As emerging contaminants, antibiotic resistance genes (ARGs) have become a public concern. This study aimed to investigate the occurrence and diversity of ARGs, and variation in the composition of ...bacterial communities in source water, drinking water treatment plants, and tap water in the Pearl River Delta region, South China. Various ARGs were present in the different types of water. Among the 27 target ARGs, floR and sul1 dominated in source water from three large rivers in the region. Pearson correlation analysis suggested that sul1, sul2, floR, and cmlA could be potential indicators for ARGs in water samples. The total abundance of the detected ARGs in tap water was much lower than that in source water. Sand filtration and sedimentation in drinking water treatment plants could effectively remove ARGs; in contrast, granular activated carbon filtration increased the abundance of ARGs. It was found that Pseudomonas may be involved in the proliferation and dissemination of ARGs in the studied drinking water treatment system. Bacteria and ARGs were still present in tap water after treatment, though they were significantly reduced. More research is needed to optimize the water treatment process for ARG removal.
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•Diverse ARGs present in different types of waters.•Sul1, sul2, floR, cmlA could be potential indicators for ARGs in the water samples.•Sand filter and sedimentation were effective in removing ARGs.•Granular activated carbon filtration increased the ARGs abundance.•ARGs still existed in tap water after treatment despite significantly reduced.
Antibiotics are widely used in humans and animals, but there is a big concern about their negative impacts on ecosystem and human health after use. So far there is a lack of information on emission ...inventory and environmental fate of antibiotics in China. We studied national consumption, emissions, and multimedia fate of 36 frequently detected antibiotics in China by market survey, data analysis, and level III fugacity modeling tools. Based on our survey, the total usage for the 36 chemicals was 92700 tons in 2013, an estimated 54000 tons of the antibiotics was excreted by human and animals, and eventually 53800 tons of them entered into the receiving environment following various wastewater treatments. The fugacity model successfully predicted environmental concentrations (PECs) in all 58 river basins of China, which are comparable to the reported measured environmental concentrations (MECs) available in some basins. The bacterial resistance rates in the hospitals and aquatic environments were found to be related to the PECs and antibiotic usages, especially for those antibiotics used in the most recent period. This is the first comprehensive study which demonstrates an alarming usage and emission of various antibiotics in China.
Perfluoroalkyl substances (PFASs) are a group of chemicals with wide industrial and commercial applications, and have been received great attentions due to their persistence in the environment. The ...information about their presence in urban water cycle is still limited. This study aimed to investigate the occurrence and removal efficiency of eighteen PFASs in wastewater treatment plants (WWTPs) and drinking water plants (DWTPs) with different treatment processes. The results showed that both perfluorobutane sulfonic acid (PFBS) and perfluorooctane sulfonic acid (PFOS) were the predominant compounds in the water phase of WWTPs and DWTPs, while PFOS was dominant in dewatered sludge of WWTPs. The average total PFASs concentrations in the three selected WWTPs were 19.6–232 ng/L in influents, 15.5–234 ng/L in effluents, and 31.5–49.1 ng/g dry weight in sludge. The distribution pattern of PFASs differed between the wastewater and sludge samples, indicating strong partition of PFASs with long carbon chains to sludge. In the WWTPs, most PFASs were not eliminated efficiently in conventional activated sludge treatment, while the membrane bio-reactor (MBR) and Unitank removed approximately 50% of long chain (C ≥ 8) perfluorocarboxylic acids (PFCAs). The daily mass loads of total PFASs in WWTPs were in the range of 1956–24773 mg in influent and 1548–25085 mg in effluent. PFASs were found at higher concentrations in the wastewater from plant A with some industrial wastewater input than from the other two plants (plant B and plant C) with mainly domestic wastewater sources. Meanwhile, the average total PFASs concentrations in the two selected DWTPs were detected at 4.74–14.3 ng/L in the influent and 3.34–13.9 ng/L in the effluent. In DWTPs, only granular activated carbon (GAC) and powder activated carbon (PAC) showed significant removal of PFASs. The PFASs detected in the tap water would not pose immediate health risks in the short term exposure. The findings from this study showed that effective treatment technology should be applied to eliminate this group of chemicals in the urban water cycle based on the precautionary principle.
