RESUMO
Rapid phenotypic detection assays, including Carba NP and its variants, are widely applied for clinical diagnosis of carbapenemase-producing Enterobacterales (CPE). However, these tests are based on the acidification of the pH indicator during carbapenem hydrolysis, which limits test sensitivity and speed, especially for the detection of CPE producing low-activity carbapenem (e.g., OXA-48 variants). Herein, we developed a novel rapid and sensitive CPE detection method (Carba PBP) that could measure substrate (meropenem) consumption based on penicillin-binding protein (PBP). Meropenem-specific PBP was used to develop a competitive lateral flow assay (LFA) for meropenem identification. For the detection of carbapenemase activity, meropenem concentration was optimized using a checkerboard assay. The performance of Carba PBP was evaluated and compared with that of Carba NP using a panel of 94 clinical strains characterized by whole-genome sequencing and carbapenem susceptibility test. The limit of detection of PBP-based LFA for meropenem identification was 7 ng mL-1. Using 10 ng mL-1 meropenem as the substrate, Carba PBP and Carba NP could detect 10 ng mL-1 carbapenemase within 25 min and 1,280 ng mL-1 CPE in 2 h, respectively. The sensitivity and specificity were 100% (75/75) and 100% (19/19) for Carba PBP and 85.3% (64/75) and 100% (19/19) for Carba NP, respectively. When compared with Carba NP, Carba PBP showed superior performance in detecting all the tested CPE strains (including OXA-48-like variants) within 25 min and presented two orders of magnitude higher analytical sensitivity, demonstrating potential for clinical diagnosis of CPE. IMPORTANCE This study successfully achieved the goal of carbapenemase activity detection with both high sensitivity and convenience, offering a convenient lateral flow assay for clinical diagnosis of carbapenemase-producing Enterobacterales.
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Proteínas de Bactérias , beta-Lactamases , Humanos , Proteínas de Ligação às Penicilinas/genética , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , beta-Lactamases/metabolismo , Carbapenêmicos/farmacologia , Sensibilidade e EspecificidadeRESUMO
Plasmids are the primary vectors for intercellular transfer of the oxazolidinone and phenicol cross-resistance gene optrA, while insertion sequences (ISs) are mobile genetic elements that can mobilize plasmid-borne optrA intracellularly. However, little is known about how the IS-mediated intracellular mobility facilitates the dissemination of the optrA gene between plasmid categories that vary in transfer abilities, including non-mobilizable, mobilizable, and conjugative plasmids. Here, we performed a holistic genomic study of 52 optrA-carrying plasmids obtained from searches guided by the Comprehensive Antibiotic Resistance Database. Among the 132 ISs identified within 10 kbp from the optrA gene in the plasmids, IS6 family genes were the most prevalent (86/132). Homologous gene arrays containing IS6 family genes were shared between different plasmids, especially between mobilizable and conjugative plasmids. All these indicated the central role of IS6 family genes in disseminating plasmid-borne optrA. Thirty-three of the 52 plasmids were harbored by Enterococcus faecalis found mainly in humans and animals. By Nanopore sequencing and inverse PCR, the potential of the enterococcal optrA to be transmitted from a mobilizable plasmid to a conjugative plasmid mediated by IS6 family genes was further confirmed in Enterococcus faecalis strains recovered from the effluents of anaerobic digestion systems for treating chicken manure. Our findings highlight the increased intercellular transfer abilities and dissemination risk of plasmid-borne optrA gene caused by IS-mediated intracellular mobility, and underscore the importance of routinely monitoring the dynamic genetic contexts of clinically important antibiotic resistance genes to effectively control this critical public health threat. KEY POINTS: ⢠IS6 was prevalent in optrA-plasmids varying in intercellular transfer abilities. ⢠Enterococcal optrA-plasmids were widespread among human, animal, and the environment. ⢠IS6 elevated the dissemination risk of enterococcal optrA-plasmids.
