed surveillance samples (n = 35 620) and diarrheal specimens (n = 6868) from 0 to 24 months of age. Sapovirus was detected by quantitative polymerase chain reaction concurrently to other enteropathogens using multiarray cards. Logistic regression was used to identify risk factors, and longitudinal models were employed to estimate incidence rates and evaluate evidence of protective immunity. RESULTS: Sapovirus was detected in 24.7% (n = 1665) of diarrheal stools and 12.8% (n = 4429) of monthly surveillance samples. More than 90% of children were infected and 60% experienced sapovirus diarrhea in the first 2 years of life. Breastfeeding and higher socioeconomic status were associated with reduced incidence of infection and illness. Specimens with sapovirus detected had an increased odds of coinfection with rotavirus (odds ratio [OR], 1.6 [95% confidence interval {CI}, 1.3-2.0]), astrovirus (OR, 1.5 [95% CI, 1.3-1.7]), adenovirus (OR, 1.3 [95% CI, 1.1-1.5]), and Shigella (OR, 1.4 [95% CI, 1.3-1.6]). Prior infection with sapovirus conferred a risk reduction of 22% for subsequent infection (hazard ratio [HR], 0.78 [95% CI, .74-.85]) and 24% for subsequent diarrhea (95% CI, 11.0%-35.0%; HR, 0.76). CONCLUSIONS: Sapovirus is a common cause of early childhood diarrhea. Further research on coinfections is warranted. Evidence of acquired immunity was observed even in the absence of genotype-specific analysis for this pathogen of known genetic diversity.


Asunto(s)
Coinfección , Desnutrición , Sapovirus , Niño , Salud Infantil , Preescolar , Coinfección/complicaciones , Coinfección/epidemiología , Diarrea , Heces , Femenino , Humanos , Lactante , Factores de Riesgo , Sapovirus/genética
2.
Clin Infect Dis ; 72(11): e806-e814, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33033835

RESUMEN

BACKGROUND: Prolonged enteropathogen shedding after diarrhea complicates the identification of etiology in subsequent episodes and is an important driver of pathogen transmission. A standardized approach has not been applied to estimate the duration of shedding for a wide range of pathogens. METHODS: We used a multisite birth cohort of children 0-24 months of age from whom diarrheal and monthly nondiarrheal stools were previously tested by quantitative polymerase chain reaction for 29 enteropathogens. We modeled the probability of detection of the etiologic pathogen before and after diarrhea using a log-normal accelerated failure time survival model and estimated the median duration of pathogen carriage as well as differences in subclinical pathogen carriage 60 days after diarrhea onset in comparison to a prediarrhea baseline. RESULTS: We analyzed 3247 etiologic episodes of diarrhea for the 9 pathogens with the highest attributable burdens of diarrhea. The median duration of postdiarrheal carriage varied widely by pathogen, from about 1 week for rotavirus (median, 8.1 days [95% confidence interval {CI}, 6.2-9.6]) to >1 month for Cryptosporidium (39.5 days [95% CI, 30.6-49.0]). The largest increases in subclinical pathogen carriage before and after diarrhea were seen for Cryptosporidium (prevalence difference between 30 days prior and 60 days after diarrhea onset, 0.30 [95% CI, .23-.39]) and Shigella (prevalence difference, 0.21 [95% CI, .16-.27]). CONCLUSIONS: Postdiarrheal shedding was widely variable between pathogens, with strikingly prolonged shedding seen for Cryptosporidium and Shigella. Targeted antimicrobial therapy and vaccination for these pathogens may have a relatively large impact on transmission.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Infecciones por Rotavirus , Rotavirus , Niño , Preescolar , Diarrea , Heces , Humanos , Lactante
3.
J Infect Dis ; 222(11): 1858-1868, 2020 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-31984416