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•PFASs were detected in WWTPs and DWTPs.•PFBS, PFOS and PFOA were predominant compounds in WWTPs and DWTPs.•MBR and Unitank can effectively remove the long chain PFCAs.•Powder activated carbon is the best in the removal of PFASs.•PFASs in tap water of Guangzhou would not pose health risks in the short-term.
We investigated the bioaccumulation of antibiotics in bile, plasma, liver and muscle tissues of wild fish from four rivers in the Pearl River Delta region. In total, 12 antibiotics were present in at ...least one type of fish tissues from nine wild fish species in the four rivers. The mean values of log bioaccumulation factors (log BAFs) for the detected antibiotics in fish bile, plasma, liver, and muscle tissues were at the range of 2.06–4.08, 1.85–3.47, 1.41–3.51, and 0.48–2.70, respectively. As the digestion tissues, fish bile, plasma, and liver showed strong bioaccumulation ability for some antibiotics, indicating a different bioaccumulation pattern from hydrophobic organic contaminants. Human health risk assessment based on potential fish consumption indicates that these antibiotics do not appear to pose an appreciable risk to human health. To the best of our knowledge, this is first report of bioaccumulation patterns of antibiotics in wild fish bile and plasma.
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•We investigated the bioaccumulation of antibiotics in wild fish from the Pearl River Delta region.•Twelve antibiotics were found in fish bile, plasma, liver and muscle tissues.•High log bioaccumulation factors suggested strong bioaccumulation ability for some antibiotics in wild fish tissues.•The presence of antibiotics in fish bile and plasma tissues indicates a novel bioaccumulation pattern.•Potential adverse effects are possibly caused by the high internal antibiotic concentrations in tissues.
Fish bile and plasma displayed strong bioaccumulation ability for some antibiotics, indicating a novel bioaccumulation pattern for antibiotics in the contaminated environment.
Facing the COVID-19 pandemic, Taiwan demonstrated resilience at the initial stage of epidemic prevention, and effectively slowed down its spread. This study aims to document public epidemic awareness ...of COVID-19 in Taiwan through collecting social media- and Internet-based data, and provide valuable experience of Taiwan's response to COVID-19, involving citizens, news media, and the government, to aid the public in overcoming COVID-19, or infectious diseases that may emerge in the future. The volume of Google searches related to COVID-19 and face masks was regarded as an indicator of public epidemic awareness in the study. A time-series analysis was used to explore the relationships among public epidemic awareness and other COVID-19 relevant variables, which were collected based on big data analysis. Additionally, the content analysis was adopted to analyze the transmission of different types of fear information related to COVID-19 and their effects on the public. Our results indicate that public epidemic awareness was significantly correlated with the number of confirmed cases in Taiwan and the number of news reports on COVID-19 (correlation coefficient: .33-.56). Additionally, the findings from the content analysis suggested that the fear of the loss of control best explains why panic behavior occurs among the public. When confronting the highly infectious COVID-19, public epidemic awareness is vital. While fear is an inevitable result when an emerging infectious disease occurs, the government can convert resistance into assistance by understanding why fear arises and which fear factors cause excessive public panic. Moreover, in the digitalization era, online and social media activities could reflect public epidemic awareness that can e harnessed for epidemic control.