Pharmacogenomic Research in Direct Oral Anticoagulants / 中国医学科学院学报

Oral anticoagulants play an important role in the prevention and treatment of thromboembolic diseases.Warfarin,a traditional oral anticoagulant,is limited in clinical use due to its limitations such as narrow therapeutic window and requirements on frequent monitoring and dose adjustment.Direct oral anticoagulants(DOACs)such as dabigatran,rivaroxaban,apixaban,and edoxaban are increasingly used to prevent and treat venous thrombosis or thrombus formation.However,recent studies have documented inter-individual variability in plasma drug levels of DOACs.This article summarizes the recent advances in the pharmacogenomics of DOACs.

Percutaneous Nucleoplasty Using Coblation Technique for the Treatment of Chronic Nonspecific Low Back Pain: 5-year Follow-up Results / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study evaluated the efficacy of percutaneous nucleoplasty using coblation technique for the treatment of chronic nonspecific low back pain (LBP), after 5 years of follow-up.</p><p><b>METHODS</b>From September 2004 to November 2006, 172 patients underwent percutaneous nucleoplasty for chronic LBP in our department. Forty-one of these patients were followed up for a mean period of 67 months. Nucleoplasty was performed at L3/4 in 1 patient; L4/5 in 25 patients; L5/S1 in 2 patients; L3/4 and L4/5 in 2 patients; L4/5 and L5/S1 in 7 patients; and L3/4, L4/5, and L5/S1 in 4 patients. Patients were assessed preoperatively and at 1 week, 1 year, 3 years, and 5 years postoperatively. Pain was graded using a 10-cm Visual Analogue Scale (VAS) and the percentage reduction in pain score was calculated at each postoperative time point. The Oswestry Disability Index (ODI) was used to assess disability-related to lumbar spine degeneration, and patient satisfaction was assessed using the modified MacNab criteria.</p><p><b>RESULTS</b>There were significant differences among the preoperative, 1-week postoperative, and 3-year postoperative VAS and ODI scores, but not between the 3- and 5-year postoperative scores. There were no significant differences in age, sex, or preoperative symptoms between patients with effective and ineffective treatment, but there were significant differences in the number of levels treated, Pfirrmann grade of intervertebral disc degeneration, and provocative discography findings between these two groups. Excellent or good patient satisfaction was achieved in 87.9% of patients after 1 week, 72.4% after 1 year, 67.7% after 3 years, and 63.4% at the last follow-up.</p><p><b>CONCLUSIONS</b>Although previously published short- and medium-term outcomes after percutaneous nucleoplasty appeared to be satisfactory, our long-term follow-up results show a significant decline in patient satisfaction over time. Percutaneous nucleoplasty is a safe and simple technique, with therapeutic effectiveness for the treatment of chronic LBP in selected patients. The technique is minimally invasive and can be used as part of a stepwise treatment plan for chronic LBP.</p>

Case-control study on therapeutic effects between unilateral decompression via fenestration under Quadrant retractor and open decompression technique with fusion and internal fixation for the treatment of lumbar spinal stenosis / 中国骨伤

<p><b>OBJECTIVE</b>To compare therapeutic effects between unilateral decompression technique only and open decompression technique with fusion and internal fixation for the treatment of lumbar spinal stenosis.</p><p><b>METHODS</b>From March 2008 to February 2011, 82 patients with lumbar spinal stenosis were treated with operations, and divided into two groups. There were 13 males and 19 females in group A, with a mean age of (56.31±4.31) years old. The patients in group A were treated with unilateral decompression via fenestration technique only, including 23 patients obtaining single level decompression and 9 patients obtaining two levels decompression. In group B, there were 18 males and 32 females, with a mean age of (57.53±4.28) years old. The patients in group B were treated with open decompressive technique with fusion and internal fixation, including 38 patients obtaining single level decompression and 12 patients obtaining two levels decompression. The VAS of back pain and leg pain, ODI were recorded before and after surgery to evaluate low back pain,leg pain and walking tolerance.</p><p><b>RESULTS</b>All the patients were followed up, and the duration ranged from 10.9 to 43.4 months,with a mean of 32.8 months. There were no differences in age, stenosis level, VAS of back and leg pain and ODI before surgery between two groups. Compared with the corresponding ones in group B, the operation time, blood loss, hospitalization time,recovery time of routine daily life and finacial expenditure of patients were all shorter or less in group A. There was no statistically difference in complications between two groups.</p><p><b>CONCLUSION</b>"Unilateral decompression via fenestration technique" is a less invasive and more effective decompressive technique for degenerative spinal stenosis without posterior elements damage. It has advantages in operation time, blood loss, hospitalization time, recovery to daily life and financial expenditure. When controlling the operative indications strictly, the technique could be an important procedure for surgical treatment of degenerative spinal stenosis, especially in the elderly population.</p>