RESUMEN

BACKGROUND: The degree of protection conferred by natural immunity is unknown for many enteropathogens, but it is important to support the development of enteric vaccines. METHODS: We used the Andersen-Gill extension of the Cox model to estimate the effects of previous infections on the incidence of subsequent subclinical infections and diarrhea in children under 2 using quantitative molecular diagnostics in the MAL-ED cohort. We used cross-pathogen negative control associations to correct bias due to confounding by unmeasured heterogeneity of exposure and susceptibility. RESULTS: Prior rotavirus infection was associated with a 50% lower hazard (calibrated hazard ratio [cHR], 0.50; 95% confidence interval [CI], 0.41-0.62) of subsequent rotavirus diarrhea. Strong protection was evident against Cryptosporidium diarrhea (cHR, 0.32; 95% CI, 0.20-0.51). There was also protection due to prior infections for norovirus GII (cHR against diarrhea, 0.67; 95% CI, 0.49-0.91), astrovirus (cHR, 0.62; 95% CI, 0.48-0.81), and Shigella (cHR, 0.79; 95% CI, 0.65-0.95). Minimal protection was observed for other bacteria, adenovirus 40/41, and sapovirus. CONCLUSIONS: Natural immunity was generally stronger for the enteric viruses than bacteria, potentially due to less antigenic diversity. Vaccines against major causes of diarrhea may be feasible but likely need to be more immunogenic than natural infection.


Asunto(s)
Diarrea/inmunología , Inmunidad Innata , Adenoviridae , Bacterias , Preescolar , Estudios de Cohortes , Criptosporidiosis , Cryptosporidium , Diarrea/microbiología , Diarrea/parasitología , Diarrea/virología , Heces/virología , Humanos , Lactante , Recién Nacido , Norovirus , Rotavirus
4.
Clin Infect Dis ; 67(11): 1660-1669, 2018 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-29701852

RESUMEN

Background: Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America. Methods: Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly. Results: Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2-4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (ß = -.26 [95% CI, -.51 to -.01]) and Bangladesh (ß = -.20 [95% CI, -.44 to .05]) sites. Conclusions: This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.


Asunto(s)
Criptosporidiosis/epidemiología , Diarrea/epidemiología , Áreas de Pobreza , África/epidemiología , Asia/epidemiología , Preescolar , Estudios de Cohortes , Aglomeración , Cryptosporidium/aislamiento & purificación , Diarrea/parasitología , Heces/parasitología , Femenino , Trastornos del Crecimiento/parasitología , Humanos , Lactante , Recién Nacido , Masculino , Desnutrición/parasitología , Análisis de Regresión , Factores de Riesgo , Factores Socioeconómicos , América del Sur/epidemiología , Encuestas y Cuestionarios
5.
J Pediatr Gastroenterol Nutr ; 66(2): 325-333, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29356769

RESUMEN

OBJECTIVE: We evaluated the impact of subclinical enteroaggregative Escherichia coli (EAEC) infection alone and in combination with other pathogens in the first 6 months of life on child growth. METHODS: Nondiarrheal samples from 1684 children across 8 Multisite Birth Cohort Study, Malnutrition and Enteric Diseases (MAL-ED) sites in Asia, Africa, and Latin America were tested monthly; more than 90% of children were followed-up twice weekly for the first 6 months of life. RESULTS: Children with subclinical EAEC infection did not show altered growth between enrollment and 6 months. Conversely, EAEC coinfection with any other pathogen was negatively associated with delta weight-for-length (P < 0.05) and weight-for-age (P > 0.05) z scores between 0 and 6 months. The presence of 2 or more pathogens without EAEC was not significantly associated with delta weight-for-length and weight-for-age. The most frequent EAEC coinfections included Campylobacter spp, heat-labile toxin-producing enterotoxigenic E coli, Cryptosporidium spp, and atypical enteropathogenic E coli. Myeloperoxidase levels were increased with EAEC coinfection (P < 0.05). EAEC pathogen codetection was associated with lower neopterin levels compared to those of no-pathogen control children (P < 0.05). Mothers of children with EAEC coinfections had lower levels of education, poorer hygiene and sanitation, lower socioeconomic status, and lower breast-feeding rates compared to mothers of children in whom no pathogen was detected (P < 0.05). CONCLUSIONS: These data emphasize the public health importance of subclinical EAEC infection in early infancy in association with other pathogens and the need for improved maternal and child care, hygiene, sanitation, and socioeconomic factors.


