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1.
World J Diabetes ; 15(4): 645-653, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38680689

ABSTRACT

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have large fluctuations in blood glucose (BG), abnormal metabolic function and low immunity to varying degrees, which increases the risk of malignant tumor diseases and affects the efficacy of tumor chemotherapy. Controlling hyperglycemia may have important therapeutic implications for cancer patients. AIM: To clarify the influence of BG fluctuations on chemotherapy efficacy and safety in T2DM patients complicated with lung carcinoma (LC). METHODS: The clinical data of 60 T2DM + LC patients who presented to the First Affiliated Hospital of Ningbo University between January 2019 and January 2021 were retrospectively analyzed. All patients underwent chemotherapy and were grouped as a control group (CG; normal BG fluctuation with a mean fluctuation < 3.9 mmol/L) and an observation group (OG; high BG fluctuation with a mean fluctuation ≥ 3.9 mmol/L) based on their BG fluctuations, with 30 cases each. BG-related indices, tumor markers, serum inflammatory cytokines and adverse reactions were comparatively analyzed. Pearson correlation analysis was performed to analyze the correlation between BG fluctuations and tumor markers. RESULTS: The fasting blood glucose and 2-hour postprandial blood glucose levels in the OG were notably elevated compared with those in the CG, together with markedly higher mean amplitude of glycemic excursions (MAGE), mean of daily differences, largest amplitude of glycemic excursions and standard deviation of blood glucose (P < 0.05). In addition, the OG exhibited evidently higher levels of carbohydrate antigen 19-9, carbohydrate antigen 125, carcinoembryonic antigen, neuron-specific enolase, cytokeratin 19, tumor necrosis factor-α, interleukin-6, and high-sensitivity C-reactive protein than the CG (P < 0.05). Pearson analysis revealed a positive association of MAGE with serum tumor markers. The incidence of adverse reactions was significantly higher in the OG than in the CG (P < 0.05). CONCLUSION: The greater the BG fluctuation in LC patients after chemotherapy, the more unfavorable the therapeutic effect of chemotherapy; the higher the level of tumor markers and inflammatory cytokines, the more adverse reactions the patient experiences.

2.
FEMS Microbiol Ecol ; 97(8)2021 07 22.
Article in English | MEDLINE | ID: mdl-34244753

ABSTRACT

The spatial dynamics of picophytoplankton were investigated by flow cytometry and high-throughput sequencing in Lake Hongze, a large river-connecting lake. Picophytoplankton were mainly composed of phycocyanin-rich picocyanobacteria (PCY) and photosynthetic picoeukaryotes (PPEs). Picocyanobacteria was the dominant picophytoplankton group since the contribution of PPEs to total picophytoplankton was only 11.78%. However, PPEs were highly diverse and were composed of Chlorophyta, Bacillariophyta and Chrysophyceae. Environmental factors showed spatial differences, particularly in total phosphorus (TP), suspended solids (SS) and chemical oxygen demand (CODMn), which showed relatively high concentrations around the river channel. The abundances of PPEs and PCY showed similar spatial patterns, which were relatively low in the river course since they were negatively related to SS and CODMn. The top 10 OTUs contributed 79.18% of the total PPEs reads and affiliated with main species in PPEs. CCA results showed that, PPEs community composition was significantly impacted by temperature and DO at sites away from river channel, while was only influenced by nitrite at sites around the river channel.


Subject(s)
Chlorophyta , Diatoms , China , Environmental Monitoring , Lakes , Phosphorus , Photosynthesis , Rivers
3.
J Microbiol ; 56(11): 783-789, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30353463

ABSTRACT

Two Gram-stain negative halophilic strains, designated as LM2T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C18:1ω7c/C18:1ω6c, C16:0, C19:0 cyclo ω8c, and 11-methyl C18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2T and LM4, 24.9% relatedness between LM2T and R. tolerans EL-172T, and 36.3% relatedness between LM4 and R. tolerans EL-172T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2T (= CGMCC 1.16230T = KCTC 62028T).


