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The objective of this study was to evaluate anti-obesity effects of kimchi microbial community (KMC) on obesity and gut microbiota using a high fat diet-induced mouse model compared to effects of a single strain. Administration of KMC decreased body weight, adipose tissue, and liver weight gains. Relative content of Muribaculaceae in the gut of the KMC-treated group was higher than that in the high-fat diet (HFD) group whereas relative contents of Akkermansiaceae, Coriobacteriaceae, and Erysipelotrichaceae were lower in KMC-treated group. Metabolic profile of blood was found to change differently according to the administration of KMC and a single strain of Lactobacillus plantarum. Serum metabolites significantly increased in the HFD group but decreased in the KMC-treated group included arachidic acid, stearic acid, fumaric acid, and glucose, suggesting that the administration of KMC could influence energy metabolism. The main genus in KMC was not detected in guts of mice in KMC-treated group. Since the use of KMC has advantages in terms of safety, it has potential to improve gut microbial community for obese people.

Humans carry numerous symbiotic microorganisms in their body, most of which are present in the gut. Although recent technological advances have produced extensive research data on gut microbiota, there are various confounding factors (e.g., diet, race, medications) to consider. Sex is one of the important variables affecting the gut microbiota, but the association has not yet been sufficiently investigated. Although the results are inconsistent, several animal and human studies have shown sex differences in gut microbiota. Herein, we review these studies to discuss the sex-dependent differences as well as the possible mechanisms involved.

(1) Background: The intestinal microbiota plays an essential role in maintaining the host’s health. Dysbiosis of the equine hindgut microbiota can alter the fermentation patterns and cause metabolic disorders. (2) Methods: This study compared the fecal microbiota composition of horses with intestinal disease and their healthy counterparts living in Korea using 16S rRNA sequencing from fecal samples. A total of 52 fecal samples were collected and divided into three groups: horses with large intestinal disease (n = 20), horses with small intestinal disease (n = 8), and healthy horses (n = 24). (3) Results: Horses with intestinal diseases had fewer species and a less diverse bacterial population than healthy horses. Lactic acid bacteria, Lachnospiraceae, and Lactobacillaceae were overgrown in horses with large intestinal colic. The Firmicutes to Bacteroidetes ratio (F/B), which is a relevant marker of gut dysbiosis, was 1.94, 2.37, and 1.74 for horses with large intestinal colic, small intestinal colic, and healthy horses, respectively. (4) Conclusions: The overgrowth of two lactic acid bacteria families, Lachnospiraceae and Lactobacillaceae, led to a decrease in hindgut pH that interfered with normal fermentation, which might cause large intestinal colic. The overgrowth of Streptococcus also led to a decrease in pH in the hindgut, which suppressed the proliferation of the methanogen and reduced methanogenesis in horses with small intestinal colic.

Antibiotic resistance in soil environment has eminently been compared and studied between agricultural and pristine soils, and the role of concentrated animal feeding operations has markedly been recognized as one of the major sources of antibiotic resistance. This study described the tetracycline resistance in small-scale farms in pursuit of presenting its possible role and contribution to the persistence of antibiotic resistance in the environment. Results of the study would render additional information on the occurrence of the ribosomal protection protein (RPP) tet genes among the isolated bacteria from the selected agricultural soils. Four tetracycline resistance and RPP genes were determined in two different agricultural soil settings. Both the culture and molecular method were used to determine and measure tetracycline resistance in soils from arable land and animal house. Results revealed a significantly higher number of culturable antibiotic-resistant bacteria in animal houses than arable lands which was suggestive of higher antibiotic resistance in areas where there was direct administration of the antibiotics. However, quantification of the gene copy numbers in the agricultural soils indicated a different result. Higher gene copy number of tetO was determined in one animal house (IAH-3), while the two other tet genes tetQ and tetW were found to be higher in arable lands. Of the total 110 bacterial isolates, tetW gene was frequently detected, while tetO gene was absent in any of the culturable bacterial isolates. Principal component analysis of occurrence and gene copy number of RPP tet genes tetO, tetQ, and tetW also revealed highest abundance of RPP tet genes in the manure and arable soils. Another important highlight of this study was the similarity of the RPP tet genes detected in the isolated bacteria from the agricultural soils to the identified RPP tet genes among pathogenic bacteria. Some of the tetracycline-resistant bacterial isolates were also multidrug resistant as it displayed resistance to tetracycline, erythromycin, and streptomycin using disk diffusion testing.

Probiotics and prebiotics are commonly used to improve the gut microbiota. Since prebiotics can support the growth of probiotics, co-administration of these is called synbiotics. It has been demonstrated that obesity-induced gut dysbiosis can worsen inflammatory bowel disease symptoms. This study evaluated how modulation of gut microbiota with Schizophyllum commune-derived β-glucan (BG), probiotics (PRO), and synbiotics containing both BG and PRO (SYN) could improve the symptoms of obesity-associated colitis and hepatic manifestation. Mice were fed a normal diet (ND), high-fat diet (HFD), and HFD with different additives (BG, PRO, and SYN) for 12 weeks, followed by 5 days of colitis induction. Mice were sacrificed before and after colitis induction. During the experiment, body weight, food and water consumption, and rectal bleeding were monitored. Proteins from the colon were subjected to western blotting, and serum biomarkers such as alanine transaminase, alkaline phosphatase, triglycerides, and total cholesterol were analyzed. Colon and liver samples were sectioned for histological analysis. The fecal microbiota was analyzed based on partial 16S rRNA gene sequences. Although BG and PRO secured intestinal tight junctions, these two treatments did not modulate inflammatory cell infiltration and inflammatory markers (i.e., IL-6 and TNF-α). In contrast, SYN demonstrated stronger and broader effects in reducing colonic inflammation. While BG treatment increased the abundance of indigenous Lactobacillus, PRO treatment decreased bacterial diversity by suppressing the growth of several species of bacteria. SYN treatment groups, however, supported the growth of both indigenous and supplemented bacteria while maintaining bacterial diversity. Obesity-associated colitis can be improved by modulating gut bacteria with β-glucan and probiotics. The co-administration of both outperformed β-glucan and probiotic treatment alone by fostering both indigenous and supplemented probiotic strains.

