During the period of rapid economic growth since the 1970s, Korea imported many polluting industrial facilities from Japan, resulting in the generation of huge amounts of hazardous waste. While the ...problems of environmental degradation such as these were an integral part of Korea’s development process, they have received only scant attention in the official history of the country’s economic development, often being dismissed as peripheral issues. This paper aims to go beyond this tendency by rewriting the history of economic growth that underlay the disputes caused by the importation of polluting industries from Japan in the 1970s. Its features can be summarized as follows.
First, Japan was the most damaging pollution exporter to Korea in the 1970s, and it was also the direct channel to import the knowledge of pollution, and alternative logic against the pollution issues.
Second, discussions over industrial pollution in the 1970s occurred in the antagonistic relationship between four groups: the government, media, opposition party, and scholars.
Third, a group of experts played various roles, including bureaucrats, researchers, and policy makers, leading the discussion of pollution in Korean society in the 1970s.
It has been well over 50 years since 1970. Nevertheless, Korean society still does not hesitate to create areas and people that become shadows in the wake of development. This explains why we should focus on the “sick body” rather than the “numbers” in this age of science and technology.
Wastewater treatment plants (WWTPs) constantly receive a wide variety of contaminants, including pharmaceuticals, and are potential reservoirs of antibiotic resistance genes (ARGs). This favors the ...development of multidrug-resistant bacteria (MRB) through horizontal gene transfer. Samples from five different WWTP processes were collected in September 2020 and January 2021 to monitor ARG resistomes and culturable MRB in the presence of eight different antibiotics. Nanopore-based ARG abundance and bacterial community analyses suggested that ARG accumulation favors the generation of MRB. Activated and mixed sludges tended to have lower bacterial diversity and ARG abundance because of selective forces that favored the growth of specific microorganisms during aeration processes. Escherichia strains enriched in WWTPs (up to 71%) were dominant in all the samples, whereas Cloacamonas species were highly abundant only in anaerobically digested sludge samples (60%–79%). Two ARG types sulfonamide resistance genes (sul1) and aminoglycoside resistance genes (aadA1, aadA13, and aadA2) were prevalent in all the processes. The total counts of culturable MRB, such as Niabella, Enterococcus, Bacillus, and Chryseobacterium species, gradually increased during aerobic WWTP processes. Genomic analyses of all MRB isolated from the samples revealed that the resistome of Enterococcus species harbored the highest number of ARGs (7–18 ARGs), commonly encoding ant(6)-la, lnu(B), erm(B), and tet(S/M). On the other hand, Niablella strains possibly had intrinsic resistant phenotypes without ARGs. All MRB possessed ARGs originating from the same mobile genetic elements, suggesting that WWTPs are hotspots for the migration of ARGs and emergence of MRB.
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•ARB and ARG subtypes decreased during WWTP; however, many MRB were still generated.•Transposon-mediated ARGs were most dominant in all WWTP processes.•Enterococcus and Chryseobacterium species were the main drivers for HGT of ARGs.•Several culturable MRB had either intrinsic resistance or unknown ARGs.
The rapid growth of cyanobacteria, particularly Microcystis aeruginosa, poses a significant threat to global water security. The proliferation of toxic Microcystis aeruginosa raises concerns due to ...its potential harm to human health and socioeconomic impacts. Dense blooms contribute to spatiotemporal inorganic carbon depletion, promoting interest in the roles of carbon-concentrating mechanisms (CCMs) for competitive carbon uptake. Despite the importance of HCO3− transporters, genetic evaluations and functional predictions in M. aeruginosa remain insufficient. In this study, we explored the diversity of HCO3− transporters in the genomes of 46 strains of M. aeruginosa, assessing positive selection for each. Intriguingly, although the Microcystis BicA transporter became a partial gene in 23 out of 46 genomic strains, we observed significant positive sites. Structural analyses, including predicted 2D and 3D models, confirmed the structural conservation of the Microcystis BicA transporter. Our findings suggest that the Microcystis BicA transport likely plays a crucial role in competitive carbon uptake, emphasizing its ecological significance. The ecological function of the Microcystis BicA transport in competitive growth during cyanobacterial blooms raises important questions. Future studies require experimental confirmation to better understand the role of the Microcysits BicA transporter in cyanobacterial blooms dynamics.
•The HCO3− transporters of M. aeruginosa were investigated in the genomes of 46 strains.•The presence of three transporters, BicA, SbtA, and BCT1, was inconsistent among strains.•Synteny analysis of the loci of bicA–sbtA genes resulted in a variety of combinations.•In the PAML analysis, the BicA transporter revealed six sites under positive selection.•The carbon binding sites of Microcystis BicA were structurally well conserved.
