Targeted disruption of the PD78 gene ( traF ) reduces pheromone-inducible conjugal transfer of the bacteriocin plasmid pPD1 in Enterococcus faecalis

Bacterial sex pheromone, cPD1, induces sexual aggregation of Enterococcus faecalis harboring the bacteriocin plasmid, pPD1, and enables pPD1 to transfer at high frequency in a liquid culture. PD78 is a cPD1-inducible cell surface protein encoded by pPD1. The PD78 gene, traF , was disrupted by homologous recombination between pPD1 and an artificial vector having a deletion in the middle portion of traF . The disruption of traF did not affect the cPD1-inducible aggregation but reduced the transfer frequency of pPD1 to 2% of the wild-type level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72850/1/j.1574-6968.1995.tb07537.x.pd

No Significant Differences Were Observed in the Amounts of DNA Strand Breaks Produced by Copper between Male and Female Liver Cells of Long-Evans Cinnamon（LEC) Strain Rats

肝炎を自然発症するLECラットの肝細胞に蓄積する銅による酸化損傷と考えられるDNA単鎖切断の量をコメット法で検出した。LECラットの肝臓では4週齢でコントロールとして用いたWKAHの30倍の銅が蓄積していた。4週齢から15週齢では雄、雌ともに週齢に依存して肝臓の銅の蓄積量は増加したが、WKAHラットでは週齢による増加は認められなかった。LECラットの肝臓でのDNA単鎖切断の量は10週齢から15週齢まで週齢に依存して急激に増加した。肝炎発症は雌が雄に比べて頻度が高いことが報告されているが、肝細胞における雌のDNA単鎖切断の量は雄に比べて大きな違いは認められなかった

Hepatic iron Accumulation Is Not Directly Associated with Induction of DNA Strand Breaks in the Liver Cells of Long-Evans Cinnamon（LEC) Rats

肝炎を自然発症するLECラットにおいてDNA単鎖切断に及ぼす銅の蓄積の影響を調べた。LECラットの肝臓において銅と鉄は4週齢から15週齢に蓄積した。低鉄食で飼育したラットでは鉄の蓄積は認められなかったが、銅の蓄積は普通食のラットと同様量認められた。肝細胞のDNA単鎖切断の量はcomet法を用いて検出した。テールが認められた細胞の頻度とテールの長さの平均値を求めたところ、低鉄食を与えたLECラットの肝細胞と普通食を与えたLECラットの間にほとんど違いは認められなかった。これらの結果からLECラットの肝細胞におけるDNA損傷の誘発には鉄の蓄積は関与していないことが示唆された

Drosophila Host Model Reveals New Enterococcus faecalis Quorum-Sensing Associated Virulence Factors

Enterococcus faecalis V583 is a vancomycin-resistant clinical isolate which belongs to the hospital-adapted clade, CC2. This strain harbours several factors that have been associated with virulence, including the fsr quorum-sensing regulatory system that is known to control the expression of GelE and SprE proteases. To discriminate between genes directly regulated by Fsr, and those indirectly regulated as the result of protease expression or activity, we compared gene expression in isogenic mutants of V583 variously defective in either Fsr quorum sensing or protease expression. Quorum sensing was artificially induced by addition of the quorum signal, GBAP, exogenously in a controlled manner. The Fsr regulon was found to be restricted to five genes, gelE, sprE, ef1097, ef1351 and ef1352. Twelve additional genes were found to be dependent on the presence of GBAP-induced proteases. Induction of GelE and SprE by GBAP via Fsr resulted in accumulation of mRNA encoding lrgAB, and this induction was found to be lytRS dependent. Drosophila infection was used to discern varying levels of toxicity stemming from mutations in the fsr quorum regulatory system and the genes that it regulates, highlighting the contribution of LrgAB and bacteriocin EF1097 to infection toxicity. A contribution of SprE to infection toxicity was also detected. This work brought to light new players in E. faecalis success as a pathogen and paves the way for future studies on host tolerance mechanisms to infections caused by this important nosocomial pathogen

Aldose reductase inhibition ameliorates pupillary light reflex and F-wave latency in patients with mild diabetic neuropathy