Metabolic syndrome is associated with usual dietary patterns that may be involved in enterotypes. We aimed to understand the potential relationship of enterotypes and dietary patterns to influence metabolic syndrome in the Koreans. Using the Korea National Health and Nutrition Examination Survey (KNHANES)-VI in 2014, metabolic parameters were also analyzed among the dietary patterns classified by principal component analysis in Korean adults. The fecal microbiota data of 1199 Korean adults collected in 2014 were obtained from the Korea Centers for Disease Control and Prevention. Enterotypes were classified based on Dirichlet multinomial mixtures (DMM) by Mothur v.1.36. The functional abundance of fecal bacteria was analyzed using the PICRUSt2 pipeline. Korean adults were clustered into three dietary patterns including Korean-style balanced diets (KBD, 20.4%), rice-based diets (RBD, 17.2%), and Western-style diets (WSD, 62.4%) in KNHANES. The incidence of metabolic syndrome was lowered in the order of RBD, WSD, and KBD. The participants having a KBD had lower serum C-reactive protein and triglyceride concentrations than those with RBD and WSD (p &lt, 0.05). Three types of fecal bacteria were classified as Ruminococcaceae type (ET-R, 28.7%), Prevotella type (ET-P, 52.2%), and Bacteroides type (ET-B, 42.1%, p &lt, 0.05). ET-P had a higher abundance of Prevotella copri, while ET-R contained a higher abundance of Alistipes, Akkermansia muciniphila, Bifidobacterium adolescentis, and Faecalibacterium prausnitzii. ET-B had a higher abundance of the order Bilophila (p &lt, 0.05). Metabolism of propanoate, starch, and sucrose in fecal microbiome was higher in ET-P and ET-R, whereas fatty acid metabolism was enhanced in ET-B. Fecal microbiota in ET-P and ET-B had higher lipopolysaccharide biosynthesis activity than that in ET-R. The metabolic results of KBD and RBD were consistent with ET-R and ET-P’s gut microbiota metabolism, respectively. In conclusion, Korean enterotypes of ET-P, ET-B, and ET-R were associated with RBD, WSD, and KBD, respectively. This study suggests a potential link between dietary patterns, metabolic syndrome, and enterotypes among Korean adults.

Synbiotics synergistically favors beneficial effects of prebiotics and probiotics towards host metabolic health by modulating gut ecosystem. In this study, we sought to examine the effects of prebiotics (Schizophyllum commune derived β-(1,3/1,6)-glucan), probiotics (concoction made of eight different bacterial strains) and synbiotics (prebiotics + probiotics) on gut microbiota and its associated metabolic functions through 16S rRNA gene sequences analysis. Results showed that probiotics strains used in this study were detected more in the synbiotic and probiotic treatments, while prebiotic dietary intervention increased the total bacterial abundance and metabolisms related to host immune strengthening. Probiotics and synbiotics dietary interventions enhanced similar metabolisms relating to butanediol and s-adenosyl-l-methionine biosynthesis. Probiotics treatment also showed depleted metabolic activities related to SCFA productions, that were not depleted in prebiotics treatment. With varying differential abundance patterns and metabolic activities across the treatments, our results suggest that synbiotic treatment provide more beneficial effects over probiotics and prebiotics.

Increasing evidence indicates that alterations in gut microbiota are associated with mammalian development and physiology. The gut microbiota has been proposed as an essential player in metabolic diseases including brain health. This study aimed to determine the impact of probiotics on degenerative changes in the gut microbiota and cognitive behavior. Assessment of various behavioral and physiological functions was performed using Y-maze tests, wheel running tests, accelerated rotarod tests, balance beam tests, and forced swimming tests (FSTs), using adult mice after 50 weeks of administering living probiotic bacterium Lactobacillus fermentum strain JDFM216 or a vehicle. Immunomodulatory function was investigated using immune organs, immune cells and immune molecules in the mice, and gut microbiota was also evaluated in their feces. Notably, the L. fermentum JDFM216-treated group showed significantly better performance in the behavior tests (P Lactobacillus genus when compared to young mice. While administering the supplementation of L. fermentum JDFM216 to aged mice did not shift the whole gut microbiota, the abundance of Lactobacillus species was significantly increased (P L. fermentum JDFM216 also provided beneficial effects on the regulation of immune responses, which has promising implications for functional foods. Taken together, L. fermentum JDFM216 could confer the benefit of improving health with enhanced cognition, physiological behavior, and immunity by modulating the gut microbiota.