The emergence of multidrug resistance (MDR) has become a global health threat due to the increasing unnecessary use of antibiotics. Multidrug resistant bacteria occur mainly by accumulating ...resistance genes on mobile genetic elements (MGEs), made possible by horizontal gene transfer (HGT). Humans and animal guts along with natural and engineered environments such as wastewater treatment plants and manured soils have proven to be the major reservoirs and hotspots of spreading antibiotic resistance genes (ARGs). As those environments support the dissemination of MGEs through the complex interactions that take place at the human-animal-environment interfaces, a growing One Health challenge is for multiple sectors to communicate and work together to prevent the emergence and spread of MDR bacteria. However, maintenance of ARGs in a bacterial chromosome and/or plasmids in the environments might place energy burdens on bacterial fitness in the absence of antibiotics, and those unnecessary ARGs could eventually be lost. This review highlights and summarizes the current investigations into the gain and loss of ARG genes in MDR bacteria among human-animal-environment interfaces. We also suggest alternative treatments such as combinatory therapies or sequential use of different classes of antibiotics/adjuvants, treatment with enzyme-inhibitors, and phage therapy with antibiotics to solve the MDR problem from the perspective of One Health issues.
Microprocessor, composed of DROSHA and its cofactor DGCR8, initiates microRNA (miRNA) biogenesis by processing the primary transcripts of miRNA (pri-miRNAs). Here we investigate the mechanism by ...which Microprocessor selects the cleavage site with single-nucleotide precision, which is crucial for the specificity and functionality of miRNAs. By testing ∼40,000 pri-miRNA variants, we find that for some pri-miRNAs the cleavage site is dictated mainly by the mGHG motif embedded in the lower stem region of pri-miRNA. Structural modeling and deep-sequencing-based complementation experiments show that the double-stranded RNA-binding domain (dsRBD) of DROSHA recognizes mGHG to place the catalytic center in the appropriate position. The mGHG motif as well as the mGHG-recognizing residues in DROSHA dsRBD are conserved across eumetazoans, suggesting that this mechanism emerged in an early ancestor of the animal lineage. Our findings provide a basis for the understanding of miRNA biogenesis and rational design of accurate small-RNA-based gene silencing.
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•The mGHG motif can dictate the cleavage site with single-nucleotide precision•Processing site of primary microRNA is determined by DROSHA rather than DGCR8•The dsRBD of DROSHA recognizes the mGHG motif
Target specificity of microRNA is determined by DROSHA cleavage sites. Kwon et al. show how DROSHA precisely selects the cleavage sites using the interaction between its double-stranded RNA-binding domain (dsRBD) and the mGHG motif of the primary microRNA.
Order-preserving encryption (OPE) produces ciphertexts that preserve the numerical order of plaintexts. Many researchers have focused on designing ideally-secure OPE schemes. This security notion, ...known as IND-OCPA, has been shown to be achievable by the mutability of ciphertexts and interaction between a database server and a client. This implies that the ciphertexts stored on the server can be updated. Unfortunately, existing update algorithms of mutable OPE schemes are designed to generate ciphertexts uniformly regardless of the distribution of the plaintexts. This leads to inefficiency that requires frequent ciphertext updates for a certain input data pattern (e.g., sequential data). In this paper, we propose a more efficient ciphertext update algorithm that is suitable for mutable OPE schemes. This algorithm makes it possible to reduce the number of updates by considering the input pattern of encrypted data without loss of security. Our experimental results show that, when applied to existing mutable OPE schemes, our update algorithm delivers significantly improved performance on a variety of datasets.
Modification of the outer membrane charge by a polymyxin B (PMB)-induced PmrAB two-component system appears to be a dominant phenomenon in PMB-resistant Acinetobacter baumannii. PMB-resistant ...variants and many clinical isolates also appeared to produce outer membrane vesicles (OMVs). Genomic, transcriptomic, and proteomic analyses revealed that upregulation of the pmr operon and decreased membrane-linkage proteins (OmpA, OmpW, and BamE) are linked to overproduction of OMVs, which also promoted enhanced biofilm formation. The addition of OMVs from PMB-resistant variants into the cultures of PMB-susceptible A. baumannii and the clinical isolates protected these susceptible bacteria from PMB. Taxonomic profiling of in vitro human gut microbiomes under anaerobic conditions demonstrated that OMVs completely protected the microbial community against PMB treatment. A Galleria mellonella-infection model with PMB treatment showed that OMVs increased the mortality rate of larvae by protecting A. baumannii from PMB. Taken together, OMVs released from A. baumannii functioned as decoys against PMB.
