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Guozhang Xu,
Yanyan Ying,
Yan Liu,
Wenjun Chang,
Hongxia Ni,
Yinchao Zhu,
Rong Xu, Hongjun Dong,
Nanfeng Shi,
Xu Ma,
Lairong Xu,
Yibiao Cai,
Jianming Ping,
Yifang Han,
Guangwen Cao
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ABSTRACT: Objective: The incidence, types, and influencing factors of injuries due to snow-ice disasters are essential for public health preparedness. This study was designed to assess such factors of injuries during the 22-day snowstorm in Ningbo, Zhejiang Province, China, in 2008. Methods: A multistage cluster probability sampling method was applied to select the study population in urban, rural, and mountainous areas. Data including sociodemographic characteristics, frequency, and types of injuries during the snowstorm between January 20 and February 10, 2008, were obtained by face-to-face interviews using a structured questionnaire and by checking the participants' medical records. Univariate and multivariate regression analyses were used to determine the factors significantly associated with the risk of injuries. Results: A total of 3169 residents of 1416 families took part in this survey. In 581 residents, 602 injuries were identified. Incidences of frostbite, falling injury, and traffic accident-related injury were 12.78%, 5.30%, and 0.50%, respectively. Injury occurred more frequently in women than in men (odds ratio [OR], 1.42; 95% CI, 1.19-1.70). Frostbite occurred more frequently in women than in men (adjusted OR, 1.86; 95% CI, 1.43-2.41) and more frequently in urban areas than in other areas (adjusted OR, 1.65; 95% CI, 1.24-2.20). Travel by bus or car, wearing a scarf, wearing gloves, wearing a raincoat, reducing outdoor activity, and performing regular physical exercise were independent protective factors of frostbite, with an adjusted OR (95% CI) of 0.35 (0.20-0.61), 0.45 (0.33-0.62), 0.35 (0.26-0.48), 0.45 (0.33-0.61), 0.36 (0.27-0.48), and 0.18 (0.13-0.24), respectively. Falling injury occurred more often in mountainous areas than in other areas (adjusted OR, 1.74; 95% CI, 1.27-2.42). Age 45 years or older, working outside more than 15 days, and wearing a raincoat were independent risk factors of falling injury, with an adjusted OR (95% CI) of 2.30 (1.60-3.32), 1.92 (1.36-2.72), and 2.21 (1.56-3.11), respectively. Falling and traffic accident-related injuries were mainly due to slippery roads. Conclusions: Frostbite and falling injury were the major injuries caused by an unprecedented snow-ice disaster. Keeping warm and maintaining regular physical exercise appeared to reduce frostbite risk. Public health intervention also reduced the risk of falling and traffic accident-related injuries.
Disaster Medicine and Public Health Preparedness 12/2012; 6(4):363-369. · 1.53 Impact Factor
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ABSTRACT: BACKGROUND: Previously we have developed a butanol tolerant mutant of Clostridium acetobutylicum, Rh8, from the wild type strain DSM 1731. Strain Rh8 can tolerate up to 19 g/L butanol, with solvent titer improved accordingly, thus exhibiting industrial application potential. To test if strain Rh8 can be used for production of high level mixed alcohols, a single secondary alcohol dehydrogenase from Clostridium beijerinckii NRRL B593 was overexpressed in strain Rh8 under the control of constitutive thl promoter. RESULTS: The heterogenous gene sADH was functionally expressed in C. acetobutylicum Rh8. This simple, one-step engineering approach led to the complete conversion of acetone into isopropanol, achieving a total alcohol titer of 23.88 g/l (7.6 g/l isopropanol, 15 g/l butanol, and 1.28 g/l ethanol) with a yield to glucose of 31.42%. The acid (butyrate and acetate) assimilation rate in isopropanol producing strain Rh8(psADH) was increased. CONCLUSIONS: The improved butanol tolerance and the enhanced solvent biosynthesis machinery in strain Rh8 is beneficial for production of high concentration of mixed alcohols. Strain Rh8 thus can be considered as a good host for further engineering of solvent/alcohol production.
