1.Environment surveillance of filamentous fungi in two tertiary care hospitals in China.
Zhen-feng HAO ; Jun-hong AO ; Fei HAO ; Rong-ya YANG ; He ZHU ; Jie ZHANG
Chinese Medical Journal 2011;124(13):1970-1975
BACKGROUNDInvasive fungal infections have constituted an increasingly important cause of morbidity and mortality in immunocompromised patients. In this study, a surveillance project was conducted in three different intensive care units of two large tertiary hospitals in China.
METHODSA one-year surveillance project was conducted in two tertiary hospitals which located in northern China and southwest China respectively. Air, surfaces and tap water were sampled twice a month in a central intensive care unit, a bone marrow transplant unit, a neurosurgery intensive care unit and a live transplant department. Environmental conditions such as humidity, temperature and events taking place, for example the present of the visitors, healthcare staff and cleaning crew were also recorded at the time of sampling.
RESULTSThe air fungal load was 91.94 cfu/m(3) and 71.02 cfu/m(3) in the southwest China hospital and the northern China hospital respectively. The five most prevalent fungi collected from air and surfaces were Penicillium spp., Cladospcrium spp., Alternaria spp., Aspergillus spp. and Saccharomyces spp. in the southwest China hospital, meanwhile Penicillium spp., Fusarium spp., Aspergillus spp., Alternaria spp. and Cladospcrium spp. in the northern China hospital. The least contaminated department was intensive care units, and the heaviest contaminated department was neurosurgery intensive care unit. Seventy-three percent of all surfaces examined in the northern China hospital and eighty-six percent in the southwest China hospital yielded fungi. Fifty-four percent of water samples from the northern China hospital and forty-nine percent from the southwest China hospital yielded fungi.
CONCLUSIONSThese findings suggested that the fungus exist in the environment of the hospital including air, surface and water. Air and surface fungal load fluctuated over the year. Air fungal load was lower in winter and higher in summer and autumn, but seldom exceeded acceptable level. The higher values were created during May to August in the northern China hospital and May to June and September to October in the southwest China hospital. A correlation between air fungal load and humidity, as well as personnel was observed.
Air Microbiology ; China ; Environmental Monitoring ; methods ; Fungi ; isolation & purification ; Hospitals ; Intensive Care Units ; Water Microbiology
2.Contamination status and molecular biological characteristics of Legionella in cooling water samples from different places in Wuxi city.
Qi ZHANG ; Rong CHEN ; Yong XIAO ; Bin LIU ; Tian QIN ; Zhu-Jun SHAO ; Wei-Jie ZHOU
Chinese Journal of Preventive Medicine 2012;46(3):264-268
OBJECTIVETo investigate the contamination state of Legionella in cooling water samples from different places in Wuxi city and reveal the molecular biological characteristics of Legionella strains.
METHODS112 parallel water samples (500 ml each) were collected from 56 sites in Wuxi city during year 2009 - 2010. The samples were used for Legionella test and quantitative culture. The isolated Legionella strains were used for serotyping, pulsed-field gel electrophoresis (PFGE), sequence-based typing (SBT), and intracellular growth were tested.
RESULTSThe positive proportion of Legionella was 39. 3% (22/56) among all sampling sites. A total of 29 Legionella strains were isolated, and the serotypes include LP1, LP3, LP5 and LP6. LP1 serotype was the major one with a proportion of 65.5% (19/29). 29 Legionella strains got 17 PFGE types. There were 10 SBT types among 10 Legionella strains with different PFGE types. Comparing to LP1 strain (ATCC 33152), WX2011062 (LP6) and WX2011067 (LP5) had strong intracellular growth ability in mouse peritoneal macrophages J774 cell line (the amount of intracellular bacteria on day 0 after infection were (5.5 +/- 1.32) x 10(5), (3.9 +/- 0.60) x 10(5), (7.8 +/- 0.76) x 10(5) CFU/ml, respectively; the amount of intracellular bacteria on day 3 after infection were (58.3 +/- 1.61) x 10(5), (2700.0 +/- 655.74) x 10(5), (3066.7 +/- 208.17) x 10(5) CFU/ml, respectively).