Subject(s)
Lakes/microbiology , Phylogeny , Rhodobacteraceae/classification , Rhodobacteraceae/isolation & purification , Water Microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/analysis , Genes, Bacterial/genetics , Lakes/chemistry , Nucleic Acid Hybridization , Phospholipids/analysis , Quinones/analysis , RNA, Ribosomal, 16S/genetics , Rhodobacteraceae/genetics , Rhodobacteraceae/physiology , Sequence Analysis, DNA , Species Specificity , Tibet , Ubiquinone
4.
Huan Jing Ke Xue ; 39(9): 4206-4214, 2018 Sep 08.
Article in Chinese | MEDLINE | ID: mdl-30188062

ABSTRACT

The abundance and diversity of ammonia-oxidizing microorganisms in sediments of an aquacultural area of Eastern Lake Taihu were investigated. Real-time quantitative PCR was used to analyze the abundance of archaeal and bacterial amoA genes. Cloned libraries were constructed to investigate the structure and diversity of the microbial community. By comparing community characteristics of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in different zones, we found that:①Copy numbers of the bacterial amoA gene outnumbered those of archaeal amoA genes in the aquacultural zone; ②Diversity of AOA and AOB was higher in the aquaculture zone and control zone, respectively; ③ The dominant cluster of AOA and AOB in both sediments of aquiculture zone and control zone was Nitrosopumilus and Nitrosospira respectively. It was therefore the community structure of AOA (rather than AOB) in lake sediments that was affected by aquacultural activity.


Subject(s)
Ammonia/chemistry , Aquaculture , Bacteria , Geologic Sediments/microbiology , Lakes/microbiology , Archaea , Biodiversity , China , Genes, Archaeal , Genes, Bacterial , Lakes/chemistry , Oxidation-Reduction , Phylogeny
5.
J Microbiol ; 56(7): 493-499, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29948829

ABSTRACT

Strains pyc13T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEnT as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C18:1ω6c/C18:1ω7c, C16:1ω6c/C16:1ω7c, C16:0, and C12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEnT, H. sediminicola CPS11T, H. mongoliensis Z-7009T, H. ventosae Al12T, and H. fontilapidosi 5CRT, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13T (= CGMCC 1.15949T = KCTC 52660T).


Subject(s)
Halomonas/genetics , Halomonas/isolation & purification , Lakes/microbiology , Salinity , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/analysis , Halomonas/chemistry , Halomonas/classification , Nucleic Acid Hybridization , Phospholipids/analysis , Phylogeny , Quinones/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Tibet
6.
Huan Jing Ke Xue ; 38(11): 4562-4569, 2017 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-29965399

ABSTRACT

The farming of lake fisheries is an important part of the freshwater fishery industry in China. However, farming patterns of traditional fisheries maintain serious negative effects on the ecosystem of Eastern Lake Taihu. In recent years, the enclosure culture model of this lake has been optimized. In order to investigate the effects of aquaculture on the sediment properties, samples were collected from different areas of the lake (i.e. within the culture areas, outside the culture areas; from the crab-plant co-culture areas, mixed culture areas, ecological restoration areas, and control areas), in different months (January, March, April, August, and November), and at different depths (0-1 cm and 9-10 cm). The results of this sampling indicates that ① the concentrations of total nitrogen (TN) and total phosphorus (TP) in the sediments samples collected within the culture areas are slightly higher than samples collected outside the culture areas; ② compared to the crab-plant co-culture areas, lower concentrations of TN and TP are found in the samples collected from the mixed culture areas; ③ in the ecological restoration areas, aquatic plants exhibit certain positive effects with decreasing concentrations of TN and TP in the sediment. The lowest concentrations of TN and TP are detected in the sediment during the growing season of aquatic plants.