Porphyra tenera (PT) is a functional seaweed food that has been reported for health benefits such as antioxidant, immunostimulant, anti-inflammation, and hepatoprotective effects. In this study, we investigated the effect of PT extracts on gut microbiota modulation in colitis-induced mice. The mice experiment was designed as three groups including normal mice (CTL), dextran sodium sulfate (DSS)-fed mice, and DSS plus PT extracts-fed mice (PTE). DSS was administrated through drinking water containing DSS for 1 week, and the PT extract was ingested into the gastrointestinal tract in mice. PT extract ameliorated the decreased body weight and colon length and improved disease activity index and pro-inflammatory cytokine expression. In addition, PT extract significantly shifted the gut microbiota of mice. DSS treatment significantly increased the portion of harmful bacteria (i.e., Helicobacter, Mucipirillum, and Parasutterella) and decreased the butyrate producing bacteria (i.e., Acetatifactor, Alistipes, Oscillibacter, and Clostridium_XIVb). PT extract increased the abundance of genera Clostridium_XIVb and also enriched some of predicted metabolic activities such as glyoxylate cycle, ethylmalonyl-CoA pathway, nitrate reduction, creatinine degradation, and glycine betaine metabolism. These results suggest that PT extract may ameliorate the DSS-induced colitis inflammation through regulating the compositions and functions of gut microbiota in mice.

This study evaluated the protective effects of Dendropanax morbifera leaf (DML) extracts in the liver due to excessive ethanol consumption. Our results showed that the ethanol extract had better antioxidant activity than the water extract, likely due to the higher levels of total flavonoid and phenolic compounds in the former. We found that the main phenolic acid was chlorogenic acid and the major flavonoid was rutin. Results from the animal model experiment showed concentration-dependent liver protection with the distilled water extract showing better liver protection than the ethanol extract. Gut microbiota dysbiosis induced by alcohol consumption was significantly shifted by DML extracts through increasing mainly Bacteroides and Allobaculum. Moreover, predicted metabolic activities of biosynthesis of beneficial monounsaturated fatty acids such as oleate and palmitoleate were enhanced. Our results suggest that these hepatoprotective effects are likely due to the increased activities of antioxidant enzymes and partially promoted by intestinal microbiota shifts.

경제발전으로 인해 한국인의 식습관이 점차 서구화됨에 따라 웰빙(Well-being)의 문제가 야기되고 있다. 웰빙은 장내 미생물 군집과 밀접하게 연관되어 있으며, 이는 섭취한 음식에 따라 가변적이다. 이에 본 연구에서는 장내 미생물의 16S rRNA 유전자를 기반으로 하여 MiSeq을 진행하였고, 고지방 식이(HFD) 및 저식이섬유 식이(LFD)로 인한 장내의 미생물 생태 비교 및 분석하고자 수행되었다. 일반 대조군(CTL) 그룹과 비교하여 각각 LFD 그룹과 HFD 그룹은 species richness가 유의적으로 감소하였고, species evenness에서는 차이가 나타나지 않았다. phylum 수준에서는 Proteobacteria는 두 처리군에서 유의적으로 증가하였고(p

The wide use of antibiotics in aquaculture for prophylactic and therapeutic purposes can potentially lead to the prevalence of antibiotic resistance genes (ARGs). This study reports for the first time the profile of ARGs from effluents of coastal aquaculture located in South Jeolla province and Jeju Island, South Korea. Using quantitative PCR (qPCR), twenty-two ARGs encoding tetracycline resistance ( tetA , tetB , tetD , tetE , tetG , tetH , tetM , tetQ , tetX , tetZ , tetBP ), sulfonamide resistance ( sul1 , sul2 ), quinolone resistance ( qnrD , qnrS , aac(6′)-Ib-cr ), β-lactams resistance ( bla TEM , bla CTX , bla SHV ), macrolide resistance ( ermC ), florfenicol resistance ( floR ) and multidrug resistance ( oqxA ) and a class 1 integrons-integrase gene ( intI1 ) were quantified. In addition, Illumina Miseq sequencing was applied to investigate microbial community differences across fish farm effluents. Results from qPCR showed that the total number of detected ARGs ranged from 4.24 × 10 −3 to 1.46 × 10 −2 copies/16S rRNA gene. Among them, tetB and tetD were predominant, accounting for 74.8%–98.0% of the total ARGs. Furthermore, intI1 gene showed positive correlation with tetB , tetD , tetE , tetH , tetX , tetZ tetQ and sul1 . Microbial community analysis revealed potential host bacteria for ARGs and intI1 . Two genera, Vibrio and Marinomonas belonging to Gammaproteobacteria , showed significant correlation with tetB and tetD , the most dominant ARGs in all samples. Also, operational taxonomic units (OTUs)-based network analysis revealed that ten OTUs, classified into the phyla Proteobacteria , Cyanobacteria/Chloroplast , Bacteroidetes , Verrucomicrobia and an unclassified phylum, were potential hosts of tetracycline resistance genes (i.e., tetA , tetG , tetH , tetM , tetQ and tetZ ). Further systematic monitoring of ARGs is warranted for risk assessment and management of antibacterial resistance from fish farm effluents.

The widespread use of metals influenced many researchers to examine the relationship between heavy metal toxicity and bacterial resistance. In this study, we have inoculated heavy metal-contaminated soil from Janghang region of South Korea in the nickel-containing media (20 mM Ni2+) for the enrichment. Among dozens of the colonies acquired from the several transfers and serial dilutions with the same concentrations of Ni, the strain Ni-2 was chosen for further studies. The isolates were identified for their phylogenetic affiliations using 16S rRNA gene analysis. The strain Ni-2 was close to Cupriavidus metallidurans and was found to be resistant to antibiotics of vancomycin, erythromycin, chloramphenicol, ampicillin, gentamicin, streptomycin, and kanamycin by disk diffusion method. Of the isolated strains, Ni-2 was sequenced for the whole genome, since the Ni-resistance seemed to be better than the other strains. From the genome sequence we have found that there was a total of 89 metal-resistance-related genes including 11 Ni-resistance genes, 41 heavy metal (As, Cd, Zn, Hg, Cu, and Co)-resistance genes, 22 cation-efflux genes, 4 metal pumping ATPase genes, and 11 metal transporter genes.