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Elementos de DNA Transponíveis , Genes Bacterianos , Animais , Humanos , Farmacorresistência Bacteriana/genética , Plasmídeos/genética , Antibacterianos/farmacologia , Enterococcus , Enterococcus faecalis/genética , Testes de Sensibilidade MicrobianaRESUMO
We established an efficient and simplified single-cell proteomics (ES-SCP) workflow to realize proteomics profiling at the single-oocyte level. With the ES-SCP workflow, we constructed a deep coverage proteome library during oocyte maturation, which contained more than 6000 protein groups, and identified and quantified more than 4000 protein groups from a pool of only 15 oocytes at germinal vesicle (GV), GV breakdown (GVBD), and metaphase II (MII) stages. More than 1500 protein groups can be identified from single oocytes. We found that marker proteins including maternal factors and mRNA regulators, such as ZAR1, TLE6, and BTG4, showed significant variations in abundance during oocyte maturation, and it was discovered that maternal mRNA degradation was indispensable during oocyte maturation. Proteomics analysis from single oocytes revealed that changes in antioxidant factors, maternal factors, mRNA stabilization, and energy metabolism were the factors that affect the oocyte quality during ovary aging. Our data laid the foundation for future innovations in assisted reproduction.
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Oócitos , Proteômica , Feminino , Animais , Camundongos , Oogênese/genética , Proteoma/genética , Proteoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Objective: To investigate the application effects of prostate perineural block combined with pudendal nerve block under transrectal ultrasound guidance in transrectal prostate biopsy. Methods: Ninety patients who underwent their first transrectal prostate biopsy from November 2021 to July 2022 were included in the study. The patients were divided into three groups: Group A received prostate perineural block, Group B received intrathecal anesthesia, and Group C received pudendal nerve block combined with prostate perineural block. Perioperative indicators, pain levels, and occurrence of complications were compared among the three groups. Results: Regarding perioperative indicators, after 5 minutes of anesthesia, Group B had the lowest mean arterial pressure (MAP) (P < .05), while Group A had the highest MAP (P < .05). The VAS scores in Groups B and C were lower than that in Group A during probe insertion, prostate puncture, and 2 hours after biopsy (P < .05). There were no significant differences in the occurrence of complications among the three groups (P > .05). Conclusion: Compared to intrathecal anesthesia, the combination of prostate perineural block and pudendal nerve block provided more stable hemodynamics after 5 minutes of anesthesia. It effectively controlled pain compared to prostate perineural block alone. Nerve block anesthesia facilitated earlier postoperative ambulation, making it suitable for day surgery and in line with the Enhanced Recovery After Surgery concept. Additionally, it had no complications and can be considered for wider application.
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OBJECTIVES: Recently, epidemiological research has shown an unusually high prevalence of telithromycin-resistant Campylobacter. This study was designed to investigate the potential resistance mechanism of telithromycin resistance in Campylobacter. METHODS: A total of 122 Campylobacter isolates of chicken origin collected in 2019 from three regions of China were tested for susceptibility to telithromycin. The potential mechanism of resistance to telithromycin in Campylobacter was revealed through WGS analysis and natural transformation. RESULTS: In this study, 51.3% (61/119) of Campylobacter coli and 100.0% (3/3) of Campylobacter jejuni were resistant to telithromycin. erm(B) or A2075G mutation in 23S rRNA (23S_A2075G) was identified in the telithromycin-resistant C. coli. Cloning of the erm(B) or 23S_A2075G into C. jejuni NCTC 11168 resulted in a 256-fold increase in the MIC of telithromycin. MLST results indicated that various STs were involved in the dissemination of 23S_A2075G and erm(B). Phylogenetic analysis showed that the C. coli isolates with 23S_A2075G and erm(B) from chickens and humans were closely related. CONCLUSIONS: 23S_A2075G and erm(B), which have been widely spread in different genotypes of C. coli isolated from animals and humans, could mediate high levels of resistance to telithromycin in C. coli. C. coli containing 23S_A2075G or erm(B) are clonally related and have the potential to spread zoonotic diseases.