Biotechnology for Biofuels 06/2012; 5(1):44. · 6.09 Impact Factor
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Hongxia Ni,
Bo Yi,
Jianhua Yin,
Ting Fang,
Tianfeng He,
Yan Du,
Jin Wang,
Hongwei Zhang,
Lei Xie,
Yibo Ding,
Wenzhen Gu,
Shu Zhang,
Yifang Han, Hongjun Dong,
Tong Su,
Guozhang Xu,
Guangwen Cao
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ABSTRACT: Outbreaks of hand, foot, and mouth disease (HFMD) in central China have caused public health concerns since 2007. It is of particular public health significance to update epidemiology of HFMD in port cities.
To investigate epidemical, etiological and clinical characteristics of HFMD in Ningbo, China, from 2008 to 2011.
From May 2008 to December 2011, a total of 37,404 HFMD cases including 196 severe and 12 fatal cases were investigated. Human enteroviruses from 2360 cases were determined by real-time RT-PCR. The VP1 gene of EV71 from 78 cases and CA16 from 21 cases, the VP4 gene from 28 cases, and full-length genomes of 10 isolates were analyzed. Neutralizing antibodies were evaluated in 258 healthy subjects. Parameters associated with severe HFMD were evaluated.
Annual incidence of HFMD was 3066.8/100,000 in the population of ≤5 years. EV71 C4a, CA16 B1, and other enteroviruses accounted for 63.7%, 24.0% and 12.3%, respectively. The genomes of EV71 from fatal and non-fatal cases were nearly identical. The positive rates of neutralizing antibody to EV71 increased from 13.5% to 67.6% in 1- to 5-year healthy groups. The neutralizing antibody to CA16 B1 isolate was negative. EV71, exposure history and certain early manifestations including fever, vomiting, limb exanthema and peripheral neutrophil ratio were significantly associated with HFMD severity.
HFMD mainly caused by EV71 C4a and CA16 B1 is seriously epidemic in Ningbo. Future emphasis should be paid on EV71 immuno-prophylaxis and early identification of severe cases upon the etiological and clinical characteristics.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 05/2012; 54(4):342-8. · 3.12 Impact Factor
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ABSTRACT: A small fraction of hand-foot-mouth disease (HFMD) progression from the onset of severity to fatality may be remarkably rapid. Early recognition of children at risk of severity is critical to increase treatment effectiveness and reduce acute mortality.
A frequency-matched case-control study was conducted between January 2010 and June 2011 in Ningbo to identify risk factors associated with the occurrence of severity in children with HFMD. Data including demographic characteristics, clinical features, and laboratory test results were collected by trained interviewers through retrospective medical record review and/or face-to-face interviews with children's parents using a standardized questionnaire.
Eighty-nine cases with severe HFMD and 267 controls with mild HFMD were recruited in this study. Palm rashes (OR = 0.004, 95%CI = 0.000-0.039, p < 0.001), oral ulcers or herpes (OR = 0.001, 95%CI = 0.000-0.009, p < 0.001) were significantly associated with protection against severity, and an increased risk of severity was significantly associated with the presence of, e.g., a high fever of over 39°C for more than 3 days (OR = 2.217, 95%CI = 1.082-4.541, p = 0.030), leg trembling (OR = 29.008, 95%CI = 1.535-548.178, p = 0.025), papule rash (OR = 4.622, 95%CI = 1.110-19.252, p = 0.035), a raised WBC count > 10.8 × 10(9)/L (OR = 4.495, 95%CI = 1.311-15.415, p = 0.017), and human enterovirus 71 infection (OR = 39.172, 95%CI = 9.803-156.522, p < 0.001).
Clinicians should pay increased attention to children diagnosed as HFMD with the independent risk factors above.