WSTĘP. Zbadanie wpływu inhibitora reduktazy aldozy, epalrestatu, na wczesną fazę neuropatii autonomicznej i somatycznej u chorych na cukrzycę typu 2 przez ocenę odruchu źrenicznego na światło oraz minimalnej latencji fali F. MATERIAŁ I METODY. Badanie objęło 30 chorych na cukrzycę z podkliniczną lub łagodną neuropatią cukrzycową, których losowo przydzielono do grupy kontrolnej (n = 15) lub do grupy leczonej epalrestatem (150 mg/d., n = 15). Po 24 tygodniach przeprowadzono badanie odruchu źrenicznego na światło, testy włókien autonomicznych układu sercowo-naczyniowego oraz badanie przewodzenia nerwowego. WYNIKI. Korzystny wpływ epalrestatu na odruch źreniczny na światło zaobserwowano w odniesieniu do minimalnej średnicy po bodźcu świetlnym (p = 0,044), wskaźnika zwężenia (p = 0,014) oraz maksymalnej szybkości zwężania (p = 0,008). Spośród testów autonomicznych układu sercowo-naczyniowego leczenie epalrestatem spowodowało poprawę wskaźnika najdłuższego odstępu RR podczas wydechu do najkrótszego odstępu RR w czasie wdechu obserwowanego podczas testu głębokiego oddychania (p = 0,037). Minimalna latencja fali F nerwów pośrodkowego oraz piszczelowego uległa istotnemu skróceniu w grupie chorych leczonych epalrestatem (odpowiednio p = 0,002 oraz p = 0,001); nie stwierdzono jednak istotnego wpływu na prędkość przewodzenia nerwowego w nerwach czuciowych oraz ruchowych. WNIOSKI. Powyższe obserwacje sugerują, że epalrestat może korzystnie działać we wczesnej fazie neuropatii cukrzycowej oraz że odruch źreniczny na światło i minimalna latencja fali F mogą stanowić przydatne wskaźniki neuropatii cukrzycowej.INTRODUCTION. The present study was conducted to investigate the effect of an aldose reductase inhibitor, epalrestat, on autonomic and somatic neuropathy at an early stage in type 2 diabetic patients by assessing the pupillary light reflex and minimum latency of the F-wave. MATERIAL AND METHODS. A total of 30 diabetic patients with subclinical or mild diabetic neuropathy were randomly allocated to a control group (n = 15) and epalrestat (150 mg/day) group (n = 15). After 24 weeks, the pupillary light reflex test, cardiovascular autonomic function tests, and nerve conduction study were performed. RESULTS. The beneficial effect of epalrestat on the pupillary light reflex was observed in the minimum diameter after light stimuli (P = 0.044), constriction ratio (P = 0.014), and maximum velocity of constriction (P = 0.008). Among cardiovascular autonomic nerve functions, the ratio of the longest expiratory R-R interval to the shortest inspiratory R-R interval during deep breathing was significantly improved by epalrestat (P = 0.037). Minimum latencies of F-wave of median and tibial motor nerves were significantly shortened by epalrestat (P = 0.002 and P = 0.001, respectively); however, no significant effects were observed in motor or sensory nerve conduction velocity. CONCLUSIONS. These observations suggest that epalrestat may have therapeutic value at the early stage of diabetic neuropathy and that the pupillary light reflex and minimum latency of F-wave may be useful indicators of diabetic neuropathy

Indonesian children fecal microbiome from birth until weaning was different from microbiomes of their mothers

Gastrointestinal (GI) microbiota play an important role in human health and wellbeing and the first wave of gut microbes arrives mostly through vertical transmission from mother to child. This study has undertaken to understand the microbiota profile of healthy Southeast Asian mother-infant pairs. Here, we examined the fecal, vaginal and breast milk microbiota of Indonesian mothers and the fecal microbiota of their children from less than 1 month to 48 months old. To determine the immune status of children and the effect of diet at different ages, we examined the level of cytokines, bile acids in the fecal water and weaning food frequency. The fecal microbiota of the children before weaning contained mainlyBacteroidesandBifidobacterium, which presented at low abundance in the samples of mothers. After weaning, the fecal microbiome of children was mainly of thePrevotellatype, with decreasing levels ofBifidobacterium, thus becoming more like the fecal microbiome of the mother. The abundance of infant fecal commensals generally correlated inversely with potential pathogens before weaning. The fecalBifidobacteriumin children correlated inversely with the consumption of complex carbohydrates and fruits after weaning. The specific cytokines related to the proliferation and maturation of immunity were found to increase after weaning. A decreasing level of primary bile acids and an increase of secondary bile acids were observed after weaning. This study highlights the change in the GI microbiota of infants to adult-type microbiota after weaning and identifies diet as a major contributing factor

The Gelatinase Biosynthesis‐Activating Pheromone binds and stabilizes the FsrB membrane protein in Enterococcus faecalis quorum sensing

Quorum‐sensing mechanisms regulate gene expression in response to changing cell‐population density detected through pheromones. In Enterococcus faecalis, Fsr quorum sensing produces and responds to the gelatinase biosynthesis‐activating pheromone (GBAP). Here we establish that the enterococcal FsrB membrane protein has a direct role connected with GBAP by showing that GBAP binds to purified FsrB. Far‐UV CD measurements demonstrated a predominantly α‐helical protein exhibiting a small level of conformational flexibility. Fivefold (400 μm) GBAP stabilised FsrB (80 μm) secondary structure. FsrB thermal denaturation in the presence and absence of GBAP revealed melting temperatures of 70.1 and 60.8 °C, respectively, demonstrating GBAP interactions and increased thermal stability conferred by GBAP. Addition of GBAP also resulted in tertiary structural changes, confirming GBAP binding

Gut microbiome signatures associated with type 2 diabetes in obesity in Mongolia

Mongolian people possess a unique dietary habit characterized by high consumption of meat and dairy products and fewer vegetables, resulting in the highest obesity rate in East Asia. Although obesity is a known cause of type 2 diabetes (T2D), the T2D rate is moderate in this population; this is known as the “Mongolian paradox.” Since the gut microbiota plays a key role in energy and metabolic homeostasis as an interface between food and body, we investigated gut microbial factors involved in the prevention of the co-occurrence of T2D with obesity in Mongolians. We compared the gut microbiome and metabolome of Mongolian adults with obesity with T2D (DO: n = 31) or without T2D (NDO: n = 35). Dysbiotic signatures were found in the gut microbiome of the DO group; lower levels of Faecalibacterium and Anaerostipes which are known as short-chain fatty acid (SCFA) producers and higher levels of Methanobrevibacter, Desulfovibrio, and Solobacterium which are known to be associated with certain diseases. On the other hand, the NDO group exhibited a higher level of fecal SCFA concentration, particularly acetate. This is consistent with the results of the whole shotgun metagenomic analysis, which revealed a higher relative abundance of SCFA biosynthesis-related genes encoded largely by Anaerostipes hadrus in the NDO group. Multiple logistic regression analysis including host demographic parameters indicated that acetate had the highest negative contribution to the onset of T2D. These findings suggest that SCFAs produced by the gut microbial community participate in preventing the development of T2D in obesity in Mongolians

Diversity in gut bacterial community of school-age children in Asia

10.1038/srep08397Scientific Reports