Bartonella Prevalence and Genome Sequences in Rodents in Some Regions of Xinjiang, China.

In this study, we investigated Bartonella infection and its genetic diversity in rodents in Beitun, Xinjiang Uygur Autonomous Region, China. Small mammals were captured using snap traps at four sampling sites in 2018. Spleen and liver tissues were collected and cultured to isolate Bartonella strains. Whole-genome sequencing was performed on the strains identified as Bartonella by gltA gene PCR, and the average nucleotide identity (ANI) of the genomes was calculated by using FastANI v1.33. Phylogenetic trees were constructed for the samples positive for Bartonella spp. by the gltA PCR assay based on 1,290-bp gltA genes, 2,903-bp rpoB genes, and core-genome single nucleotide polymorphisms (SNPs). Among 66 rodents, 11 were positive for Bartonella, with an infection rate of 16.67%. The rodent infection rates in different tissues (χ2 = 2.133; P = 0.242), species (χ2 = 9.631; P = 0.141), and habitats (χ2 = 4.309; P = 0.312) did not show statistical differences. Bartonella spp. isolated from the rodents were phylogenetically divided into six clades (two different Bartonella species were detected in two rodents). By comparing phylogenetic trees based on gltA genes, rpoB genes, and SNPs, we found that the topological structures of several evolutionary trees are different. However, the Bartonella strains isolated in this study were clustered into six clusters in different phylogenetic trees. Broad distributions and high genetic diversity of Bartonella strains were observed among rodents in Beitun, Xinjiang. IMPORTANCE Rodent-borne Bartonella species have been associated with zoonotic diseases. Bartonella species such as Bartonella elizabethae, Bartonella grahamii, and Bartonella tribocorum can cause disease in humans. Humans can be infected by blood-sucking arthropods through the scratches and bites of an infected reservoir host or via contact with infectious rodents. Xinjiang is one of the provinces with the most abundant species of Bartonella in China, but there are few reports about the prevalence of Bartonella in the Beitun area. This research aims to investigate the occurrence and prevalence of Bartonella infection in rodents at these sampling sites and provide a basis for the prevention and control of rodent Bartonella species in Beitun and the surrounding areas of Xinjiang.

Variation of Bacterial and Archaeal Community Structures in a Full-Scale Constructed Wetlands for Wastewater Treatment.

Microorganisms play important roles in the reduction of organic and inorganic pollutants in constructed wetlands used for the treatment of wastewater. However, the diversity and structure of microbial community in constructed wetland system remain poorly known. In this study, the Illumina MiSeq Sequencing of 16S rDNA was used to analyze the bacterial and archaeal microbial community structures of soil and water in a free surface flow constructed wetland, and the differences of bacterial communities and archaeal compositions between soil and water were compared. The results showed that the Proteobacteria were the dominant bacteria, making up 35.38%~48.66% relative abundance. Euryarchaeotic were the absolute dominant archaea in the influent sample with the relative abundance of 93.29%, while Thaumarchaeota showed dominance in the other three samples, making up 50.58%~75.70%. The relative abundances of different species showed great changes in bacteria and archaea, and the number of dominant species in bacteria was much higher than that in archaea. Compared to archaea, the community compositions of bacteria were more abundant and the changes were more significant. Meanwhile, bacteria and archaea had large differences in compositions between water and soil. The microbial richness in water was significantly higher than that in soil. Simultaneously, soil had a significant enrichment effect on some microbial flora.

Immune response- and viral control-related pathways in the progression of chronic hepatitis B.

