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Enterotoxigenic Escherichia coli (ETEC) ranks among the most relevant diarrheagenic pathogens. Efforts to design vaccines to fight ETEC have been focused on colonizing factors (CFs) and atypical virulence factors (AVF). An effective vaccine must account for differences in the regional prevalence of these CFs and AVFs to be truly effective in a given area. In the present study, the presence of 16 CFs and 9 AVFs, as well as the heat-stable (ST) variants (STh or STp), was established by polymerase chain reaction in 205 Peruvian ETEC isolates (120 from diarrhea cases and 85 from healthy controls). Ninety-nine (48.3%) isolates were heat-labile, 63 (30.7%) ST, and 43 (21.0%) presented both toxins. Of ST isolates, 59 (28.8%) possessed STh, 30 (14.6%) STp, five (2.4%) both STh and STp, and 12 (5.8%) were not amplified for any variant tested. The presence of CFs was associated with diarrhea (P < 0.0001). The presence of eatA as well as concomitant presence of CSI, CS3, and CS21 and of C5 and C6 was statistically related to diarrhea cases. The present results suggests that, if effective, a vaccine considering CS6, CS20, and CS21, together with EtpA, would provide protection against 64.4% of the isolates analyzed, whereas the addition of CS12 and EAST1 would lead to 83.9% coverage. Large studies are needed to establish both the ideal candidates to be considered to develop a vaccine effective in the area, and continuous surveillance is needed to detect displacement of circulating isolates that may compromise future vaccines.

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RESUMEN El objetivo del estudio fue describir las características de los ensayos clínicos (EC) supervisados por el Instituto de Evaluación de Tecnologías en Salud e Investigación en EsSalud entre el 2015 y 2018 y las principales observaciones de las supervisiones realizadas. Se realizó un estudio descriptivo de 82 ensayos clínicos supervisados entre 2015 y 2018. La mayoría de los ensayos clínicos fueron estudios de fase III (81,7%), la vía de administración más frecuente de los productos de estudio fue oral (47,6%) y la mayoría fueron patrocinados por la industria farmacéutica (96,3%). Las observaciones más frecuentes fueron las relacionadas al contrato de estudio (83,8%), al pago por concepto de overhead (57,3%) y a la falta de documentos regulatorios (47,6%). Estos hallazgos permiten la identificación de oportunidades de mejora en la regulación y gestión de la investigación.

ABSTRACT The objective of the study was to describe the characteristics of the Clinical Trials (CT) supervised by the Institute of Health Technology Assessment and Research carried out in EsSalud between 2015 and 2018 and the main observations of the supervisions completed. A descriptive study of 82 supervised clinical trials was conducted between 2015 and 2018. Most of the clinical trials were phase III studies (81.7%); the most frequent route of administration of the study products was oral (47.6%), and most were sponsored by the pharmaceutical industry (96.3%). The most frequent observations were those related to the study contract (83.8%), overhead payment (57.3%), and the lack of regulatory documents (47.6%). These findings allow the identification of opportunities for improvement in research regulation and management.

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The objective of the study was to describe the characteristics of the Clinical Trials (CT) supervised by the Institute of Health Technology Assessment and Research carried out in EsSalud between 2015 and 2018 and the main observations of the supervisions completed. A descriptive study of 82 supervised clinical trials was conducted between 2015 and 2018. Most of the clinical trials were phase III studies (81.7%); the most frequent route of administration of the study products was oral (47.6%), and most were sponsored by the pharmaceutical industry (96.3%). The most frequent observations were those related to the study contract (83.8%), overhead payment (57.3%), and the lack of regulatory documents (47.6%). These findings allow the identification of opportunities for improvement in research regulation and management.

El objetivo del estudio fue describir las características de los ensayos clínicos (EC) supervisados por el Instituto de Evaluación de Tecnologías en Salud e Investigación en EsSalud entre el 2015 y 2018 y las principales observaciones de las supervisiones realizadas. Se realizó un estudio descriptivo de 82 ensayos clínicos supervisados entre 2015 y 2018. La mayoría de los ensayos clínicos fueron estudios de fase III (81,7%), la vía de administración más frecuente de los productos de estudio fue oral (47,6%) y la mayoría fueron patrocinados por la industria farmacéutica (96,3%). Las observaciones más frecuentes fueron las relacionadas al contrato de estudio (83,8%), al pago por concepto de overhead (57,3%) y a la falta de documentos regulatorios (47,6%). Estos hallazgos permiten la identificación de oportunidades de mejora en la regulación y gestión de la investigación.