CONCLUSIONThe Legionella contamination existed in cooling water samples from different places in Wuxi city. Legionella strains isolated showed high genetic variation. Some Legionella strains had vigorous intracellular growth ability.
Air Conditioning ; Animals ; Cells, Cultured ; Environmental Microbiology ; Legionella ; genetics ; growth & development ; isolation & purification ; Legionella pneumophila ; growth & development ; isolation & purification ; Macrophages ; microbiology ; Mice ; Serotyping ; Water Microbiology
3.Preliminary study on bacteroides as the potential fecal contamination indicator bacteria.
Jing-yan YANG ; Zhi-jin CHEN ; Xiao-bei DING ; Wei HUANG ; Rui-jia YANG ; Xiao-fang PEI
Chinese Journal of Preventive Medicine 2011;45(3):230-234
OBJECTIVETo explore the possibility of Bacteroides spp. as fecal contamination indicator bacteria with real-time quantitative PCR (RT-PCR) assay through analyzing the correlation between Bacteroides spp. and coliform group in external environment.
METHODSQuantity of coliform group and Bacteroides in water samples were detected by most-probable-number method (MPN) and RT-PCR, respectively, and their detection correlation was evaluated with linear correlation analysis. Both methods were also applied to detect the contaminated time limits and river water samples collected at four sampling sites in three different times.
RESULTSSeventy two hours were needed for the numeration of coliform group with MPN method, while RT-PCR could detect Bacteroides within 3 hours. The contaminated time limit of indoor and outdoor water samples of coliform group was more than 40 days and 9 days, and Bacteroides 13 days and 5 days, respectively. Also, the positive correlation between the quantity of Bacteroides and coliform group in outdoor water samples was obtained, the quantity of Bacteroides was from 8.3 × 10(6) copies/ml to less than 10(4) copies/ml during the first day to the fifth day, while coliform group was 4.3 × 10(6) MPN/100 ml to 2.4 × 10(3) MPN/100 ml. A 100% coincidence rate of the detection results with both methods was also observed. These results indicated that the detection results of both methods had perfect consistency.
CONCLUSIONBacteroides spp. can be potentially used as fecal contamination indicator bacteria with RT-PCR rapid detection.
Bacteroides ; Environmental Microbiology ; Environmental Monitoring ; methods ; Escherichia coli ; Feces ; microbiology ; Rivers ; microbiology ; Water Pollutants ; analysis
4.Development of bioremediation in China--a review.
Chinese Journal of Biotechnology 2015;31(6):901-916
The development of bioremediation for contaminated soil in China during past 30 years was briefly reviewed, mainly including the developing stages, bioremediation techniques/strategies and their applications, and isolation, screening and characterizations of microbial strains for bioremediation as well as their efficiencies in bioremediation of contaminated soils. Finally, future development of bioremediation techniques/strategies and their applications were also discussed.
Biodegradation, Environmental
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China
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Environmental Pollution
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Soil Microbiology
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Soil Pollutants
5.Advances in the bioaugmentation-assisted remediation of petroleum contaminated soil.
Jin ZHENG ; Yali FU ; Quanwei SONG ; Jiacai XIE ; Shuangjun LIN ; Rubing LIANG
Chinese Journal of Biotechnology 2021;37(10):3622-3635
Bioremediation is considered as a cost-effective, efficient and free-of-secondary-pollution technology for petroleum pollution remediation. Due to the limitation of soil environmental conditions and the nature of petroleum pollutants, the insufficient number and the low growth rate of indigenous petroleum-degrading microorganisms in soil lead to long remediation cycle and poor remediation efficiency. Bioaugmentation can effectively improve the biodegradation efficiency. By supplying functional microbes or microbial consortia, immobilized microbes, surfactants and growth substrates, the remediation effect of indigenous microorganisms on petroleum pollutants in soil can be boosted. This article summarizes the reported petroleum-degrading microbes and the main factors influencing microbial remediation of petroleum contaminated soil. Moreover, this article discusses a variety of effective strategies to enhance the bioremediation efficiency, as well as future directions of bioaugmentation strategies.
