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1.
A novel isolate belonging to the genus Streptomyces, strain SL-4T, was isolated from soil sample collected from a sanitary landfill, New Delhi, India. The taxonomic status of this isolate was studied by polyphasic approach including morphological, physiological and chemo-taxonomic characterization. Spore chains of SL-4T were open loops, hooks or extended spirals of wide diameter (retinaculiperti). The cell wall peptidoglycan of the isolate SL-4T contained L,L-diaminopimelic acid, suggesting that the strain has a cell wall of chemotype-I. The polar lipid profile of the isolate was of Type II, with phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The 16SrRNA gene sequence similarity between SL-4T and its phylogenetic relatives Streptomyces atrovirens NRRLB 16357T (DQ026672), S. albogriseolus NRRLB 1305T (AJ494865), S viridodiastaticus NBRC 13106T (AB184317), S. caelestis NRRL 2418T (X80824), S. flavoviridis NBRC 12772T (AB184842), S. pilosus NBRC 12807T (AB184161) and S. longispororuber NBRC 13488T (AB184440) was 99.65, 99.65, 99.64, 99.23, 99.15, 99.14 and 99.13 % respectively. Subsequent DNA–DNA hybridization experiments with the test strain and its clade members showed 55.27, 44.27, 36.86, and 15.65 % relatedness between SL-4T and its relatives S. atrovirens,S. albogriseolus, S. viridodiastaticus and S. longispororuber respectively. The genotypic and phenotypic data was analyzed to verify possibility of the isolate SL-4T representing novel member of the genus Streptomyces, for which the name S. antibioticalis is being proposed. The type strain is SL-4T (=CCM 7434T=MTCC 8588T).  相似文献   

2.

Background

Impaired corticosteroid action caused by genetic and environmental influence, including exposure to hazardous xenobiotics, contributes to the development and progression of metabolic diseases, cardiovascular complications and immune disorders. Novel strategies are thus needed for identifying xenobiotics that interfere with corticosteroid homeostasis. 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) and mineralocorticoid receptors (MR) are major regulators of corticosteroid action. 11β-HSD2 converts the active glucocorticoid cortisol to the inactive cortisone and protects MR from activation by glucocorticoids. 11β-HSD2 has also an essential role in the placenta to protect the fetus from high maternal cortisol concentrations.

Methods and Principal Findings

We employed a previously constructed 3D-structural library of chemicals with proven and suspected endocrine disrupting effects for virtual screening using a chemical feature-based 11β-HSD pharmacophore. We tested several in silico predicted chemicals in a 11β-HSD2 bioassay. The identified antibiotic lasalocid and the silane-coupling agent AB110873 were found to concentration-dependently inhibit 11β-HSD2. Moreover, the silane AB110873 was shown to activate MR and stimulate mitochondrial ROS generation and the production of the proinflammatory cytokine interleukin-6 (IL-6). Finally, we constructed a MR pharmacophore, which successfully identified the silane AB110873.

Conclusions

Screening of virtual chemical structure libraries can facilitate the identification of xenobiotics inhibiting 11β-HSD2 and/or activating MR. Lasalocid and AB110873 belong to new classes of 11β-HSD2 inhibitors. The silane AB110873 represents to the best of our knowledge the first industrial chemical shown to activate MR. Furthermore, the MR pharmacophore can now be used for future screening purposes.  相似文献   

3.
A population of Butlerius butleri Goodey, 1929 was isolated from vermicompost in Kerman in the Kerman Province of Iran during a nematode survey that was conducted during 2014. This population of B. butleri is characterized by the presence of a dorsal thorn-like tooth (4 to 5 μm long), long spicules (44 to 47 μm long), gubernaculum (33 to 37 μm or more than half of the spicule length), three pairs of precloacal papillae, five pairs of postcloacal papillae (papillae V3 and V5 comprising three small papillae), and a long filiform tail (304 to 409 μm in females, 312 to 380 μm in males). Molecular and phylogenetic analysis of B. butleri individuals from this Iranian population based on 18S ribosomal deoxyribonucleic acid (rDNA) sequence placed this species close to Pseudodiplogasteroides compositus (AB597237) and an unidentified Pseudodiplogasteroides species (AB597238). Measurements, illustrations, and the phylogenetic tree, including the position of B. butleri are provided.  相似文献   

4.
CDDP [cisplatin or cis-diamminedichloroplatinum(II)] and CDDP-based combination chemotherapy have been confirmed effective against gastric cancer. However, CDDP efficiency is limited because of development of drug resistance. In this study, we found that PAK4 (p21-activated kinase 4) expression and activity were elevated in gastric cancer cells with acquired CDDP resistance (AGS/CDDP and MKN-45/CDDP) compared with their parental cells. Inhibition of PAK4 or knockdown of PAK4 expression by specific siRNA (small interfering RNA)-sensitized CDDP-resistant cells to CDDP and overcome CDDP resistance. Combination treatment of LY294002 [the inhibitor of PI3K (phosphoinositide 3-kinase)/Akt (protein kinase B or PKB) pathway] or PD98509 {the inhibitor of MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] pathway} with PF-3758309 (the PAK4 inhibitor) resulted in increased CDDP efficacy compared with LY294002 or PD98509 alone. However, after the concomitant treatment of LY294002 and PD98509, PF-3758309 administration exerted no additional enhancement of CDDP cytotoxicity in CDDP-resistant cells. Inhibition of PAK4 by PF-3758309 could significantly suppress MEK/ERK and PI3K/Akt signalling in CDDP-resistant cells. Furthermore, inhibition of PI3K/Akt pathway while not MEK/ERK pathway could inhibit PAK4 activity in these cells. The in vivo results were similar with those of in vitro. In conclusion, these results indicate that PAK4 confers CDDP resistance via the activation of MEK/ERK and PI3K/Akt pathways. PAK4 and PI3K/Akt pathways can reciprocally activate each other. Therefore, PAK4 may be a potential target for overcoming CDDP resistance in gastric cancer.  相似文献   