Western diet, rich in carbohydrates and fat, is said to be a major factor underlying metabolic syndrome. Interventions with prebiotics, the key modulators of the gut microbiota, have paramount impact on host-associated metabolic disorders. Herein, we investigated the effect of fungus-derived (1,3)/(1,6)-β-glucan, a highly soluble dietary fiber, on high-fat diet (HFD)-induced metabolic distress. Male C57BL/6 J mice were fed with different diet groups (n = 11): control diet, HFD, 3 g/kg or 5 g/kg of β-glucan-incorporated HFD. At the end of experimental study period (12th week), body weight, feces weight and fecal moisture content were observed. Further, colonic motility was measured using activated charcoal meal study. Proteins extracted from liver and intestine tissues were subjected to western blot technique. Paraffin-embedded intestinal tissues were sectioned for histochemical [Periodic acid-Schiff (PAS) and Alcian blue (AB) staining] analysis. Fecal microbiota analysis was performed using MOTHUR bioinformatic software. β-glucan consumption exhibited anti-obesity property in mice groups fed with HFD. In addition, β-glucan ameliorated HFD-induced hepatic stress, colonic motility and intestinal atrophy (reduction in colon length, goblet cells, and mucosal layer thickness). Further, β-glucan incorporation shifted bacterial community by increasing butyrate-producing bacteria such as Anaerostipes, Coprobacillus, and Roseburia and decreasing reportedly obesity-associated bacteria such as Parabacteroides and Lactococcus. Altogether, the outcomes of this present pre-clinical animal study show β-glucan to be a promising therapeutic candidate in the treatment of HFD-induced metabolic distress. Further comprehensive research has to be conducted to brace its clinical relevance, reproducibility and efficacy for aiding human health.

We investigated the anti-obesity effects of the potential prebiotic, laminarin, on mice fed a high-fat diet. A metagenomics approach was applied to characterize the ecological and functional differences of gut microbiota among mice fed a normal diet (CTL), a high-fat diet (HFD), and a laminarin-supplemented high-fat diet (HFL). The HFL mice showed a slower weight gain than the HFD mice during the laminarin-feeding period, but the rate of weight gain increased after the termination of laminarin supplementation. Gut microbial community analysis showed clear differences between the CTL and HFD mice, whereas the HFL mice were between the two. A higher abundance of carbohydrate active enzymes was observed in the HFL mice compared to the HFD mice, with especially notable increases in glycoside hydrolase and polysaccharide lyases. A significant decrease in Firmicutes and an increase in the Bacteroidetes phylum, especially the genus Bacteroides, were observed during laminarin ingestion. Laminarin ingestion altered the gut microbiota at the species level, which was re-shifted after termination of laminarin ingestion. Therefore, supplementing laminarin could reduce the adverse effects of a high-fat diet by shifting the gut microbiota towards a higher energy metabolism. Thus, laminarin could be used to develop anti-obesity functional foods. Our results also suggest that laminarin would need to be consumed regularly in order to prevent or manage obesity.

Codium fragile (CF) is a functional seaweed food that has been used for its health effects, including immunostimulatory, anti-inflammatory, anti-obesity and anti-cancer activities, but the effect of CF extracts on obesity via regulation of intestinal microflora is still unknown. This study investigated anti-obesity effects of CF extracts on gut microbiota of diet-induced obese mice. C57BL/6 mice fed a high-fat (HF) diet were given CF extracts intragastrically for 12 weeks. CF extracts significantly decreased animal body weight and the size of adipocytes, while reducing serum levels of cholesterol and glucose. In addition, CF extracts significantly shifted the gut microbiota of mice by increasing the abundance of Bacteroidetes and decreasing the abundance of Verrucomicrobia species, in which the portion of beneficial bacteria (i.e., Ruminococcaceae, Lachnospiraceae and Acetatifactor) were increased. This resulted in shifting predicted intestinal metabolic pathways involved in regulating adipocytes (i.e., mevalonate metabolism), energy harvest (i.e., pyruvate fermentation and glycolysis), appetite (i.e., chorismate biosynthesis) and metabolic disorders (i.e., isoprene biosynthesis, urea metabolism, and peptidoglycan biosynthesis). In conclusion, our study showed that CF extracts ameliorate intestinal metabolism in HF-induced obese mice by modulating the gut microbiota.

Unbalanced dietary habits and gut dysmotility are causative factors in metabolic and functional gut disorders, including obesity, diabetes, and constipation. Reduction in luminal butyrate synthesis is known to be associated with gut dysbioses, and studies have suggested that restoring butyrate formation in the colon may improve gut health. In contrast, shifts in different types of gut microbiota may inhibit luminal butyrate synthesis, requiring different treatments to restore colonic bacterial butyrate synthesis. We investigated the influence of high-fat diets (HFD) and low-fiber diets (LFD), and loperamide (LPM) administration, on key bacteria and genes involved in reduction of butyrate synthesis in mice. MiSeq-based microbiota analysis and HiSeq-based differential gene analysis indicated that different types of bacteria and genes were involved in butyrate metabolism in each treatment. Dietary modulation depleted butyrate kinase and phosphate butyryl transferase by decreasing members of the Bacteroidales and Parabacteroides. The HFD also depleted genes involved in succinate synthesis by decreasing Lactobacillus. The LFD and LPM treatments depleted genes involved in crotonoyl-CoA synthesis by decreasing Roseburia and Oscilllibacter. Taken together, our results suggest that different types of bacteria and genes were involved in gut dysbiosis, and that selected treatments may be needed depending on the cause of gut dysfunction.