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Campylobacter coli , Campylobacter jejuni , Campylobacter , Animais , Antibacterianos/farmacologia , Campylobacter coli/genética , Campylobacter jejuni/genética , Galinhas , Farmacorresistência Bacteriana/genética , Cetolídeos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Mutação , Filogenia , RNA Ribossômico 23S/genéticaRESUMO
BACKGROUND: The rs1401999 gene in ABCC5 gene was the first locus confirmed by a genome-wide association study (GWAS) to be associated with both anterior chamber depth (ACD) and primary angle closure glaucoma (PACG); however, this locus was of obvious heterogeneity among different populations in the GWAS, and the conclusion has not been further verified by other studies. Therefore, this study was carried out to investigate whether the single-nucleotide polymorphisms (SNPs) in ABCC5 gene are associated with PACG and the ocular biometric parameters ACD and axial length (AL) in samples from northern China. METHODS: Case-control association study included 500 PACG patients and 720 unrelated controls from northern China, and genotyping was performed for ten SNPs in ABCC5 gene using an improved multiplex ligation detection reaction technique. The association between these SNPs and risk of PACG was estimated by PLINK using a logistic regression model, while the association between genotypes and ocular biometric parameters was performed by SPSS using generalized estimation equation. RESULTS: An SNP rs4148568 (p = 0.046) and a haplotype TCGGAG (p = 0.0364) in ABCC5 were associated with PACG, and rs4148568 was nominally associated with AL (ß = 0.092, p = 0.08). CONCLUSIONS: The SNP rs4148568 and a haplotype TCGGAG in ABCC5 contribute to PACG in northern Chinese people. In addition, rs4148568 might be associated with the AL, the variant allele of which may have effect of making the AL longer. Further studies are needed to elucidate the exact mechanism of ABCC5 in the progress of PACG.
Assuntos
Glaucoma de Ângulo Fechado , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Humanos , Câmara Anterior , Biometria , Estudo de Associação Genômica Ampla , Glaucoma de Ângulo Fechado/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Natural transformation mediates horizontal gene transfer, and thereby promotes exchange of antibiotic resistance and virulence traits among bacteria. Streptococcus pneumoniae, the first known transformable bacterium, rapidly activates and then terminates the transformation state, but it is unclear how the bacterium accomplishes this rapid turn-around at the protein level. This work determined the transcriptomic and proteomic dynamics during the window of pneumococcal transformation. RNA sequencing revealed a nearly uniform temporal pattern of rapid transcriptional activation and subsequent shutdown for the genes encoding transformation proteins. In contrast, mass spectrometry analysis showed that the majority of transformation proteins were substantially preserved beyond the window of transformation. However, ComEA and ComEC, major components of the DNA uptake apparatus for transformation, were completely degraded at the end of transformation. Further mutagenesis screening revealed that the membrane-associated serine protease HtrA mediates selective degradation of ComEA and ComEC, strongly suggesting that breakdown of the DNA uptake apparatus by HtrA is an important mechanism for termination of pneumococcal transformation. Finally, our mutagenesis analysis showed that HtrA inhibits natural transformation of Streptococcus mitis and Streptococcus gordonii. Together, this work has revealed that HtrA regulates the level and duration of natural transformation in multiple streptococcal species.
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Serina Endopeptidases/metabolismo , Transformação Bacteriana/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA/metabolismo , Transferência Genética Horizontal , Proteômica , Serina Endopeptidases/genética , Serina Proteases/metabolismo , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Transcriptoma/genética , Transformação Genética/genética , Virulência/genéticaRESUMO
BACKGROUND: Plasmid-mediated mechanisms of drug resistance accelerate the spread of polymyxin resistance, leaving clinicians with few or no antibacterial options for the treatment of infections caused by MDR bacteria, especially carbapenemase-producing strains. OBJECTIVES: To evaluate the associations among promoter sequence variation, mcr-1 expression, host factors and levels of colistin resistance and to propose antisense agents such as peptide nucleic acids (PNAs) targeting mcr-1 as a tool to restore colistin susceptibility through modulation of MCR-1 expression in Escherichia coli. METHODS: A ß-galactosidase assay was performed to study mcr-1 promoter activity. Quantitative real-time PCR and western blot assays were used to identify the expression level of MCR-1 in WT strains and transformants. Three PNAs targeting different regions of mcr-1 were designed and synthesized to determine whether they can effectively inhibit MCR-1 expression. MIC was measured to test colistin susceptibility in the presence or absence of PNA-1 in mcr-1-carrying E. coli. RESULTS: Variation in the mcr-1 promoter sequence and host species affect promoter activity, MCR-1 expression levels and colistin MICs. One PNA targeting the ribosome-binding site fully inhibited the expression of mcr-1 at a concentration of 4 µM, resulting in significantly increased susceptibility to colistin. The MIC90 of colistin decreased from 8 to 2 mg/L (P < 0.05) in the presence of 4 µM PNA. CONCLUSIONS: These findings suggest that the antisense approach is a possible strategy to combat mcr-1-mediated resistance as well as other causes of emerging global resistance.
