Circulation of enterotoxigenic Escherichia coli (ETEC) isolates expressing CS23 from the environment to clinical settings.

IMPORTANCE: The importance of clean water cannot be overstated. It is a vital resource for maintaining health and well-being. Unfortunately, water sources contaminated with fecal discharges from animal and human origin due to a lack of wastewater management pose a significant risk to communities, as they can become a means of transmission of pathogenic bacteria like enterotoxigenic E. coli (ETEC). ETEC is frequently found in polluted water in countries with a high prevalence of diarrheal diseases, such as Bolivia. This study provides novel insights into the circulation of ETEC between diarrheal cases and polluted water sources in areas with high rates of diarrheal disease. These findings highlight the Choqueyapu River as a potential reservoir for emerging pathogens carrying antibiotic-resistance genes, making it a crucial area for monitoring and intervention. Furthermore, the results demonstrate the feasibility of a low-cost, high-throughput method for tracking bacterial pathogens in low- and middle-income countries, making it a valuable tool for One Health monitoring efforts.

Estilos de alimentación y su asociación con apreciación corporal, internalización del sesgo del peso y autocompasión / Eating styles and their association with body appreciation, weight bias internalization and self-compassion

Resumen Antecedentes: La valoración de la delgadez y sesgo hacia las personas con sobrepeso, pueden promover menor valoración del cuerpo y estilos de alimentación desadaptativos; la autocompasión podría actuar mitigando estas relaciones. Objetivo: comprender la asociación entre apreciación corporal, internalización del sesgo del peso y estilos de alimentación (EA), así como el rol que cumple una actitud autocompasiva en la apreciación corporal. Método: Estudio correlacional, transversal, en el que participaron 837 adultos residentes en Chile. En el análisis de datos se empleó regresión múltiple y análisis de mediación. Resultados: La apreciación corporal y la internalización del sesgo del peso predijeron EA emocional (β = -,126; p <,001 y β = ,146 p <,001, respectivamente), EA externo (β = -,095; p <,001 y β = ,064 p <,001, respectivamente) y EA restrictivo (β = ,134; p <,001 y β = ,258; p <,001, respectivamente). La autocompasión medió la relación entre internalización del sesgo del peso y apreciación corporal (β = -,133; IC:[-,157; −0,11]). Conclusiones: La valoración del cuerpo y la internalización del sesgo del peso influyen en los EA, y una actitud compasiva hacia sí mismo media en el efecto del sesgo del peso sobre la devaluación hacia el propio cuerpo.

Abstract Background: The assessment of thinness and bias towards overweight people can promote body appreciation and maladaptive eating styles; self-compassion could act mitigating these relationships. Objective: to understand the association between body appreciation, weight bias internalization and eating styles (ES), as well as the role of a self-compassionate attitude in body appreciation. Method: Correlational, cross-sectional study, with 837 adults living in Chile. In the data analysis, multiple regression and mediation analysis were used. Results: Body appreciation and internalization of weight bias predicted emotional ES (β = -.126; p < .001 and β = .146; p < .001, respectively), external ES (β = -.095; p < .001 and β = .064; p < .001, respectively) and restrictive ES (β = -.134; p < 001 and β = .258; p < .001, respectively). Self-compassion mediated the relationship between internalization of weight bias and body appreciation (β = -.133, CI: [- .157, -.11]). Conclusions: The assessment of the body and the weight bias internalization influence eating styles, and a compassionate attitude towards oneself intervenes in the effect of the weight bias on the devaluation towards the own body.

Fecal Pollution Drives Antibiotic Resistance and Class 1 Integron Abundance in Aquatic Environments of the Bolivian Andes Impacted by Mining and Wastewater.

An increased abundance of antibiotic resistance genes (ARGs) in aquatic environments has been linked to environmental pollution. Mining polluted sites with high concentration of metals could favor the in situ coselection of ARGs, whereas wastewater discharges release fecal antibiotic resistant bacteria in the environment. To study the effect of human fecal contamination and mining pollution, water and sediment samples affected by mining activities and sewage discharges were collected from three lakes in Bolivia, the pristine Andean lake Pata Khota, the Milluni Chico lake directly impacted by acid mine drainage, and the Uru-Uru lake located close to Oruro city and highly polluted by mining activities and human wastewater discharges. Physicochemical parameters, including metal composition, were analyzed in water and sediment samples. ARGs were screened for and verified by quantitative polymerase chain reaction (PCR) together with the mobile element class 1 integron (intl1), as well as crAssphage, a marker of human fecal pollution. The gene intl1 was positively correlated with sul1, sul2, tetA, and blaOXA-2. CrAssphage was only detected in the Uru-Uru lake, and its tributaries and significantly higher abundance of ARGs were found in these sites. Multivariate analysis showed that crAssphage abundance, electrical conductivity, and pH were positively correlated with higher levels of intl1 and ARGs. Taken together, our results suggest that fecal pollution is the major driver of higher levels of ARGs and intl1 in environments contaminated by wastewater and mining activities.