Asunto(s)
Escherichia coli Enteropatógena/aislamiento & purificación , Infecciones por Escherichia coli/complicaciones , Trastornos del Crecimiento/microbiología , Antropometría/métodos , Desarrollo Infantil , Estudios de Cohortes , Coinfección/complicaciones , Coinfección/epidemiología , Heces/microbiología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Intestinos/inmunología , Intestinos/microbiología , Masculino , Factores de Riesgo
6.
J Infect Dis ; 216(12): 1592-1600, 2017 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-29236996

RESUMEN

Background: Diarrhea is frequent in communities without clean water, which include low-income South African populations in Giyani and Pretoria. In these populations, the amount of diarrhea caused by Entamoeba histolytica, inclusive of all ages, sexes, and human immunodeficiency virus status, is uncertain. Infection with E. histolytica can modulate the host microbiota, and a key species indicative of this is the Prevotella copri pathobiont. Methods: A cross-sectional study of patients attending gastroenterology clinics was conducted to determine the frequency and burden of 4 Entamoeba species and P. copri. Results: Entamoeba species were present in 27% of patients (129/484), with E. histolytica detected in 8.5% (41), E. dispar in 8% (38), E. bangladeshi in 4.75% (23), and E. moshkovskii in 0%. This is the first description of E. bangladeshi outside Bangladesh. In E. histolytica-positive samples, the levels of both the parasite and P. copri were lower in nondiarrheal samples, validating the results of a study in Bangladesh (P = .0034). By contrast, in E. histolytica-negative samples positive for either of the nonpathogenic species E. dispar or E. bangladeshi, neither P. copri nor Entamoeba levels were linked to gastrointestinal status. Conclusions: Nonmorphologic identification of this parasite is essential. In South Africa, 3 morphologically identical Entamoeba were common, but only E. histolytica was linked to both disease and changes in the microbiota.


Asunto(s)
Entamoeba/clasificación , Entamoeba/aislamiento & purificación , Entamebiasis/epidemiología , Entamebiasis/parasitología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios Transversales , Diarrea/epidemiología , Diarrea/parasitología , Entamoeba/genética , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Carga de Parásitos , Prevalencia , Sudáfrica/epidemiología , Adulto Joven
7.
J Infect Dis ; 215(8): 1294-1302, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-28186296

RESUMEN

Understanding the mechanisms by which Entamoeba histolytica drives gut inflammation is critical for the development of improved preventive and therapeutic strategies. E. histolytica encodes a homolog of the human cytokine macrophage migration inhibitory factor (MIF). Here, we investigated the role of E. histolytica MIF (EhMIF) during infection. We found that the concentration of fecal EhMIF correlated with the level of intestinal inflammation in persons with intestinal amebiasis. Mice treated with antibodies that specifically block EhMIF had reduced chemokine expression and neutrophil infiltration in the mucosa. In addition to antibody-mediated neutralization, we used a genetic approach to test the effect of EhMIF on mucosal inflammation. Mice infected with parasites overexpressing EhMIF had increased chemokine expression, neutrophil influx, and mucosal damage. Together, these results uncover a specific parasite protein that increases mucosal inflammation, expands our knowledge of host-parasite interaction during amebic colitis, and highlights a potential immunomodulatory target.


Asunto(s)
Disentería Amebiana/patología , Factores Inhibidores de la Migración de Macrófagos/inmunología , Neutrófilos/inmunología , Proteínas Protozoarias/inmunología , Animales , Anticuerpos Bloqueadores/farmacología , Células CACO-2 , Técnicas de Cultivo de Célula , Preescolar , Disentería Amebiana/tratamiento farmacológico , Entamoeba histolytica/efectos de los fármacos , Heces/química , Interacciones Huésped-Parásitos , Humanos , Mucosa Intestinal/parasitología , Mucosa Intestinal/patología , Factores Inhibidores de la Migración de Macrófagos/genética , Masculino , Ratones , Ratones Endogámicos CBA , Infiltración Neutrófila/efectos de los fármacos , Proteínas Protozoarias/genética
8.
J Infect Dis ; 216(3): 305-316, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28472348

RESUMEN

Background: In a multicountry birth cohort study, we describe rotavirus infection in the first 2 years of life in sites with and without rotavirus vaccination programs. Methods: Children were recruited by 17 days of age and followed to 24 months with collection of monthly surveillance and diarrheal stools. Data on sociodemographics, feeding, and illness were collected at defined intervals. Stools were tested for rotavirus and sera for antirotavirus immunoglobulins by enzyme immunoassays. Results: A total of 1737 children contributed 22646 surveillance and 7440 diarrheal specimens. Overall, rotavirus was detected in 5.5% (408/7440) of diarrheal stools, and 344 (19.8%) children ever had rotavirus gastroenteritis. Household overcrowding and a high pathogen load were consistent risk factors for infection and disease. Three prior infections conferred 74% (P < .001) protection against subsequent infection in sites not using vaccine. In Peru, incidence of rotavirus disease was relatively higher during the second year of life despite high vaccination coverage. Conclusions: Rotavirus infection and disease were common, but with significant heterogeneity by site. Protection by vaccination may not be sustained in the second year of life in settings with high burdens of transmission and poor response to oral vaccines.


