objective To investigate the epidemiological and molecular typing features of the pathogenic Haemophilus influenzae(H.influenzae)by biotyping,serotyping and pulsed-field gel electrophoresis(PFGE).Methods A total of 273 invasive isolates of H influenzae were collected from the pediatric patients with pneumonia at Chengdu Children Hospital of Sichuan province from 1988 and 2004 to 2007.The idenbfication of H.influenzae strains were done according to the laboratory standard methodology described by Manual of Clinical Microbiology(American).All strains were biotyped according to Kilian's classification with the API[R]NH system.And serotyped by a slide agglutination assay with type a to f specific antlaerum as described by Pittman.PCR method for identification of H.influenzae were performed as described by Falla.One hundred of 273 strains were analyzed by PFGE as described by Saito with some modifications.The resuIts of PFGE were analyzed by Bionumerics soft(Version 4.0,Applied Maths BVBA,Belium).Restilts 78.2%of 273 cases occurred under 1 years old.Eight biotypes were found among the 273 H.influenzae isolates.17.6%(48/273)of all isolates belonged to biotype Ⅰ,43.6%(119/273)were biotype Ⅱ,22.7%(62/273)were biotype Ⅲ,7.3%(20/273)were biotype Ⅳ,5.9%(16/273)were biotype Ⅴ,0.4%(1/273)were biotype Ⅵ,1.8%(5/273)were biotype Ⅶ and 0.7%(2/273)were biotype Ⅷ.respeetively.99.6% of all 273 isolates were nontypeable.There was only one isolate was serotvpe f Ninty-six PFGE genotypes were obtained in this study.One hundred strains demonstrated a variety of genomic Datterns by PFGE.The most isolates of the flame PFGE genotype(type 35)was 3 isolates.Each of93 PFGE genotypes was represented by only a single isolate.The genotypes distribution didn't correlate with the time distribution of the strains were isolated.Conclusion Nontypeable H.influenzae primarily caused acute Dneumoma in children under 1 years old.They mostly belonged to biotype Ⅰ,Ⅱ and Ⅲ biotypes.The nontypeable H.influenzae strains appeared to more heterogeneous patterns by PFGE genotyping.Genotyping may helP understand the molecular characteristics of outbreak and endemicity according to the results of PFGE.PFGE genotyping proved to have a much stronger discriminatory power than either serotyping or biotyping.Our findings suggest that PFGE analysis is useful for the epidemiologieal study of H.influenzae infections.

ObjectiveTo explore the distribution of pharyngeal microbiota in coal miners exposed to dust. Methods Eight coal miners who had been engaged in occupational dust exposure for more than 20 years were selected as the dust-exposed group, and four coal miners who were not exposed to dust at work were selected as the control group using the judgment sampling method. Pharyngeal secretions of the coal miners were collected with throat swabs, and its pharyngeal microbiota was analyzed. The diversity, abundance and evenness of the microbiota were analyzed by gene sequencing using the 16sRNA gene high-throughput sequencing technology. Results A total of 254 operational taxonomic units of pharyngeal microbiota were detected in the coal miners in the control group, which was 210 more than that in the dust-exposed group. The Chao1 index, Shannon index, PD-tree index and Pielou index of pharyngeal microbiota in the dust-exposed group decreased compared with the control group (all P<0.01). The abundance of Bacteroidetes and Clostridum, at the phylum level, in the pharynx of coal miners in the dust-exposed group was higher than that in the control group (all P<0.05). The abundance of Prevotella, Neisseria, and Monas, at the genus level, in the pharynx of coal miners in the dust-exposed group was higher than that in the control group(all P<0.05), while the abundance of Lactobacillus decreased (P<0.05). The analysis results of the receiver operating characteristic curve showed that Lactobacillus, Fusobacterium and Rothia may play a role for pharyngeal microbiota imbalance prediction in dust-exposed workers, and the area under the curves were all 1.00±0.00. Conclusion The species diversity and evenness of pharyngeal microbiota in coal miners exposed to dust are decreased, which may be related to the continuous inhalation of coal dust that disrupts the microbial environment of the throat.

Endophytic fungus is an important treasure trove for discovery of structurally unusual and biologically diverse compounds. A phytochemical investigation on a fungus Clonostachys rosea inhabits inner tissue of Blumea balsamifera (L.) DC. was initiatedrecently in our lab. Six pure compounds were isolated through silica gel column chromatography, sephadex LH-20, and semi-preparative HPLC techniques, with bio-guided strategy. Their structures were characterized as verticillin A (1), (S)-(+)-fusarinolic acid (2), 8-hydroxyfusaric acid (3), cerebroside C (4), 3-Maleimide-5-oxime (5), and bionectriol A (6) by analyses of NMR and MS data. All compounds were tested in vitro antibacterial activities against four strains of bacteria, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa, and results revealed that 1, 4 and 6 display notableinhibition againstthree bacteria, with MIC values ranging from 2 to 16 μg/mL. Our findings provide references for mining novel antibiotics from endophytes originated from Li Minority medicinal plant B. balsamifera (L.) DC.

OBJECTIVE: To investigate the effects of high-altitude hypoxic environment on the expression of pregnane X receptor (PXR) in rat liver and related mechanism. METHODS: Wistar rats were randomly divided into five groups with 8 rats in each group, the rats were exposed to high-plateau hypoxia for 0 (control group), 12, 24, 36 and 48 h, respectively. Abdominal aortic blood samples were collected for blood gas analysis. HE staining was used to observe the pathological changes of liver tissue. The expression levels of PXR mRNA in liver tissues were determined by RT-PCR. Western blot analysis was performed to determine the protein expression of PXR and protease SUG1 in liver tissues of rats. RESULTS Compared with the control group, the blood pH of the rats decreased after 12 h of acute hypoxia. After 24 h exposed to hypoxia, SaO₂ was lower than 80%, PaO₂ was lower than 60 mmHg (1 mmHg=0.133 kPa); and PaCO₂ increased after 48 h exposed to hypoxia (P<0.05). There was obvious edema in the central vein of the liver tissue at 12 h and 24 h after exposure to hypoxia. The liver tissue of the rats exposed to hypoxia for 36 h and 48 h showed inflammatory infiltration. The expression of PXR mRNA was significantly decreased by 63%, 96%, 86%, and 85%at 12, 24, 36 h, and 48 h after exposure to hypoxia (all P<0.05), respectively. The protein expression of PXR was significantly up-regulated by 93%and 99%after 36 h and 48 h exposure to hypoxia (all P<0.05), respectively. The protein expression of proteinase SUG1 decreased by 14%, 34%and 46%after 24, 36 and 48 h after hypoxia (all P<0.01). CONCLUSIONS Acute hypoxia at high altitude can affect the expression of nuclear receptor PXR in rat liver, and protease SUG1 may be a regulatory factor for PXR expression in hypoxia.