Quantitative real-time polymerase chain reaction for enteropathogenic Escherichia coli: a tool for investigation of asymptomatic versus symptomatic infections

BACKGROUND: Enteropathogenic Escherichia coli (EPEC) strains are pediatric pathogens commonly isolated from both healthy and sick children with diarrhea in areas of endemicity. The aim of this study was to compare the bacterial load of EPEC isolated from stool samples from children with and without diarrhea to determine whether bacterial load might be a useful tool for further study of this phenomenon. METHODS: EPEC was detected by polymerase chain reaction (PCR) of colonies isolated on MacConkey plates from 53 diarrheal and 90 healthy children aged <2 years. DNA was isolated from stool samples by cetyltrimethylammonium bromide extraction. To standardize quantification by quantitative real-time PCR (qRT-PCR), the correlation between fluorescence threshold cycle and copy number of the intimin gene of EPEC E2348/69 was determined. RESULTS: The detection limit of qRT-PCR was 5 bacteria/mg stool. The geometric mean load in diarrhea was 299 bacteria/mg (95% confidence interval [CI], 77-1164 bacteria/mg), compared with 29 bacteria/mg (95% CI, 10-87 bacteria/mg) in control subjects (P = .016). Bacterial load was significantly higher in children with diarrhea than in control subjects among children <12 months of age (178 vs 5 bacteria/mg; P = .006) and among children with EPEC as the sole pathogen (463 vs 24 bacteria/mg; P = .006). CONCLUSIONS: EPEC load measured by qRT-PCR is higher in diarrheal than in healthy children. qRT-PCR may be useful to study the relationship between disease and colonization in settings of endemicity.
Authors: Barletta, Francesca; Ochoa, Theresa J.; Mercado, Erik H.; Ruiz, Joaquim; Ecker, Lucie; Lopez, Giovanni; Mispireta, Monica;Gil, Ana I.; Lanata, Claudio F.; Cleary, Thomas G.
Source: Clinical Infectious Diseases (Clin Infect Dis)

URL: http://hdl.handle.net/10757/556075

Age-related susceptibility to infection with diarrheagenic Escherichia coli among infants from Periurban areas in Lima, Peru

BACKGROUND: Diarrheagenic Escherichia coli strains are being recognized as important pediatric enteropathogens worldwide. However, it is unclear whether there are differences in age-related susceptibility to specific strains, especially among infants. METHODS: We conducted a passive surveillance cohort study of diarrhea that involved 1034 children aged 2-12 months in Lima, Peru. Control stool samples were collected from randomly selected children without diarrhea. All samples were analyzed for common enteric pathogens and for diarrheagenic E. coli with use of multiplex real-time polymerase chain reaction. RESULTS: The most frequently isolated pathogens in 1065 diarrheal episodes were diarrheagenic E. coli strains (31%), including enteroaggregative (15.1%) and enteropathogenic E. coli (7.6%). Diarrheagenic E. coli, Campylobacter species, and rotavirus were more frequently isolated from infants aged >or=6 months. Among older infants, diffusely adherent E. coli and enterotoxigenic E. coli were more frequently isolated from diarrheal samples than from control samples (P <.05). Children aged >or=6 months who were infected with enterotoxigenic E. coli had a 4.56-fold increased risk of diarrhea (95% confidence interval, 1.20-17.28), compared with younger children. Persistent diarrhea was more common in infants aged <6 months (13.5% vs 3.6%; P <.001). Among children with diarrheagenic E. coli-positive samples, coinfections with other pathogens were more common in children with diarrhea than in control children (40.1% vs 15.6%; P <.001). CONCLUSIONS: Diarrheagenic E. coli strains were more frequently isolated in samples from older infants. In this setting with high frequency of pathogen exposure and high frequency of breastfeeding, we hypothesize that the major age-related differences result from decreased exposure to milk-related protective factors and from increased exposure to contaminated food and water.
Authors: Ochoa, Theresa J.; Ecker, Lucie; Barletta, Francesca; Mispireta, Mónica L.; Gil, Ana I.; Contreras, Carmen; Molina, Margarita; Amemiya, Isabel; Verastegui, Hector; Hall, Eric R.; Cleary, Thomas G.; Lanata, Claudio F.
Source:  Clinical Infectious Diseases (Clin Infect Dis)

URL: http://hdl.handle.net/10757/556074

Association of poor subjective sleep quality with suicidal ideation among pregnant Peruvian women