European Journal of Pediatrics 04/2012; 171(9):1359-64. · 1.88 Impact Factor
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ABSTRACT: China initiated its acetone-butanol-ethanol (ABE) industry in the 1950s; it peaked in the 1980s, and ended at the end of the last century owing to the development of more competitive petrochemical pathways. However, driven by the high price of crude oil and environmental concerns raised by the over-consumption of petrochemical products, biofuels and bio-based chemicals including butanol have garnered global attention again. Currently, butanol produced from ABE fermentation is mainly used as an industrial solvent or a platform chemical for several bulk derivatives, and is also believed to be a potential biofuel. A number of plants have been built or rebuilt in recent years in China for butanol production with the ABE process. Chinese researchers also show great interest in the improvement of the production strains and corresponding processes. They have applied conventional mutagenesis methods to improve butanol-producing strains such as the Clostridium acetobutylicum mutant strains EA2018 (butanol ratio of 70%) and Rh8 (butanol tolerance of 19 g/L). The omics technologies, such as genome sequencing, proteomic and transcriptomic analysis, have been adapted to elucidate the characteristics of different butanol-producing bacteria. Based on the group II intron method, the genetic manipulation system of C. acetobutylicum was greatly improved, and some successful engineering strains were developed. In addition, research in China also covers the downstream processes. This article reviews up-to-date progress on biobutanol production in China.
Advances in biochemical engineering/biotechnology 12/2011; 128:85-100. · 1.64 Impact Factor
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Yang Gu,
Yu Jiang,
Hui Wu,
Xudong Liu,
Zhilin Li,
Jian Li,
Han Xiao,
Zhaobing Shen, Hongjun Dong,
Yunliu Yang,
Yin Li,
Weihong Jiang,
Sheng Yang
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ABSTRACT: Butanol is an important solvent and transport fuel additive, and can be produced by microbial fermentation. Attempts to generate a superior microbial producer of butanol have been made through different metabolic engineering strategies. However, to date, butanol bio-production is still not economically competitive compared to petrochemical-derived production because of its major drawbacks, such as, high cost of the feedstocks, low butanol concentration in the fermentation broth and the co-production of low-value by-products acetone and ethanol. Here we analyze the main bottlenecks in microbial butanol production and summarize relevant advances from recently reported studies. Further needs and directions for developing real industrially applicable strains in butanol production are also discussed.
Biotechnology Journal 11/2011; 6(11):1348-57.
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ABSTRACT: Clostridium acetobutylicum is an important solvent (acetone-butanol-ethanol) producing bacterium. However, a stringent, effective, and convenient-to-use inducible gene expression system that can be used for regulating the gene expression strength in C. acetobutylicum is currently not available. Here, we report an anhydrotetracycline-inducible gene expression system for solvent-producing bacterium C. acetobutylicum. This system consists of a functional chloramphenicol acetyltransferase gene promoter containing tet operators (tetO), Pthl promoter (thiolase gene promoter from C. acetobutylicum) controlling TetR repressor expression cassette, and the chemical inducer anhydrotetracycline (aTc). The optimized system, designated as pGusA2-2tetO1, allows gene regulation in an inducer aTc concentration-dependent way, with an inducibility of over two orders of magnitude. The stringency of TetR repression supports the introduction of the genes encoding counterselective marker into C. acetobutylicum, which can be used to increase the mutant screening efficiency. This aTc-inducible gene expression system will thus increase the genetic manipulation capability for engineering C. acetobutylicum.
Metabolic Engineering 10/2011; 14(1):59-67. · 5.61 Impact Factor
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ABSTRACT: Clostridium acetobutylicum is an important microorganism for solvent production. We report the complete genome sequence of C. acetobutylicum DSM 1731, a genome with multireplicon architecture. Comparison with the sequenced type strain C. acetobutylicum ATCC 824, the genome of strain DSM1731 harbors a 1.7-kb insertion and a novel 11.1-kb plasmid, which might have been acquired during evolution.
Journal of bacteriology 07/2011; 193(18):5007-8. · 3.94 Impact Factor
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ABSTRACT: To simplify the electrotransformation process of Clostridium acetobutylicum, which currently needs to be performed in an anaerobic chamber, thus laborious and time-consuming.