5.
Streptococcus suis is an emerging zoonotic pathogen causing severe infections in pigs and humans. In previous studies, 33 serotypes of S. suis have been identified using serum agglutination. Here, we describe a novel S. suis strain, CZ130302, isolated from an outbreak of acute piglet meningitis in eastern China. Strong pathogenicity of meningitis caused by strain CZ130302 was reproduced in the BALB/c mouse model. The strain showed a high fatality rate (8/10), higher than those for known virulent serotype 2 strains P1/7 (1/10) and 9801 (2/10). Cell adhesion assay results with bEnd.3 and HEp2 cells showed that CZ130302 was significantly close to P1/7 and 9801. Both the agglutination test and its complementary test showed that strain CZ130302 had no strong cross-reaction with the other 33 S. suis serotypes. The multiplex PCR assays revealed no specified bands for all four sets used to detect the other 33 serotypes. In addition, genetic analysis of the whole cps gene clusters of all serotypes was performed in this study. The results of comparative genomics showed that the cps gene cluster of CZ130302, which was not previously reported, showed no homology to the gene sequences of the other strains. Especially, the wzy, wzx, and acetyltransferase genes of strain CZ130302 are phylogenetically distinct from strains of the other 33 serotypes. Therefore, this study suggested that strain CZ130302 represents a novel variant serotype of S. suis (designated serotype Chz) which has a high potential to be virulent and associated with meningitis in animals.  相似文献   

6.
SARA has been shown to be a regulator of epithelial cell phenotype, with reduced expression during TGF-β1-mediated epithelial-to-mesenchymal transition. Examination of the pathways that might play a role in regulating SARA expression identified phosphatidylinositol 3-kinase (PI3K) pathway inhibition as sufficient to reduce SARA expression. The mechanism of PI3K inhibition-mediated SARA down-regulation differs from that induced by TGF-β1 in that, unlike TGF-β1, PI3K-dependent depletion of SARA was apparent within 6 h and did not occur at the mRNA or promoter level but was blocked by inhibition of proteasome-mediated degradation. This effect was independent of Akt activity because neither reducing nor enhancing Akt activity modulated the expression of SARA. Therefore, this is likely a direct effect of p85α action, and co-immunoprecipitation of SARA and p85α confirmed that these proteins interact. Both SARA and PI3K have been shown to be associated with endosomes, and either LY294002 or p85α knockdown enlarged SARA-containing endocytic vesicles. Inhibition of clathrin-mediated endocytosis blocked SARA down-regulation, and a localization-deficient mutant SARA was protected against down-regulation. As inhibiting PI3K can activate the endosomal fusion-regulatory small GTPase Rab5, we expressed GTPase-deficient Rab5 and observed endosomal enlargement and reduced SARA protein expression, similar to that seen with PI3K inhibition. Importantly, either interference with PI3K via LY294002 or p85α knockdown, or constitutive activity of the Rab5 pathway, enhanced the expression of smooth muscle α-actin. Together, these data suggest that although TGF-β1 can induce epithelial-to-mesenchymal transition through reduction in SARA expression, SARA is also basally regulated by its interaction with PI3K.  相似文献   

7.
8.
The combination of docetaxel, cisplatin, and S-1 (DCS) is a common chemotherapy regimen for patients with gastric cancer (GC). However, studies on long noncoding RNAs (lncRNAs) associated with the chemotherapeutic response to and prognosis after DCS remain lacking. The aim of the present study was to identify DCS mRNAs-lncRNAs associated with chemotherapy response and prognosis in GC patients. In the present study, we identified 548 lncRNAs associated with these 16 mRNAs in the TCGA and GSE31811 datasets. Eleven lncRNAs were used to construct a prognostic signature by least absolute shrinkage and selection operator (LASSO) regression. A model including the 11 lncRNAs (LINC02532, AC007277.1, AC005324.4, AL512506.1, AC068790.7, AC022509.2, AC113139.1, LINC00106, AC005165.1, MIR100HG, and UBE2R2-AS1) associated with the prognosis of GC was constructed. The signature was validated in the TCGA database, model comparison, and qRT-PCR experiments. The results showed that the risk signature was a more effective prognostic factor for GC patients. Furthermore, the results showed that this model can well predicting chemotherapy drug response and immune infiltration of GC patients. In addition, our experimental results indicated that lower expression levels of LINC00106 and UBE2R2-AS1 predicted worse drug resistance in AGS/DDP cells. The experimental results agreed with the predictions. Furthermore, knockdown of LINC00106 or UBE2R2-AS1 can significantly enhanced the proliferation and migration of GC AGS cells in vitro. In conclusion, a novel DCS therapy-related lncRNA signature may become a new strategy to predict chemotherapy response and prognosis in GC patients. LINC00106 and UBE2R2-AS1 may exhibit a tumor suppressive function in GC.  相似文献   