BACKGROUND: Chronic hepatitis B (CHB) is a complicated and dynamic course, and is associated with advanced liver disease. Host immune response against viral infection plays a pivotal role in the progression of CHB. However, it is still uncharted that how the hepatic transcriptomes in patients with CHB are correlated with the clinical phases. OBJECTIVE: This study aimed to identify the specific sub-networks across various phases of CHB and infer potential pathways for phenotypic outcome prediction. METHODS: In this study, we performed the pairwise comparisons of the hepatic transcriptomes of CHB patients under different phases, and constructed the differential co-expression networks (DCNs). We firstly identified the critical genes from each DCN according to the adjacency matrix of the network. Then, the specific sub-networks were digged by iteratively affiliating genes that can increase the classification accuracy, using a snow-ball sampling strategy. Permutation test was implemented to determine the statistical significance of these sub-networks. Finally, each sub-network was given a most significant functional pathway. RESULTS: We constructed 3 DCNs by pairwise comparing the hepatic transcriptomes among three CHB phases, and systemically tracked 1, 1 and 2 specific sub-networks and pathways, respectively. Relative to immune tolerant phase, TGF-beta receptor signaling in EMT (epithelial to mesenchymal transition) pathway was significantly changed in the immune clearance phase, and nuclear receptor transcription pathway and adenylate cyclase activating pathway were altered in inactive carrier state. The host genes related to DNA strand elongation showed significant difference between the immune clearance phase and inactive carrier state. CONCLUSIONS: By pairwise comparing the hepatic transcriptomes of CHB patients under a network view, several immune- and viral control-related pathways were identified in this study. These results might serve as a foundation for characterizing the host transcriptomes responded to CHB infection, and hold clues for the development of potential targets for disease control.

The effect of energy substrates on PHB accumulation of Acidiphilium cryptum DX1-1.

The effect of glucose and elemental sulfur on the growth and PHB accumulation of Acidiphilium cryptum DX1-1 was investigated. Meanwhile, the differential expressions of 19 genes related with PHB accumulation, sulfur metabolism and carbon fixed in heterotrophy, phytotrophy and mixotrophy were studied by RT-qPCR. The results showed that strain DX1-1 could accumulate PHB with sulfur as the energy substance and atmospheric CO2 as carbon resource. Glucose could improve the growth of strain DX1-1 cultured in medium with sulfur as the energy substance, and almost all the key enzyme-encoding genes related with PHB, sulfur metabolism and carbon fixed were basically up-regulated. PHB polymerase (Arcy_3030), ribulose-bisphosphate carboxylase (Acry_0825), ribulose-phosphate-epimerase (Acry_0022), and cysteine synthase A (Acry_2560) played important role in PHB accumulation, the modified expression of which could influence the PHB yield. With CO2 as carbon resource, the main initial substance of PHB accumulation for strain DX1-1 was acetyl-CoA, instead of acetate with the glucose as the carbon resource. Because of accumulating PHB by fixed atmospheric CO2 while independent of light, A. cryptum DX1-1 may have specifically potential in production of PHB.

[Seasonal Variation and Influencing Factors of Bacterial Communities in Storage Reservoirs].

In order to explore the seasonal variation and influencing factors of bacterial community structure in storage reservoirs, the impact of environmental factors must first be examined. In this study, the seasonal variation in bacterial community structure and its response to water quality factors were explored by monitoring the water quality of Qingdao Jihongtan Reservoir, the only reservoir of the Yellow River diversion project, using high-throughput sequencing technology and symbiotic network analysis. The results showed that the diversity and richness of bacterial communities were highest in summer and lowest in winter, and those in the inlet were higher than those in the outlet. The structure of the bacterial community was similar in spring and winter and in summer to autumn. The dominant bacteria phyla were:Actinobacteriota (6.63%-57.38%), Proteobacteria (11.32%-48.60%), Bacteroidota (5.05%-25.74%), and Cyanobacteria (0.65%-24.74%). Additionally, the abundances of Chloroflexi, Dependentiae, Fusobacteriota, and Margulisbacteria were the highest in autumn and the lowest in winter. The dominant bacterial genera were:hgcI_clade (3.72%-34.66%), CL500_29_marine_group (0.31%-20.13%), and Limnohabitans (0.16%-10.37%). Further, the abundances of Flavobacterium, Polaromonas, and Rhodoferax were the highest in winter and the lowest in summer; the trend of Domibacillus and Limnobacter was the opposite. The abundance of Proteobacteria and Campilobacteria in the inlet was significantly higher than that in the outlet, and the Planctomycetota showed the opposite. The abundances of Dinghuibacter, Arenimonas, and Rhodobacter in the inlet were significantly higher than those in the outlet. Competition and antagonism dominated the interaction relationship of bacterial communities in spring, whereas mutualism dominated in winter. There were significant differences among key species in the symbiotic network at different seasons and sampling sites. Water temperature, DO, water storage capacity, and water storage sources had a great influence on bacterial community structure in the Jihongtan Reservoir.

Increased frequency of circulating Th17 cells in acute-on-chronic hepatitis B liver failure.

