RESUMO
Early detection of emerging SARS-CoV-2 variants is critical to guiding rapid risk assessments, providing clear and timely communication messages, and coordinating public health action. CDC identifies and monitors novel SARS-CoV-2 variants through diverse surveillance approaches, including genomic, wastewater, traveler-based, and digital public health surveillance (e.g., global data repositories, news, and social media). The SARS-CoV-2 variant BA.2.86 was first sequenced in Israel and reported on August 13, 2023. The first U.S. COVID-19 case caused by this variant was reported on August 17, 2023, after a patient received testing for SARS-CoV-2 at a health care facility on August 3. In the following month, eight additional U.S. states detected BA.2.86 across various surveillance systems, including specimens from health care settings, wastewater surveillance, and traveler-based genomic surveillance. As of October 23, 2023, sequences have been reported from at least 32 countries. Continued variant tracking and further evidence are needed to evaluate the full public health impact of BA.2.86. Timely genomic sequence submissions to global public databases aided early detection of BA.2.86 despite the decline in the number of specimens being sequenced during the past year. This report describes how multicomponent surveillance and genomic sequencing were used in real time to track the emergence and transmission of the BA.2.86 variant. This surveillance approach provides valuable information regarding implementing and sustaining comprehensive surveillance not only for novel SARS-CoV-2 variants but also for future pathogen threats.
Assuntos
COVID-19 , Humanos , SARS-CoV-2/genética , Águas Residuárias , Vigilância Epidemiológica Baseada em Águas ResiduáriasRESUMO
Human exposure to polybrominated diphenyl ethers (PBDEs) through various routes poses deleterious health effects. PBDEs are biotransformed into hydroxylated metabolites (OH-BDEs) via cytochrome P450s (P450s), which may add to their neurotoxic effects. This study characterizes the in vitro metabolism of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), one of the most abundant PBDE congeners found in humans, by recombinant human P450s and pooled human liver microsomes (HLMs). Ten recombinant P450s were individually incubated with BDE-100 to monitor P450-specific metabolism. P450 2B6 was found to be the predominant enzyme responsible for nearly all formation of six mono-OH-pentaBDE and two di-OH-pentaBDE metabolites. Four metabolites were identified as 3-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (3-OH-BDE-100), 5'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (5'-OH-BDE-100), 6'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (6'-OH-BDE-100), and 4'-hydroxy-2,2',4,5',6-pentabromodiphenyl ether (4'-OH-BDE-103) through use of reference standards. The two remaining mono-OH-pentaBDE metabolites were hypothesized using mass spectral fragmentation characteristics of derivatized OH-BDEs, which allowed prediction of an ortho-OH-pentaBDE and a para-OH-pentaBDE positional isomer. Additional information based on theoretical boiling point calculations using COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) and experimental chromatographic retention times were used to identify the hypothesized metabolites as 2'-hydroxy-2,3',4,4',6-pentabromodiphenyl ether (2'-OH-BDE-119) and 4-hydroxy-2,2',4',5,6-pentabromodiphenyl ether (4-OH-BDE-91), respectively. Kinetic studies of BDE-100 metabolism using P450 2B6 and HLMs revealed Km values ranging from 4.9 to 7.0 µM and 6-10 µM, respectively, suggesting a high affinity toward the formation of OH-BDEs. Compared to the metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) reported in previous studies, BDE-100 appears to be more slowly metabolized by P450s due to the presence of a third ortho-substituted bromine atom.