9.
DNA sequencing has been revolutionized by the development of high-throughput sequencing technologies. Plummeting costs and the massive throughput capacities of second and third generation sequencing platforms have transformed many fields of biological research. Concurrently, new data processing pipelines made rapid de novo genome assemblies possible. However, high quality data are critically important for all investigations in the genomic era. We used chloroplast genomes of one Oryza species (O. australiensis) to compare differences in sequence quality: one genome (GU592209) was obtained through Illumina sequencing and reference-guided assembly and the other genome (KJ830774) was obtained via target enrichment libraries and shotgun sequencing. Based on the whole genome alignment, GU592209 was more similar to the reference genome (O. sativa: AY522330) with 99.2% sequence identity (SI value) compared with the 98.8% SI values in the KJ830774 genome; whereas the opposite result was obtained when the SI values in coding and noncoding regions of GU592209 and KJ830774 were compared. Additionally, the junctions of two single copies and repeat copies in the chloroplast genome exhibited differences. Phylogenetic analyses were conducted using these sequences, and the different data sets yielded dissimilar topologies: phylogenetic replacements of the two individuals were remarkably different based on whole genome sequencing or SNP data and insertions and deletions (indels) data. Thus, we concluded that the genomic composition of GU592209 was heterogeneous in coding and non-coding regions. These findings should impel biologists to carefully consider the quality of sequencing and assembly when working with next-generation data.  相似文献   

10.
Growth factor signaling pathways are tightly regulated by phosphorylation and include many important kinase targets of interest for drug discovery. Small molecule inhibitors of the bone morphogenetic protein (BMP) receptor kinase ALK2 (ACVR1) are needed urgently to treat the progressively debilitating musculoskeletal disease fibrodysplasia ossificans progressiva (FOP). Dorsomorphin analogues, first identified in zebrafish, remain the only BMP inhibitor chemotype reported to date. By screening an assay panel of 250 recombinant human kinases we identified a highly selective 2-aminopyridine-based inhibitor K02288 with in vitro activity against ALK2 at low nanomolar concentrations similar to the current lead compound LDN-193189. K02288 specifically inhibited the BMP-induced Smad pathway without affecting TGF-β signaling and induced dorsalization of zebrafish embryos. Comparison of the crystal structures of ALK2 with K02288 and LDN-193189 revealed additional contacts in the K02288 complex affording improved shape complementarity and identified the exposed phenol group for further optimization of pharmacokinetics. The discovery of a new chemical series provides an independent pharmacological tool to investigate BMP signaling and offers multiple opportunities for pre-clinical development.  相似文献   

11.
Anisakis spp. (Nematoda: Anisakidae) parasitize a wide range of marine animals, mammals serving as the definitive host and different fish species as intermediate or paratenic hosts. In this study, 18 fish species were investigated for Anisakis infection. Katsuwonus pelamis, Euthynnus affinis, Caranx sp., and Auxis thazard were infected with high prevalence of Anisakis type I, while Cephalopholis cyanostigma and Rastrelliger kanagurta revealed low prevalence. The mean intensity of Anisakis larvae in K. pelamis and A. thazard was 49.7 and 5.6, respectively. A total of 73 Anisakis type I larvae collected from K. pelamis and A. thazard were all identified as Anisakis typica by PCR-RFLP analysis. Five specimens of Anisakis from K. pelamis and 15 specimens from A. thazard were sequenced using ITS1-5.8S-ITS2 region and 6 specimens from A. thazard and 4 specimens from K. pelamis were sequenced in mtDNA cox2 region. Alignments of the samples in the ITS region showed 2 patterns of nucleotides. The first pattern (genotype) of Anisakis from A. thazard had 100% similarity with adult A. typica from dolphins from USA, whereas the second genotype from A. thazard and K. pelamis had 4 base pairs different in ITS1 region with adult A. typica from USA. In the mtDNA cox2 regions, Anisakis type I specimens from A. thazard and K. pelamis showed similarity range from 94% to 99% with A. typica AB517571/DQ116427. The difference of 4 bp nucleotides in ITS1 regions and divergence into 2 subgroups in mtDNA cox2 indicating the existence of A. typica sibling species in the Makassar Strait.  相似文献   

12.
Pathogenic Klebsiella pneumoniae, resistant to beta-lactam and quinolone drugs, is widely recognized as important bacteria causing array of diseases. The resistance property is obtained by acquisition of plasmid encoded blaTEM, blaSHV, blaCTX-M, QNRA, QNRB and QNRS genes. The aim of this study was to document the prevalence and association of these resistant genes in K. pneumoniae infecting patients in India. Approximately 97 and 76.7 % of the 73 K. pneumoniae isolates showed resistance towards beta-lactam and quinolone drugs respectively. Bla genes were detected in 74 % of K. pneumoniae isolates; with prevalence in the following order: blaTEM > blaSHV > blaCTXM. QNR genes were detected in 67 % samples. Chi-square analysis revealed significant association between presence of bla and qnr genes in our study (P value = 0.000125). Sequence analysis of some blaTEM, blaSHV, blaCTX-M and QNRB PCR products revealed presence of blaTEM1 (GenBank accession: JN193522), blaTEM116 (JN193523 and JN193524), blaSHV11, blaCTXM72 variants (JF523199) and QNRB1 (JN193526 and JN193527) in our samples.  相似文献   

