Hydramethylnon induces mitochondria-mediated apoptosis in BEAS-2B human bronchial epithelial cells.

Typically used household chemicals comprise numerous compounds. Determining mixture toxicity, as observed when using household chemicals containing multiple substances, is of considerable importance from a regulatory perspective. Upon examining the toxic effects of household chemical mixtures, we observed that hydramethylnon combined with tetramethrin resulted in synergistic toxicity. To determine the unknown toxicity mechanism of hydramethylnon, which carries the risk of inhalation exposure when using household chemicals, we conducted a further investigation using BEAS-2B cells, a human bronchial epithelial cell line. Hydramethylnon-induced cytotoxicity was determined following 24 and 48 h of exposure using the water-soluble tetrazolium 1 and lactate dehydrogenase assays. To elucidate the toxicity mechanism, we utilized flow cytometry and measured the levels of apoptosis-related proteins and caspase activities. Given that hydramethylnon, as an insecticide, disrupts the mitochondrial electron transfer chain, we analyzed the relevant mechanisms, including mitochondrial superoxide levels as well as the mitochondrial membrane potential (MMP). Hydramethylnon dose-dependently induced BEAS-2B cell apoptosis via the intrinsic pathway. Furthermore, it significantly increased mitochondrial superoxide levels and disrupted the MMP. Pre-treatment with a caspase inhibitor (Z-DEVD-FMK) confirmed that hydramethylnon induced caspase-dependent apoptosis. Apoptosis, a key event in the toxicological process of chemicals, can lead to lung diseases, including fibrosis and cancer. The results of the present study suggest a mechanism of toxicity of hydramethrylnon, an organofluorine biocide whose toxicity has been little studied, to the lung epithelium. Considering the potential risks associated with inhalation exposure, these results highlight the need for careful management and regulation of hydramethylnon.

Cluster of serogroup W-135 meningococcal disease in 3 military recruits.

We describe a group of 3 cases of invasive meningococcal disease that occurred in a military training camp in April 2011. All three patients were hospitalized. Ultimately, two patients recovered and one died. One patient had meningitis, one patient had septicemia and meningitis, and the other had no definite septicemia or meningitis. Neisseria meningitidis serogroup W-135 was detected in the serum and cerebrospinal fluid (CSF) of all patients by real-time polymerase chain reaction. In the one case of mortality, two strains were isolated from the patient's blood and CSF. Using multilocus sequence typing analysis, these strains were identified as a novel sequence type, ST-8912. Special attention is required for the meningococcal disease in military camp because the military personnels are in high risk of contact transmission.

Comparative proteomic label-free analysis of Campylobacter jejuni NCTC 11168 cultured with porcine mucin.

Campylobacter jejuni is a major gastrointestinal pathogen in humans. Poultry is a primary reservoir for C. jejuni, and C. jejuni appears to be highly adapted to the gastrointestinal tracts of avian species. We determined the protein expression profiles of C. jejuni NCTC 11168 cultured in medium containing porcine mucin. Differentially expressed proteins in the presence and absence of porcine mucin were identified using the label-free method. We identified 52 proteins with expression that was either upregulated (32 proteins) or downregulated (20 proteins) by porcine mucin. These proteins are involved in diverse cellular functions, such as motility, cell wall synthesis, iron transport, energy production, and amino acid metabolism. In particular, the upregulated proteins were involved in chemotaxis (CheV and CetA), motility (FlaA), colonization and adherence (CadF, FrdA, CfrA, MapA, and HydA), and stress tolerance (TrxB and ClpB). These results suggest that C. jejuni changes its protein expression in response to porcine mucin and that this change in expression may contribute to host adaptation of C. jejuni NCTC 11168.

Hepatoprotective effects of paeonol by suppressing hepatic stellate cell activation via inhibition of SMAD2/3 and STAT3 pathways.

Hepatic stellate cell (HSC) activation is a key event in extracellular matrix accumulation, causing hepatic fibrosis. Therefore, identifying chemicals that inhibit HSC activation is an important therapeutic strategy for hepatic fibrosis. The aim of this study was to investigate the therapeutic effects of paeonol on HSC activation. In LX-2 cells, paeonol inhibited the expression of collagen and decreased the expression of HSC activation markers. In mice with thioacetamide-induced liver fibrosis, paeonol treatment decreased the serum levels of aspartate aminotransferase and alanine transaminase and mRNA expression of α-smooth muscle actin, platelet-derived growth factor-ß, and connective-tissue growth factor. Investigation of the underlying molecular mechanism of paeonol showed that paeonol inhibits the SMAD2/3 and STAT3 signaling pathways that are important for HSC activation. On the basis of these results, paeonol should be investigated and developed further for hepatic fibrosis treatment. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01440-9.