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In an active diarrhea surveillance study of children aged 12-24 months in Lima, Peru, norovirus was the most common pathogen identified. The percentage of mixed (bacterial and noroviral) infections was significantly higher among norovirus-positive samples (53%) than among norovirus-negative samples (12%). The combination of norovirus with the most common bacterial pathogens was associated with increased clinical severity over that of either single-pathogen norovirus or single-pathogen bacterial infections.

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Typical hemolytic uremic syndrome (HUS) is responsible for acute and chronic renal failure in children younger than 5 years old in Argentina. Renal damages have been associated with Shiga toxin type 1 and/or 2 (Stx1, Stx2) produced by Escherichia coli O157:H7, although strains expressing Stx2 are highly prevalent in Argentina. Human glomerular endothelial cells (HGEC) and proximal tubule epithelial cells are very Stx-sensitive since they express high levels of Stx receptor (Gb3). Nowadays, there is no available therapy to protect patients from acute toxin-mediated cellular injury. New strategies have been developed based on the Gb3 biosynthesis inhibition through blocking the enzyme glucosylceramide (GL1) synthase. We assayed the action of a GL1 inhibitor (Miglustat: MG), on the prevention of the renal damage induced by Stx2. HGEC primary cultures and HK-2 cell line were pre-treated with MG and then incubated with Stx2. HK- 2 and HGEC express Gb3 and MG was able to decrease the levels of this receptor. As a consequence, both types of cells were protected from Stx2 cytotoxicity and morphology damage. MG was able to avoid Stx2 effects in human renal cells and could be a feasible strategy to protect kidney tissues from the cytotoxic effects of Stx2 in vivo.

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BACKGROUND: Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children <24 months in Lima, Peru. METHODS: ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. RESULTS: ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), p<0.05. Only 10% of isolates were resistant to nalidixic acid and none to ciprofloxacin or cefotaxime. Ampicillin and sulfamethoxazole resistance were most often associated with blaTEM (69%) and sul2 genes (68%), respectively. Tetracycline resistance was associated with tet(A) (49%) and tet(B) (39%) genes. Azithromycin inhibitory diameters were ≤15 mm in 36% of isolates, with 5% of those presenting the mph(A) gene. CONCLUSIONS: ETEC from Peruvian children are often resistant to older, inexpensive antibiotics, while remaining susceptible to ciprofloxacin, cephalosporins and furazolidone. Fluoroquinolones and azithromycin remain the drugs of choice for ETEC infections in Peru. However, further development of resistance should be closely monitored.

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Secretory diarrhea caused by cholera toxin (CT) is initiated by binding of CT's B subunit (CTB) to GM1-ganglioside on the surface of intestinal cells. Lactoferrin, a breast milk glycoprotein, has shown protective effect against several enteropathogens. The aims of this study were to determine the effect of bovine-lactoferrin (bLF) on CT-induced intestinal fluid accumulation in mice, and the interaction between bLF and CT/CTB with the GM1-ganglioside receptor. Fluid accumulation induced by CT was evaluated in the mouse ileal loop model using 56 BALB/c mice, with and without bLF added before, after or at the same time of CT administration. The effect of bLF in the interaction of CT and CTB with GM1-ganglioside was evaluated by a GM1-enzyme-linked immunosorbent assay. bLF decreased CT-induced fluid accumulation in the ileal loop of mice. The greatest effect was when bLF was added before CT (median, 0.066 vs. 0.166 g/cm, with and without bLF respectively, p<0.01). We conclude that bLF decreases binding of CT and CTB to GM1-ganglioside, suggesting that bLF suppresses CT-induced fluid accumulation by blocking the binding of CTB to GM1-ganglioside. bLF may be effective as adjunctive therapy for treatment of cholera diarrhea.

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This study aims to characterize the presence of virulence factors of enterotoxigenic Escherichia coli (ETEC) causing traveler's diarrhea. Among 52 ETEC isolates, the most common toxin type was STh, and the most frequent colonization factors (CFs) were CS21, CS6, and CS3. On the other hand, the nonclassical virulence factors EAST1 and EatA were frequently present.

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Norovirus was detected in 17.4% of 224 diarrhoeal samples from children younger than 24 months of age in Lima, in whom all common pathogens had been excluded (pathogen negative). Norovirus was identified more frequently in children older than 12 months of age than in younger children (34% vs 8%, P<0.001). Among norovirus-positive samples, genogroup II was the predominant group (92%). Compared with rotavirus, norovirus episodes tended to be of shorter duration and less severe. The role of norovirus as a cause of diarrhoea and the ascertainment of its severity in developing countries needs further confirmation by future epidemiological studies.

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