Antibiotic burden of school children from Tibetan, Hui, and Han groups in the Qinghai-Tibetan Plateau

The role of residual (veterinary) antibiotics in chemical exposome analysis: Current progress and future perspectives

Humans are exposed to a complex mixture of environmental and food-related chemicals throughout their lifetime. Exposome research intends to explore the nongenetic, that is, environmental causes of chronic disease and their interactions comprehensively. Residual antibiotics can enter the human body through therapeutics, foods of animal origin, aquatic products, or drinking water. In the last decade, significant levels of residual antibiotics in human urine have been described, demonstrating frequent exposure throughout populations. To which extent they contribute to human health risks is debated. Human biomonitoring (HBM) aims to determine and quantify concentrations of xenobiotics in human specimens and provides the toolbox to monitor exposure to diverse chemical exposures. Due to their public health implications, priority-listed xenobiotics are routinely monitored in the European Union and other countries. However, antibiotics, an important class of (food-derived) xenobiotics, are still not systematically investigated for a better and more holistic understanding in the context of exposomics. This review provides a comprehensive summary of HBM research related to antibiotics, existing liquid chromatography-mass spectrometry (LC-MS)-based analytical methods, and potential health risks caused by unintended exposure. Incorporating antibiotics into the chemical exposome framework through routine HBM using multiclass analytical methods will provide a better understanding of the toxicological or pharmacological mixture effects and, ultimately, the chemical exposome.

Environmental exposure and child health in China

Chinese children are exposed to broad environmental risks ranging from well-known hazards, such as pesticides and heavy metals, to emerging threats including many new man-made chemicals. Although anecdotal evidence suggests that the exposure levels in Chinese children are substantially higher than those of children in developed countries, a systematic assessment is lacking. Further, while these exposures have been linked to a variety of childhood diseases, such as respiratory, endocrine, neurological, behavioral, and malignant disorders, the magnitude of the associations is often unclear. This review provides a current epidemiologic overview of commonly reported environmental contaminants and their potential impact on children's health in China. We found that despite a large volume of studies on various topics, there is a need for more high-quality research and better-coordinated regional and national data collection. Moreover, prevention of such diseases will depend not only on training of environmental health professionals and enhanced research programs, but also on public education, legislation, and networking.

IVT cell-free biosensors for tetracycline and macrolide detection based on allosteric transcription factors (aTFs)

In recent years, the issue of food safety has received a lot of attention. The Food and Drug Administration (FDA) prescribes the antibiotic's maximum residue limit (MRL) in food production. The standard detection methods of antibiotics are liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and high-performance liquid chromatography (HPLC), with complex operations and precision instruments. In this study, allosteric transcription factor (aTF)-based in vitro transcription (IVT) cell-free biosensors were developed for tetracyclines and macrolides with nucleic acid sequence-based amplification (NASBA). Characterization of binding and dissociation processes between aTF and DNA was carried out by BIAcore assay and electrophoretic mobility shift assay (EMSA). BIAcore was innovatively used to directly observe the real-time process of binding and dissociation of aTF with DNA. The biosensors produce more fluorescence RNA when target antibiotics are added to the three-way junction dimeric Broccoli (3WJdB). Four tetracyclines and two macrolides were quantified in the 0.5-15 μM range, while erythromycin and clarithromycin were detected over a range of 0.1-15 μM. NASBA, commonly used for viral detection, was used to amplify 3WJdB RNA generated by IVT, which greatly increased the LOD for tetracyclines and macrolides to 0.01 μM. The use of biosensors in milk samples demonstrated their on-site detection performance. Overall, our proposed biosensors are simple, rapid, selective, and sensitive, with the potential for field application.

Association between fluoroquinolone exposure and children's growth and development: A multisite biomonitoring-based study in northern China

BACKGROUND

Although animal experiments found that antibiotic exposure during early life increased adiposity, limited human epidemiological evidence is available for the effects of veterinary antibiotic exposure on children's growth and development.

OBJECTIVE

This study was conducted to examine the body burden of fluoroquinolones in northern Chinese children and assess its association with growth and development.

METHODS

After recruiting 233 children aged 0-15 years from 12 different sites in northern China in 2020, we measured urinary concentrations of 5 respective fluoroquinolones (fleroxacin, ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin) by high performance liquid chromatography. Categories of children's growth and development were identified based on the Z score of body mass index. The health risks of individual and combined antibiotic exposure were estimated by the hazard quotient (HQ) and hazard index (HI), respectively. The association between children's growth and development with antibiotic concentrations was evaluated via multiple logistic regression analysis.

RESULTS

In total, 4 antibiotics, fleroxacin, ofloxacin, ciprofloxacin, and enrofloxacin, were found in urine samples of northern Chinese children at an overall frequency of 57.08%. Due to diet and economic differences, antibiotic concentrations in urine samples differed by study area, and the highest concentrations were found in Tianjin, Henan, and Beijing. The percentage of the participants with HQ > 1 caused by ciprofloxacin exposure was 20.61%, and the HI values in 23.18% of samples exceeded 1, suggesting potential health risks. The odds ratio (95% confidence interval) of overweight or obesity risk of tertile 2 of enrofloxacin was 3.01 (1.12, 8.11), indicating an increase in overweight or obesity risk for children with middle-concentration enrofloxacin exposure.

CONCLUSION

This is the first study to show a positive association of enrofloxacin internal exposure with overweight or obesity risk in children, demonstrating that more attention should be given to the usage and disposal of fluoroquinolones to safeguard children's health.

Comprehensive lipidomic analysis reveals regulation of glyceride metabolism in rat visceral adipose tissue by high-altitude chronic hypoxia

Adipose tissue plays a central role in energy substrate homeostasis and is a key regulator of lipid flow throughout these processes. As hypoxia affects lipid metabolism in adipose tissue, we aimed to investigate the effects of high-altitude chronic hypoxia on lipid metabolism in the adipose tissue of rats using a lipidomic analysis approach. Visceral adipose tissues from rats housed in a high-altitude hypoxia environment representing 4,300 m with 14.07% oxygen (hypoxia group) and from rats housed in a low-altitude normoxia environment representing 41 m with 20.95% oxygen (normoxia group) for 8 weeks were analyzed using an ultra-performance liquid chromatography-Orbitrap mass spectrometry system. After 8 weeks, the body weight and visceral adipose tissue weight of the hypoxia group were significantly decreased compared to those of the normoxia group (p < 0.05). The area and diameter of visceral adipose cells in the hypoxia group were significantly smaller than those of visceral adipose cells in the normoxia group (p < 0.05). The results of lipidomic analysis showed a total of 21 lipid classes and 819 lipid species. The total lipid concentration of the hypoxia group was lower than that in the normoxia group (p < 0.05). Concentrations of diacylglycerols and triacylglycerols in the hypoxia group were significantly lower than those in the normoxia group (p < 0.05). Using univariate and multivariate analyses, we identified 74 lipids that were significantly altered between the normoxia and hypoxia groups. These results demonstrate that high-altitude chronic hypoxia changes the metabolism of visceral adipose glycerides, which may potentially modulate other metabolic processes.