Macrolide resistance of Mycoplasma pneumoniae, South Korea, 2000-2011.

In Korea, Mycoplasma pneumoniae was detected in 255/2,089 respiratory specimens collected during 2000-2011; 80 isolates carried 23S rRNA gene mutations, and 69/123 culture-positive samples with the mutation were resistant to 5 macrolides. During 2000-2011, prevalence of the mutation increased substantially. These findings have critical implications for the treatment of children with mycoplasma pneumonia.

Structural analysis and serological test of arginine periplasmic binding protein 2 from Chlamydophila pneumoniae.

The 'art' genes encode specific arginine uptake proteins, and are repressed by the repressible promoters of ArgR, affecting transcription of artJ. Cpb0502, the arginine-binding periplasmic protein 2 precursor from Chlamydophila pneumoniae TW-183 strains, is responsible for arginine transport. As C. pneumoniae is difficult to isolate and culture, there have been many studies of better ways to detect it. A microimmunofluorescence assay (MIF) is still considered to be the 'gold standard' for detecting C. pneumoniae. Although MIF has its own limitations, a number of immunogenic antigens have been shown to be C. pneumoniae specific by this test. Here, we report Cpb0502 as a specific immunogenic antigen against C. pneumoniae as it was detected only in human infection sera of C. pneumoniae but not in Legionella pneumophila and Mycoplasma pneumoniae infection sera, showing high specificity and sensitivity by MIF, western blot and ELISA analysis. And also the crystal structure of Cpb0502 was determined to be a dimer at 2.07Å, revealing a similar backbone structure to a histidine kinase receptor, HK29S. Therefore we may suggest that Cpb0502 is a candidate immunogenic antigen for better diagnosis of C. pneumoniae.

(1)H NMR-based metabolomic profiling in mice infected with Mycobacterium tuberculosis.

Tuberculosis (TB) is one of three major infectious diseases, and the control of TB is becoming more difficult because of the emergence of multidrug-resistant and extensively drug-resistant strains. In this study, we explored the (1)H NMR-based metabolomics of TB using an aerobic TB infection model. Global profiling was applied to characterize the responses of C57Bl/6 mice to an aerobic infection with virulent Mycobacterium tuberculosis (MTB). The metabolic changes in organs (i.e., the lung, the target organ of TB, and the spleen and liver, remote systemic organs) and in serum from control and MTB-infected rats were investigated to clarify the host-pathogen interactions in MTB-infected host systems. Principal components analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) score plots showed distinct separation between control and MTB-infected rats for all tissue and serum samples. Several tissue and serum metabolites were changed in MTB-infected rats, as compared to control rats. The precursors of membrane phospholipids, phosphocholine, and phosphoethanolamine, as well as glycolysis, amino acid metabolism, nucleotide metabolism, and the antioxidative stress response were altered based on the presence of MTB infection. This study suggests that NMR-based global metabolite profiling of organ tissues and serum could provide insight into the metabolic changes in host infected aerobically with virulent Mycobacterium tuberculosis.

Distribution of Legionella species from environmental water sources of public facilities and genetic diversity of L. pneumophila serogroup 1 in South Korea.

A total of 560 Legionella species were isolated from environmental water sources from public facilities from June to September 2008 throughout South Korea. The distribution of Legionella isolates was investigated according to geographical region, facility type, and sample type. The genetic diversity of 104 isolates of Legionella pneumophila serogroup 1 (sg 1) was analyzed by sequence-based typing (SBT). L. pneumophila was distributed broadly throughout Korea, accounting for 85.0% of the isolates, and L. pneumophila sg 1 predominated in all of the public facilities except for the springs. Legionella anisa and Legionella bozemanii predominated among non-L. pneumophila species (48.1% and 21.0%, respectively). The second most dominant strain differed depending on the facility type: L. anisa was the second most dominant strain in the buildings (10.8%), L. pneumophila sg 5 in public baths (21.6%), L. pneumophila sg 6 in factories (12.0%), and L. pneumophila sg 7 in hospitals (13.1%). In the SBT analysis, 104 L. pneumophila sg 1 isolates were differentiated into 26 sequence types (STs) and categorized into 3 clonal groups (CGs) and 10 singleton STs via the eBURST V3 program. ST1, a potential founder of major CG1, was commonly distributed (48.1%). The dominant ST in hot water was ST-K1 (7, 12, 17, 3, 35, 11, 11), which was designated in this study (36.1%). The second most dominant strain differed depending on the type of facility from which the samples were obtained. The unique allelic profile of ST-K1, obtained from hot water, was not found in the European Working Group for Legionella Infections (EWGLI) SBT database.