The CAC2634 gene encoding PerR is a known peroxide regulon repressor in Cl. acetobutylicum. CAC2634 in a previously constructed Restriction-Modification system deficient Cl. acetobutylicum mutant SMB009 was disrupted using ClosTron method. The resulted mutant SMB012 can be electrotransformed in air with an efficiency of 1.2-3.1 × 10(3) transformants μg(-1) DNA.
We demonstrated that the disruption of CAC2634 in Cl. acetobutylicum enables its electrotransformation in air.
The electrotransformation process of Cl. acetobutylicum could be significantly simplified, especially when operating multiple electrotransformations.
Letters in Applied Microbiology 06/2011; 53(3):379-82. · 1.62 Impact Factor
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ABSTRACT: The bioaugmentation of petroleum-contaminated soil using Enterobacter cloacae was profiled from the evolution of microbial community, soil dehydrogenase activity, to the degradation of petroleum contaminants. The seeding and proliferation of inoculant and the consequential microbial community were monitored by denaturing gradient gel electrophoresis analysis of the amplification of V3 zone of 16S rDNA. Degradation process kinetics was characterized by the degradation ratio of nC17 to nC18. The dehydrogenase activity was also determined during the degradation process. An abrupt change in the microbial community after inoculation was illustrated as well as successive changes in response to degradation of the petroleum contaminants. Seeding with E. cloacae stimulated the growth of other degrading stains such as Pseudomonas sp. and Rhodothermus sp. The application of wheat straw as a representative lignin waste, at 5% (w/w), induced an increase in the total dehydrogenase activity from 0.50 to 0.79, an increase in the microbial content of 130% for bacteria and 84% for fungi, and an increase of the overall degradation ratio from 44% to 56% after 56 days of treatment. The above mentioned results have provided a microbial ecological insight being essential for the design and implementation of bioaugmentation processes.
Applied biochemistry and biotechnology 02/2011; 164(7):1071-82. · 1.94 Impact Factor
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ABSTRACT: To improve the aero- and solvent tolerance of the solvent-producing Clostridium acetobutylicum, glutathione biosynthetic capability was introduced into C. acetobutylicum DSM1731 by cloning and over-expressing the gshAB genes from Escherichia coli. Strain DSM1731(pITAB) produces glutathione, and shows a significantly improved survival upon aeration and butanol challenge, as compared with the control. In addition, strain DSM1731(pITAB) exhibited an improved butanol tolerance and an increased butanol production capability, as compared with the recombinant strains with only gshA or gshB gene. These results illustrated that introducing glutathione biosynthetic pathway, which is redundant for the metabolism of C. acetobutylicum, can increase the robustness of the host to achieve a better solvent production.
Metabolic Engineering 02/2011; 13(4):426-34. · 5.61 Impact Factor
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ABSTRACT: Solvent production by Clostridium acetobutylicum collapses when cells are grown in pH-uncontrolled glucose medium, the so-called "acid crash" phenomenon. It is generally accepted that the fast accumulation of acetic acid and butyric acid triggers the acid crash. We found that addition of 1 mM formic acid into corn mash medium could trigger acid crash, suggesting that formic acid might be related to acid crash. When it was grown in pH-uncontrolled glucose medium or glucose-rich medium, C. acetobutylicum DSM 1731 containing the empty plasmid pIMP1 failed to produce solvents and was found to accumulate 0.5 to 1.24 mM formic acid intracellularly. In contrast, recombinant strain DSM 1731 with formate dehydrogenase activity did not accumulate formic acid intracellularly and could produce solvent as usual. We therefore conclude that the accumulation of formic acid, rather than acetic acid and butyric acid, is responsible for the acid crash of acetone-butanol-ethanol fermentation.