Assuntos
Citocromo P-450 CYP2B6/metabolismo , Bifenil Polibromatos/toxicidade , Humanos , Hidroxilação , Cinética , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , OxirreduçãoRESUMO
Polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (OH-BDEs) are endocrine disrupting compounds prevalent in human serum and breast milk. Retention of PBDEs and OH-BDEs in humans may be affected by differences in PBDE metabolism due to variants in cytochrome P450 2B6 (CYP2B6). The objectives of this study are to assess the partitioning profiles of PBDEs and OH-BDEs in forty-eight paired human serum and milk samples, and to evaluate the relationship between variants in CYP2B6 genotype and PBDE and OH-BDE accumulation in humans. Results show that the geometric mean (GM) concentrations of PBDEs are similar in serum (GMâ¯=â¯43.4â¯ng/g lipid) and milk samples (GMâ¯=â¯52.9â¯ng/g lipid), while OH-BDEs are retained primarily in serum (GMâ¯=â¯2.31â¯ng/g lipid), compared to milk (GMâ¯=â¯0.045â¯ng/g lipid). Participants with CYP2B6*6 genotype had a greater relative retention of PBDEs in serum and milk, and significant relationships (pâ¯<⯠0.05) were also observed for PBDE-47, 5-OH-BDE-47 and 6-OH-BDE-47 concentrations relative to CYP2B6*5 and CYP2B6*6 genotypes. These results are the first to show that CYP2B6 genotype is significantly related to the relative retention of PBDEs in humans, which may have direct implications for variability in the susceptibility of individuals to the potential adverse effects of these contaminants.
Assuntos
Citocromo P-450 CYP2B6/metabolismo , Disruptores Endócrinos/sangue , Poluentes Ambientais/sangue , Retardadores de Chama/análise , Éteres Difenil Halogenados/sangue , Leite Humano/química , Animais , Citocromo P-450 CYP2B6/genética , Disruptores Endócrinos/análise , Poluentes Ambientais/análise , Feminino , Genótipo , Éteres Difenil Halogenados/análise , Humanos , Hidroxilação , Bifenil Polibromatos/análise , Bifenil Polibromatos/sangueRESUMO
Antimicrobial resistance is a worldwide problem that is both pressing and challenging due to the rate at which it is spreading, and the lack of understanding of the mechanisms that link human, animal and environmental sources contributing to its proliferation. One knowledge gap that requires immediate attention is the significance of antimicrobial residues and other pharmaceuticals that are being discharged from wastewater treatment plants (WWTPs) on the dissemination of antimicrobial resistance in the environment. In this work we provide an approach to develop a harmonized analytical method for 8 classes of antimicrobials and other pharmaceuticals that can be used for global monitoring in wastewater and receiving waters. Analysis of these trace organic chemicals in the influent and effluent wastewater, and in the respective upstream and downstream receiving waters from different countries across the globe is not trivial. Here, we demonstrated that sample preparation using solid-phase extraction (SPE) not only provides a convenient and cost-effective shipping of samples, but also adds stability to the analytes during international shipping. It is important that SPE cartridges are maintained at cold temperature during shipment if the duration is longer than 7â¯days because a significant decrease in recoveries were observed after 7â¯days in the cartridges stored at room temperature, especially for sulfonamides and tetracyclines. To compensate for sample degradation during shipment, and matrix effects in liquid chromatography/mass spectrometry, the use of stable isotope labeled compounds should be employed when available and affordable. The importance of applying a defined tolerance for the ion ratios (Q/q) that have been optimized for wastewater and surface water is discussed. The tolerance range was set to be the mean Q/q of the analyte standard at various concentrations ±40% for the influent, and ±30% for the effluent, upstream, and downstream samples; for tetracyclines and quinolones, however, the tolerance range was ±80% in order to minimize false negative and false positive detection. The optimized procedures were employed to reveal differences in antimicrobial and pharmaceutical concentrations in influent, effluent, and surface water samples from Hong Kong, India, Philippines, Sweden, Switzerland, and United States. The antimicrobials with the highest concentrations in influent and effluent samples were ciprofloxacin (48,103â¯ng/L, Hong Kong WWTP 1) and clarithromycin (5178â¯ng/L, India WWTP 2), respectively. On the other hand, diclofenac (108,000â¯ng/L, Sweden WWTP 2), caffeine (67,000â¯ng/L, India WWTP 1), and acetaminophen (28,000â¯ng/L, India WWTP 1) were the highest detected pharmaceuticals in the receiving surface water samples. Hong Kong showed the highest total antimicrobial concentrations that included macrolides, quinolones, and sulfonamides with concentrations reaching 60,000â¯ng/L levels in the influent. Antidepressants were predominant in Sweden, Switzerland, and the United States.