Biodegradation, Environmental
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Petroleum
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Soil
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Soil Microbiology
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Soil Pollutants
6.Advances in bioremediation of hydrocarbon-contaminated soil.
Lei ZHONG ; Jinwu QING ; Hongyun CHEN ; Gaoyuan LI ; Guanyi CHEN ; Yuru SUN ; Jinlei LI ; Yingjin SONG ; Beibei YAN
Chinese Journal of Biotechnology 2021;37(10):3636-3652
With continuous improvement of people's living standards, great efforts have been paid to environmental protection. Among those environmental issues, soil contamination by petroleum hydrocarbons has received widespread concerns due to the persistence and the degradation difficulty of the pollutants. Among the various remediation technologies, in-situ microbial remediation enhancement technologies have become the current hotspot because of its low cost, environmental friendliness, and in-situ availability. This review summarizes several in-situ microbial remediation technologies such as bioaugmentation, biostimulation, and integrated remediation, as well as their engineering applications, providing references for the selection of in-situ bioremediation technologies in engineering applications. Moreover, this review discusses future research directions in this area.
Biodegradation, Environmental
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Humans
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Hydrocarbons
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Petroleum
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Soil
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Soil Microbiology
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Soil Pollutants
7.Epidemiology of Campylobacter jejuni Outbreak in a Middle School in Incheon, Korea.
Jun Hwan YU ; Na Yeon KIM ; Nam Gue CHO ; Jung Hee KIM ; Young Ah KANG ; Ha Gyung LEE
Journal of Korean Medical Science 2010;25(11):1595-1600
On July 6, 2009, an outbreak of gastroenteritis occurred among middle school students in Incheon. An investigation to identify the source and describe the extent of the outbreak was conducted. A retrospective cohort study among students, teachers, and food handlers exposed to canteen food in the middle school was performed. Using self-administered questionnaires, information was collected concerning on symptoms, days that canteen food was consumed, and food items consumed. Stool samples were collected from 66 patients and 11 food handlers. The catering kitchen was inspected and food samples were taken. Of the 791 people who ate canteen food, 92 cases became ill, representing an attack rate of 11.6%. Thirty-one (40.3%) of the 77 stool specimens were positive for Campylobacter jejuni. Interviews with kitchen staff indicated the likelihood that undercooked chicken was provided. This is the first recognized major C. jejuni outbreak associated with contaminated chicken documented in Korea.
Adolescent
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Adult
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Animals
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Campylobacter Infections/*epidemiology
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*Campylobacter jejuni
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Chickens
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Cohort Studies
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*Disease Outbreaks
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Electrophoresis, Gel, Pulsed-Field
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Environmental Exposure
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Female
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Food Contamination
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Humans
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Male
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Middle Aged
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Questionnaires
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Republic of Korea
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Retrospective Studies
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Risk Factors
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Water Microbiology
8.Study on the status of pollution by Legionella species in hot spring vacation center and the related factors.
Lian-Xiu WANG ; Ge-Bin YAN ; Li-Na GE ; Gui-Fang QIAO
Chinese Journal of Epidemiology 2006;27(11):943-946
OBJECTIVETo study the pollution status of Legionella species in hot spring vacation center and the related factors.
METHODSField surveys were performed in four big hot spring vacation centers of Changping district. Uniform questionnaires was used and colony count was made together with the isolation of Legionella species from hot spring water based on mip gene typing.
RESULTS47 isolates of Legionella pneumophila (Lp) from 87 samples showed 4 serotypes as Lp1, Lp6, Lp12, Lp5 with percent of 57.45%, 21.28%, 14.89%, 6.38% respectively. The hot spring centers controlled the temperature of recycled water between 34-47 degrees C by hot water heating and filtrating system. All the isolates were cultured from the hot water with temperature between 34-44 degrees C: 56.75% (21/37) in high temperature (40-47 degrees C) and 61.90% (26/42) in low temperature (34-39.9 degrees C). There were no statistically significant difference between the high and the low temperature samples (P > 0.05). In the four hot spring vacation centers, the pH value was under control at 6.4-7.3 and the ambient temperature was under control between 26-28 degrees C. The humidity was controlled between 56% -69% relative humidity, which were the best growing conditions for the Legionella species. Disinfectors as chlorine deviratives was used in the four hot spring vacation centers. Though the concentration of chlorine in the water was 0.3-0.5 mg/L, 14.29%-48.00% of the samples were still positive of having Legionella species.