Quantitative risk assessment of Listeria monocytogenes in bulk cooked meat products / 中华预防医学杂志

<p><b>OBJECTIVE</b>To conduct a quantitative risk assessment for Listeria monocytogenes in bulk cooked meat products in China.</p><p><b>METHODS</b>The data on the contamination level of Listeria monocytogenes in cooked meat products was from national foodborne disease surveillance network, involving a total of 841 samples. All the samples were detected by a qualitative method and 97 samples among them were detected using a quantitative method. The intake data of cooked meats was from Chinese National Nutrition and Health Survey in 2002 and population data in the monitoring sites was collected from National Bureau of Statistics in 2008 to estimate the composition of the population of different ages, which would be the base of assessing the probability of listeriosis in the different subpopulations. Using @Risk software to estimate the risk of listeriosis caused by consuming deli meats for different subpopulation (0 - 4 years old, 5 - 64 years old and 65 years and older) by quantitative risk assessments which involved hazard identification, hazard characterization, exposure assessment and risk characterization and conduct sensitivity analysis.</p><p><b>RESULTS</b>The contamination level of Listeria monocytogenes in the most of samples (96.08%, 808/841) was less than 3 MPN/g (0.5 lg MPN/g), and the average concentration of Listeria monocytogenes was -0.61 lg CFU/g (90%CI: -1.22 - 0.46 lg CFU/g). Estimated servings of cooked meat consumption for 0 - 4, 5 - 64 and 65 years and older were 5.52 × 10(9), 8.99 × 10(10), 1.01 × 10(10), respectively. Estimated number of cases (median) of listeriosis each year per million people caused by consuming cooked meats in young (0 - 4 years old), intermediate age (5 - 64 years old) and elderly (65 years and older) population were 5.53 × 10(-3), 1.72 × 10(-4), 7.57 × 10(-3), respectively. Results of sensitivity analysis showed that contamination level at retail, serving size of cooked meats, storage time at home, storage temperature and ERG at 5°C were positive factors for the risk of listeriosis (r value was 0.607, 0.408, 0.339, 0.259, 0.183 respectively, P < 0.05).</p><p><b>CONCLUSION</b>Cooked meat products in bulk is a risk food, which could cause listeriosis. Contamination level of Listeria monocytogenes in cooked meat products in bulk is the top risk factor for the listeriosis.</p>

Analysis of main risk factors causing foodborne diseases in food catering business / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study main risk factors that cause foodborne diseases in food catering business.</p><p><b>METHODS</b>Data from references and investigations conducted in food catering units were used to establish models which based on @Risk 4.5 with Monte Carlo method referring to food handling practice model (FHPM) to make risk assessment on factors of food contamination in food catering units. The Beta-Poisson models on dose-response relationship to Salmonella (developed by WHO/FAO and United States Department of Agriculture) and Vibrio parahaemolyticus (developed by US FDA) were used in this article to analyze the dose-response relationship of pathogens.</p><p><b>RESULTS</b>The average probability of food poisoning by consuming Salmonella contaminated cooked meat under refrigeration was 1.96 × 10(-4) which was 1/2800 of the food under non-refrigeration (the average probability of food poisoning was 0.35 at room temperature 25°C). The average probability by consuming 6 hours stored meat under room temperature was 0.11 which was 16 times of 2 hours storage (6.79 × 10(-3)). The average probability by consuming contaminated meat without fully cooking was 1.71 × 10(-4) which was 100 times of consuming fully cooked meat (1.88 × 10(-6)). The probability growth of food poisoning by consuming Vibrio parahaemolyticus contaminated fresh seafood was proportional with contamination level and prevalence.</p><p><b>CONCLUSION</b>The primary contamination level, storage temperature and time, cooking process and cross contamination are important factors of catering food safety.</p>