Asunto(s)
Diarrea/epidemiología , Gastroenteritis/epidemiología , Infecciones por Rotavirus/complicaciones , Infecciones por Rotavirus/prevención & control , Vacunas contra Rotavirus/administración & dosificación , Vacunación/estadística & datos numéricos , Distribución por Edad , Anticuerpos Antivirales/sangre , Preescolar , Estudios de Cohortes , Diarrea/virología , Heces/virología , Femenino , Gastroenteritis/virología , Humanos , Incidencia , Lactante , Recién Nacido , Cooperación Internacional , Masculino , Análisis de Regresión , Vacunas contra Rotavirus/uso terapéutico
9.
J Pediatr Gastroenterol Nutr ; 65(1): 31-39, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28644347

RESUMEN

OBJECTIVES: The aim of the study was to describe changes in intestinal permeability in early childhood in diverse epidemiologic settings. METHODS: In a birth cohort study, the lactulose:mannitol (L:M) test was administered to 1980 children at 4 time points in the first 24 months of life in 8 countries. Data from the Brazil site with an incidence of diarrhea similar to that seen in the United States and no growth faltering was used as an internal study reference to derive age- and sex-specific z scores for mannitol and lactulose recoveries and the L:M ratio. RESULTS: A total of 6602 tests demonstrated mannitol recovery, lactulose recovery, and the L:M ratio were associated with country, sex, and age. There was heterogeneity in the recovery of both probes between sites with mean mannitol recovery ranging for 1.34% to 5.88%, lactulose recovery of 0.19% to 0.58%, and L:M ratios 0.10 to 0.17 in boys of 3 months of age across different sites. We observed strong sex-specific differences in both mannitol and lactulose recovery, with boys having higher recovery of both probes. Alterations in intestinal barrier function increased in most sites from 3 to 9 months of age and plateaued or diminished from 9 to 15 months of age. CONCLUSIONS: Alterations in recovery of the probes differ markedly in different epidemiologic contexts in children living in the developing world. The rate of change in the L:M-z ratio was most rapid and consistently disparate from the reference standard in the period between 6 and 9 months of age, suggesting that this is a critical period of physiologic impact of enteropathy in these populations.


Asunto(s)
Enfermedades Intestinales/diagnóstico , Mucosa Intestinal/metabolismo , Lactulosa/metabolismo , Manitol/metabolismo , África del Sur del Sahara/epidemiología , Factores de Edad , Asia Occidental/epidemiología , Biomarcadores/metabolismo , Femenino , Humanos , Lactante , Enfermedades Intestinales/epidemiología , Enfermedades Intestinales/metabolismo , Estudios Longitudinales , Masculino , Permeabilidad , Valores de Referencia , Factores Sexuales , América del Sur/epidemiología
10.
Clin Infect Dis ; 62(10): 1210-7, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27013692

RESUMEN

BACKGROUND: Norovirus is an important cause of childhood diarrhea. We present data from a longitudinal, multicountry study describing norovirus epidemiology during the first 2 years of life. METHODS: A birth cohort of 1457 children across 8 countries contributed 7077 diarrheal stools for norovirus testing. A subset of 199 children contributed additional asymptomatic samples (2307) and diarrheal stools (770), which were used to derive incidence rates and evaluate evidence for acquired immunity. RESULTS: Across sites, 89% of children experienced at least 1 norovirus infection before 24 months, and 22.7% of all diarrheal stools were norovirus positive. Severity of norovirus-positive diarrhea was comparable to other enteropathogens, with the exception of rotavirus. Incidence of genogroup II (GII) infection was higher than genogroup I and peaked at 6-11 months across sites. Undernutrition was a risk factor for symptomatic norovirus infection, with an increase in 1 standard deviation of length-for-age z score associated with a 17% reduction (odds ratio, 0.83 [95% confidence interval, .72-.97]; P = .011) in the odds of experiencing diarrhea when norovirus was present, after accounting for genogroup, rotavirus vaccine, and age. Evidence of acquired immunity was observed among GII infections only: Children with prior GII infection were found to have a 27% reduction in the hazard of subsequent infection (hazard ratio, 0.727; P = .010). CONCLUSIONS: The high prevalence of norovirus across 8 sites in highly variable epidemiologic settings and demonstration of protective immunity for GII infections provide support for investment in vaccine development.