13.
Bacteroidales species were detected in (tap) water samples from treatment plants with three different PCR assays. 16S rRNA gene sequence analysis indicated that the sequences had an environmental rather than fecal origin. We conclude that assays for Bacteroidales 16S rRNA genes are not specific enough to discern fecal contamination of drinking water in the Netherlands.Drinking water in many countries is routinely monitored for recent fecal contamination by testing for fecal indicator organisms Escherichia coli, thermotolerant coliforms, and/or intestinal enterococci to demonstrate microbial safety (13, 21, 42). Although these indicator organisms have been used for many decades, they have some limitations: the number of E. coli/coliform/enterococcus bacteria in feces is relatively low (18, 38), and they sometimes might be able to grow in the environment (10, 11, 14, 27). Consequently, scientists have been searching for alternative indicator organisms to determine fecal contamination of water. In 1967, bacteria belonging to the genus Bacteroides were suggested as alternative indicator organisms (26). Bacteroides spp. might have some advantages over the traditional indicator organisms. The numbers of Bacteroides spp. in the intestinal tract of humans and animals are 10 to 100 times higher than the numbers of E. coli or intestinal enterococci (1, 2, 12, 26). However, the use of Bacteroides spp. as indicator organisms was hampered by the complex cultivation conditions required (1, 2). The introduction of molecular methods made it possible to detect bacterial species that belong to the order Bacteroidales, an order that includes the genus Bacteroides, without cultivation. As a result, real-time PCR methods were developed for the quantitative detection of Bacteroidales in surface and recreation water and the potential of Bacteroidales species as an indication of fecal contamination of recreational waters was demonstrated (6, 12, 16, 19, 20, 29). Bacteroidales species might be useful indicator organisms for fecal contamination of drinking water as well. However, methods to detect fecal contamination in drinking water should be more sensitive, because people ingest more drinking water and the quality assessments and standards for fecal contamination are stricter than for bathing water. Studies exploring real-time PCR for the detection of Bacteroidales genes in drinking water have not been published to our knowledge. The objective of our study was, therefore, to determine if assays for the detection of Bacteroidales 16S rRNA genes can be used to detect fecal contamination in drinking water.Unchlorinated tap water samples were obtained in November 2007 and February 2010 from one or more locations in the distribution systems of nine different drinking water treatment plants (plants A to I; Table Table1)1) that produced unchlorinated drinking water from confined (plants B, C, E, F, and G) and unconfined (plants A, D, H, and I) groundwater. The treatment plants are located in the central part of the Netherlands within 90 km of each other. In addition, untreated groundwater from extraction wells and/or untreated raw groundwater (mixture of groundwater from different extraction wells) was sampled in March 2008 (Table (Table1).1). Water samples (100 ml) were filtered over a 25-mm polycarbonate filter (0.22-μm pore size, type GTTP; Millipore, Netherlands) and a DNA fragment was added as internal control to determine the recovery efficiency of DNA isolation and PCR analysis (2a, 40). DNA was isolated using a FastDNA spin kit for soil (Qbiogene, United States) according to the supplier''s protocol. Primer sets AllBac 296f and AllBac 412r, resulting in a PCR product of 108 bp, were used in combination with TaqMan probe AllBac375Bhqr to quantitatively determine the number of Bacteroidales 16S rRNA gene copies in the water samples using a real-time PCR instrument (20). The PCR cycle after which the fluorescence signal of the amplified DNA was detected (threshold cycle [CT]) was used to quantify the concentration of 16S rRNA gene copies. Quantification was based on comparison of the sample CT value with the CT values of a calibration curve graphed using known copy numbers of the Bacteroidales 16S rRNA gene, as previously described (12, 20). The correlation coefficient of the calibration curve was 0.99, and the efficiency of the PCR 95 to 105%. Finally, the Bacteroidales cell number was calculated by using the recovery rate of the internal standard and assuming five 16S rRNA gene copy numbers per cell (5). The detection limit of this gene assay was 50 Bacteroidales cells 100 ml−1 (corresponding to 10 16S rRNA gene copies per reaction mixture). Furthermore, the 16S rRNA genes that were obtained from several water samples from treatment plant C with the AllBac and TotBac (12) primer sets were sequenced, and the nearest relatives were obtained from the GenBank database using BLAST searches.

TABLE 1.