Virulent gene prevalence of foodborne Listeria monocytogenes in China in 2005 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the virulent gene prevalence of foodborne Listeria monocytogenes (LM) isolated from China.</p><p><b>METHODS</b>78 LM isolates derived from raw meat, cooked food, aquatic products and vegetables of 13 provinces and cities.LM isolates were investigated for prevalence of virulence genes (LIPI-1 (prfA, plcA, hly, mpl, actA, plcB); LIPI-2 (inlA, inlB), and iap) by PCR method.</p><p><b>RESULTS</b>87.2% (68/78) of the isolates were prfA positive, 98.7% (77/78) of the isolates were plcA, actA and plcB positive, 97.4% (76/78) of the isolates were hly positive, 87.2% (68/78) of the isolates were mpl positive, 92.3% (72/78) of the isolates were inlA positive, 100% (78/78) of the isolates were inlB positive, 98.7% (77/78) of the isolates were iap positive. Among 21 virulent gene negative isolates, there was 7 isolates lack of two or more virulence genes. The rate of virulence genes deletion isolates from cooked meat was 31.3% (10/32), the rate of virulence genes deletion isolates from raw meat was 16.1% (5/31), the rate of virulence genes deletion isolates from vegetables was 36.4% (4/11) and rate of virulence genes deletion isolates from seafood was 50% (2/4). No significant difference was found (χ(2) = 3.721, P > 0.05). The virulence gene array-1 strains were dominant among these isolates.</p><p><b>CONCLUSION</b>Among 78 LM isolates, prevalent of virulent genes were different except inlB, virulence genes of LIP-1 were deleted prevalently among isolates, virulence gene deletion patterns were diverse.</p>

Foodborne pathogens in retail oysters in south China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the occurrence of important foodborne pathogens in shellstock Pacific oysters in the food markets in South China.</p><p><b>METHODS</b>From July 2007 to June 2008, retail oysters were collected in different seasons from South China and analyzed for the prevalence and levels of Listeria monocytogenes, Vibrio vulnificus and Vibrio parahaemolyticus.</p><p><b>RESULTS</b>None of L. monocytogenes could be detected in any of the 202 oyster samples tested, while E vulnificus and V. parahaemolyticus could be detected in 67 (54.9%) and 109 (89.3%) of the 122 oyster samples analyzed, respectively, with an MPN (most probable number) value greater than or equal to 3. V. vulnificus and V. parahaemolyticus with a more than 102 MPN/g were found in 36 (29.5%) and 59 (48.4%) of the 122 oyster samples, respectively. The tdh and trh genes were detected in 4 (0.3%) and 8 (0.6%) of the 1 349 V parahaemolyticus isolates, respectively. Of the 122 samples, 4 (3.3%) was positive for either tdh or trh. The levels of V. vulnificus and total V. parahaemolyticus in oysters in South China varied in different seasons.</p><p><b>CONCLUSION</b>V. vulnificus and pathogenic V. parahaemolyticus are frequently found in oysters in south China, which may pose a potential threat to public health. Data presented here will be useful for the microbiological risk assessment in oysters in China.</p>