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Infecções por Escherichia coli , Proteínas de Escherichia coli , Ácidos Nucleicos Peptídicos , Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Ácidos Nucleicos Peptídicos/genética , Ácidos Nucleicos Peptídicos/farmacologia , Plasmídeos/genéticaRESUMO
OBJECTIVES: This study was designed to understand the prevalence of antibiotic-resistant bacteria in the Beijing subway environment and the potential transmission of carbapenem-resistant Enterobacteriaceae in a public transportation environment. METHODS: Carbapenem-resistant isolates were selected on brain heart infusion agar supplemented with meropenem (0.5 mg/L) and antimicrobial susceptibility testing was conducted using the broth microdilution method. WGS analyses were conducted for 11 Klebsiella pneumoniae isolates to identify resistance genes. The genetic relationships among the isolates were evaluated by MLST and PFGE. RESULTS: We identified 11 carbapenem-resistant K. pneumoniae isolates from the Beijing subway environment. WGS revealed three STs among the 11 isolates, with 9 isolates classified as ST726 and containing a blaNDM-5-carrying IncX3 plasmid. The genetic environment of blaNDM-5 was very similar to that observed in other blaNDM-5-containing clinical isolates. CONCLUSIONS: The presence of carbapenem-resistant Enterobacteriaceae in a public transportation environment is concerning and indicates that regular antimicrobial resistance surveillance is urgent and necessary.
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Antibacterianos , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Klebsiella , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Carbapenêmicos/farmacologia , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Saúde Pública , Meios de Transporte , beta-LactamasesRESUMO
BACKGROUND: Tigecycline is a last-resort antibiotic used to treat severe infections caused by extensively drug-resistant bacteria. Recently, novel tigecycline resistance genes tet(X3) and tet(X4) have been reported, which pose a great challenge to human health and food security. The current study aimed to establish a TaqMan-based real-time PCR assay for the rapid detection of the tigecycline-resistant genes tet(X3) and tet(X4). RESULTS: No false-positive result was found, and the results of the TaqMan-based real-time PCR assay showed 100% concordance with the results of the sequencing analyses. This proposed method can detect the two genes at the level of 1 × 102 copies/µL, and the whole process is completed within an hour, allowing rapid screening of tet(X3) and tet(X4) genes in cultured bacteria, faeces, and soil samples. CONCLUSION: Taken together, the TaqMan-based real-time PCR method established in this study is rapid, sensitive, specific, and is capable of detecting the two genes not only in bacteria, but also in environmental samples.
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Bactérias/genética , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Fezes/microbiologia , Tigeciclina/farmacologia , Animais , Bactérias/efeitos dos fármacos , Primers do DNA/genética , Microbiologia Ambiental , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase em Tempo RealRESUMO
As highly toxic and accessible chemical reagents, phosgene and triphosgene have become a serious threat to public safety. So, it is highly desirable to develop facile methods to detect and recognize them. In this article, a novel fluorescent chemosensor, Phos-4, has been constructed with 1,8-naphthalimide as the fluorophore and 2-(2-aminophenyl)imidazol as the recognition sites for discrimination between phosgene and triphosgene in a dual-channel mode for the first time. Owing to the difference in electrophilicity between chlorocarbonyl and trichloromethoxycarbonyl, the sensing reaction of Phos-4 with phosgene undergoes two carbamylations to afford a cyclic product with green fluorescence, and only one carbamylation occurs for triphosgene to form a noncyclic product with blue fluorescence. The sensor Phos-4 exhibits high sensitivity (the limit of detection, 3.2 nM, for phosgene, and 1.9 nM, for triphosgene) and high selectivity in solutions. Furthermore, facile test papers containing Phos-4-embedded nanofibrous membrane have been fabricated by the electrospinning technology. The test papers can provide visual and selective detection of phosgene with a lower limit of detection (42 ppb) and a faster response (≤10 s) in the gas phase over those in solutions. The test paper with Phos-4 is promising to be a practical detection tool of gaseous phosgene.