Subject(s)
Aquaculture , Geologic Sediments/chemistry , Lakes/chemistry , Nitrogen/analysis , Phosphorus/analysis , Animals , China , Environmental Monitoring , Plants , Seasons , Water Pollutants, Chemical/analysis
7.
Chin J Integr Med ; 22(6): 457-66, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26033318

ABSTRACT

OBJECTIVE: To explore the neuroprotective effects of electroacupuncture (EA) on hypoxic-ischemic encephalopathy (HIE) and to further investigate the role of glial cell line-derived neurotrophic factor (GDNF) family receptor member RET (rearranged during transfection) and its key downstream phosphatidylinositol 3 kinase (PI-3K)/protein kinase B (Akt) pathway in the process. METHODS: A total of 220 seven-day-old SD rats (of either sex, from 22 broods) were randomly divided into two groups, one (30 rats) for sham-surgery group and the other (190 rats) for HIE model group. The HIE model was established using the left common carotid artery ligation method in combination with hypoxic treatment. The successfully established rats were randomly divided into five groups, including control model group, EA group, sham-EA group, antagonist group and antagonist plus electroacupuncture group, with 35 rats in each group. Baihui (GV 20), Dazhui (GV 14), Quchi (LI 11) and Yongquan (KI 1) acupoints were chosen for acupuncture. EA was performed at Baihui and Quchi for 10 min once a day for continuous 1, 3, 7 and 21 days, respectively. The rats were then killed after the operation and injured cerebral cortex was taken for the measurement of neurologic damage by hematoxylin-eosin (HE) staining and the degenerative changes of cortical ultrastructure by transmission electron microscopy. RET mRNA level and Akt protein level were detected by real-time reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively. RESULTS: EA could ameliorate neurologic damage of the first somatic sensory area (S1Tr) and alleviate the degenerative changes of ultrastructure of cortical neurons in rats subjected to HIE. And the longer acupuncture treatment lasted, the better its therapeutic effect would be. This was accompanied by gradually increased expression of GDNF family receptor RET at the mRNA level and its downstream signaling Akt at the protein level in the ischemic cortex. CONCLUSION: EA has neuroprotective effects on HIE and could be a potential therapeutic strategy for HIE in the neonate. Activation of RET/Akt signaling pathway might be involved in this process.


Subject(s)
Electroacupuncture , Glial Cell Line-Derived Neurotrophic Factor/genetics , Hypoxia-Ischemia, Brain/genetics , Hypoxia-Ischemia, Brain/therapy , Neuroprotective Agents/therapeutic use , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-ret/genetics , Animals , Blotting, Western , Cerebral Cortex/pathology , Cerebral Cortex/ultrastructure , Female , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Hypoxia-Ischemia, Brain/pathology , Male , Nerve Degeneration/pathology , Neurons/pathology , Neurons/ultrastructure , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-ret/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction
8.
Int J Syst Evol Microbiol ; 65(7): 2194-2198, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25858243

ABSTRACT

Bacterial strain THMBR28(T) was isolated from decomposing algal scum that was collected during an algal bloom in Taihu lake, China. Cells of strain THMBR28(T) were Gram-staining-positive, facultatively anaerobic and rod-shaped. Growth was observed at 20-45 °C (optimum, 30 °C), at pH 5.0-9.5 (optimum, pH 6.5-7.5), and in the presence of 0-1.0% (w/v) NaCl (optimum, 0.5%). Strain THMBR28(T) contained MK-7 as the major menaquinone and iso-C15 : 0 as the major cellular fatty acid. The polar lipid profile contained phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and six unidentified polar lipids. The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The DNA G+C content was 57.6 mol% (Tm). Phylogenetic analysis of 16S rRNA gene sequences showed that strain THMBR28(T) belonged to the genus Tumebacillus, most closely related to Tumebacillus ginsengisoli DSM 18389(T) (95.0%) and Tumebacillus permanentifrigoris Eur1 9.5(T) (93.4%). Based on phylogenetic and phenotypic characterization, it is concluded that strain THMBR28(T) represents a novel species of the genus Tumebacillus, for which the name Tumebacillus algifaecis sp. nov. is proposed, with THMBR28(T) ( = CGMCC 1.10949(T) = NBRC 108765(T)) as the type strain.