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Background /Purpose: Multidrug-resistant strains of Citrobacter have emerged, which carry Amp-C β-lactamase (Amp-C), broad-spectrum β-lactamase, extended-spectrum β-lactamase (ESBL), and ...other resistance mechanisms. These strains are associated with a higher rate of in-hospital mortality. The object of this study is to determine the mortality risk factors, susceptibility pattern to antibiotics, and prevalence of resistance genes in patients with Citrobacter freundii bacteremia. Methods From January 2009 to December 2014, blood isolates of C. freundii were collected in MacKay Memorial Hospital, Taipei, Taiwan. PCR technique and sequencing were performed for resistance genes. Pulsed-field gel electrophoresis (PFGE) was done using Xba I restriction enzyme. The clinical characteristics and risk factors for mortality are demonstrated. Results The 36 blood isolates of C. freundii belonged to 32 different PFGE pulsotypes , and 15 isolates (41.7%) were polymicrobial. The most common source of infection was intra-abdominal origin (61.1%), followed by unknown sources (22.2%), the urinary tract (8.3%), intravascular catheter (5.6%), and soft tissue (2.8%). High degree of antibiotic resistance was noted for cefazolin (100%), cefoxitin (97.2%), and cefuroxime (66.7%). The blaTEM-1 resistance gene was present in 16.7% isolates. 72.2% isolates carried blaAmpC and 5.6% isolates carried ESBL genes ( blaSHV-12 or blaCTX-M-15 ). Multivariate analysis indicated that the independent risk factor for 28-day mortality was carrying the blaTEM-1 resistance gene. Conclusion For patients with C. freundii bacteremia, carrying the blaTEM-1 resistance gene was an independent risk factor for 28-day mortality. Carbapenems, fourth-generation cephalosporins, amikacin, and quinolones are still reliable agents for drug-resistant strains.
This paper evaluated the excretion masses and environmental occurrence of 11 classes of 50 antibiotics in six typical swine and dairy cattle farms in southern China. Animal feeds, wastewater and ...solid manure samples as well as environmental samples (soil, stream and well water) were collected in December 2010 from these farms. Twenty eight antibiotics, including tetracyclines, bacitracin, lincomycin, sulfonamides, fluoroquinolones, ceftiofur, trimethoprim, macrolides, and florfenicol, were detected in the feeds, animal wastes and receiving environments. The normalized daily excretion masses per swine and cattle were estimated to be 18.2mg/day/swine and 4.24mg/day/cattle. Chlortetracycline (11.6mg/day/swine), bacitracin (3.81mg/day/swine), lincomycin (1.19mg/day/swine) and tetracycline (1.04mg/day/swine) were the main contributors to the normalized daily excretion masses of antibiotics per swine, while chlortetracycline (3.66mg/day/cattle) contributed 86% of the normalized daily excretion masses of antibiotics per cattle. Based on the survey of feeds and animal wastes from the swine farms and interview with the farmers, antibiotics excreted by swine were mainly originated from the feeds, while antibiotics excreted by dairy cattle were mainly from the injection route. If we assume that the swine and cattle in China excrete the same masses of antibiotics as the selected livestock farms, the total excretion mass by swine and cattle per annum in China could reach 3,080,000kg/year and 164,000kg/year. Various antibiotics such as sulfonamides, tetracyclines, fluroquinolones, macrolides, trimethoprim, lincomycin and florfenicol were detected in well water, stream and field soil, suggesting that livestock farms could be an important pollution source of various antibiotics to the receiving environments.
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► Twenty six antibiotics were quantified in six swine and dairy farms. ► The normalized excretion mass of antibiotics per swine was more than per cattle. ► Growth promoters contributed above 80% of the excretion mass in swine farms. ► Total excretion mass by swine and cattle in China could reach 3080 and 164t/a. ► Significant concentrations of antibiotics were found in the receiving environment.
This study reported a tandem strategy on sequential base-controlled benzylation/Pd-catalyzed secondary amide arylation for one-pot synthesis of highly functionalized hydroquinolin-2-ones. This ...strategy involves creation of 3 bonds, 1 ring, and 1 quaternary carbon center while synthesizing diverse 3-cyano substituted hydroquinolin-2-ones in 41–83% yields.