A horizontal, fluorophore-enhanced, repetitive extragenic palindromic-polymerase chain reaction (rep-PCR) DNA fingerprinting technique was adapted to examine the genotypic richness and source differentiation of Vibrio parahaemolyticus (n = 1749) isolated from tidal water and mud of southern coast of South Korea. The number of unique genotypes observed from June (163, 51.9%), September (307, 63.9%), December (205, 73.8%) and February (136, 74.7%), indicating a high degree of genetic diversity. Contrary, lower genetic diversity was detected in April (99, 46.8%), including predominant genotypes comprised >30 V. parahaemolyticus isolates. Jackknife analysis indicated that 65.1% tidal water isolates and 87.1% mud isolates were correctly assigned to their source groups. Sixty-nine isolates of pathogenic V. parahaemolyticus were clustered into two groups, separated by sampling month, source of isolation and serogroups. Serotypes O1, O4, O5, O10/O12 and O11 were the dominant serovariants, while serotypes O3/O13 were highly detected in April where there were no pathogenic V. parahaemolyticus isolates. Most of the V. parahaemolyticus isolates were resistant to ampicillin, ceftazidime and sulfamethoxazole. Interestingly, four V. parahaemolyticus isolates resistant to carbepenem did not contain the known carbapenemase-encoding gene, but possess an extended-spectrum β-lactamase blaTEM.

The objective of this study was to examine the anti-colitis activity of Jakyakgamcho-tang (JGT) in dextran sulfate sodium (DSS)-induced colitis and explore changes of the gut microbial community using 16S rRNA amplicon sequencing and metabolomics approaches. It was found that treatment with JGT or 5-aminosalicylic acid (5-ASA) alleviated the severity of colitis symptoms by suppressing inflammatory cytokine levels of IL-6, IL-12, and IFN-&gamma, The non-metric multidimensional scaling analysis of gut microbiome revealed that JGT groups were clearly separated from the DSS group, suggesting that JGT administration altered gut microbiota. The operational taxonomic units (OTUs) that were decreased by DSS but increased by JGT include Akkermansia and Allobaculum. On the other hand, OTUs that were increased by DSS but decreased by 5-ASA or JGT treatments include Bacteroidales S24-7, Ruminococcaceae, and Rikenellaceae, and the genera Bacteroides, Parabacteroides, Oscillospira, and Coprobacillus. After JGT administration, the metabolites, including most amino acids and lactic acid that were altered by colitis induction, became similar to those of the control group. This study demonstrates that JGT might have potential to effectively treat colitis by restoring dysbiosis of gut microbiota and host metabolites.

Blue chanterelle (Polyozellus multiplex), known as an edible mushroom, was extracted using methanol to screen on anti-viral agent. Syncytium formation in Newcastle disease virus (NDV)-infected baby hamster kidney (BHK) cell originates from the trafficking of viral glycoprotein into cell-surface. Blue chanterelle inhibited not only syncytium formation, but also trafficking of glycoprotein, hemagglutinin-neuramidase (HN), onto cell-surface. Viral glycoprotein is processed within the endoplasmic reticulum during routing to surface. Blue chanterelle extracts showed the inhibitory activities (IC50 10 μg/mL) against α-glucosidase. These results suggested that blue chanterelle extracts inhibited the cell-surface expression of NDV-HN glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.

A total of 3564 E. coli isolates obtained from Yeongsan River basin of South Korea were investigated for their production of extended-spectrum β-lactamases (ESBLs) and potential pathogenicity to better understand the linkage between antibiotic-resistant pathogens in the environment and their public health risks. Interestingly, 60% (53 of 89) of the screen-positive ESBL producers were determined to be potentially one or both of the diarrheagenic and extraintestinal pathogenic (ExPEC) pathotypes, suggesting that trade-off between resistance and virulence of E. coli may not apply to this study. In addition, 67% (60 of 89) of the screen-positive ESBL producers possessed more than one β-lactamase gene, and most (59 of 63) of the ESBL producers had the CTX-M-14 enzyme, which is the most dominant ESBL and seems to be related to urban anthropogenic activities. About 68% (36 of 53) of the potential pathogenic strains were resistant to more than 2 non-β-lactam antibiotics. Results from this study indicate that the Yeongsan River basin has been contaminated with antibiotic-resistant and potential pathogenic E. coli strains. While few studies have examined pathogenecity of ESBL-producing bacteria, this study reports the possible public health risk which could be caused by the fecal indicator bacterium itself containing both ESBL genes and virulence factors. This will likely impact the dissemination of potential pathogenic E. coli producing ESBLs in the environment and suggests the need for further investigations of antibiotic-resistant pathogens to prevent public health impacts in the Yeongsan River basin.