Assuntos
Técnicas Biossensoriais/métodos , Fluorescência , Corantes Fluorescentes/química , Fosgênio/análogos & derivados , Fosgênio/análise , Espectrometria de FluorescênciaRESUMO
OBJECTIVES: Characterization of non-Escherichia coli NDM-carrying Enterobacteriaceae in the poultry production environment. METHODS: A total of 36 NDM-positive Enterobacteriaceae (22 Klebsiella pneumoniae, 13 Enterobacter cloacae and 1 Salmonella enterica) were isolated from a chicken farm and WGS was conducted using Illumina Hiseq2500. The genomic characterization of the isolates acquired through WGS analysis included the genomic context-flanking blaNDM genes, MLST, the antibiotic resistance genes (ARGs) and replicon types of plasmids. WGS information for another 73 K. pneumoniae isolates from different sources was retrieved from GenBank and then combined with isolates in this study for comparative genomic and phylogenetic analysis. RESULTS: Three types of genetic environment carrying blaNDM were identified in 36 non-E. coli Enterobacteriaceae isolates. Sequence comparison analysis indicated these genetic environments were completely identical to our previous findings. WGS further revealed three major types of plasmids (IncFIB, IncX3 and IncFII) from these isolates and the phylogenetic analysis suggested several K. pneumoniae isolates with ST11, ST37 and ST147 from the commercial chicken farm that were closely related to isolates of human origin. CONCLUSIONS: The blaNDM-harbouring genetic contexts were identified not only in E. coli, but also in K. pneumoniae, E. cloacae and S. enterica, which may indicate that blaNDM has been widely disseminated to non-E. coli Enterobacteriaceae species in animal farms. The close relationship of K. pneumoniae isolates from different origins suggests they could serve as a key vehicle for the transfer of ARGs between humans and food animal production environments.
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Infecções por Enterobacteriaceae/veterinária , Enterobacteriaceae/genética , Filogenia , Aves Domésticas/microbiologia , Animais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , China , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/enzimologia , Enterobacter cloacae/genética , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/enzimologia , Genes MDR/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/enzimologia , Salmonella enterica/genética , Sequenciamento Completo do GenomaRESUMO
OBJECTIVES: Since the identification of VIM-1, point substitutions resulting in variants with differing hydrolytic activities have occurred, driving the evolution of the VIM enzymes. We previously detected a novel variant, VIM-48, containing 11 successive amino acid (aa) alterations in the C-terminal region compared with VIM-2. Single aa substitutions significantly change enzyme properties, but the effects of successive aa alterations have not previously been studied. Herein, we aimed to investigate the sequence and biochemical characteristics of VIM-48, including the role of the 11 successive aa substitutions. METHODS: VIM-48, VIM-2 and a truncated VIM-D(Δ) mutant missing 11 aa at the C-terminus relative to VIM-48 were characterized by antimicrobial susceptibility testing, protein expression and purification, determination of kinetic parameters, and homology modelling. Protein secondary structure and thermal stability measurements were also performed using circular dichroism spectral analysis. RESULTS: Compared with blaVIM-2, blaVIM-48 conferred higher resistance to carbapenems. VIM expression in Pseudomonas putida resulted in higher MICs than in E. coli. VIM-48 demonstrated increased hydrolytic activity against carbapenems relative to VIM-2, while VIM-D(Δ) had significantly decreased catalytic efficiency compared with VIM-2 and VIM-48 as a result of aa deletion. In addition, secondary structure analysis revealed that VIM-48 had the greatest proportion of α-helices among the tested enzymes, corresponding to increased thermostability, while VIM-D(Δ) had the lowest proportion of α-helices and decreased thermostability. CONCLUSIONS: VIM-48 has increased enzymatic activity and thermostability and increases host ß-lactam resistance. Observed changes in the secondary structure of VIM-48 resulted from successive aa alterations. Therefore, VIM evolution likely occurs via both single and successive aa substitutions.