Exposure assessment of liver cancer attributed to dietary aflatoxins exposure in Chinese residents / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the risk of liver cancer attributed to dietary aflatoxins exposure in Chinese residents.</p><p><b>METHODS</b>Mathematics model and "Margin of Exposure (MOE)" methods were employed in this study. The data used in mathematics model came from Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the detection results of hepatitis B virus ( HBV) indicator in Chinese residents' blood sample in 2004. The data used in MOE model came from animal experiments, the fourth nutrition and health investigation among Chinese residents, and national inspection network for food contaminations.</p><p><b>RESULTS</b>Mathematics model indicated that for those people who were exposed to aflatoxins at average level (665.43 ng/d), the liver cancer incidence rate resulting from aflatoxins exposure was 0.4033 per 100 thousand person years. For those people who were exposed to aflatoxins at a high level (97.5 percentile, 24 787.20 ng/d) the liver cancer incidence rate attributed to aflatoxins exposure was 15.0215 per 100 thousand person years. Results from the MOE method showed that for the people in whole country, urban and rural areas who were exposed to aflatoxins at average level (0.011 09, 0.008 13 and 0.012 49 microg x kg(-1) x d(-1) respectively), the MOE values for aflatoxins to cause liver cancer were 9017.1, 12 304.7 and 8006.4 respectively. For those people who were exposed to aflatoxins at a high level (97.5 percentile, 0.413 10, 0.289 30 and 0.489 50 microg x kg(-1) x d(-1) respectively), the MOE values for aflatoxins to cause liver cancer were 242.1, 345.7 and 204.3 for whole country, urban and rural areas, respectively.</p><p><b>CONCLUSION</b>For the people whose dietary aflatoxins exposure at average level, the risk of liver cancer attributed to aflatoxins is middle. For the people whose dietary aflatoxins exposure at high level, this kind of risk should be high.</p>

Study on the automatic ribotyping for Enterobacter sakazakii / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the ribotyping fingerprint of Enterobacter sakazakii (E. sakazakii) isolated from food and its typing power.</p><p><b>METHODS</b>Two standard strains and twenty-eight isolates of E.sakazakii were analyzed by the DuPont Riboprinter(TM) microbial characterization system. The relevant database was established and the fingerprint patterns were analyzed with BioNumerics software.</p><p><b>RESULTS</b>This system grouped two standard strains and twenty-eight E.sakazakii isolates into 26 ribotypes, and four ribotypes included two strains respectively, the other twenty-two strains showed different ribotypes. The lowest similarity was 31.58%. The number of bands by ribotyping was approximately ten and the molecular weight of these bands ranged from 1 to 50 kb. By the clustering program in BioNumerics, these isolates could be grouped into four clusters.</p><p><b>CONCLUSION</b>The automatic ribotyping method is convenient and fast in E.sakazakii typing.</p>

Risk assessment of Listeria monocytogenes in deli meats and vegetable salads / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analysis risk from Listeria monocytogenes in deli meats and vegetable salads.</p><p><b>METHODS</b>Use Risk Ranger which is a software programme developed by the University of Hobart, Australia and answer 11 questions on affecting the risk from hazards in the specific foods by combining data from national foodborne diseases surveillance network and some references to make semi-quantitative risk assessment for the specific food.</p><p><b>RESULTS</b>Relative risk from Listeria monocytogenes in deli meats and vegetable salads is 61 and 52, respectively. Incidence of listeriosis caused by deli meats-Listeria monocytogenes pairs and vegetable salads-Listeria monocytogenes pairs is 5.4 and 0.2 cases per million people, respectively. Risk from the former is 32 times than that from the latter. By changing the selection for some risk factors in the model, it was known that the risks from two food-hazard combinations could decrease 10 times, if taking necessary actions after processing.</p><p><b>CONCLUSION</b>Deli meats is a kind of high risk food for listeriosis.</p>

Quantitative microbiological risk assessment of Salmonella spp. in connmmon catering foods / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the relationship between foodborne diseases (FBD) and contamination of Salmonella spp. in catering foods, quantitative microbiological risk assessment (QMRA) of Salmonella spp. was used to evaluate the food material or the ready to eat food.</p><p><b>METHODS</b>The contamination data of Salmonella spp. in 10 896 food samples of 9 categories of food which were collected by National Food Contamination and Food Borne Disease Surveillance Net, combining with diet consumption data from National Food Nutrition Survey in 2002, were analyzed by the microbiological risk assessment model developed by WHO/FAO or FDA/FSIS of US to predict probability of FBD.</p><p><b>RESULTS</b>The results of MRA showed that the probability of salmonellosis by consuming ready to eat meat in summer and autumn was 0.20, much higher than the other foods. Although the contamination level in raw poultry was higher than meat, the probability of salmonellosis by raw poultry (9.11 x 10(-6)) was lower than meat (3.14 x 10(-5)) because of the low consumption volume.</p><p><b>CONCLUSION</b>Probability of FBD was significantly correlated with the volume of food consumption, the status of economy and bacteria contamination level. The level of FBD in summer season was higher than in winter and spring because of ambient temperature.</p>