Are Chileans exposed to dietary furan?

Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g(-1). In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed "American"-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g(-1)) and low moisture starchy products like crisps and "soda"-type crackers showed the highest furan concentrations (259 and 91 ng g(-1), respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g(-1)), jarred fruit baby foods (8.5 ng g(-1)) and orange juice (7.0 ng g(-1)). School children (aged 9-13 years) represented the highest intake of furan (about 500 ng kg(-1)(bw) day(-1)), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk.

Tetrahydrohyperforin increases adult hippocampal neurogenesis in wild-type and APPswe/PS1ΔE9 mice.

Tetrahydrohyperforin (IDN5706), a semi-synthetic derivative of hyperforin, has shown neuroprotective properties preventing the impairment of synaptic plasticity and cognitive decline in an in vivo model of Alzheimer's disease (AD). Considering the reported role of adult neurogenesis in the plasticity of the hippocampal network, we investigated whether IDN5706 affects adult neurogenesis and hippocampal function. In hippocampal progenitors cultured from adult rats, IDN5706 increased proliferation. Moreover, treatment with IDN5706 for 4 weeks increased cell proliferation in the subgranular zone (SGZ) of the hippocampus in 2 month-old wild-type mice in vivo. As determined by double labeling with BrdU and neuronal markers, IDN5706 treatment increased the number of immature neurons and newborn mature neurons in the adult dentate gyrus. In addition, IDN5706 treatment improved long-term memory in a hippocampal-dependent spatial memory task. Finally, IDN5706 treatment increased cell proliferation and neural commitment in the SGZ of the double transgenic APPswe/PS1ΔE9 mouse model of AD. These results indicate that IDN5706 increases adult hippocampal neurogenesis and may have therapeutic value in neurological disorders in which adult neurogenesis is impaired.

Cross-reactive protection against enterohemorrhagic Escherichia coli infection by enteropathogenic E. coli in a mouse model.

Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) are related attaching and effacing (A/E) pathogens. The genes responsible for the A/E pathology are carried on a chromosomal pathogenicity island termed the locus of enterocyte effacement (LEE). Both pathogens share a high degree of homology in the LEE and additional O islands. EHEC prevalence is much lower in areas where EPEC is endemic. This may be due to the development of antibodies against common EPEC and EHEC antigens. This study investigated the hypothesis that EPEC infections may protect against EHEC infections. We used a mouse model to inoculate BALB/c mice intragastrically, first with EPEC and then with EHEC (E. coli O157:H7). Four control groups received either a nonpathogenic E. coli (NPEC) strain followed by EHEC (NPEC/EHEC), phosphate-buffered saline (PBS) followed by EHEC (PBS/EHEC), EPEC/PBS, or PBS/PBS. Mice were monitored for weight loss and symptoms. EPEC colonized the intestine after challenge, and mice developed serum antibodies to intimin and E. coli secreted protein B (encoded in the LEE). Prechallenge with an EPEC strain had a protective effect after EHEC infection, as only a few mice developed mild symptoms, from which they recovered. These mice had an increase in body weight similar to that in control animals, and tissue morphology exhibited mild intestinal changes and normal renal histology. All mice that were not prechallenged with the EPEC strain developed mild to severe symptoms after EHEC infection, with weight loss as well as intestinal and renal histopathological changes. These data suggest that EPEC may protect against EHEC infection in this mouse model.

Intestinal damage in enterohemorrhagic Escherichia coli infection.