BACKGROUND: T helper (Th) 17 cells participate in the pathogenesis of liver diseases but their exact role in acute-on-chronic hepatitis B liver failure (ACHBLF) still remains obscure. AIMS: This present study was aimed to characterize the circulating Th17 cells and to analyze their association with disease progression in ACHBLF. METHODS: This retrospective study consisted of 40 ACHBLF patients, 40 chronic hepatitis B (CHB) patients and 20 healthy controls. The frequency of peripheral Th17 cells and IL-17 mRNA level in peripheral blood mononuclear cells (PBMCs) were estimated by flow cytometry and relative quantitative real-time polymerase chain reaction. RESULTS: We found that the frequency of peripheral Th17 cells, as well as the level of IL-17 mRNA in PBMCs, was significantly increased in ACHBLF patients compared with CHB patients and healthy controls. In ACHBLF patients, the frequency of Th17 cells was positively correlated with serum total bilirubin (r = 0.392, P = 0.012) and model for end-stage liver disease scores (r = 0.383, P = 0.015), but negatively correlated with prothrombin activity (r = -0.317, P = 0.046). The same trend was observed as for relative expression of IL-17. Furthermore, the frequency of Th17 cells and IL-17 mRNA level were significantly elevated in non-survivors compared with survivors in ACHBLF patients. CONCLUSIONS: These results suggested that Th17 cells as well as IL-17 might be related with disease severity and prognosis in ACHBLF patients.

Methylation of the glutathione-S-transferase M3 gene promoter is associated with oxidative stress in acute-on-chronic hepatitis B liver failure.

Chronic hepatitis B (CHB) is a major cause for liver disease worldwide, ranking as the first cause for liver cirrhosis and hepatocellular carcinoma. Acute-on-chronic hepatitis B liver failure (ACHBLF) is most commonly caused by acute severe exacerbation during CHB virus infection. The pathophysiology of ACHBLF is still poorly understood. Glutathione-S-transferase (GST) M3 belongs to GSTs superfamily and it has been demonstrated to contribute to oxidative stress-mediated liver damage. The present study was aimed to determine the potential association between GSTM3 promoter methylation and oxidative stress in ACHBLF patients. Thirty ACHBLF patients, 30 CHB patients and 10 healthy controls were included in this study. Methylation of GSTM3 promoter was determined using methylation-specific PCR (MSP) method. Plasma biomarkers for oxidative stress including malondialdehyde (MDA) and GST were detected by enzyme-linked immunosorbent assay (ELISA). Model for end-stage liver disease (MELD) scoring system was used for predicting the severity and prognosis of liver failure. ACHBLF patients had significant higher GSTM3 promoter methylation rate than CHB patients (30% versus 6.7%, χ(2) = 5.455, P = 0.020). Plasma MDA and GST levels were significantly increased in ACHBLF patients compared with CHB patients. Meanwhile, MDA, MELD scores and mortality rate were significantly higher in methylated group than those in unmethylated group of ACHBLF patients. Furthermore, plasma MDA levels were positively correlated with MELD scores of ACHBLF (r = 0.588, P = 0.001). In conclusion, the methylation of GSTM3 promoter may contribute to oxidative stress-associated liver damage and correlate with the disease severity in ACHBLF.

Enhanced demethylation of interferon-γ gene promoter in peripheral blood mononuclear cells is associated with acute-on-chronic hepatitis B liver failure.

Acute-on-chronic hepatitis B liver failure (ACHBLF) refers to liver failure occurring in patients with chronic hepatitis B (CHB) related liver diseases. Interferon-γ (IFN-γ) plays an important role in the exacerbation of liver function. However, the exact mechanism, by which IFN-γ mediates ACHBLF, is not fully understood. Forty patients with ACHBLF, fifteen patients with CHB and ten healthy controls were included in this present study. ELISA was performed to measure the level of serum IFN-γ. The methylation status of IFN-γ promoter in peripheral blood mononuclear cells (PBMCs) was determined using methylation-specific PCR. Model for End-stage Liver Disease (MELD) scoring was performed for evaluating the severity of liver failure. The serum level of IFN-γ in patients with ACHBLF or CHB was significantly lower than that in healthy controls, while the serum IFN-γ level in ACHBLF patients was significantly higher than that in CHB patients. In ACHBLF patients, the level of IFN-γ was positively correlated with total bilirubin and MELD score, but negatively correlated with prothrombin time activity. These results suggest the involvement of IFN-γ in the pathogenesis of ACHBLF. Importantly, the degree of methylation of the IFN-γ gene promoter in ACHBLF patients (60%, 24/40) was significantly lower than that in CHB patients (93%, 14/15), but was higher than that in the control group (20%, 2/10). Furthermore, in ACHBLF patients, the serum IFN-γ level was significantly higher in unmethylation group than that in methylation group. In conclusion, enhanced demethylation of IFN-γ gene promoter in PBMCs may be associated with the onset of ACHBLF.