Contamination of aflatoxins in different kinds of foods in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the contamination of total aflatoxins (AFs) in different kinds of foods including corn, peanut, rice, walnut, and pine nut in six provinces and two municipalities in China.</p><p><b>METHODS</b>A total of 283 samples of corn, peanut, rice, walnut and pine nut were randomly collected from local markets in Fujian, Guangdong, Guangxi, Hubei, Jiangsu, and Zhejiang provinces, as well as in Shanghai and Chongqing municipalities. The samples were ground to which acetonitrile/water solution was added. After filtering, the extract was transferred into a MycoSep purifying column and was pressed slowly. Then the purified liquid was derivatized with trifluoroacetic acid (TFA) and assayed using high performance liquid chromatography (HPLC).</p><p><b>RESULTS</b>AFs were detected in 70.27% of corn samples, with a mean level of 27.44 microg/kg and the highest level of 1098.36 microg/kg. In peanut, the AFs detection rate was 23.08%, with a mean level of 0.82 microg/kg and the highest level of 28.39 microg/kg. Very few rice samples with AFs were detected. The AFs levels were very low in walnut and pine nut.</p><p><b>CONCLUSION</b>Corn is the food most seriously contaminated with AFs in China. AFB1 is the main aflatoxin which is found as a contaminant in foods.</p>

Diagnostic value of 2-dimentional ultrasonography and color Doppler flow imaging in primary bone tumor / 中南大学学报(医学版)

OBJECTIVE@#To explore the diagnostic value of 2-dimentional ultrasonography and color Doppler flow imaging (CDFI) in primary bone tumor.@*METHODS@#The hemodynamic parameters such as systolic maximum velocity (Vmax), diastolic minimum velocity (Vmin), resistance index (RI), and pulsatility index (PI) of intratumoral folw in 93 patients with primary bone tumors proved by histopathology were studied using 2-dimentional ultrasonography and CDFI techniques.@*RESULTS@#The bone destruction periosteum response and soft tissue mass were essentially revealed with 2-dimentional ultrasonography techniques. The intratumoral flow features were clearly shown by CDFI. The Vmax and Vmin in malignant bone tumor were significantly higher than those in benign one (P < 0.01). RI and PI in malignant bone tumor were lower than those in benign one (P < 0.01).@*CONCLUSION@#Observing the features of bone tumor and hemodynamic parameters by 2-dimentional ultrasonography and CDFI has a great clinical value in diagnosing primary bone tumor and distinguishing the malignant and benign bone tumors.

Surveillance on contamination of total aflatoxins in corn, peanut, rice, walnut and pine nut in several areas in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To realize the contamination of total aflatoxins in corn, peanut, rice, walnut and pine nut in China, and provide the base data for establishing a China tolerance limit standard and an international control practice for total aflatoxins.</p><p><b>METHODS</b>The samples of corn, peanut, rice, walnut and pine nut from Chongqing, Fujian, Guangdong, Guangxi, Hubei, Jiangsu, Shanghai and Zhejiang provinces and municipalities were collected randomly from markets, with the totally 284 samples. The samples were grounded and added to acetonitrile/water mixture. After filtering, the extract was transferred into a purifying column and pressed slowly. Then the purified liquid was derivatized with trifluoroacetic acid (TFA) and detected by using a high performance liquid chromatography (HPLC).</p><p><b>RESULTS</b>There was 70.27% corn having been detected out an average level of aflatoxins of 36.51 microg/kg and the highest level was 1098.36 microg/kg. At the same time, there was 14.86% corn exceeding the China national tolerance limit. In peanut, the aflatoxins detected rate was 24.24%. The average level was 80.27 microg/kg and the highest level was 437.09 microg/kg. While there was 3.03% peanut exceeding the China national and Codex tolerance limits. All of the rice, walnut and pine nut samples met the China tolerance limit for aflatoxins.</p><p><b>CONCLUSION</b>Corn and peanut might be the severely contaminated foods with aflatoxins in China. The aflatoxin B(1) in foods might be can not delegate the contamination of aflatoxins completely. Surveillance of total aflatoxins in foods suggested an actual need of establishing the China national and international standards for total aflatoxins.</p>