Assuntos
Anti-Infecciosos/análise , Monitoramento Ambiental , Águas Residuárias/química , Poluentes Químicos da Água/análise , Abastecimento de Água , Cromatografia Líquida , Monitoramento Ambiental/métodos , Hong Kong , Índia , Filipinas , Extração em Fase Sólida , Suécia , Suíça , Espectrometria de Massas em Tandem/métodos , Ciclo HidrológicoRESUMO
Hydroxylated polybrominated diphenyl ethers (OH-BDEs), which have anthropogenic and natural origins, have exhibited neurotoxic and endocrine disrupting effects in humans and wildlife. Therefore, there is an increased interest in the analysis of these compounds in biological matrices in order to assess their potential toxicological risks. Analysis of OH-BDEs is conventionally completed using liquid chromatography/mass spectrometry (LC/MS), or by gas chromatography/mass spectrometry (GC/MS) after derivatization. Issues with resolution in separating congeners have limited the analysis of OH-BDEs via LC/MS, with published methods only able to include 13 congeners in the analysis. On the other hand, while GC/MS analysis can analyze more OH-BDE congeners, derivatization of OH-BDEs to convert them to GC amenable compounds adds to sample preparation time and limits the column lifetime due to trace residues of highly reactive derivatization agents entering the column. Herein we report the development of a supercritical fluid chromatography/mass spectrometry (SFC/MS) method for the analysis of 22 OH-BDE congeners. Instrument limits of detection for the developed method ranged from 2 to 106fg injected on column, which is lower than previously optimized LC/MS and GC/MS methods. The developed SFC/MS method was successfully applied towards the analysis of in vitro metabolism samples and human serum samples to demonstrate its applicability with different biological matrices.
RESUMO
The presence of polybrominated diphenyl ethers (PBDEs) and their hydroxylated (OH-BDE) and methoxylated (MeO-BDE) analogs in humans is an area of high interest to scientists and the public due to their neurotoxic and endocrine disrupting effects. Consequently, there is a rise in the investigation of the occurrence of these three classes of compounds together in environmental matrices and in humans in order to understand their bioaccumulation patterns. Analysis of PBDEs, OH-BDEs, and MeO-BDEs using liquid chromatography-mass spectrometry (LC-MS) can be accomplished simultaneously, but detection limits for PBDEs and MeO-BDEs in LC-MS is insufficient for trace level quantification. Therefore, fractionation steps of the phenolic (OH-BDEs) and neutral (PBDEs and MeO-BDEs) compounds during sample preparation are typically performed so that different analytical techniques can be used to achieve the needed sensitivities. However, this approach involves multiple injections, ultimately increasing analysis time. In this study, an analytical method was developed for a "one-shot" analysis of 12 PBDEs, 12 OH-BDEs, and 13 MeO-BDEs using gas chromatography with tandem mass spectrometry (GC-MS/MS). This overall method includes simultaneous extraction of all analytes via pressurized liquid extraction followed by lipid removal steps to reduce matrix interferences. The OH-BDEs were derivatized using N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (TBDMS-MTFA), producing OH-TBDMS derivatives that can be analyzed together with PBDEs and MeO-BDEs by GC-MS/MS in "one shot" within a 25-min run time. The overall recoveries were generally higher than 65%, and the limits of detection ranged from 2 to 14 pg in both breast milk and serum matrices. The applicability of the method was successfully validated on four paired human breast milk and serum samples. The mean concentrations of total PBDEs, OH-BDEs, and MeO-BDEs in breast milk were 59, 2.2, and 0.57 ng g(-1) lipid, respectively. In serum, the mean total concentrations were 79, 38, and 0.96 ng g(-1) lipid, respectively, exhibiting different distribution profiles from the levels detected in breast milk. This "one-shot" GC-MS/MS method will prove useful and cost-effective in large-scale studies needed to further understand the partitioning behavior, and ultimately the adverse health effects, of these important classes of brominated flame retardants in humans.