CONCLUSIONThe pollution of Legionella species was considered to be quite serious in the four hot spring vacation centers and the predominant serotype was Lp1. The pH and temperature of the hot spring water, ambient temperature and humidity and the way of heating up the water were the best conditions for the growth of Legionella species in these centers. Because of the high temperature of the hot spring water, chlorine of the disinfector volatilized quickly, affecting the effect of disinfection. The result revealed that water temperature achieving 44 degrees C could have had the effect of prevention.
China ; Disinfection ; Environmental Monitoring ; Hot Springs ; microbiology ; Legionella ; growth & development ; isolation & purification ; Temperature ; Travel ; Water Microbiology
9.Biomass and microbial activity in a biofilter during backwashing.
Yu BAI ; Jie ZHANG ; Yi-Fan LI ; Yu-Nan GAO ; Yong LI
Journal of Zhejiang University. Science. B 2005;6(5):427-432
Biomass and microbial activity in backwashing processes of a biofilter for tertiary treatment were investigated. The microbial groups revealed new distribution along the biofilter depth after low flow rate backwashing for a short time. Then the start-up process was accelerated by backwashing. The biomass profile and microbial activity profile both varying with depth before and after backwashing, can be mathematically described by quadratic equations. Using the profiles, the difference of oxygen demand can be calculated to determine the airflow rate during backwashing. Combined with the difference between biofilters and rapid gravity filters, analysis of biomass and microbial activity can determine more accurately the required airflow rate during backwashing.
Biomass
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Environmental Microbiology
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Filtration
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instrumentation
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methods
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Oxygen
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metabolism
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Sewage
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microbiology
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Water Purification
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instrumentation
;
methods
10.Three quantitative methods to continuously monitor Legionella in spring water.
Ge-bin YAN ; Huan-xin WANG ; Tian QIN ; Hai-jian ZHOU ; Ma-chao LI ; Ying XU ; Ming-qiang ZHAO ; Zhu-jun SHAO ; Hong-yu REN
Chinese Journal of Preventive Medicine 2013;47(7):637-640
OBJECTIVETo compare the detection effect of Legionella pollution in spring water by three methods, namely traditional plating method, fluorescent quantitation PCR method and ethidium monoazide (EMA) fluorescent quantitation PCR method.
METHODSEvery month (except May), we collected 11 water samples from the 5 selected hot spring pools in one hot spring resort in Beijing in 2011. A total of 121 water samples were collected, and then were detected by the above three methods qualitatively and quantitatively.
RESULTSIn our study, the Legionella pollution rate was separately 74.4% (90/121), 100.0% (121/121) and 100.0% (121/121) by the above three methods. The quantitative value of Legionella in the 121 water samples detected by the three methods were around 0.10-216.00 colony-forming units (CFU)/ml, 1.47-1557.75 gene units (GU)/ml and 0.20-301.69 GU/ml, respectively. The median (25th and 75th percentiles) was 75.30 (32.51-192.10) GU/ml, 36.46 (16.08-91.21) GU/ml and 5.30 (0.00-33.70) CFU/ml, respectively. The difference in the quantitative value of Legionella detected by the three methods showed statistical significance (χ(2) = 187.900, P < 0.01). The quantitative value of Legionella detected by fluorescent quantitation PCR method was the highest, followed by the value Legionella detected by EMA-fluorescent quantitation PCR method and traditional plating method.
CONCLUSIONThe sensitivity of the PCR methods was higher than traditional plating method, in detecting Legionella pollution in spring water, especially the EMA- fluorescent quantitation PCR method, which was more suitable for detecting Legionella in water.
Environmental Monitoring ; methods ; Hot Springs ; microbiology ; Legionella ; classification ; isolation & purification ; Microbiological Techniques ; Water Microbiology