Novel diagnostic algorithm using tuf gene amplification and restriction fragment length polymorphism is promising tool for identification of nontuberculous mycobacteria.

Nontuberculous mycobacteria (NTM) are a major cause of opportunistic infections in immunocompromised patients, making the reliable and rapid identification of NTM to the species level very important for the treatment of such patients. Therefore, this study evaluated the usefulness of the novel target genes tuf and tmRNA for the identification of NTM to the species level, using a PCRrestriction fragment length polymorphism analysis (PRA). A total of 44 reference strains and 17 clinical isolates of the genus Mycobacterium were used. The 741 bp or 744 bp tuf genes were amplified, restricted with two restriction enzymes (HaeIII/MboI), and sequenced. The tuf gene-PRA patterns were compared with those for the tmRNA (AvaII), hsp65 (HaeIII/HphI), rpoB (MspI/HaeIII), and 16S rRNA (HaeIII) genes. For the reference strains, the tuf gene-PRA yielded 43 HaeIII patterns, of which 35 (81.4%) showed unique patterns on the species level, whereas the tmRNA, hsp65, rpoB, and 16S rRNA-PRAs only showed 10 (23.3%), 32 (74.4%), 19 (44.2%), and 3 (7%) unique patterns after single digestion, respectively. The tuf gene-PRA produced a clear distinction between closely related NTM species, such as M. abscessus (557-84- 58) and M. chelonae (477-84-80-58), and M. kansasii (141- 136-80-63-58-54-51) and M. gastri (141-136-117-80-58-51). No difference was observed between the tuf-PRA patterns for the reference strains and clinical isolates. Thus, a diagnostic algorithm using a tuf gene-targeting PRA is a promising tool with more advantages than the previously used hsp65, rpoB, and 16S rRNA genes for the identification of NTM to the species level.

Correction: HIF-1α:CRAT:miR-144-3p axis dysregulation promotes osteoarthritis chondrocyte apoptosis and VLCFA accumulation.

[This corrects the article DOI: 10.18632/oncotarget.20615.].

Targeting the rpoB gene using nested PCR-restriction fragment length polymorphism for identification of nontuberculous mycobacteria in hospital tap water.

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and can cause nosocomial infections in immunocompromised patients. Recently the presence of NTM in public drinking water and hospital water distribution systems has been reported. Their ability to form biofilms and their resistance to chlorine both contribute to their survival and colonization in water distribution systems. Here we analyzed thirty-two hospital tap water samples that were collected from different locations in three hospitals so as to evaluate the prevalence of NTM species. The water samples were concentrated by membrane filtration and then eluted with sterilized water following sonication. Two-step direct PCR targeting the rpoB gene, restriction fragment length polymorphism (RFLP) using the MspI restriction enzyme, and sequence analysis were performed for identification of NTM to the species level. The sequences of each PCR product were analyzed using BLASTN. Seven samples (7/32, 21.9%) were positive for NTM as determined by nested-PCR. The PCR-RFLP results indicated five different patterns among the seven positive PCR samples. The water-born NTM were identified, including M. peregrinum, M. chelonae (2 cases), M. abscessus, M. gordonae (2 cases), and Mycobacterium sp. JLS. The direct two-step PCR-RFLP method targeting the rpoB gene was effective for the detection and the differentiation of NTM species from hospital tap water.

Prevalence of antibodies in response to Legionella species, analysis of a healthy population from Jeollanam-do Province, Korea.

Seroepidemological investigation of antibodies to Legionella species in 500 healthy individuals from a single geographical location in Korea was conducted by indirect fluorescent antibody assay (IFA). Considering an antibody titer of > or =1:128 as positive reaction, 15.2% of total sera were positive. In males and females older than 40 years old, levels of IgM and IgG were 1.2% and 14%, respectively. The sera with antibody titers of > or =1:128 to Legionella species accounted for 85 sera, and 9 sera of these were reacted to more than one Legionella species. Reactivity to L. bozemanii, L. micdadei, L. longbeachae, L. pneumophila sg 6, and L. gormanii were 32.9%, 20%, 15%, 10.6%, and 8%, respectively. However, L. pneumophila sg 1, sg 2, and sg 3 did not react to any sera. Serological analysis revealed that the level of antibody in response to L. bozemanii was more prevalent than L. pneumophila. Our results suggest that the antibodies of non-L. pneumophila species, such as L. bozemanii, may be highly prevalent in healthy population within Korea. Although conclusions based on the findings of this study must be cautiously considered given that the population sampled were sourced from a single province, we have added to the knowledge base of serodiagnosis of infections due to non-L. pneumophila species in Korea.