Subject(s)
Alicyclobacillus/classification , Eutrophication , Phylogeny , Alicyclobacillus/genetics , Alicyclobacillus/isolation & purification , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry , Lakes , Molecular Sequence Data , Nucleic Acid Hybridization , Peptidoglycan/chemistry , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
9.
Huan Jing Ke Xue ; 35(6): 2314-21, 2014 Jun.
Article in Chinese | MEDLINE | ID: mdl-25158512

ABSTRACT

To better understand the effects of Corbicula fluminea bioturbation on the ammonia-oxidizing microorganisms in the surface sediment, sediment-water microcosms with different densities of Corbicula fluminea were constructed. Clone libraries and real-time qPCR were applied to analyze the community composition and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in the surface sediments. The results obtained indicated that the bioturbation of Corbicula fluminea accelerated the release of nitrogen from the surface sediment. In the amoA gene clone libraries, the identified AOA amoA gene sequences affiliated with the two known clusters (marine and soil clusters). The identified AOB amoA gene sequences mostly belonged to the Nitrosomonas of beta-Proteobacteria. The abundance of the bacterial amoA gene was higher than that of the archaeal amoA gene in all treatments. With increasing density of Corbicula fluminea, decreased abundances of the bacterial amoA gene were observed. At the same time, the diversity of AOA and AOB reduced in the Corbicula fluminea containing microcosms. In conclusion, the bioturbation of Corbicula fluminea could affected the community composition and abundance of ammonia-oxidizing microorganisms in surface sediments.


Subject(s)
Ammonia/metabolism , Archaea/classification , Bacteria/classification , Corbicula , Geologic Sediments/microbiology , Animals , Biodiversity , Genes, Archaeal , Genes, Bacterial , Oxidation-Reduction
10.
Int J Syst Evol Microbiol ; 64(Pt 11): 3844-3848, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25168611

ABSTRACT

Two anaerobic bacterial strains, MB9-7(T) and MB9-9, were isolated from decomposing algal scum and were characterized using a polyphasic approach. Phylogenetic analysis of 16S rRNA gene sequences showed that strains MB9-7(T) and MB9-9 are closely related to each other (99.7% similarity) and they are also closely related to Clostridium tyrobutyricum (96.5%). The two strains were Gram-stain positive and rod-shaped. Growth occurred at 20-45 °C, at pH 4.0-8.0 and at NaCl concentrations of up to 2% (w/v). Acid was produced from glucose, xylose and mannose. Products of fermentation in PYG medium were mainly butyrate, acetate, carbon dioxide and hydrogen. The predominant cellular fatty acids were C(14:0) and C(16:0). The cellular polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, two glycolipids, one phospholipid, one aminophospholipid and two aminolipids. The DNA G+C contents of strain MB9-7(T) and MB9-9 were 27.9 and 28.7 mol%, respectively. These results support the assignment of the new isolates to the genus Clostridium and also distinguish them from other species of the genus Clostridium. Hence, it is proposed that strains MB9-7(T) and MB9-9 represent a novel species of the genus Clostridium, with the suggested name Clostridium algifaecis sp. nov. The type strain is MB9-7(T) ( =CGMCC 1.5188(T) =DSM 28783(T)).