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Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Proteínas Mutantes/metabolismo , Mutação de Sentido Incorreto , Resistência beta-Lactâmica , beta-Lactamases/metabolismo , Substituição de Aminoácidos , Dicroísmo Circular , Estabilidade Enzimática , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Expressão Gênica , Temperatura Alta , Hidrólise , Cinética , Testes de Sensibilidade Microbiana , Proteínas Mutantes/química , Proteínas Mutantes/genética , Mutação Puntual , Conformação Proteica , Pseudomonas putida/efeitos dos fármacos , Pseudomonas putida/genética , Deleção de Sequência , beta-Lactamases/química , beta-Lactamases/genéticaRESUMO
The global spread of carbapenem-resistant Enterobacteriaceae (CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance gene mcr-1 among CRE strains greatly compromises the use of colistin as a last resort for the treatment of infections caused by CRE. This study aimed to understand the current epidemiological trends and characteristics of CRE from a large hospital in Henan, the most populous province in China. From 2014 to 2016, a total of 7,249 Enterobacteriaceae isolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistant Klebsiella pneumoniae and carbapenem-resistant Escherichia coli were the two most common CRE species, with Klebsiella pneumoniae carbapenemases (KPC) and New Delhi metallo-ß-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% (n = 589) of the K. pneumoniae isolates from the intensive care unit were carbapenem resistant. Furthermore, blaNDM-5 and mcr-1 were found to coexist in one E. coli isolate, which exhibited resistance to almost all tested antibiotics. Overall, we observed a significant increase in the prevalence of CRE isolates during the study period and suggest that carbapenems may no longer be considered to be an effective treatment for infections caused by K. pneumoniae in the studied hospital.
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Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Carbapenêmicos/farmacologia , Colistina/farmacologia , Infecções por Enterobacteriaceae/epidemiologia , Proteínas de Escherichia coli/genética , Antibacterianos/farmacologia , China/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Hospitais , Humanos , Unidades de Terapia Intensiva , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Prevalência , beta-Lactamases/genéticaRESUMO
Phosgene and its substitutes, diphosgene and triphosgene, are highly toxic and widely used chemicals, so it is necessary to investigate their reactivity and develop facile, sensitive, and specific methods for detecting them. In this work, we have developed a new 1,8-naphthalimide-based fluorescent chemosensor, Phos-2, which exhibits high sensitivity (detection limits: 0.2-0.7â nm), high selectivity to phosgene and its substitutes over nitric oxide (NO), various acyl chlorides, and nerve agent mimics in solutions. Based on investigation of the reaction kinetics of Phos-2 with phosgene and its substitutes, a two-step sensing mechanism was clarified. The second-order rate constants (k2 ) of Phos-2 reveal that the relative rate constants of phosgene, diphosgene, and triphosgene are 40:4:1. Moreover, a Phos-2 test paper has been fabricated as a low-cost, sensitive (≈5â ppm from observation by the naked eye or 0.1â ppm from a measurement), and efficient method for visual detection of a low concentration of phosgene in the gas phase.
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This paper estimates the impact of spousal bereavement on hospital inpatient use for the surviving bereaved by following the experience of 94,272 married Scottish individuals from 1991 until 2009 using a difference-in-difference model. We also consider the sample selection issues related to differences in survival between the bereaved and non-bereaved using a simple Cox Proportional-Hazard model. Before conducting these estimations, propensity score approaches are used to re-weight the non-bereaved to generate a more random-like comparison sample for the bereaved. We find that those bereaved who survive are both more likely to be admitted and to stay longer in hospital than a comparable non-bereaved cohort. Bereavement is estimated to induce on average an extra 0.24 (95% CI [0.15, 0.33]) hospital inpatient days per year. Similar to previous studies, we estimate the bereaved have a 19.2% (95% CI [12.5%, 26.3%]) higher mortality rate than the comparable non-bereaved cohort.