Numbers of Bacteroidales cells in extraction wells, raw groundwater, and unchlorinated tap water of nine different groundwater plants in the Netherlandsa
PlantSource of sampleNo. (100 ml−1) of Bacteroidales cells in:
200720082010
ATap water 1b5,948 ± 950
Tap water 22,682 ± 1,4591,254 ± 216
Tap water 34,362 ± 947439 ± 136
Raw water96 ± 15
BTap water 13,553 ± 9815,302 ± 2,952
Tap water 24,487 ± 3912,119 ± 1,367
Tap water 37,862 ± 4,5883,896 ± 3,003
Raw water3,209 ± 833
CTap water 1661 ± 75386 ± 199
Tap water 21,051 ± 626
Tap water 3831 ± 584
Tap water 41,254 ± 216
Extraction well 11,126 ± 262
Extraction well 22,666 ± 51
Extraction well 3<50
Raw water90 ± 44
DTap water1,103 ± 291,254 ± 216
Raw water48 ± 16
ETap water1,302 ± 2221,254 ± 216
Extraction well 1671 ± 97
FTap water1,317 ± 198
Raw water<50
GTap water 1675 ± 92439 ± 300
Tap water 2216 ± 65249 ± 98
Tap water 3154 ± 6322 ± 137
Raw water<50
HTap water7,073 ± 845
Raw water511 ± 254
ITap water1,577 ± 176
Raw water420 ± 66
Open in a separate windowaValues are the average results and standard deviations from replicate PCRs on the same water sample using the AllBac primer set (20). In November 2007, the distribution systems (tap water) of plants A, B, and G were sampled at three different locations, whereas for the other plants, one location in the distribution system was sampled. In March 2008, raw water of plants A to G was sampled, as well as one (plant E) or three (plant C) different extraction wells. Finally, in February 2010, the distribution systems of plants A, B, C, D, E, and G were sampled again.bMore than one tap water sample from a treatment plant means that samples were taken at different locations in the distribution system.The Bacteroidales 16S rRNA gene, quantified with the AllBac primer set, was detected in all tap water samples in November 2007 and February 2010. The number of cells varied between 154 and 7,862 Bacteroidales cells 100 ml−1, and the numbers in tap water of each plant were similar in 2007 and 2010 (Table (Table1).1). The Bacteroidales counts were high compared to the number of E. coli that are occasionally observed in fecally contaminated drinking water (17a) but low compared to numbers observed in surface water (4, 20, 22). Water from the extraction wells and raw water used for unchlorinated drinking water production were analyzed, and Bacteroidales species were detected in 10 out of 15 samples (Table (Table1).1). These results would imply that the extracted groundwater, raw water, and tap water were fecally contaminated. According to the Dutch drinking water decree (2b), both raw and tap water from the nine different treatment plants are regularly analyzed for fecal contamination by monitoring for E. coli, F-specific RNA phages, and somatic coliphages. For at least the last 10 years, these indicator organisms have not been detected in these waters.Additional qualitative PCR analyses using TotBac and BacUni primer sets (12, 19) targeting other parts of the Bacteroidales 16S rRNA gene were performed to confirm the presence of Bacteroidales species in the water samples of November 2007 and March 2008. Nine or 10 of the 11 samples that were positive with the AllBac primer set were also positive with the TotBac and BacUni primer sets (data not shown). The BacUni primer set has a higher detection limit (30 gene copies per PCR; 19), which could explain the difference from the results with the AllBac primer set. The TotBac primer set has the same detection limit as the AllBac primer set (12), but small differences in PCR efficiencies might have resulted in different results, since some water samples showed Bacteroidales 16S rRNA gene copy numbers around the detection limit (Table (Table1).1). Nevertheless, the additional PCR analyses demonstrated that the detection of Bacteroidales species in tap, raw, and extracted well water with the AllBac primer set was not an artifact. The primer sets used were developed in three different studies (12, 19, 20) but have been applied in a number of recent studies to detect fecal contamination of surface water (3, 4, 16, 22, 33, 34). The results from most of these studies showed that 16S rRNA genes of Bacteroidales were present in all surface water samples tested. Only Sinigalliano et al. (34) observed that 2 out of 4 water samples were negative with the TotBac primer set. However, the detection limit of the assay was not specified in that study.The nine different treatment plants tested in our study produce unchlorinated drinking water from groundwater, which is considered to be of high hygienic quality. In addition, the extraction wells are protected from fecal contamination by a protection zone where no activities related to human waste or animal manure are allowed. In the Netherlands, this protection zone is based on a 60-day residence time of the water. Previous studies have demonstrated that a residence time of 60 days is highly effective in removing fecal bacteria and viruses (30, 31, 39). Moreover, the Bacteroidales numbers in tap water in November 2007 were significantly higher than the numbers in raw groundwater in March 2008 (Mann-Whitney U test; P < 0.01). Because the recovery efficiency of the internal control was the same between raw water and tap water samples, this result demonstrates that Bacteroidales cell numbers increased during treatment and/or drinking water distribution. This result could suggest that the water was fecally contaminated during drinking water treatment and/or distribution. However, it is unlikely that the integrity of nine different treatment trains and/or supply systems was affected in the sampling period. The statutory monitoring did not show the presence of E. coli at these sites. Another hypothesis is that the increase of Bacteroidales cell numbers in tap water was caused by the growth of Bacteroidales species in (drinking) water systems. In summary, it is unexpected that the majority of the tap water, raw water, and extracted groundwater samples were fecally contaminated. These unexpected observations raise the question of whether the PCR methods detect only fecal Bacteroidales species and, thus, if the gene assays are suitable to discern fecal contamination in drinking water in the Netherlands.Sequence analyses of the Bacteroidales 16S rRNA genes were performed to determine the relatedness of sequences from the different sampling sites to sequences from the nearest relatives in the GenBank database. All sequences contained the primer regions, indicating that nonspecific amplification had not occurred in the PCRs. Because the PCR product from the AllBac primer set was small (108 bp), many 16S rRNA gene sequences (100 to 5,000) in the GenBank database were identical to the Bacteroidales 16S rRNA gene sequences obtained from groundwater and unchlorinated tap water samples from plant C. These identical 16S rRNA gene sequences were in general obtained from fecal sources, but some of them came from environmental rather than fecal sources (Table (Table2).2). The AllBac 16S rRNA gene sequences from tap water and groundwater had relative high similarities (96.3 to 100%) to sequences from bacterial species of the genera Bacteroides, Prevotella, and Tannerella (Table (Table2),2), which all belong to the order Bacteroidales.

TABLE 2.