Summary Seasonal and spatial variation in the genotypic rich- ness of 3480 Escherichia coli isolates obtained from the Yeongsan River basin in South Korea was inves- tigated by using the horizontal fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. The relationship between 60 E. coli isolates from each of 58 freshwater samples was determined by using multidimensional scaling (MDS) analysis and self- organized maps (SOMs). The MDS analysis, done based on HFERP DNA fingerprints, showed that E. coli isolates obtained in October through Decem- ber clustered tightly, while those obtained in other sampling periods were more genetically diverse. However, site-specific E. coli genotypes were not observed. SOMs analysis, done using the 10 most frequently isolated E. coli genotypes, showed the occurrence of season-specific E. coli genotypes and the main SOMs clusters were most influenced by tem- perature, strain diversity and biochemical oxygen demand. Diversity among E. coli genotypes tended to decrease as water temperature decreased, and the numbers of E. coli genotypes observed in urban area were greater, more diverse and less dependent on water temperature than those obtained from agricul- tural areas. Taken together, our findings indicate that that an ecological approach needs to be considered in order to obtain a better understanding of E. coli community dynamics in the environment and that SOMs analysis is useful to visualize the multidimen- sional dependent variables that are influencing the types and dynamics of specific E. coli genotypes in the environment.

Enterococcus isolates (1500) obtained from the feces of 48 humans, 209 domesticated food animals, and 155 wild geese in South Korea were characterized with respect to species status by PCR analyses and resistance to antibiotics. Of the 1500 strains examined, the majority (n=577) were Enterococcus faecalis from 224 (54.4%) of the samples feces, while 299 were of E. faecium from 125 of the samples (30.3%), 224 were E. hirae from 101 (24.5%) of the samples, 94 were E. casseliflavus from 43 (10.4%) of the samples, and one was E. gallinarum. While 305 isolated from 125 (30.3%) of the samples were unidentified species. Approximately 15, 60, 50, 55, 3, and 40% of samples obtained from beef cattle, chickens, ducks, swine, wild geese, and humans, respectively, yielded Enterococcus isolates that were resistant to high-levels of aminoglycosides (i.e., of gentamicin, kanamycin, and streptomycin, minimum inhibitory concentrations were >1000 mg/l). The 180 Enterococcus isolates that showed high levels of resistance to aminoglycoside antibiotics (HLAR) were screened for virulence genes encoding for aggregation substance (agg), cytolysin activator (cylA), gelatinase (gelE) and surface protein (esp). Of those, the gelE gene was found most frequently in chickens and ducks of the HLAR isolates, while 56 E. faecalis and 13 E. faecium HLAR were gelatinase positive and showed hemolysin activity. Multiple antibiotic resistant Enterococcus isolates carrying virulence genes were most frequently isolated from poultry and swine, and were mostly E. faecalis or E. faecium. These findings suggest that restriction of the use of antibiotics in food animal operations in South Korea, especially those involved in poultry and swine production would be desirable.

South Korea uses more antibiotics for animal production than any other member of the OECD. The excessive use could potentially lead to a greater incidence of antibiotic resistant microorganisms, some of which may be pathogenic. In this study, we examined potential diarrheagenic and extraintestinal pathogenic E. coli (ExPEC) isolates using virulence gene profiling (eaeA, est, elt, ipaH, stx1 and stx2 as diarrheagenic and afa/dra, iutA, kpsMT II, papA/C, and sfa/foc as extraintestinal pathogenic virulence genes). A cluster analysis of DNA fingerprint data indicated that certain genotypes of chicken E. coli isolates are likely ExPEC. Moreover, our results showed 38 of the 60 potential diarrheagenic and ExPEC isolates obtained from animals and humans were also resistant to antibiotics, mostly to tetracycline groups, penicillin groups, and folate pathway inhibitors. Our results suggest that the use of antibiotics in agriculture should be controlled due to potential impacts on human health.

Drug resistance is a major problem in the treatment of non-small-cell lung cancer (NSCLC). In this study, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed to identify the differentially expressed genes in Adriamycin (ADR)-resistant NSCLC A549/ADR cells compared with parental A549 cells. Among the tested phytochemicals, nobiletin (NBT) is able to overcome the ADR resistance of A549/ADR cells. NBT treatment decreased the expression of a neuroblastoma-derived MYC (MYCN) and multidrug resistance-associated protein 1 (MRP1) as well as downregulating Akt, GSK3&beta, and &beta, catenin. Consistent with these results, NBT treatment resulted in the accumulation of intracellular ADR. A combination index (CI) assay confirmed the synergistic effect of combined treatment with NBT and ADR in reducing the viability of A549/ADR cells (CI = 0.152). Combined treatment with NBT and ADR enhanced apoptosis in A549/ADR cells, as evidenced by increased caspase-3 activation, poly (ADP-ribose) polymerase (PARP) cleavage, and sub-G1 population compared to treatment with ADR alone. In vivo experiments using a mouse xenograft model revealed that combination therapy with NBT and ADR significantly reduced tumor volume by 84.15%. These data suggest that NBT can sensitize ADR-induced cytotoxicity against A549/ADR cells by inhibiting MRP1 expression, indicating that NBT could serve as an effective adjuvant agent for ADR-based chemotherapy in lung cancer.

The spread of antibiotics resistance among bacteria is a threat to human health. Since South Korea uses approximately 1.5 times more antibiotics than do other OECD countries, this is likely to impact the numbers and types of antibiotic-resistant bacteria found in the environment. In this study we examined feces from domesticated animals and humans for the diversity and abundance of antibiotic-resistant Escherichia coli. Abundant antibiotic-resistant E. coli were isolated from all the tested animals and humans and were examined by horizontal, fluorophore-enhanced, rep-PCR (HFERP) DNA fingerprint analysis. A total of 793 unique, non-clonal, E. coli isolates were obtained from the 513 human and animal hosts examined. Antibiotic resistance analysis, done using 14 antibiotics, indicated that 72.3% of the isolates (573 of 793) were found resistant to more than one antibiotic. The E. coli isolated from swine were resistant to the greatest number of antibiotics. Tetracycline resistant E. coli were routinely isolated from all animal hosts (36 to 77% per host), except for dairy cattle (9.3%). Twenty nine E. coli isolates from all hosts, except for duck, were resistant to more than 10 antibiotics. Gene transfer and southern hybridization studies revealed that resistance to 13 of the antibiotics was self-transmissible, and likely mediated by plasmids and integrons. Since genetically diverse and numerically abundant antibiotic-resistant E. coli were consistently recovered from chicken, swine and other domesticated animals in South Korea, our results suggest that the use of sub-therapeutic levels of antibiotics for disease prophylaxis and growth promotion should be curtailed.