Objective: To examine the independent and joint relationships of poor subjective sleep quality and antepartum depression with suicidal ideation among pregnant women. Methods: A cross-sectional study was conducted among 641 pregnant women attending prenatal care clinics in Lima, Peru. Antepartumdepression and suicidal ideationwere assessed using the Patient Health Questionnaire-9 scale. Antepartumsubjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression procedures were performed to estimate odds ratios (aOR) and 95% confidence intervals (95% CI) adjusted for confounders. Results: Overall, the prevalence of suicidal ideation in this cohort was 16.8% and poor subjective sleep qualitywas more common among women endorsing suicidal ideation as compared to their counterpartswho did not (47.2% vs. 24.8%, Pb.001). After adjustment for confounders including maternal depression, poor subjective sleep quality (defined using the recommended criteria of PSQI global score of N5 vs. ≤5) was associated with a 1.7-fold increased odds of suicidal ideation (aOR=1.67; 95% CI 1.02–2.71). When assessed as a continuous variable, each 1-unit increase in the global PSQI score resulted in an 18% increase in odds for suicidal ideation, even after adjusting for depression (aOR=1.18; 95% CI 1.08–1.28). Women with both poor subjective sleep quality and depression had a 3.5-fold increased odds of suicidal ideation (aOR=3.48; 95% CI 1.96–6.18) as compared with those who had neither risk factor. Conclusion: Poor subjective sleep quality was associated with increased odds of suicidal ideation. Replication of these findings may promote investments in studies designed to examine the efficacy of sleep-focused interventions to treat pregnant women with sleep disorders and suicidal ideation.
Authors: Gelaye, Bizu; Barrios, Yasmin V.; Zhong, Qiu-Yue; Rondon, Marta B.; Borba, Christina P.C.; Sánchez, Sixto E.; Henderson, David C.; Williams, Michelle A.
Source:  General Hospital Psychiatry (Gen Hosp Psychiatry)

URL:  http://hdl.handle.net/10757/555873

Características de los cursos de investigación en escuelas de medicina del Perú

Objetivo: Describir las características de los cursos de investigación y la producción científica de sus docentes en las escuelas de medicina del Perú. Métodos: Se realizó un estudio descriptivo, con los datos de las 32 escuelas de medicina del Perú existentes al 2011, las currículas de los cursos de investigación de estas escuelas, y los docentes de dichos cursos. Se evaluó el número de cursos, docentes y sus publicaciones. Resultados: La mediana de créditos de investigación fue 5,5 [rango 2 a 18] por escuela, y la mediana del porcentaje del total de créditos fue de 1,75% [rango 0,6 a 6,3]. En 18/32 (56%) escuelas existió algún curso en el que se solicitó al estudiante la presentación de un informe final, pero solo una escuela tuvo algún curso que incluyó prácticas de envío a publicación. Además, solo 5 (15,6%) escuelas contaron con algún docente que haya publicado al menos un artículo original como autor corresponsal en Scopus alguna vez en su vida. Conclusión: Los cursos de investigación de las escuelas de medicina del Perú no enseñan el proceso de publicación en revistas indizadas y los docentes de estos cursos tienen una baja producción científica.
Authors: Taype Rondán, Á; Huaccho Rojas, J.; Pereyra Elías, R.; Mejia, C. R; Mayta Tristán, Percy
Source:  Archivos de Medicina

URL:  http://hdl.handle.net/10757/555579

Reducing salt in bread: a quasi-experimental feasibility study in a bakery in Lima, Peru

Objectives: To explore salt content in bread and to evaluate the feasibility of reducing salt contained in ‘pan francés’ bread. Design: The study had two phases. Phase 1, an exploratory phase, involved the estimation of salt contained in bread as well as a triangle taste test to establish the amount of salt to be reduced in ‘pan francés’ bread without detection by consumers. In Phase 2, a quasi-experimental, pre–post intervention study assessed the effects of the introduction of low-salt bread on bakery sales. Setting: A municipal bakery in Miraflores, Lima, Peru. Subjects: Sixty-five clients of the bakery in Phase 1 of the study; sales to usual costumers in Phase 2. Results: On average, there was 1·25 g of salt per 100 g of bread. Sixty-five consumers were enrolled in the triangle taste test: fifty-four (83·1 %) females, mean age 58·9 (SD 13·7) years. Based on taste, bread samples prepared with salt reductions of 10 % (P = 0·82) and 20 % (P =0·37) were not discernible from regular bread. The introduction of bread with 20 % of salt reduction, which contained 1 g of salt per 100 g of bread, did not change sales of ‘pan francés’ (P=0·70) or other types of bread (P =0·36). Results were consistent when using different statistical techniques. Conclusions: The introduction of bread with a 20 % reduction in salt is feasible without affecting taste or bakery sales. Results suggest that these interventions are easily implementable, with the potential to contribute to larger sodium reduction strategies impacting the population’s cardiovascular health.
Authors: Saavedra Garcia, Lorena; Sosa Zevallos, Vanessa; Diez Canseco, Francisco
Source:  Public Health Nutrition (Public Health Nutrition)

URL:  http://hdl.handle.net/10757/555477