Nearest relatives in GenBank to the Bacteroidales 16S rRNA gene sequences obtained from groundwater and unchlorinated tap water from plant C using different primer setsa
Primer set used, source of sample, and OTUsbGenBank sequence accession no.Source of sequence (GenBank sequence accession no.)SimilaritycNearest cultivated bacterium in GenBank (sequence accession no.)Similarity
AllBac
    Extraction well 1 (3/6)GQ169588Rhizosphere (EF605968)108/108Prevotella oralis (AY323522)105/108
    Extraction well 1 (3/6)GQ169589Water from watershed (DQ886209)108/108Tannerella forsythia(AB035460)107/108
    Extraction well 2 (1/6)GQ169590Phyllosphere Brazilian forest (DQ221468)108/108Tannerella forsythia(AB035460)106/108
    Extraction well 2 (5/6)GQ169591Bovine rumen (EU348207)108/108Tannerella forsythia(AB035460)106/108
    Extraction well 3 (1/6)GQ169592Phyllosphere Brazilian forest (DQ221468)108/108Prevotella oralis (AY323522)104/108
    Extraction well 3 (5/6)GQ169593Prevotella corporis (L16465)108/108Prevotella corporis (L16465)108/108
    Raw water (3/6)GQ169594Spitsbergen permafrost (EF034756)108/108Tannerella forsythia(AB035460)106/108
    Raw water (3/6)GQ169595Hindgut beetle larvae (FJ374179)108/108Tannerella forsythia(AB035460)107/108
    Tap water (6/6)GQ169596Prevotella timonensis (DQ518919)108/108Prevotella timonensis (DQ518919)108/108
    Prevotella buccalis (L16476)Prevotella buccalis (L16476)
    Prevotella ruminicola (AF218617)Prevotella ruminicola (AF218617)
    Bacteroides vulgatus (NC_009614)Bacteroides vulgatus (NC_009614)
TotBac
    Extraction well 1 (1/10)GQ169597Deep subsurface groundwater (AB237705)339/369Salinimicrobium terrae (EU135614)315/370
    Extraction well 1 (1/10)GQ169598Songhuajiang River sediment (DQ444125)363/377Paludibacter propionicigenes (AB078842)357/376
    Extraction well 1 (4/10)GQ169599Freshwater pond sediment (DQ676447)352/360Paludibacter propionicigenes (AB078842)313/372
    Extraction well 1 (4/10)GQ169600Pine River sediment (DQ833352)364/371Bacteroides oleiciplenus (AB490803)334/375
    Extraction well 2 (4/10)GQ169601Groundwater (AF273319)364/371Xanthobacillum maris (AB362815)338/375
    Extraction well 2 (6/10)GQ169602Human saliva (AB028385)381/382Prevotella intermedia (AY689226)380/382
    Extraction well 3 (1/10)GQ169603Pig manure (AY816766)354/377Bacteroides thetaiotaomicron (AE015928)311/380
    Extraction well 3 (3/10)GQ169604Pig manure (AY816867)371/376Butyricimonas virosa (AB443949)307/379
    Extraction well 3 (6/10)GQ169605Swedish lake (AY509350)343/362Parabacteroides distasonis (AB238927)320/374
    Raw water (10/10)GQ169606Prevotella timonensis (AF218617)378/379Prevotella timonensis (AF218617)378/379
    Tap water (1/10)GQ169607Deep subsurface groundwater (AB237705)338/369Salinimicrobium terrae (EU135614)312/370
    Tap water (2/10)GQ169608Yukon River, AK(FJ694652)367/372Psychroserpens burtonensis (U62913)312/375
    Tap water (7/10)GQ169609Deep subsurface groundwater (AB237705)341/369Salinimicrobium terrae (EU135614)315/370
Open in a separate windowaPrimer sets AllBac (20) and TotBac (12) were used in PCRs of samples, and GenBank was searched for relatives using BLAST.bOTUs are indicated by the values in parentheses (number of sequences belonging to the OTU/total number of sequences analyzed).cNumber of base pairs identical in both sequences/total number of base pairs in sequences.16S rRNA gene sequences obtained with the TotBac primer set were longer (∼370 bp) and did not show 100% similarity with the nearest relatives in the GenBank database (Table (Table2).2). Sequences from the GenBank database that showed the highest similarity (91.6% to 99.7%) with the 16S rRNA gene sequences from tap water and groundwater from plant C were in general isolated from environmental sources (Table (Table2).2). The 16S rRNA gene sequences from cultivated bacterial species that showed the highest similarity to the 16S rRNA gene sequences obtained in our study belonged to different genera (Table (Table2).2). Some of these genera (Salinimicrobium, Xanthobacillum, and Psychroserpens) did not belong to the order Bacteroidales. However, the 16S rRNA gene sequences from bacterial species of these genera showed low similarities with the sequences obtained in this study (83.2% to 90.1%) and six mismatches to the TotBac primers. Thus, it is unlikely that DNA from bacterial species belonging to Salinimicrobium, Xanthobacillum, and Psychroserpens was amplified in the gene assay. More importantly, the majority of the nearest environmental clone sequences retrieved from the GenBank database showed no or a single mismatch with the AllBac and TotBac primer and probe sequences. Thus, these primer sets are capable of amplifying 16S rRNA genes from bacteria that have been observed in ecosystems outside the intestinal tract of humans and animals.16S rRNA gene sequences related to Prevotella species were commonly observed in extracted groundwater, raw water, and tap water (Table (Table2).2). The isolation of Prevotella paludivivens from rice roots in a rice field soil (35) demonstrated the environmental nature of some Prevotella species. In addition, primer sequences developed for the detection of fecal Bacteroidales species (8, 12, 19, 20, 25, 29) showed no or a single mismatch with 16S rRNA gene sequences from P. paludivivens, Xylanibacterium oryzae, Paludibacter propionicigenes, Proteiniphilum acetatigenes, and Petrimonas sulfuriphila that are present in the GenBank database. These five Bacteroidales species have all been isolated from ecosystems other than the gastrointestinal tract. Consequently, primer sets for 16S rRNA genes of Bacteroidales species cannot always be used to discern fecal contamination in water.A number of 16S rRNA gene