Asunto(s)
Infecciones por Caliciviridae , Diarrea , Norovirus/genética , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/inmunología , Infecciones por Caliciviridae/virología , Preescolar , Estudios de Cohortes , Diarrea/epidemiología , Diarrea/inmunología , Diarrea/virología , Heces/virología , Humanos , Incidencia , Lactante , Recién Nacido
11.
Clin Infect Dis ; 63(9): 1171-1179, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-27501842

RESUMEN

BACKGROUND: Enteropathogen infections have been associated with enteric dysfunction and impaired growth in children in low-resource settings. In a multisite birth cohort study (MAL-ED), we describe the epidemiology and impact of Campylobacter infection in the first 2 years of life. METHODS: Children were actively followed up until 24 months of age. Diarrheal and nondiarrheal stool samples were collected and tested by enzyme immunoassay for Campylobacter Stool and blood samples were assayed for markers of intestinal permeability and inflammation. RESULTS: A total of 1892 children had 7601 diarrheal and 26 267 nondiarrheal stool samples tested for Campylobacter We describe a high prevalence of infection, with most children (n = 1606; 84.9%) having a Campylobacter-positive stool sample by 1 year of age. Factors associated with a reduced risk of Campylobacter detection included exclusive breastfeeding (risk ratio, 0.57; 95% confidence interval, .47-.67), treatment of drinking water (0.76; 0.70-0.83), access to an improved latrine (0.89; 0.82-0.97), and recent macrolide antibiotic use (0.68; 0.63-0.74). A high Campylobacter burden was associated with a lower length-for-age Z score at 24 months (-1.82; 95% confidence interval, -1.94 to -1.70) compared with a low burden (-1.49; -1.60 to -1.38). This association was robust to confounders and consistent across sites. Campylobacter infection was also associated with increased intestinal permeability and intestinal and systemic inflammation. CONCLUSIONS: Campylobacter was prevalent across diverse settings and associated with growth shortfalls. Promotion of exclusive breastfeeding, drinking water treatment, improved latrines, and targeted antibiotic treatment may reduce the burden of Campylobacter infection and improve growth in children in these settings.


Asunto(s)
Infecciones por Campylobacter/epidemiología , Costo de Enfermedad , Infecciones por Campylobacter/fisiopatología , Infecciones por Campylobacter/prevención & control , Desarrollo Infantil , Estudios de Cohortes , Diarrea/epidemiología , Diarrea/microbiología , Femenino , Estudios de Seguimiento , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Humanos , Lactante , Recién Nacido , Masculino , Prevalencia , Estudios Prospectivos , Factores de Riesgo
12.
J Clin Microbiol ; 53(2): 493-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25428152

RESUMEN

Rapid point-of-care detection of enteric protozoa in diarrheal stool is desirable in clinical and research settings to efficiently determine the etiology of diarrhea. We analyzed the ability of the third-generation E. histolytica Quik Chek assay developed by Techlab to detect amebic antigens in fecal samples collected from independent study populations in South Africa and Bangladesh. We compared the performance of this recently released rapid test to that of the commercially available ProSpecT Entamoeba histolytica microplate assay from Remel and the E. histolytica II enzyme-linked immunosorbent assay (ELISA) from Techlab, using real-time and nested-PCR for Entamoeba species to resolve any discrepant results. After discrepant resolution, The E. histolytica Quik Chek assay exhibited sensitivity and specificity compared to the E. histolytica II ELISA of 98.0% (95% confidence interval [CI], 92.9% to 99.8%) and 100% (95% CI, 99.0% to 100%), respectively. Compared to the ProSpecT microplate assay, the E. histolytica Quik Chek (Quik Chek) assay exhibited 97.0% sensitivity (95% CI, 91.5% to 99.4%) and 100% specificity (95% CI, 99.0% to 100%). Our results indicate that the Quik Chek is a robust assay for the specific detection of E. histolytica trophozoites in unfixed frozen clinical stool samples.