[Micro-morphological Characteristics of Particles on Holly and Ligustrum Leaf Surfaces and Seasonal Changes in Bacterial Communities].

The characteristics of particles and microorganisms on leaf surfaces have great significance for the near-surface environment and ecology. Here, fresh leaves of holly and Ligustrum were examined from different functional areas in Qingdao. Environmental scanning electron microscopy was used to observe particles and microorganisms on the leaf surfaces during different seasonal, and Illumina high-throughput sequencing was performed to analyze the phyllosphere bacterial community structure. The results showed that the retention of TSP on leaves in autumn and winter was higher than in spring and summer. The leaves of the two plants were more likely to retain PM10 and PM2.5; however, the dust retention capacity of holly leaves was higher than that of Ligustrum, especially for particle sizes greater than 10 µm. The numbers of particles on the leaf surfaces along an urban main road were higher than in two other locations, and were greatly affected by ground dust and automobile exhaust emissions. The community structure of phyllospheric microorganisms showed distinct seasonal variation, with different types of fungi, fungal spores, and mycelium observed on the leaf surfaces. Mycelium was more frequently detected on leathery leaves, and fungal spores with even folds were detected on the leaf epidermis of Ligustrum. The relative abundances of phyllospheric microorganisms were highest on leaves from an urban park, explained by a positive effect of humidity on growth. Significant differences in bacterial community abundance were observed between seasons. Specifically, bacterial abundance was highest in spring and lowest in summer. γ-Proteobacteria were the dominant bacteria, and the two plants shared a similar core microbial community. In addition, the phyllospheric bacterial community structure of leaves from urban arterial roads with ground dust pollution was significantly different from the leaves collected from other city areas. Our research results suggest a significant correlation between the leaf-surface particles and microbial community structure on representative plants in different areas of the city, which provides reference information for urban greening activities.

Gpc-3 is a notable diagnostic, prognostic and a latent targeted therapy marker in hepatocellular carcinoma.

BACKGROUND/AIMS: To describe the features of the Gpc-3, explore the significance and value about the role of Gpc-3 in pathological diagnosis and prognostic evaluation of hepatocellular carcinoma. METHODOLOGY: Take an overview of Gpc-3 expression in hepatocellular carcinoma and its expression of the relationship between the clinicopathological features of hepatocellular carcinoma, analysis the expression of Gpc-3 in liver cell adenoma, heterosexual hyperplasia and hepatitis C. RESULTS: The expression of GPC-3 has a certain amount of specificity and sensitivity in hepatocellular carcinoma. CONCLUSIONS: Gpc-3 is not only a diagnostic and prognostic marker in hepatocellular carcinoma, but also is expected to be an ideal target for the therapy of hepatocellular carcinoma.

Real-time PCR analysis of metabolic pathway of PHB in Acidiphilium cryptum DX1-1.

The time, yield and related genes expression of PHB accumulation of Acidiphilium cryptum DX1-1 were investigated under four different initial C/N ratios 1.2, 2.4, 7.5, and 24. The results of time and yield of PHB accumulation show that the initial C/N ratio 2.4 was optimum for strain DX1-1 to accumulate PHB, both higher and lower initial C/N ratios did not favor that process. Based on the genome of Acidiphilium cryptum JF-5, 13 PHB accumulation related genes in strain JF-5 were chosen and successfully cloned from strain DX1-1. The differential expression of the 13 functional genes, in different C/N ratios as cited above, was then studied by Real-time PCR. The results show that all the 13 genes were most upregulated when initial C/N ratio was 2.4, and among which the gene Acry_3030 encoding poly-beta-hydroxybutyrate polymerase and Acry_0626 encoding acetyl-CoA synthetase were much more upregulated than the other genes, which prove that they play the most important role for PHB accumulation and acetate is the main initial substance for PHB accumulation for strain DX1-1. Potential regulatory motifs analysis shows that the genes related to PHB accumulation are regulated by different promoters and that the motif had weak similarity to the model promoters, suggesting that PHB- metabolism in Acidiphilium cryptum may be mediated by a different mechanism.