Enterohemorrhagic Escherichia coli (EHEC) infection leads to marked intestinal injury. Sigmoid colon obtained from two children during EHEC infection exhibited abundant TUNEL-positive cells. To define which bacterial virulence factors contribute to intestinal injury the presence of Shiga toxin-2 (Stx2), intimin and the type III secretion system were correlated with symptoms and intestinal damage. C3H/HeN mice were inoculated with Stx2-producing (86-24) and non-producing (87-23) E. coli O157:H7 strains and 86-24 mutants lacking eae, encoding intimin (strain UMD619) or escN regulating the expression of type III secretion effectors (strain CVD451). Severe symptoms developed in mice inoculated with 86-24 and 87-23. Few mice inoculated with the mutant strains developed severe symptoms. Strain 86-24 exhibited higher fecal bacterial counts, followed by 87-23, whereas strains UMD619 and CVD451 showed minimal fecal counts. More TUNEL-positive cells were found in proximal and distal colons of mice inoculated with strain 86-24 compared with strains 87-23 and CVD451 (p ≤ 0.01) or UMD619 (p < 0.05, proximal colon, p < 0.01, distal colon). The results show that strains 86-24 and 87-23 exhibited better colonic persistence and more symptoms, presumably due to the presence of intimin and type III secretion effectors. Extensive intestinal mucosal cell death was related to the presence of Stx2.

Shiga toxin-mediated disease in MyD88-deficient mice infected with Escherichia coli O157:H7.

Toll-like receptors (TLRs) are key factors of innate immunity that detect pathogen invasion and trigger a host response. TLR4 can mediate a response through adaptor molecules, MyD88 or TRIF. In the present study, streptomycin-treated MyD88(-/-), Tlr4(-/-), Trif (Lps2/Lps2), and C57BL/6 wild-type (WT) mice were infected with either Shiga toxin (Stx)-producing or non-producing Escherichia coli O157:H7. Moderate to severe clinical signs of disease developed in MyD88(-/-) (n = 21/21), Tlr4(-/-) (n = 12/16), Trif (Lps2/Lps2) (n = 7/15) and WT mice (n = 6/20) infected with Stx-producing E. coli O157:H7 but not in mice inoculated with the Stx non-producing strain (n = 0/54, P < 0.001). MyD88(-/-) mice infected with Stx-producing E. coli O157:H7 developed the most severe disease and had the highest bacterial burden. Hematological analysis of sick MyD88(-/-) mice showed reduced red blood cell counts and reticulocytosis, suggesting hemolysis. Thrombocytopenia developed in MyD88(-/-), Trif (Lps2/Lps2), and WT mice, and creatinine levels were elevated in both MyD88(-/-) and WT mice infected with the Stx-producing strain. Renal histopathology showed evidence of glomerular capillary congestion, tubular desquamation, and fibrinogen deposition, and intestinal histopathology showed mucosal injury, edema, and inflammation in sick mice. Administration of purified Stx2 to MyD88(-/-) and WT mice led to severe disease in both groups, suggesting that MyD88(-/-) mice are not more sensitive to Stx than WT mice. As MyD88(-/-) mice developed the most severe disease hematological and pathological changes, the results suggest that dysfunctional innate immune responses via MyD88 enhanced Stx-induced disease.

Determination of polychlorinated biphenyls in biosolids using continuous ultrasound-assisted pressurized solvent extraction and gas chromatography-mass spectrometry.

An efficient continuous pressurized solvent extraction (PSE) method assisted by ultrasound energy was developed for the extraction of polychlorinated biphenyls (PCBs) from biosolids. Analytes were determined in the extracts by gas chromatography-mass spectrometry in selected ion monitoring (SIM) mode. A screening-type experimental design pointing to dynamic extraction time as the only significant variable in the extraction process was carried out to optimize PCB extraction from the biosolids. Final selected conditions for PSE were extraction temperature, 50 degrees C; static extraction time, 0 min; and dynamic extraction time, 30 min. Recovery of the PSE method was 73%, which was significantly improved (103%) when PSE was assisted with 30-min ultrasound (US-PSE). Precision of the overall method, expressed as relative standard deviation, was 3.6% and the detection limit was 0.037 mg/kg. The method was applied to the determination of PCBs in biosolids from different water treatment plants from central Chile.

Subcritical water extraction and determination of nifedipine in pharmaceutical formulations.

A rapid and simple continuous method for the extraction of nifedipine from tablets was developed by using pressurized hot water at 150 degrees C. This is the first time that subcritical water was applied to the extraction of low-polarity compounds in pharmaceutical analysis. The method is based on the increment in solubility of nifedipine in subcritical water. Extraction temperature and static and dynamic extraction time were optimized in order to reach quantitative extraction of the drug from the tablets. After extraction, the drug was determined by spectrophotometry by measuring absorbance at 338 nm. Accuracy and precision of the method were determined by analysis of 10 synthetic samples of pharmaceutical formulations prepared with common tablet excipients. Recovery was found to be 99.2% with a relative standard deviation of 1.9%, which indicates that the excipients of the formulation do not interfere in the determination. The method was applied to the determination of the drug content uniformity in tablets.