Subject(s)
Clostridium/classification , Phylogeny , Water Microbiology , Bacterial Typing Techniques , Base Composition , China , Clostridium/genetics , Clostridium/isolation & purification , DNA, Bacterial/genetics , Eutrophication , Fatty Acids/chemistry , Glycolipids/chemistry , Molecular Sequence Data , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
11.
Int J Syst Evol Microbiol ; 63(Pt 10): 3652-3658, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23625256

ABSTRACT

Two Gram-stain-negative, facultatively anaerobic and endospore-forming rod-shaped bacterial strains, THMBG22(T) and R24, were isolated from decomposing algal scum. Phylogenetic analysis of 16S rRNA gene sequences showed that the two strains were closely related to each other (99.7 % similarity) and that they were also closely related to Paenibacillus sacheonensis DSM 23054(T) (97-97.1 %) and Paenibacillus phyllosphaerae DSM 17399(T) (96.1-96.4 %). This affiliation was also supported by rpoB-based phylogenetic analyses. Growth was observed at 20-40 °C (optimum, 30-37 °C) and at pH 5.0-9.0 (optimum, pH 6.0-7.0). The cells contained MK-7 as the sole respiratory quinone and anteiso-C15 : 0 as the major cellular fatty acid. Their cellular polar lipids were composed of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and 12 unidentified polar lipids. The diamino acid of their cell-wall peptidoglycan was meso-diaminopimelic acid. The DNA-DNA hybridization value between THMBG22(T) and R24 was 84 %, and DNA-DNA relatedness to the most closely related species with a validly published name (P. sacheonensis) was 35-37 %. These results supported the assignment of the new isolates to the genus Paenibacillus and also distinguished them from the previously described species of the genus Paenibacillus. Hence, it is proposed that strains THMBG22(T) and R24 represent a novel species of the genus Paenibacillus, with the name Paenibacillus taihuensis sp. nov. The type strain is THMBG22(T) ( = CGMCC 1.10966(T) = NBRC 108766(T)).


Subject(s)
Eutrophication , Lakes/microbiology , Paenibacillus/classification , Phylogeny , Base Composition , China , DNA, Bacterial/genetics , Diaminopimelic Acid/analysis , Fatty Acids/analysis , Molecular Sequence Data , Nucleic Acid Hybridization , Paenibacillus/genetics , Paenibacillus/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/analysis , Water Microbiology
12.
Int J Syst Evol Microbiol ; 63(Pt 3): 913-919, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22634705

ABSTRACT

Bacterial strain THMBM1(T) was isolated from decomposing algal scum that was collected during an algal bloom in Lake Taihu, Wuxi City, Jiangsu Province, China. Cells of strain THMBM1(T) were Gram-negative, facultatively anaerobic, non-motile rods. Colonies on tryptic soy agar were translucent and shiny with entire edges; yellow flexirubin-type pigments were produced. Growth was observed at 15-45 °C (optimum 30-37 °C), at pH 5.0-9.0 (optimum pH 8.0) and in the presence of 0-4.0 % (w/v) NaCl (optimum 0-1.0 %). Strain THMBM1(T) contained MK-6 as the sole respiratory quinone and sym-homospermidine as the predominant polyamine. The predominant cellular fatty acids were iso-C15 : 0 (53.2 %), iso-C17 : 0 3-OH (15.6 %) and iso-C17 : 1ω9c (11.9 %). The polar lipid profile consisted of phosphatidylethanolamine and five unidentified lipids. The DNA G+C content was 36.8 mol% (Tm). Strain THMBM1(T) was closely related to members of the genus Chryseobacterium, with 16S rRNA gene sequence similarities ranging from 92.9 to 97.2 %, the highest sequence similarities being with Chryseobacterium taiwanense BCRC 17412(T) (97.2 %) and C. gambrini 5-1St1a(T) (97.1 %). DNA-DNA relatedness between strain THMBM1(T) and C. taiwanense JCM 21767(T) and C. gambrini DSM 18014(T) was 34.1  and 23.0 %, respectively. Based on these results, it is concluded that strain THMBM1(T) represents a novel species, for which the name Chryseobacterium taihuense sp. nov. is proposed. The type strain is THMBM1(T) ( = CGMCC 1.10941(T)  = NBRC 108747(T)). Emended descriptions of the genus Chryseobacterium and C. taiwanense, C. jejuense and C. indoltheticum are also proposed.