Background Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infection (CDI) that often fails standard antibiotic therapy. Despite its widespread recent use, however, little is known about the stability of the fecal microbiota following FMT. Results Here we report on short- and long-term changes and provide kinetic visualization of fecal microbiota composition in patients with multiply recurrent CDI that were refractory to antibiotic therapy and treated using FMT. Fecal samples were collected from four patients before and up to 151 days after FMT, with daily collections until 28 days and weekly collections until 84 days post-FMT. The composition of fecal bacteria was characterized using high throughput 16S rRNA gene sequence analysis, compared to microbiota across body sites in the Human Microbiome Project (HMP) database, and visualized in a movie-like, kinetic format. FMT resulted in rapid normalization of bacterial fecal sample composition from a markedly dysbiotic state to one representative of normal fecal microbiota. While the microbiome appeared most similar to the donor implant material 1 day post-FMT, the composition diverged variably at later time points. The donor microbiota composition also varied over time. However, both post-FMT and donor samples remained within the larger cloud of fecal microbiota characterized as healthy by the HMP. Conclusions Dynamic behavior is an intrinsic property of normal fecal microbiota and should be accounted for in comparing microbial communities among normal individuals and those with disease states. This also suggests that more frequent sample analyses are needed in order to properly assess success of FMT procedures. Electronic supplementary material The online version of this article (doi:10.1186/s40168-015-0070-0) contains supplementary material, which is available to authorized users.

Radiotherapy for malignant tumours often elicits anorexia or loss of appetite as an adverse effect. However, the mechanism for this is poorly understood. The present study was undertaken to investigate if visceral afferents are responsible for reduction of food intake following X-ray irradiation. Rats were exposed bilaterally to X-ray (10 MV) irradiation with total doses of 1.5, 3 and 6 Gy, using a high-energy electron linear accelerator at a dose rate of 4.9 Gy min−1. X-ray irradiation of the whole body, abdomen or head with doses of 1.5, 3 and 6 Gy reduced food intake in a dose-dependent manner. The reduction of food intake after X-ray irradiation of the whole body or abdomen was significantly greater than when only the head was irradiated. Reduction of food intake was observed for the first 4 days after 6 Gy X-ray irradiation of the abdomen, while it was observed only on the first day after the same 6-Gy irradiation of the abdomen in animals whose small-diameter afferents were ablated by capsaicin pre-treatment. These results suggested that the abdominal afferent nerves at least contribute to the reduction of food intake observed on second to fourth days after 6-Gy abdominal irradiation. Taken together, the present evidence suggests that the reduction of food intake following X-ray irradiation of the whole body or the abdomen is partly mediated via abdominal afferent nerves. Moreover, the results of X-ray irradiation to the head suggest that X-ray irradiation directly influences the central nervous system to reduce food intake.

Objectives To examine the presence of pathogenic bacteria carrying New Delhi metallo-β-lactamase in the environment and to characterize the genome structures of these strains. Methods Phenotypic screening of antimicrobial susceptibility and WGS were conducted on three Klebsiella variicola strains possessing NDM-9 isolated from an urban river. Results Three carbapenem-resistant K. variicola isolated from Gwangju tributary were found to possess bla NDM-9 genes. Antimicrobial susceptibility testing indicated resistance of these strains to aminoglycosides, carbapenems, cephems, folate pathway inhibitors, fosfomycin and penicillins, but susceptibility to fluoroquinolones, phenicols, tetracyclines and miscellaneous agents. WGS revealed that the 108 kb IncFII(Y)-like plasmids carry bla NDM-9 sandwiched between IS 15 for the GJ1 strain, IS 26 for the GJ2 strain, IS 15D1 for the GJ3 strain and IS Vsa3 , and further bracketed by IS 26 and Tn AS3 along with the mercury resistance operon upstream and the class 1 integron composed of gene cassettes of aadA2 , dfrA12 and sul1 downstream. An aph(3')-Ia gene conferring resistance to aminoglycosides is located after the integrons. Chromosomally encoded bla LEN-13 , fosA , aqxA and oqxB genes, as well as plasmid-mediated bla TEM-1B and bla CTX-M-65 encoding ESBL, ant(3')-Ia and mph (A) genes, were also identified. Conclusions The findings of the present study provide us with the information that NDM-9 has been spreading into the environment. Dissemination of NDM-9 in the environment has raised a health risk alarm as this variant of NDM carries MDR genes with highly transferable mobile genetic elements, increasing the possibility of resistance gene transfer among microorganisms in the environment.