sequences observed in groundwater and tap water fell in the genus Bacteroides. The presence of Bacteroides 16S rRNA gene sequences in groundwater and tap water might also suggest that some Bacteroides species are capable of growth in the environment. However, until now, type strains of Bacteroides species growing outside the animal intestinal tract have not been published. Another possible explanation is that the observed 16S rRNA gene sequences originate from Bacteroides species that inhabit the anoxic intestinal tract of insects. Previous studies have shown that bacterial species belonging to the genus Bacteroides are common inhabitants of the hindguts of insects (15, 23, 24, 28, 32). Some of the 16S rRNA gene sequences obtained with the AllBac primer set in our study showed 100% similarity to 16S rRNA gene sequences from the hindgut of insects. Moreover, a number of 16S rRNA gene sequences isolated from the hindguts of insects (15, 23, 24, 32) showed no or a single mismatch with the TotBac and AllBac primer and probe sequences. In conclusion, these primer sets are capable of detecting Bacteroides species from the hindgut of insects as well. Water insects are normal inhabitants of groundwater and drinking water distribution systems (7, 41) and might be a source of Bacteroides species in water. Bacteroides species from insect feces do not indicate fecal pollution by warm-blooded animals, and insects do not normally shed human fecal pathogenic microorganisms. Bacteroides species from insect feces, therefore, can hamper Bacteroides gene assays developed for the detection of water fecally contaminated by warm-blooded animals. Additional cultivation techniques in combination with molecular tools are required to demonstrate the persistence or growth of Bacteroides bacteria in groundwater and drinking water or whether Bacteroides bacteria are present in water insects. However, these experiments were beyond the scope of our study.The three extraction wells of plant C are located close to each other and extract water from the same aquifer. Subsequently, extracted water from the three wells is mixed and enters the treatment plant as raw water. We hypothesize that if a fecal source in the vicinity of the extraction field of plant C contaminated the groundwater, water from the extraction wells and raw water should (partly) have the same Bacteroidales species. Although a relatively limited amount of clones was sequenced per sample (16), the diversity of Bacteroidales operational taxonomic units (OTU) within a sample was low (Table (Table2).2). In contrast, unique 16S rRNA gene sequences were observed between the different water types (e.g., extracted groundwater, raw water, and tap water) and sequence overlap between water types was low. These results demonstrate that the Bacteroidales 16S rRNA gene sequences at the sampling locations were not from the same fecal source and imply once again that Bacteroidales species were environmental rather than fecal.Finally, we hypothesized that if the Bacteroidales species observed in tap water were of nonfecal origin, human- and/or bovine-specific Bacteroidales strains should not be present in tap water. We tested for the presence of human- or bovine-specific Bacteroidales strains by using source-specific 16S rRNA gene assays (5) on tap water samples from February 2010. The results showed that human- and bovine-specific Bacteroidales 16S rRNA genes could not be detected in tap water, whereas a PCR product was always detected with the positive control. Again, these results indicate that the Bacteroidales species observed in tap water were of nonfecal origin.Overall, the results from our study indicate that gene assays for Bacteroidales detected environmental rather than fecal Bacteroidales species in groundwater and tap water from treatment plants in the Netherlands. First, Bacteroidales 16S rRNA gene sequences obtained from water samples taken at plant C showed (high) similarity to clone sequences that were isolated from environmental sources. The majority of these clone sequences and several Bacteroides clone sequences from the hindguts of insects showed no or a single mismatch with AllBac, TotBac, and BacUni primer and probe sequences. Second, the primer and probe sequences used for the gene assays have no or a single mismatch with 16S rRNA gene sequences of environmental Bacteroidales species P. paludivivens, X. oryzae, P. propionicigenes, P. acetatigenes, and/or P. sulfuriphila (9, 17, 35-37). Third, Bacteroidales 16S rRNA gene sequences from raw water and water from extraction wells were unique, and sequence overlap between water types was low. It is expected that in the case of fecal contamination of groundwater, different water types from the same groundwater area have similar Bacteroidales species. Fourth, the quantitative assays for Bacteroidales 16S rRNA genes commonly used to detect fecal contamination (3, 4, 12, 16, 19, 20, 22, 33, 34) detected Bacteroidales species in deep groundwater and tap water that have no history of fecal contamination. Fifth, Bacteroidales gene copy numbers were significantly higher in tap water than in raw groundwater, demonstrating an increase or growth of Bacteroidales species during the treatment and/or distribution of drinking water. Finally, human- and bovine-specific Bacteroidales strains were not detected in tap water. Consequently, (quantitative) assays for general Bacteroidales 16S rRNA genes are not suitable to discern fecal contamination in groundwater and unchlorinated drinking water in the Netherlands.Nucleotide sequence accession numbers.The 16S rRNA gene sequences obtained in this study were deposited in the GenBank database under accession numbers GQ169588 to GQ169609.  相似文献   