Applied and environmental microbiology 01/2011; 77(5):1674-80. · 3.69 Impact Factor
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Jianhua Yin,
Jiaxin Xie,
Shijian Liu,
Hongwei Zhang,
Lei Han,
Wenying Lu,
Qiuxia Shen,
Guozhang Xu, Hongjun Dong,
Jie Shen,
Jun Zhang,
Jiankang Han,
Lin Wang,
Yan Liu,
Fan Wang,
Jun Zhao,
Qian Zhang,
Wu Ni,
Hongyang Wang,
Guangwen Cao
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ABSTRACT: The objective of this study was to determine the association of 19 mutations with frequencies ≥ 10% in the core promoter region of hepatitis B virus (HBV) with chronic hepatitis B (CHB), liver cirrhosis, and hepatocellular carcinoma (HCC).
Eight hundred forty-six asymptomatic hepatitis B surface antigen carriers (ASCs), 235 CHB patients, 188 cirrhosis patients, and 190 HCC patients with intact data of HBV genotyping, DNA sequencing, and serological parameters were studied. Nucleotides with the highest frequencies in HBV genotypes B and C from all ASCs were treated as wild-type nucleotides.
Mutations at nt.1674, nt.1719, nt.1762, nt.1764, nt.1846, nt.1896, and nt.1913 in genotype C were significantly associated with CHB, cirrhosis, and HCC, as compared with ASCs. C1673T, A1726C, A1727T, C1730G, C1766T, T1768A, C1773T, and C1799G in genotype C were significantly associated with cirrhosis compared with the CHB patients, whereas these mutations were inversely associated with HCC compared with the cirrhosis patients. Multivariate regression analyses showed that age, male, abnormal alanine aminotransferase (ALT), T1768A, A1762T/G1764A, and A1846T were independently associated with cirrhosis compared with ASCs and the patients with CHB. Age, abnormal ALT, HBV DNA (≥10(4) copies/ml), genotype C, C1653T, T1674C/G, T1753V, and A1762T/G1764A were independently associated with HCC compared with those without HCC. Haplotypic carriages with two or more HBV mutations were significantly associated with HCC. T1674C/G, C1653T, and T1753V were specific for HCC. A1762T/G1764A had a moderate sensitivity and specificity for HCC.
C1673T, A1726C, A1727T, C1730G, C1766T, T1768A, C1773T, and C1799G in genotype C are specific for cirrhosis. A1846T and T1674C/G are novel factors independently associated with cirrhosis and HCC, respectively.
The American Journal of Gastroenterology 10/2010; 106(1):81-92. · 7.28 Impact Factor
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ABSTRACT: Clostridium acetobutylicum, a biofuel-butanol producer, has attracted worldwide interests. Strain improvement is important for the process of biobutanol industrialization where efficient genetic modification systems are essential. In this review, the history of genetic modification systems of C. acetobutylicum was introduced, and the types and principles of these systems and their disadvantages are summarized and analysed. The development of updated genetic modification systems for C. acetobutylicum is also proposed.
Sheng wu gong cheng xue bao = Chinese journal of biotechnology 10/2010; 26(10):1372-8.
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ABSTRACT: To investigate the genotyping and distribution pattern of the variable number tandem repeats (VNTR) of Mycobacterium tuberculosis clinical isolates in Ningbo with multiple-locus VNTR analysis (MLVA).
M. tuberculosis clinical isolates selected from Ningbo randomly were cultured with Lowenstein-Jensen medium. The bacteria from which the genome DNA was extracted were collected. The polymorphism of VNTR locus was tested in the DNA sample with PCR respectively. The clustering of genotype was analyzed with BioNumerics.
15 VNTR loci of 90 M. tuberculosis clinical isolates were analyzed respectively. There were obvious polymorphisms of VNTRs. The clustering of genotype showed that these strains could be categorized into 4 gene clusters (I, II, III, IV) and 84 genotypes. 11.1% were cluster I including 10 genotypes, 17.8% were cluster II including 15 genotypes, 65.6% were cluster III including 54 genotypes, 5.6% were cluster IV including 5 genotypes.
The results showed that there were obvious polymorphisms of VNTRs of M. tuberculosis clinical strains preliminarily. There were at least 4 clusters of VNTR genotype and cluster III was the predominant prevalent strain in Ningbo.
Wei sheng yan jiu = Journal of hygiene research 09/2010; 39(5):618-20.