We present a new optical method for the detection of defect in dielectric materials. This method is based on the optical visualization of the microwave near-field distribution around defects in a ...dielectric material. In this study, we visualized the microwave near-field distributions in various types of defects in dielectric plates through thermoelastic optical indicator microscopy. The experimental results showed that the microwave near-field distribution around the defect appears in various forms depending on the structure of the defect. From the experimental results, it was shown that the present method can provide information on the position and structure of defects in dielectric materials in a non-contact, non-invasive and non-destructive manner.
The presence or absence of BlsA, a protein with a blue light-sensing flavin domain in the genomes of Acinetobacter species has aroused curiosity about its roles in the regulation of bacterial ...lifestyle under light. Genomic and transcriptomic analyses revealed the loss of BlsA in several multidrug-resistant (MDR) A. baumannii strains as well as the light-mediated induction of
, along with a possible BlsA-interacting partner BipA. Their direct
interactions were verified using a bacterial two-hybrid system. The results demonstrated that the C-terminal region of BipA could bind to the C-terminal residues of BlsA under blue light at 23°C but not at 37°C. Genetic manipulations of
and
revealed that the coexistence of BlsA and BipA was required to induce the light-dependent expression of
in A. baumannii ATCC 17978 at 23°C. The same phenomenon occurred in the BlsA-deficient MDR strain in our functional complementation assay; however, the underlying molecular mechanism remains poorly understood. BlsA-modulated amounts of OmpA, the most abundant porin, in the outer membrane affected the membrane integrity and permeability of small molecules. Dark conditions or the deletion of
made the membrane more permeable to lipophilic ethidium bromide (EtBr) but not to meropenem. Interestingly, light illumination and low temperature conditions made the cells more sensitive to meropenem; however, this bactericidal effect was not noted in the
mutant or in the BlsA-deficient MDR strains. Light-mediated cell death and the reduction of biofilm formation at 23°C were abolished in the
mutant strain, suggesting multifaceted roles of BlsA in A. baumannii strains.
Little is known about the functional roles of BlsA and its interacting partners in Acinetobacter species. Intriguingly, no BlsA homolog was found in several clinical isolates, suggesting that BlsA was not required inside the host because of the lack of blue light and the warm temperature conditions. As many chromophore-harboring proteins interact with various partners to control light-dependent cellular behaviors, the maintenance of
in the genomes of many Acinetobacter species during their evolution may be beneficial when fluctuations occur in two important environmental factors: light and temperature. Our study is the first to report the novel protein partner of BlsA, namely, BipA, and its contribution to multiple phenotypic changes, including meropenem resistance and biofilm formation. Rapid physiological acclimation to changing light or temperature conditions may be possible in the presence of the light-sensing BlsA protein, which may have more interacting partners than expected.
Water-borne diseases are usually caused by the fecal-oral transmission of human fecal pathogens. Traditionally, coliforms and enterococci are widely used as indicator bacteria, but they do not allow ...to differentiate between human and animal fecal contamination. Owing to its presence only in the human gut environment, crAssphage has been suggested as an alternative indicator of human fecal contamination to overcome the above challenges. In this study, 139 human and 89 animal fecal samples (e.g., chicken, cow, dog, pig, pigeon, and mouse) were collected. For the rapid detection of human crAssphage in fecal samples, quantitative real-time PCR (qPCR) was performed using five different oligonucleotide primer/probe combinations. These included three previously reported oligonucleotide primer/probe combinations (RQ, CPQ056, and CrAssBP) and two newly developed combinations (ORF00018-targeting CrAssPFL1 and ORF00044-targeting CrAssPFL2). The detection rate (crAssphage-positive rate) in human fecal samples were 23.0, 30.2, 28.8, 20.1, and 30.9%, respectively, suggesting CrAssPFL2 showed the highest detection rate. Furthermore, the lowest copy numbers (436.16 copy numbers) could be detected using the CrAssPFL2 combination. Interestingly, no difference in crAssphage detection rates was found between healthy people and intestinal inflammatory patients. As expected, no crAssphage was detected in any animal fecal samples, indicating its human specificity. Furthermore, qPCR analysis of sewage samples collected from five different sewage treatment plants revealed that they were all contaminated with 10
copy numbers/mL of crAssphage on average. The simulation test of crAssphage-contaminated food samples also confirmed that the detection limit was from 10
copy numbers of crAssphage in foods. Therefore, the newly developed and optimized qPCR would be useful for the sensitive detection of crAssphage while identifying the source of human fecal contamination.
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