Asunto(s)
Antígenos de Protozoos/análisis , Pruebas Diagnósticas de Rutina/métodos , Entamoeba histolytica/aislamiento & purificación , Entamebiasis/diagnóstico , Heces/parasitología , Sistemas de Atención de Punto , Adolescente , Bangladesh , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos , Sensibilidad y Especificidad , Sudáfrica , Factores de Tiempo
13.
Pak J Pharm Sci ; 28(3): 1005-8, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26004707

RESUMEN

The fatty acid composition of the underutilised Cassia abbreviata seed oil was determined using gas chromatographic methods. C. abbreviata seeds yielded 9.53% of yellowish-green oil consisting mainly of oleic acid (37.8%), palmitic acid (26.5%), linoleic acid (26.7%), stearic acid (4.1%) and elaidic acid (2.1%). The oil was solid at room temperature, had a saponification value of 376.16 mg KOH/g and an iodine value of 26.48 g I2/100g oil. The fatty acid composition and saponification value of the C. abbreviata seed oil suggest that it may find application in both cosmetic and pharmaceutical natural product formulations.


Asunto(s)
Cassia , Ácidos Grasos/química , Aceites de Plantas/química , Semillas , Ácido Linoleico/química , Ácido Oléico/química , Ácidos Oléicos , Ácido Palmítico/química , Ácidos Esteáricos/química
14.
Clin Infect Dis ; 59 Suppl 4: S225-32, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305291

RESUMEN

A central hypothesis of The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study is that enteropathogens contribute to growth faltering. To examine this question, the MAL-ED network of investigators set out to achieve 3 goals: (1) develop harmonized protocols to test for a diverse range of enteropathogens, (2) provide quality-assured and comparable results from 8 global sites, and (3) achieve maximum laboratory throughput and minimum cost. This paper describes the rationale for the microbiologic assays chosen and methodologies used to accomplish the 3 goals.


Asunto(s)
Diseño de Investigaciones Epidemiológicas , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/normas , Preescolar , Infecciones por Enterobacteriaceae/diagnóstico , Ensayo de Inmunoadsorción Enzimática , Humanos , Lactante , Recién Nacido , Enfermedades Intestinales/diagnóstico , Parasitosis Intestinales/diagnóstico , Estudios Longitudinales , Microscopía , Reacción en Cadena de la Polimerasa , Garantía de la Calidad de Atención de Salud
15.
Clin Infect Dis ; 59 Suppl 4: S239-47, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25305293

RESUMEN

Individuals in the developing world live in conditions of intense exposure to enteric pathogens due to suboptimal water and sanitation. These environmental conditions lead to alterations in intestinal structure, function, and local and systemic immune activation that are collectively referred to as environmental enteropathy (EE). This condition, although poorly defined, is likely to be exacerbated by undernutrition as well as being responsible for permanent growth deficits acquired in early childhood, vaccine failure, and loss of human potential. This article addresses the underlying theoretical and analytical frameworks informing the methodology proposed by the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study to define and quantify the burden of disease caused by EE within a multisite cohort. Additionally, we will discuss efforts to improve, standardize, and harmonize laboratory practices within the MAL-ED Network. These efforts will address current limitations in the understanding of EE and its burden on children in the developing world.


Asunto(s)
Enfermedades Transmisibles , Medicina Ambiental , Diseño de Investigaciones Epidemiológicas , Enfermedades Intestinales , Desnutrición , Preescolar , Costo de Enfermedad , Humanos , Lactante , Recién Nacido , Estudios Longitudinales
16.
Artículo en Inglés | MEDLINE | ID: mdl-25427345

RESUMEN

Intestinal parasitic organisms are common pathogens among HIV patients worldwide and have been known to cause severe and life-threatening diarrhea in such subjects. In the present study, the prevalence of Cryptosporidium spp and other intestinal parasites in stool samples from 151 HIV/AIDS patients attending a HIV treatment center in South Africa was determined using' standard parasitological methods, as well as molecular methods including PCR and quantitative PCR for confirmation of Cryptosporidium spp. In addition, the loop-mediated isothermal amplification (LAMP) method was evaluated for detection of Cryptosporidium spp in 24 stool samples. Standard parasitological methods indicated that Cryptospo- ridium spp (26.5%), Entamoeba spp (26.5%) and Giardia lamblia (13%) were the most common protozoan parasites, while Ascaris lumbricoides (8%), Schistosoma mansoni (6%) and Trichuris trichiura (4.6%) were the most commonly found helminths. PCR, quantitative PCR and LAMP methods identified Cryptosporidium spp in 28% (30/106), 35% (53/151) and 58% (14/24) of the stool samples, respectively. Multiple infections (34%) were commonly found in the study population. Females above 45 years had the highest Cryptosporidium prevalence (58%). Prevention measures must be implemented in order to curb the negative impact of Cryptosporidium-causing diarrhea among HIV/AIDS patients in this region as well as other parasitic infections identified in this study.