14.
In this study, we have collected and screened a total of 268 stool samples from diarrheal patients admitted to an Infectious disease hospital in Kolkata for the presence of Cryptosporidium spp. The initial diagnosis was carried out by microscopy followed by genus specific polymerase chain reaction assays based on 70 kDa heat shock proteins (HSP70). DNA sequencing of the amplified locus has been employed for determination of genetic diversity of the local isolates. Out of 268 collected samples, 12 (4.48%) were positive for Cryptosporidium spp. Sequences analysis of 70 kDa heat shock proteins locus in 12 Cryptosporidium local isolates revealed that 2.24% and 1.86% of samples were showing 99% to 100% identity with C. parvum and C. hominis. Along with the other 2 major species one recently described globally distributed pathogenic species Cryptosporidium viatorum has been identified. The HSP70 locus sequence of the isolate showed 100% similarity with a previously described isolate of C. viatorum (Accession No. JX978274.1, JX978273.1, and JN846706.1) present in GenBank.  相似文献   

15.
Dopa-responsive dystonia, a rare disorder typically presenting in early childhood with lower limb dystonia and gait abnormality, responds well to levodopa. However, it is often misdiagnosed with the wide spectrum of phenotypes. By exome sequencing, we make a rapid genetic diagnosis for two atypical dopa-responsive dystonia pedigrees. One pedigree, presented with prominent parkinsonism, was misdiagnosed as Parkinson''s disease until a known mutation in GCH1 (GTP cyclohydrolase 1) gene (NM_000161.2: c.631_632delAT, p.Met211ValfsX38) was found. The other pedigree was detected with a new compound heterozygous mutation in TH (tyrosine hydroxylase) gene [(NM_000360.3: c.911C>T, p.Ala304Val) and (NM_000360.3: c.1358G>A, p.Arg453His)], whose proband, a pregnant woman, required a rapid and less-biased genetic diagnosis. In conclusion, we demonstrated that exome sequencing could provide a precise and rapid genetic testing in the diagnosis of Mendelian diseases, especially for diseases with wide phenotypes.  相似文献   

16.
17.
18.
Bacillus circulans MTCC 7906, an extracellular alkaline protease producer was genetically characterized. B. circulans genomic DNA was isolated, oligonucleotide primers specific to alkaline protease gene of B. circulans were designed and its PCR amplification was done. The purified PCR product and pTrcHisA vector were subjected to restriction digestion with NcoI and HindIII and transformed into Escherichia coli DH5-α competent cells. The recombinant expression of alkaline protease gene studied by inducible expression and analysis by SDS-PAGE, established that the alkaline protease protein had an estimated molecular size of 46 kDa. Gene sequencing of the insert from selected recombinant clone showed it to be a 1329 bp gene encoding a protein of 442 amino acids. The sequence was blasted and aligned with known alkaline protease genes for comparison with their nucleotide and amino acid sequences. This identified major matches with three closely related subsp. of B. subtilis (B. subtilis subsp. subtilis strain 168, B. subtilis BSn5 and B. subtilis subsp. spizizenii strain W23). The insert also showed a number of substitutions (mutations) with other sp. of Bacillus which established that alkaline protease of B. circulans MTCC 7906 is a novel gene. The phylogenetic analysis of alkaline protease gene and its predicted amino acid sequences also validated that alkaline protease gene is a novel gene and the same has been accessioned in GenBank with accession number JN645176.1.  相似文献   

19.
The acquisition of multi-drug resistance (MDR) genes by pathogenic bacterial bugs and their dispersal to different food webs has become a silent pandemic. The multiplied use of different antibacterial therapeutics during COVID-19 pandemic has accelerated the process among emerging pathogens. Wild migratory birds play an important role in the spread of MDR pathogens and MDR gene flow due to the consumption of contaminated food and water. Escherichia fergusonii is an emerging pathogen of family Enterobacteriaceae and commonly causes disease in human and animals. The present study focused on the isolation of E. fergusonii from blood, saliva, and intestine of selected migratory birds of the Hazara Division. The sensitivity of isolated strains was assessed against ten different antibiotics. The isolation frequency of E. fergusonii was 69%. In blood samples, a high rate of resistance was observed against ceftriaxone (80%) followed by ampicillin (76%) whereas, in oral and intestinal samples, ceftriaxone resistant strains were 56% and 57% while ampicillin resistance was 49% and 52% respectively. The overall ceftriaxone and ampicillin-resistant cases in all three sample sources were 71% and 65% respectively. In comparison to oral and intestinal samples, high numbers of ceftriaxone-resistant strains were isolated from the blood of mallard while ampicillin-resistant strains were observed in blood samples of cattle egrets. 16S rRNA-based confirmed strains of E. fergusonii were processed for detection of CTX-M and TEM-1 gene through Polymerase chain reaction (PCR) after DNA extraction. Hundred percent ceftriaxone resistant isolates possessed CTX-M and all ampicillin-resistant strains harbored TEM-1 genes. Amplified products were sequenced by using the Sanger sequencing method and the resulted sequences were checked for similarity in the nucleotide Database through the BLAST program. TEM-1 gene showed 99% and the CTX-M gene showed 98% similar sequences in the Database. The 16S rRNA sequence and nucleotide sequences for TEM-1 and CTX-M genes were submitted to Gene Bank with accession numbers LC521304, LC521306, LC521307 respectively. We posit to combat MDR gene flow among the bacterial pathogens across different geographical locations, regular surveillance of new zoonotic pathogens must be conducted.  相似文献   

20.
Verrucous venous malformation (VVM), also called “verrucous hemangioma,” is a non-hereditary, congenital, vascular anomaly comprised of aberrant clusters of malformed dermal venule-like channels underlying hyperkeratotic skin. We tested the hypothesis that VVM lesions arise as a consequence of a somatic mutation. We performed whole-exome sequencing (WES) on VVM tissue from six unrelated individuals and looked for somatic mutations affecting the same gene in specimens from multiple persons. We observed mosaicism for a missense mutation (NM_002401.3, c.1323C>G; NP_002392, p.Iso441Met) in mitogen-activated protein kinase kinase kinase 3 (MAP3K3) in three of six individuals. We confirmed the presence of this mutation via droplet digital PCR (ddPCR) in the three subjects and found the mutation in three additional specimens from another four participants. Mutant allele frequencies ranged from 6% to 19% in affected tissue. We did not observe this mutant allele in unaffected tissue or in affected tissue from individuals with other types of vascular anomalies. Studies using global and conditional Map3k3 knockout mice have previously implicated MAP3K3 in vascular development. MAP3K3 dysfunction probably causes VVM in humans.  相似文献   

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