Subject(s)
Chryseobacterium/classification , Lakes/microbiology , Phylogeny , Bacterial Typing Techniques , Base Composition , China , Chryseobacterium/genetics , Chryseobacterium/isolation & purification , DNA, Bacterial/genetics , Eutrophication , Fatty Acids/analysis , Molecular Sequence Data , Nucleic Acid Hybridization , Phosphatidylethanolamines/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Spermidine/analogs & derivatives , Spermidine/analysis , Vitamin K 2/analogs & derivatives , Vitamin K 2/analysis , Water Microbiology
13.
Huan Jing Ke Xue ; 32(7): 2125-31, 2011 Jul.
Article in Chinese | MEDLINE | ID: mdl-21922841

ABSTRACT

The Legionella spp. are ubiquitous in aquatic environment and could cause certain risks on human health. In order to investigate the distribution and diversity of Legionella spp. in Lake Taihu during winter time, water samples were collected from 32 sites of the whole lake in February 2010. The presence of Legionella spp. was screened by nested-PCR and their phylogenetic diversity was determined by denaturing gradient gel electrophorese (DGGE) and sequencing analysis of excised DGGE bands. The Legionella spp. was detected from 21 out of 32 sites in particle-associated bacterial samples and 11 out of 32 sites in free-living bacterial samples, which accounted for 65.63% and 34.38% of each type of bacteria, respectively. In total, 40 and 36 unique bands were identified among those particle-associated and free-living bacterial DGGE profiles, respectively. Community characteristic indices of different euthrophic areas showed that the diversity of Legionella spp. in mild eutrophic areas was higher than that in the moderate eutrophic areas. In total, thirty-four DGGE bands were excised and sequenced, which could be classified into 12 OTUs by 97% similarity. Among all the sequences, three showed a high similarity with two pathogenic Legionella species Legionella feeleii and Legionella longbeachae. This revealed potential healthy risks to the people lived around the Lake Taihu.


Subject(s)
Biodiversity , Fresh Water/analysis , Legionella/classification , Water Microbiology , China , Legionella/growth & development , Legionella/isolation & purification , Phylogeny , Population Dynamics , Seasons
14.
Huan Jing Ke Xue ; 31(9): 2178-83, 2010 Sep.
Article in Chinese | MEDLINE | ID: mdl-21072943

ABSTRACT

PCR-based techniques are commonly used to characterize ammonia-oxidizing bacterial (AOB) communities, but are subjected to the bias induced by PCR primers. In this study, the sensitivity and specificity of two pairs of primer were assessed based on a group of lake sediment samples. Compared to the low sensitivity of the CTO primer, the betaAMO primer produced intensive single bands in all samples tested. However, the sequences retrieved from one of the samples by betaAMO did not cluster with Nitrosomonadales, to which all beta-AOB affiliate. In contrast, all sequences amplified with CTO fell within the Nitrosomonas europaea/"Nitrosococcus mobilis" lineage. Furthermore, the products of four approaches were subjected to denaturing gradient gel electrophoresis (DGGE), and the patterns of the nested strategies with betaAMO followed CTO or the universal primer of 16S rRNA gene followed CTO were highly similar to that of CTO amplification. These findings suggest that betaAMO is not competent for charactering the beta-AOB communities due to the low specificity. The nested approaches with both selective and specific primers are the choice because they can amplify effectively and retrieve community composition of beta-AOB in lake sediments.


Subject(s)
Ammonia/metabolism , Fresh Water/microbiology , Geologic Sediments/microbiology , Nitrosomonas/classification , Water Microbiology , Nitrogen/metabolism , Nitrosomonas/genetics , Nitrosomonas/metabolism , Oxidation-Reduction , Phylogeny , Polymerase Chain Reaction/methods , Population Dynamics
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