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Luto , Hospitalização/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Cônjuges/psicologia , Idoso , Censos , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , EscóciaRESUMO
BACKGROUND: The membrane frizzled-related protein (MFRP) gene is involved in axial length (AL) regulation and MFRP mutations cause nanophthalmos; also, the hepatocyte growth factor (HGF) gene is reported to result in morphologic changes of the anterior segment and abnormal aqueous regulation that increases the risk of primary angle-closure glaucoma (PACG), while the zinc ring finger 3 (ZNRF3) gene is associated with AL. The present study investigated the association of single nucleotide polymorphisms (SNPs) in ZNRF3, HGF and MFRP with PACG in a northern Chinese population, as well as the association of these SNPs with the ocular biometric parameters of anterior chamber depth (ACD) and AL. METHODS: A total of 500 PACG patients and 720 controls were recruited. All individuals were genotyped for 12 SNPs in three genes (rs7290117, rs2179129, rs4823006 and rs3178915 in ZNRF3; rs5745718, rs12536657, rs12540393, rs17427817 and rs3735520 in HGF, rs2510143, rs36015759 and rs3814762 in MFRP) using an improved multiplex ligation detection reaction (iMLDR) technique. Genotypic distribution was analyzed for Hardy-Weinberg equilibrium. Differences in the allelic and genotypic frequencies were evaluated and adjusted by age and sex. Linkage disequilibrium (LD) patterns were tested and haplotype analysis was conducted by a logistic regression model. Generalized estimation equation (GEE) analysis was conducted using SPSS for primary association testing between genotypes and ocular biometric parameters. Bonferroni corrections for multiple comparisons were performed, and the statistical power was calculated by power and sample size calculations. RESULTS: The rs7290117 SNP in ZNRF3 was significantly associated with the AL, with a p-value of 0.002. We did not observe any significant associations between the SNPs and PACG or ACD. In a stratification analysis by ethnicity, rs12540393 and rs17427817 in HGF showed a nominal association with PACG in the Hui cohort, although significance was lost after correction. CONCLUSIONS: The present study suggests rs7290117 in ZNRF3 may be involved in the regulation of AL, though our results do not support a contribution of the SNPs we tested in ZNRF3, HGF and MFRP to PACG in northern Chinese people. Further studies in a larger population are warranted to confirm this conclusion.
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Câmara Anterior/patologia , Povo Asiático , Comprimento Axial do Olho/patologia , Glaucoma de Ângulo Fechado/genética , Glaucoma de Ângulo Fechado/patologia , Fator de Crescimento de Hepatócito/genética , Proteínas de Membrana/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Biometria , Estudos de Casos e Controles , China , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Metallo-ß-lactamase gene blaVIM was identified on the chromosome of four Pseudomonas sp. isolates from a chicken farm, including one Pseudomonas aeruginosa isolate from a swallow (Yanornis martini), one Pseudomonas putida isolate from a fly, and two P. putida isolates from chickens. The four isolates shared two variants of blaVIM-carrying genomic contexts that resemble the corresponding regions of clinical metallo-ß-lactamase-producing Pseudomonas spp. Our study suggests that the surveillance of carbapenemase-producing bacteria in livestock and their surrounding environment is urgently needed.
Assuntos
Pseudomonas/enzimologia , Animais , Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , Galinhas , Testes de Sensibilidade Microbiana , Pseudomonas/efeitos dos fármacos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , beta-Lactamases/metabolismoRESUMO
BACKGROUND: There is little satisfactory evidence on the harm of safety incidents to patients, in terms of lost potential health and life-years. OBJECTIVE: To estimate the healthy life-years (HLYs) lost due to 6 incidents in English hospitals between the years 2005/2006 and 2009/2010, to compare burden across incidents, and estimate excess bed-days. RESEARCH DESIGN: The study used cross-sectional analysis of the medical records of all inpatients treated in 273 English hospitals. Patients with 6 types of preventable incidents were identified. Total attributable loss of HLYs was estimated through propensity score matching by considering the hypothetical remaining length and quality of life had the incident not occurred. RESULTS: The 6 incidents resulted in an annual loss of 68 HLYs and 934 excess bed-days per 100,000 population. Preventable pressure ulcers caused the loss of 26 HLYs and 555 excess bed-days annually. Deaths in low-mortality procedures resulted in 25 lost life-years and 42 bed-days. Deep-vein thrombosis/pulmonary embolisms cost 12 HLYs, and 240 bed-days. Postoperative sepsis, hip fractures, and central-line infections cost <6 HLYs and 100 bed-days each. DISCUSSION: The burden caused by the 6 incidents is roughly comparable with the UK burden of Multiple Sclerosis (80 DALYs per 100,000), HIV/AIDS and Tuberculosis (63 DALYs), and Cervical Cancer (58 DALYs). There were marked differences in the harm caused by the incidents, despite the public attention all of them receive. Decision makers can use the results to prioritize resources into further research and effective interventions.