This study developed a tandem strategy involving a base controlled benzylation/Pd-catalyzed secondary amide arylation for the one-pot synthesis of highly functionalized hydroquinolin-2-ones. Diverse 3-cyano substituted hydroquinolin-2-ones in satisfactory yields of 41–83% could be prepared via this method through a sequence of making 3 bonds, 1 ring, and 1 quaternary carbon center en. Control experiments indicated that the synthesis of 3,4-dihydroquinolinones proceeded in a benzylation/intramolecular sequence. Display omitted
•New Benzylation/ C-N Coupling cascade.•Novel 3-cyano substituted quinolinones.•Efficient Pd/XantPhos catalyst.•Good functional groups tolerance.
The effect of biofilm formation on bacteraemic pneumonia caused by A. baumannii is unknown. We conducted a 4-year multi-center retrospective study to analyze 71 and 202 patients with A. baumannii ...bacteraemic pneumonia caused by biofilm-forming and non-biofilm-forming isolates, respectively. The clinical features and outcomes of patients were investigated. Biofilm formation was determined by a microtitre plate assay. The antimicrobial susceptibilities of biofilm-associated cells were assessed using the minimum biofilm eradication concentration (MBEC) assay. Whole-genome sequencing was conducted to identify biofilm-associated genes and their promoters. Quantitative reverse transcription polymerase chain reaction was performed to confirm the expression difference of biofilm-associated genes. There was no significant difference in the clinical characteristics or the outcomes between patients infected with biofilm-forming and non-biofilm-forming strains. Compared with non-biofilm-forming isolates, biofilm-forming isolates exhibited lower resistance to most antimicrobials tested, including imipenem, meropenem, ceftazidime, ciprofloxacin and gentamicin; however, the MBEC assay confirmed the increased antibiotic resistance of the biofilm-embedded bacteria. Biofilm-associated genes and their promoters were detected in most isolates, including the non-biofilm-forming strains. Biofilm-forming isolates showed higher levels of expression of the biofilm-associated genes than non-biofilm-forming isolates. The biofilm-forming ability of A. baumannii isolates might not be associated with worse outcomes in patients with bacteraemic pneumonia.
A novel metal–organic framework, H 2 bpy 0.5 Cd 3 (OH)(L) 2 (bpy)(H 2 O) 2 ·(bpy) 0.5 ·2H 2 O ( 1 ) (H 3 L = 3-(3,5-dicarboxylphenyl)-4-carboxylpyridine, bpy = 4,4′-bipyridine), with blue ...luminescence, was successfully synthesized under solvothermal conditions. Structure analysis indicates that this compound is composed of triangle Cd 3 (μ 3 -OH) clusters linked by L ligands, forming a novel 3D framework with a (3,3,8)-connected (4 2 ·6)(4 2 ·6)(4 4 ·5 5 ·6 4 ·7 8 ·8 7 ) topology. Cd-MOF- 1 contains microporous channels with accessible Lewis-base sites (N), uncoordinated carboxylate groups and coordinated H 2 O molecules, which are easy to recognize various small molecules. Meanwhile, this compound exhibits a microporous structure with H 2 bpy 2+ cations being located in the channels, which can be easily replaced by some cationic dyes. Particularly, Cd-MOF- 1 displays high water and pH stability. Based on the aforementioned considerations, when Cd-MOF- 1 was immersed in the different metal ion aqueous solutions and different nitro explosive EtOH solutions, it performed as a highly selective and sensitive sensor for Fe 3+ ions and TNP (2,4,6-trinitrophenol). Moreover, the probable sensing mechanism was also investigated in detail. More interestingly, dye adsorption studies revealed that Cd-MOF- 1 can adsorb cationic dyes in aqueous solution while the anionic and neutral dyes cannot be absorbed and the cationic dye adsorption amounts decrease with the increase in dye size. Therefore, Cd-MOF- 1 can potentially act as a column-chromatographic filter for the separation of dye molecules.
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