Asunto(s)
Cryptosporidium/aislamiento & purificación , Infecciones por VIH/epidemiología , Helmintiasis/epidemiología , Parasitosis Intestinales/epidemiología , Infecciones por Protozoos/epidemiología , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Adolescente , Adulto , Instituciones de Atención Ambulatoria , Niño , Preescolar , Coinfección , Criptosporidiosis/epidemiología , Heces/parasitología , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , Sudáfrica/epidemiología , Adulto Joven
17.
PeerJ ; 12: e17364, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39035159

RESUMEN

Due to the emergence of drug-resistant microorganisms, the search for broad-spectrum antimicrobial compounds has become extremely crucial. Natural sources like plants and soils have been explored for diverse metabolites with antimicrobial properties. This study aimed to identify microorganisms from agricultural soils exhibiting antimicrobial effects against known human pathogens, and to highlight the chemical space of the responsible compounds through the computational metabolomics-based bioprospecting approach. Herein, bacteria were extracted from soil samples and their antimicrobial potential was measured via the agar well diffusion method. Methanolic extracts from the active bacteria were analyzed using the liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) technique, and the subsequent data was further analyzed through molecular networking approach which aided in identification of potential anti-microbial compounds. Furthermore, 16S rRNA gene sequencing enabled identification of the active bacterial isolates, where isolate 1 and 2 were identified as strains of Bacillus pumilus, whilst isolate 3 was found to be Bacillus subtilis. Interestingly, isolate 3 (Bacillus subtilis) displayed wide-ranging antimicrobial activity against the tested human pathogens. Molecular networking revealed the presence of Diketopiperazine compounds such as cyclo (D-Pro-D-Leu), cyclo (L-Tyr-L-Pro), cyclo (L-Pro-D-Phe), and cyclo (L-Pro-L-Val), alongside Surfactin C, Surfactin B, Pumilacidin E, and Isarrin D in the Bacillus strains as the main anti-microbial compounds. The application of the molecular networking approach represents an innovation in the field of bio-guided bioprospection of microorganisms and has proved to be an effective and feasible towards unearthing potent antimicrobial compounds. Additionally, the (computational metabolomics-based) approach accelerates the discovery of bioactive compounds and isolation of strains which offer a promising avenue for discovering new clinical antimicrobials. Finally, soil microbial flora could serve an alternative source of anti-microbial compounds which can assist in the fight against emergence of multi-drug resistance bacterial pathogens.


Asunto(s)
Bioprospección , Microbiología del Suelo , Bioprospección/métodos , Espectrometría de Masas/métodos , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/metabolismo , ARN Ribosómico 16S/genética , Humanos , Metabolómica/métodos , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Cromatografía Liquida/métodos , Bacillus pumilus/metabolismo , Antibacterianos/farmacología , Antibacterianos/química
18.
Syst Rev ; 13(1): 4, 2024 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-38167510

RESUMEN

BACKGROUND: Deoxyribonucleic acid (DNA) methylation is one of the epigenetic modifications that has gained a lot of interest as a factor influencing fetal programming and as a biomarker for adverse pregnancy and birth outcomes (APBOs). Epidemiological studies have demonstrated that DNA methylation can result in adverse pregnancy and birth outcomes (APBOs) including miscarriage, intrauterine growth restriction (IUGR), low birth weight (LBW), sepsis, and preterm birth (PTB), which may later result in diseases in adulthood. However, the mechanism by which DNA methylation influences these APBOs remains unclear. The systematic review will assess the association between global and gene-specific DNA methylation with adverse pregnancy outcomes. METHOD: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020 checklist will be followed when conducting this systematic review. To develop the search strategy the PI(E)COS (population, intervention/exposure, comparator/control, outcome, and study designs) framework will be followed. Thus far, the research team has retrieved 4721 from Cochrane Library, PubMed, Web of Sciences, and MEDLINE. Out of these, 584 studies have been screened for eligibility, and approximately 124 studies meet the inclusion criteria. Pending the search results identified from the grey literature. For identification of unpublished studies in journals indexed in electronic databases, Google Scholar will be used. I.M and A.S will separately extract data from the articles and screen them, if there are any disagreements between I.M and A.S, then the L.M will resolve them. The methodological quality and bias risk of the included studies will be evaluated using the Critical Appraisal Skill Programme CASP) checklist. [Formula: see text] and [Formula: see text] alpha = 0.10 statistic will be used for assessing statistical heterogeneity between studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach will be used to assess and grade the overall quality of extracted data. ETHICS AND DISSEMINATION: Ethical approval is not required. The systematic review will assess available literature on possible associations between DNA methylation with adverse pregnancy and birth outcomes (APBOs) including LBW, IUGR, miscarriage, sepsis, and PTB. The findings could help guide future research assessing DNA methylation and other APBOs. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRCRD42022370647.