Ever since the ban on antibiotic growth promoters (AGPs), the livestock death rate has increased owing to pathogenic bacterial infections. There is a need of developing AGP alternatives; however, the mechanisms by which AGP enhances livestock growth performance are not clearly understood. In this study, we fed 3-week-old swine for 9 weeks with and without AGPs containing chlortetracycline, sulfathiazole, and penicillin to investigate the effects of AGPs on swine gut microbiota. Microbial community analysis was done based on bacterial 16S rRNA genes using MiSeq. The use of AGP showed no growth promoting effect, but inhibited the growth of potential pathogens during the early growth stage. Our results showed the significant increase in species richness after the stabilization of gut microbiota during the post-weaning period (4-week-old). Moreover, the swine gut microbiota was divided into four clusters based on the distribution of operational taxonomic units, which was significantly correlated to the swine weight regardless of AGP treatments. Taxonomic abundance analysis indicated a negative correlation between host weight and the abundance of the family Prevotellaceae species, but showed positive correlation to the abundance of the family Spirochaetaceae, Clostridiaceae_1, and Peptostreptococcaeae species. Although no growth performance enhancement was observed, the use of AGP inhibited the potential pathogens in the early growth stage of swine. In addition, our results indicated the ecological succession of swine gut microbiota according to swine weight. Here, we present a characterization of swine gut microbiota with respect to the effects of AGPs on growth performance.

Multiplex PCR analyses of DNAs from genotypically unique Escherichia coli strains isolated from the feces of 138 humans and 376 domesticated animals from Jeonnam Province, South Korea, performed using primers specific for the chuA and yjaA genes and an unknown DNA fragment, TSPE4.C2, indicated that none of the strains belonged to E. coli phylogenetic group B2. In contrast, phylogenetic group B2 strains were detected in about 17% (8 of 48) of isolates from feces of 24 wild geese and in 3% (3 of 96) of isolates obtained from the Yeongsan River in Jeonnam Province, South Korea. The distribution of E. coli strains in phylogenetic groups A, B1, and D varied depending on the host examined, and there was no apparent seasonal variation in the distribution of strains in phylogenetic groups among the Yeongsan River isolates. The distribution of four virulence genes ( eaeA , hlyA , stx 1 , and stx 2 ) in isolates was also examined by using multiplex PCR. Virulence genes were detected in about 5% (38 of 707) of the total group of unique strains examined, with 24, 13, 13, and 9 strains containing hlyA , eaeA , stx 2 , and stx 1 , respectively. The virulence genes were most frequently present in phylogenetic group B1 strains isolated from beef cattle. Taken together, results of these studies indicate that E. coli strains in phylogenetic group B2 were rarely found in humans and domesticated animals in Jeonnam Province, South Korea, and that the majority of strains containing virulence genes belonged to phylogenetic group B1 and were isolated from beef cattle. Results of this study also suggest that the relationship between the presence and types of virulence genes and phylogenetic groupings may differ among geographically distinct E. coli populations.

Although Escherichia coli has been used as an indicator to examine fecal contamination of aquatic environment, it also has been reported to become naturalized to secondary habitats, including soil, water and beach sand. A total of 2880 E. coli isolates obtained from surface water and sediment samples from the Yeongsan River in 2013 were genotyped by using the horizontal fluorophore-enhanced rep-PCR DNA fingerprinting technique. Although different E. coli genotypic groups were observed between surface water and sediments in the dry season, they were mingled and undifferentiated from each other in the rainy season. This indicates that there are frequent sediment resuspension events in the river basin. Moreover, the genotypic composition of the E. coli population in the Yeongsan River basin changes over months and years, implying that genotypic structure of E. coli populations dynamically fluctuates in the river environment. Consequently, our data suggests that the use of E. coli libraries for fecal source tracking needs to be reassessed to account for the changing structure of riverine E. coli populations.

The aim of the present study was to elucidate the influence of the hepatic sympathetic and parasympathetic (vagal) nerves on the hepatic blood flow (HBF), both tonically and when stimulated, using urethane-anesthetized rats as an in vivo experimental model. HBF was measured at the surface of the lateral left lobe of the liver using laser Doppler flowmetry and the hydrogen gas clearance method. Denervation of the hepatic sympathetic nerves had no influence on the HBF, while electrical stimulation of the hepatic sympathetic nerves caused the HBF to decrease in a frequency-dependent manner. This decrease was shown to occur via alpha-adrenergic receptors. In contrast, neither denervation nor electrical stimulation of the hepatic vagal nerves elicited significant changes in the HBF. These results demonstrate that the sympathetic and vagal hepatic nerves have little or no tonic influence on the HBF of rats under urethane anesthesia, whereas the HBF decreases in response to activation of the hepatic sympathetic nerves.

With 3,480 E. coli strains isolated from the Yeongsan River basin, South Korea, correlations between phylogenetic groups and horizontal fluorophore enhanced rep-PCR (HFERP) genotypes were examined, and environmental factors affecting E. coli phylogenetic groups in the river water were determined. Interestingly, multidimentional scaling (MDS) analyses based on HFERP DNA fingerprint data indicated that E. coli in phylogenetic groups A and B1 were uniquely clustered. Results of self-organized maps (SOMs) analyses also indicated that E. coli phylogenetic groups were seasonally affected by water temperature, with greater occurrences of phylogenetic groups A and B1 in low and high temperature seasons, respectively. The presence of E. coli in phylogenetic groups A and B1 were inversely related. Furthermore, redundancy analysis (RDA) revealed that phylogenetic group B1 correlated positively with temperature, strain diversity, and biochemical oxygen demand (BOD) but negatively with phylogenetic group A. Results of this study indicated that while E. coli strains could be clustered based on their genotypes and environment conditions, their phylogenetic groups did not change in relation to the same conditions. The distributional differences of phylogenetic groups among E. coli populations in different environments may be caused by different genomic adaptability and plasticity of E. coli strains belonging to each phylogenetic group. Although several previous studies have reported different E. coli ecological structures depending on their origins, this study is a first description of the specific environmental factors affecting E. coli phylogenetic groups in river water.