Characterization of astrocytes and microglial cells in the hippocampal CA1 region after transient focal cerebral ischemia in rats treated with Ilexonin A.

Ilexonin A is a compound isolated from the root of Ilex pubescens, a traditional Chinese medicine. Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia. However, the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear. Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats. Ilexonin A (20, 40 or 80 mg/kg) was administered immediately after ischemia/reperfusion. The astrocyte marker glial fibrillary acidic protein, microglia marker Iba-1, neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay. Expression levels of tumor necrosis factor-α and interleukin 1ß were determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue. Astrocytes were activated immediately in progressively increasing numbers from 1, 3, to 7 days post-ischemia/reperfusion. The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A. Microglial cells remained quiescent after ischemia/reperfusion, but became activated after treatment with ilexonin A. Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-α and interleukin 1ß in the hippocampus post-ischemia/reperfusion. The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion, probably through regulating astrocytes and microglia activation, promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors. This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital, China.

[Diffusion of Microorganism and Main Pathogenic Bacteria During Municipal Treated Wastewater Discharged into Sea].

Numerous microorganisms, especially pathogens, exist in treated wastewater, which leads to possible risk to population health and marine ecological security when treated wastewater is discharged into the sea. This study selects Maidao municipal sewage treatment plant as the location. The microbial community and the dynamic distribution and seasonal variation of pathogens are analyzed by high-throughput sequencing technology. The results showed that the microbes in the discharge were distributed into 20 to 27 phyla, and the dominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes, which were mainly distributed in 44 to 65 classes. The predominant pathogens are mainly composed of Gammaproteobacteria, Betaproteobacteria, and Epsilonproteobacteria in the Proteobacteria category. The proportion of most dominant phyla and classes in the sample decreased with an increase in diffusion distance. There were mainly 55 species pathogenic bacteria in the water discharging into the sea. The pathogenic genes in the discharge were mainly related to cancer, cardiovascular disease, immune system diseases, infectious diseases, metabolic diseases, and neurodegenerative diseases. When compared with the blank samples, it was found that the biomass of pathogenic bacteria decreased sharply with the diffusion by the seawater, and most of the pathogens were not detected 1000 m away from the seashore. Arcobacter spp. caused human and animal diarrhea and bacteremia, Acinetobacter spp. caused nosocomial infections, and Shewanella hafniensis posed a threat to seafood farming and fishing. The three species of pathogenic bacteria mentioned above occupied a fairly large proportion of the discharge into the sea.

[Influence of Different Patterns of Discharge on Microbial Diffusion in Municipal Treated Wastewater].

Numerous pathogens exist in treated wastewater, leading to possible population health and ecological security risks when treated waste water is reused or discharged. To investigate the influence of different patterns of discharge on microbial diffusion in the municipal treated waste water, high-throughput sequencing technology was used to analyze the bacterial community structure, dominant flora, and typical pathogens. It was found that those bacteria were distributed in 58 classes. There were 32 species with a relative abundance of more than 1%. While there were only 41 classes in the water sample taken as a direct discharge to the sea, and there were 28 species with relative abundances of more than 1%. The water sample collected as a discharge to the sea through a river displayed higher bacterial diversity than the sample collected as a direct discharge to the sea, indicating that the microorganisms in the treated waste water was more likely to diffuse in when directly discharged to the sea. The relative abundance of dominant bacteria decreased with an increase in the diffusion distance, while the relative abundance of Cyanobacteria increased as the diffusion distance increased. The relative abundance in the water sample collected as a discharge to the sea through a river was higher. The dominant bacteria in the two systems are to Proteobacteria, Bacteroidetes, and Firmicutes. However, the dominant bacteria at the class and species levels quite dissimilar in the two systems. The bacterial diversities near the outfall were much higher than that in the seawater (blank sample), and the abundance was higher, which related to sewage treatment. In addition, there was a certain amount of pathogens and potential pathogens, including Pseudoalteromonas haloplanktis and Pseudomonas anguilliseptica, which were highly pathogenic. Their relative abundances were still higher after dilution. Arcobacter spp. was related to human and animal diarrhea and bacterial and other diseases. Therefore, the detection of these types of bacteria when the treated waste water is discharged is very important.