Asunto(s)
Aborto Espontáneo , Nacimiento Prematuro , Proyectos de Investigación , Sepsis , Revisiones Sistemáticas como Asunto , Femenino , Humanos , Recién Nacido , Embarazo , Aborto Espontáneo/genética , Metilación de ADN/genética , Retardo del Crecimiento Fetal/genética , Resultado del Embarazo , Nacimiento Prematuro/genética
19.
J Environ Eng (New York) ; 139(9): 1152-1161, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25190902

RESUMEN

Resource-limited communities throughout the developing world face significant environmental health problems related to the myriad of coliform sources within those communities. This study comprehensively investigated contamination sources and the biological and chemical mechanisms sustaining them in two adjacent communities in rural Limpopo, South Africa. An 8-month study was conducted of household (n = 14) and source water quality, measurements of biofilm layers on the inside of household water storage containers and water transfer devices, and also hand-based coliforms and hand-washing effectiveness. A 7-day water container incubation experiment was also performed to determine the biological and chemical changes that occur in a household water storage container independent of human interference. Results indicate that household drinking water frequently becomes contaminated after collection but before consumption (197 versus 1,046 colony-forming units/100 mL; n = 266; p < 0.001). The most important contamination sources include biofilm layers on the inside of storage containers (1.85 ± 1.59 colony-forming units/cm2; n = 44), hands (5,097 ± 2,125 colony-forming units/hand; n = 48), and coliform regrowth resulting from high assimilable organic carbon (AOC) levels during storage. A maximum specific growth rate, µmax, of 0.072 ± 0.003 h-1 was determined for total coliform bacteria on AOC, and a high correlation between AOC concentrations and the growth potential of total coliform bacteria was observed. These results support the implementation of point-of-use water treatment and other interventions aimed at maintaining the safe water chain and preventing biological regrowth.

20.
Healthcare (Basel) ; 11(18)2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37761782

RESUMEN

Preconception care (PCC) is the provision of biomedical, behavioural, and social health interventions to women and couples before they fall pregnant. The World Health Organization (WHO) developed PCC recommendations in 2013, which were included in the South African maternity care guidelines in 2016. The purpose of PCC is to lessen behaviours and environmental factors leading to maternal ill-health, thus reducing maternal and perinatal mortality rates. OBJECTIVE: To determine the implementation of PCC recommendations at health facilities in the selected districts of Limpopo Province and the associated factors. METHODS: A qualitative exploratory design was used. Nonprobability, purposive sampling was used to sample 29 professional nurses (PNs), and 51 women of childbearing age (WCBA) (19-35 years) from clinics and community health centres (CHCs). Data were collected through in-depth interviews with the professional nurses and focus group discussions with the WCBA. Data analysis was performed through open coding. Measures of trustworthiness were adhered to. Permission to conduct the study was obtained from relevant stakeholders, participation was voluntary and participants signed a consent form prior to data collection. RESULTS: The findings of the study revealed that there was partial implementation of the PCC recommendations in the selected districts of Limpopo Province, PCC provision was dependent on clients' initiation, a knowledge gap regarding PCC recommendations was identified from the professional nurses, and a lack of awareness regarding PCC from the WCBA. CONCLUSION: The preconception period is an important determinant of the pregnancy outcome; therefore, focus should be redirected to the pre-pregnancy period and not only to when the woman is already pregnant. However, to achieve this, professional nurses and WCBA should be empowered regarding PCC and its benefits.

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