Serological and genetic characterization of meningococcal isolates in Korea.

Meningococcal disease has been regarded as a very rare infection in Korea. Until now, there have been no reports on the serological or genetic characterization of Neisseria meningitidis isolates in Korea. This study was the first report of the serogroup, PorA VR subtype, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and antimicrobial susceptibility of N. meningitidis isolates collected from 2002 to 2003. Of 11 meningococcal isolates, serogroup Y was found to be the most frequent (nine isolates). In addition, one isolate was from serogroup B and one was from serogroup 29E. Four isolates showed a reduced sensitivity to penicillin G. However, all strains tested were susceptible to chloramphenicol, cefotaxime, ciprofloxacin, and rifampin. Among the 11 isolates, seven PorA types were identified. P1.5-1, 2-2 was the most prevalent PorA type, accounting for 55.6% of the serogroup Y isolates. In terms of PFGE patterns, nine isolates of serogroup Y were divided into three clusters, but the isolates shared a high level of PFGE pattern similarity. The serogroup Y isolates were characterized as ST-1625 (five strains) and ST-23 (four). They belonged to the ST-23 complex/Cluster A3. In this study, the ST-23 complex/Cluster A3 was prevalent, with the PorA type P1.5-1, 2-2 accounting for 55.6% of the nine serogroup Y strains. Also, we identified the hypervirulent lineage strain such as ST-6667 of ST-41/44 complex/Lineage 3 in Korea. The results of this study show the need for comprehensive epidemiological surveillance to monitor any changes in the meningococcal disease situation so that prompt intervention can be initiated.

HIF-1α:CRAT:miR-144-3p axis dysregulation promotes osteoarthritis chondrocyte apoptosis and VLCFA accumulation.

The functional role(s) of peroxisomes in osteoarthritis remains unclear. We demonstrated that peroxisomal dysfunction in osteoarthritis is responsible for very-long-chain fatty acid (VLCFA) accumulation. Through gene-profiling analyses, we identified CRAT as the gene responsible for this event. CRAT expression was suppressed in osteoarthritis chondrocytes, and its knockdown yielded pathological osteoarthritic characteristics, including VLCFA accumulation, apoptosis, autophagic inhibition, and mitochondrial dysfunction. Subsequent miRNA profiling revealed that peroxisomal dysfunction upregulates miR-144-3p, which overlapped with the osteoarthritis pathological characteristics observed upon CRAT knockdown. Moreover, knocking down HIF-1α in normal chondrocytes suppressed CRAT expression while stimulating miR-144-3p. Our data indicate that deregulation of a HIF-1a:CRAT:miR-144-3p axis impairs peroxisomal function during the pathogenesis of osteoarthritis.

Surveillance of bacterial pathogens associated with acute diarrheal disease in the Republic of Korea during one year, 2003.

An epidemiological survey of human enterobacterial infections was conducted to determine the prevalence of enteropathogens in the Republic of Korea during one year, 2003. We tested for infectious diseases in 26,992 stool samples obtained from people who visited clinics located in six big cities and six rural provinces. From these samples, we isolated 1,291 cases of enteritis bacterial infection (4.8%). In the urban areas, 821 cases of bacterial infection (6.4%) were identified and, in the rural areas, 479 bacterial strains (3.3%) were isolated. Seasonal patterns were seen for diarrhea associated with S. aureus, E. coli and V. parahaemolyticus, while Salmonella and Shigella infections showed slight seasonal variation. We found that S. aureus and Salmonella were more frequently isolated from children and the elderly; however, the prevalence of E. coli, V. parahaemolyticus, and Shigella were similar in different age groups. Routine monitoring of these infections is considered a worthwhile means by which to elucidate their epidemiology and modes of transmission and ultimately to control them more effectively. Continuous laboratory-based surveillance for findings of enteritis bacterial infection should be emphasized in the prevention of these infections.