Neuroprotective effects of Ilexonin A following transient focal cerebral ischemia in rats.

Ilexonin A is a compound isolated from the root of a plant commonly used in traditional Chinese medicine. The aim of the present study was to investigate the possible protective mechanism of Ilexonin A in rats subjected to occlusion of the middle cerebral artery (MCAO). Transient focal cerebral ischemia was induced by 2 h of MCAO, followed by reperfusion. Ilexonin A at doses of 20, 40 and 80 mg/kg were administered via intraperitoneal injection immediately following ischemia/reperfusion. The expression levels of glial fibrillary acidic protein (GFAP), ionized calcium­binding adapter molecule­1 (Iba­1), vascular endothelial growth factor (VEGF), fetal liver kinase­1 (Flk­1) and Nestin were examined using immunostaining and Western blot analysis of the peri­infarct region following ischemia/reperfusion. Ilexonin A significantly decreased the infarct volume and improved neurological deficits in a dose­dependent manner. The expression levels of VEGF, Flk­1 and Nestin were significantly increased in the rats treated with Ilexonin A, compared with the rats administered with saline. Following treatment with Ilexonin A, a higher number of GFAP­positive astrocytes were found in the Ilexonin A­treated rats at 1, 3 and 7 days, compared with the rats exposed to ischemia only, however, there were fewer astrocytes at 14 days, compared with the ischemia group. Ilexonin A significantly decreased the protein expression of Iba­1. The results of the present study suggested that the protective effects of Ilexonin A were associated with revascularization, neuronal regeneration, and the regulation of astrocyte and microglia cell activation.

[Phylogenetic diversity of airborne microbes in Qingdao downtown in autumn].

To determine the community structure of airborne microbes in Qingdao downtown in autumn, the airborne bacteria and fungi were collected by the KC-6120 air sampler and analyzed using the 16S/18S rDNA gene clone library method. Phylogenetic analysis of airborne bacteria showed that they belonged to six major phylogenetic groups: Proteobacteria (78. 8%), Firmicutes (14.6%), Actinobacteria (4.0%), Planctomycetes (1.3%), Cyanobacteria (0.7%), and Deinococcus-Thermus (0.7%). The dominant genera of airborne bacteria included Acinetobacter (39.7%), Staphylococcus (11.3%), Sphingomonas (8.6%), Paracoccus (6.0%) and Massilia (5.3%). The main types of airborne fungi were Ascomycota (97.5%) and Basidiomycota (2.5%). Dominant genera of airborne fungi included Pyrenophora (76.5%), Xylaria (13.6%) and Exophiala (2.5%). The pathogens or conditioned pathogens, such as Acinetobacter, Staphylococcus, or Sphingomonas were detected in the airborne bacteria, whereas certain kinds of fungi, such as P. graminea, X. hypoxylon and Zasmidium angulare that could cause a variety of crop diseases were also detected.

[Carbon sources metabolic characteristics of airborne microbial communities in constructed wetlands].

Using BIOLOG-GN plates, this article describes the carbon sources metabolic characteristics of airborne microbial communities in a free surface-flow constructed wetland in different seasons and clarify the correlation between airborne microbial metabolic functions and environmental factors. The average well color development (AWCD), carbon metabolic profiles and McIntosh values of airborne microbial communities in different seasons were quite different. Analysis of the variations showed that AWCD in spring and summer differed significantly from that in autumn and winter (P < 0.01). In the same season, the degree of utilization of different types of carbon by airborne microbes was different. Summer had a significant difference from other seasons (P < 0.05). Dominant communities of airborne microbes in four seasons were carboxylic acids metabolic community, carbohydrates metabolic community, polymers metabolic community and carboxylic acids metabolic community respectively. Principal component analysis showed that the carbon metabolic characteristics of airborne microbial community in autumn were similar to those in winter but different from those in spring and summer. The characteristics of carbon metabolism revealed differences between summer and spring, autumn, or winter. These differences were mainly caused by amines or amides while the differences between spring and autumn or winter were mainly caused by carboxylic acids. Environmental factors, including changes in wind speed, temperature, and humidity acted to influence the carbon sources metabolic properties of airborne microbial community. The dominant environmental factors that acted to influence the carbon sources metabolic properties of airborne microbial community varied between different seasons.