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ABSTRACT: It is difficult to genetically manipulate the medically and biotechnologically important genus Clostridium due to the existence of the restriction and modification (RM) systems. We identified and engineered the RM system of a model clostridial species, C. acetobutylicum, with the aim to allow the host to accept the unmethylated DNA efficiently. A gene CAC1502 putatively encoding the type II restriction endonuclease Cac824I was identified from the genome of C. acetobutylicum DSM1731, and disrupted using the ClosTron system based on group II intron insertion. The resulting strain SMB009 lost the type II restriction endonuclease activity, and can be transformed with unmethylated DNA as efficiently as with methylated DNA. The strategy reported here makes it easy to genetically modify the clostridial species using unmethylated DNA, which will help to advance the understanding of the clostridial physiology from the molecular level.
PLoS ONE 01/2010; 5(2):e9038. · 4.09 Impact Factor
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Hongjun Dong,
Guozhang Xu,
Shuhua Li,
Qifa Song,
Shijian Liu,
Hui Lin,
Yibiao Chai,
Aimin Zhou,
Ting Fang,
Hongwei Zhang,
Chunguang Jin,
Wei Lu,
Guangwen Cao
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ABSTRACT: To determine the etiological cause of a food-borne outbreak of scarlet fever in adults.
Swabs from the throats of the patients and asymptomatic control were cultured on blood agar plates individually. Biochemical identification of all isolates was performed with a VITEX automated system. Antibiotic susceptibility was examined by using the Kirby-Bauer disc diffusion method. emm gene and extracellular pyrogenic exotoxins of each isolate were amplified by using polymerase chain reaction and subjected to DNA sequencing. Sequence differences between the isolated and the highly similar reference sequences were compared on BLAST. Bioinformatics was used to predict protein structures.
Beta-haemolytic group A streptococci (GAS) emm75 were identified from 10 of 13 available patients. The isolates were susceptible to penicillin, ampicillin, vancomycin, cefatriaxone, ofloxacin, linezolid and quinupristin. All of the isolates carried pyrogenic exotoxin A (speA) and cysteine protease (speB). Isolated speA was phylogenetically different from 30 highly similar references on BLAST. Differences in the primary sequence of the deduced protein were 14.37-20.12% between the speA and each of 11 references. Secondary protein structure of the speA was different from the references at the N-terminal.
GAS emm75 encoding altered speA was responsible for the food-borne outbreak of scarlet fever in adults.
The Journal of infection 05/2008; 56(4):261-7. · 4.13 Impact Factor
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Guozhang Xu, Hongjun Dong,
Nanfeng Shi,
Shijian Liu,
Aiming Zhou,
Zhihua Cheng,
Guohua Chen,
Jianyi Liu,
Ting Fang,
Hongwei Zhang,
Chunying Gu,
Xiaojie Tan,
Jianjie Ye,
Shuyun Xie,
Guangwen Cao
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ABSTRACT: Autochthonous dengue infections have not been reported in Ningbo, People's Republic of China since 1929. In August-October 2004, an outbreak of dengue fever was confirmed in Xiaolin, Cixi, Ningbo. Of 83 cases reported, 68 were laboratory confirmed. Fifty-three percent (34 of 64) of the cases had IgM antibodies to dengue virus. Dengue virus serotype-1 was isolated from two cases. The outbreak was linked to a traveler who returned from Thailand. Phylogenetic analysis showed that the Ningbo isolate was closely associated to strains from Thailand. Prevalence of dengue-specific IgG in asymptomatic residents was significantly higher in the epidemic-stricken area than in a control area. High density of Aedes albopictus, which resulted from waterlogging caused by Typhoon Rananim and lifestyle of local residents, was responsible for rapid spread of the virus. Eradication of mosquito infestation might interrupt transmission. This outbreak underscores the importance of maintaining surveillance and control of potential vectors for the control of emerging infectious diseases.
The American journal of tropical medicine and hygiene 07/2007; 76(6):1182-8. · 2.59 Impact Factor