Genome Sequence of Bacteriophage GG32, Which Can Infect both Salmonella enterica Serovar Typhimurium and Escherichia coli O157:H7.

We report here a new virulent Salmonella enterica serovar Typhimurium (S Typhimurium) bacteriophage, GG32, which was isolated from the Guem River in the Republic of Korea. The strain can infect both S Typhimurium and Escherichia coli (E. coli) O157:H7 and may be a good candidate for a bio-control agent.

Complete Genome Sequence of Bacteriophage MA12, Which Infects both Campylobacter jejuni and Salmonella enterica Serovar Enteritidis.

Here, we announce the complete genome sequence of Salmonella enterica serovar Enteritidis (S Enteritidis) bacteriophage MA12, a 41-Kb chromosome. The strain can infect both Campylobacter jejuni (C. jejuni) and S Enteritidis and can be used in phage therapy experiments with poultry and poultry meat.

Down-regulation of Phospholipase D Stimulates Death of Lung Cancer Cells Involving Up-regulation of the Long ncRNA ANRIL.

Dysregulation of phospholipase D (PLD) has been found in several types of human cancer, but the underlying regulatory mechanism remains poorly-understood. Herein we found PLD inhibition in human H460 lung cancer cells has anti-tumorigenic effects such as stimulation of apoptosis and autophagy. In the present study, in order to identify the responsible key regulator of these anti-tumorigenic effects of PLD inhibition, we analyzed the expression levels of 90 long non-coding RNAs (lncRNAs). Among them, the expression level of antisense noncoding RNA in the INK4 locus (ANRIL) was increased up to 13.6-fold by PLD inhibition in H460 human lung cancer cells. Moreover, knockdown of ANRIL using its specific small-interfering RNA significantly suppressed PLD inhibition-induced apoptosis. Collectively, our findings showed that ANRIL is an lncRNA responsible in anti-tumorigenesis caused by PLD inhibition and combined incorporation of ANRIL into PLD inhibition-induced anti-tumorigenic signaling network could be a new effective therapeutic approach for controlling lung cancer.

Beneficial reward-to-risk action of glucosamine during pathogenesis of osteoarthritis.

OBJECTIVE: Glucosamine is widely used to improve the symptoms and to delay the structural progression of osteoarthritis. However, its efficacy in osteoarthritis has been controversial and its underlying mechanism of action remains unclear. The aim of this study was to investigate the effects of glucosamine and the underlying mechanisms in human chondrocytes. METHODS: Chondrocytes from normal human articular cartilage were treated with glucosamine (10-100 mM). Subsequently, cell death was analyzed by Annexin V staining and FACS and mitochondrial function was studied by measuring the mitopotential. Peroxisomal function was analyzed by BODIPY staining, and gene expression of PMP70 and acyl-CoA oxidase 1, by real-time PCR. Total lipids were analyzed by gas chromatography/mass spectrometry. Autophagy activation was determined by western blotting of beclin and light chain 3B. Autophagosome formation was analyzed by introduction of green fluorescent protein (GFP) LC3, and pexophagy was determined by introduction of mRFP-EGFP-SKL plasmids. RESULTS: Treatment of chondrocytes with glucosamine exerts exposure time-dependent dual effects on apoptosis/autophagy. Short time exposure of glucosamine to chondrocytes activated autophagy, pexophagy, and peroxidation. On the other hand, long time exposure of glucosamine had opposite effects, namely accumulation of very long chain fatty acids and peroxisomal dysfunction. CONCLUSION: We highlight the dual role of glucosamine in apoptosis/autophagy in human chondrocytes depending on exposure time. Although further research is required to fully understand the dual effects of glucosamine, dosage and duration of glucosamine treatment are clear contributing factors towards the line of beneficial reward-to-risk action.

Epidemics of Norovirus GII.4 Variant in Outbreak Cases in Korea, 2004-2012.

Norovirus GII.4 is recognized as a worldwide cause of nonbacterial outbreaks. In particular, the GII.4 variant occurs every 2-3 years according to antigenic variation. The aim of our study was to identify GII.4 variants in outbreaks in Korea during 2004-2012. Partial VP1 sequence of norovirus GII.4-related outbreaks during 2004-2012 was analyzed. The partial VP1 sequence was detected with reverse transcription-polymerase chain reaction, seminested polymerase chain reaction, and nucleotide sequence of 312-314 base pairs for phylogenetic comparison. Nine variants emerged in outbreaks, with the Sydney variant showing predominance recently. This predominance may persist for at least 3 years, although new variants may appear in Korea.