[Microbial community of municipal discharges in a sewage treatment plant].

There are numerous microorganisms, especial pathogens, in the discharges. Those microorganisms are discharged into the river and sea through sewage outfalls, which results in possible health risks to coastal populations. And more attention should be paid to municipal discharges in developing countries. This study investigated the microbial community in the discharges by constructing 16S rDNA clones library and using the PCR-RFLP technology. Phylogenetic analysis of bacteria in municipal discharges showed that there were 59 species, which were divided into 11 classes. Proteobacteria accounted for 85% of all the bacteria, of which ß-Proteobacteria and γ- Proteobacteria were the dominant classes. Bacteria in the waste water treating process had important influence on microbial community in municipal discharges, therefore, municipal sewage plant should choose the process according to the characteristics and purifying capacity of the receiving water body. Legionella spp. accounted for approximately 10% , the Legionnaires' disease resulted from which might be of top risk for the residents in the surrounding of the municipal discharges outfall and receiving water. Dechloromonas aromatica could make use of chlorite ( CIO - ) , which led to its survival from chlorine disinfection, and it alerted us that several disinfection methods should be used together to ensure the bacterial safety of municipal discharges. Coliform group and other pathogenic bacteria, such as Salmonella spp. , Shigella spp. , Escherichia coli, Vibrio cholerae, Staphylococcus aureus, Arcobacter spp. were not detected in this study, and it indicated that we should do more work and use more methods to investigate the perniciousness of discharges.

[Effect of different primers on microbial community of activated sludge].

The aim of this study was to investigate the effect of different primers in PCR-DGGE and PCR-RFLP on the analysis of microbial community in activated sludge. 8 pairs of primers were chosen to amplify the variable region of 16S rDNA for PCR-DGGE analysis, while 11 pairs of primers were used to amplify the total length of 16S rDNA for PCR-RFLP analysis. The effect of different primers on the analysis of microbial community in activated sludge was determined by electrophoresis analysis of the PCR products. The microbial community of the activated sludge was different when different primers were used. For PCR-DGGE analysis, the primers B341F/B534R had good amplification results and the bands were excessive; while for PCR-RFLP, the primers 27f/8f and 1500R had good amplification results and the bands digested by the two enzymes had the highest diversity. The primers B341F/B534R and 27f/8f/ 1500R were relatively good for PCR-DGGE and PCR-RFLP, respectively, in the analysis of microbial community in activated sludge.

[Study on hepatitis C virus genotypes in Yantai district, Shandong province].

OBJECTIVE: To understand the hepatitis C virus (HCV) genotype distribution in Yantai district of Shandong province, and to explore whether the HCV genotypes was relevant to the injure of liver through the index of liver function. METHODS: Using specific PCR primers to amplify the HCV RNA 5' UTR/NS5B,then PCR products were sequenced by genetic analyzer. The genotypes were identified by alignment to the GenBank reference sequences and construction the phylogenetic tree of 5' UTR. RESULTS: Among 9 unpaid blood donors we detected two kinds of genotypes of 1b and 3a, respectively, 8 cases (88.9%) and 1 case (11.1%). Among 33 cases of hepatitis C patients we detected the 1b, 2a and 6a the three kinds of genotypes, respectively, 22 (66.7%), 10 (30.3%) and 1 (3.03%) cases. Subtype 1b is the advantage of popular genotype in HCV carriers from Yantai district, and the distribution of 1b was no significant difference in the different population (chi2 = 0.796, P = 0.373); The difference of indicator of liver damage in the different genotypes of subjects were significant (P < 0.05), the mean of ALT, AST of 2a-subtype carriers was significantly higher than the 1b-subtype population. CONCLUSIONS: The genetic diversity of HCV in Shandong Yantai district was presented. The main genotypes were 1b-subtype, and 3a and 6a-subtype was detected firstly. The genotype of HCV were relevant to the liver damage indicators, 2a-subtype hepatitis C virus infection in the liver cells may play an important role in the disease process.