Application of ultrasound-guided percutaneous biopsy in the preoperative diagnosis and treatment of bone tumors / 中南大学学报(医学版)

OBJECTIVE@#To investigate the value of color Doppler ultrasonography (CDUS)-guided percutaneous biopsy in the diagnosis and treatment of bone tumors.@*METHODS@#Ultrasound-guided percutaneous biopsy was performed in 64 patients who was diagnosed by CDUS. Puncture instruments included automatic core biopsy device and 14 to approximately 18G crude needle. All cases were identified by the operation and pathological examination.@*RESULTS@#Tissue-obtained rate was 97% (62/64). Comparing preoperative pathological diagnosis with postoperative pathological diagnosis, we found the diagnostic correct rate was 97%. No complications resulted from this procedure. According to their pathological results, 33 patients were treated with preoperative chemotherapy. The tumor sizes decreased, and 26 patients saved their limbs and had normal functions.@*CONCLUSION@#CDUS-guided percutaneous biopsy is safe and quick for the preoperative diagnosis and selecting appropriate surgical procedure for bone tumor treatment.

Determination of fumonisin biosynthesis gene and toxicity of Fusarium moniliforme strains isolated in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the relationship between fumonisin biosynthesis gene and toxicity of Fusarium moniliforme isolated in China.</p><p><b>METHODS</b>The toxigenic gene of 29 Fusarium moniliforme isolated from different provinces and varied food samples were determined. Eighteen fum5-positive strains were selected for biosyhesizing fumonisin and determined by high performance liquid chromatography (HPLC).</p><p><b>RESULTS</b>Twenty-six isolates were identified as fum5 gene positive strains. And all of these strains produced FB(1), FB(2) and FB(3). The amount of FB(1), FB(2) and FB(3) was ranging from 0.41-140.20 mg/kg, 0.06-14.30 mg/kg to 0.30-58.00 mg/kg, except one strain produced a lower level of FB(1) only. It wight be the first report showing a high level fumonisin-producing strain isolated from the sesame sample and identified in the world. The amount of FB(1), FB(2) and FB(3) produced by the isolate was 128.84 mg/kg, 11.80 mg/kg and 14.88 mg/kg.</p><p><b>CONCLUSIONS</b>It should have a close relationship between fumonisins biosynthesis gene and toxicity of Fusarium moniliforme isolated in China. The study demonstrated that strain of Fusarium moniliforme might contaminate the sesame sample and produce a high level of fumonisins.</p>

Preparation of monoclonal antibody and development of enzyme-linked immunosorbent assay specific for Escherichia coli O157 in foods / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To prepare monoclonal antibodies (MAb) and antisera specific for Escherichia coli (E. coli) O157, and to develop a sandwich enzyme-linked immunosorbent assay (ELISA) to detect E. coli O157 in foods.</p><p><b>METHODS</b>Spleen cells from BALB/c mice immunized with the somatic antigen of E. coli O157:H7 were fused with murine Sp2/0 myeloma cells. The hybridoma cell line specific for E. coli O157 was established after having been subcloned. Antisera specific for E. coli O157 was prepared by intravenous injection into New Zealand rabbits with a stain of E. coli O157:H7. The sandwich ELISA was developed with the polyclonal antibody as the capture antibody and the MAb 3A5 as the detection antibody. The inoculated ground poultry meat and pasteurized milk were tested to confirm efficiency of the method.</p><p><b>RESULTS</b>MAb 3A5 specific for E. coli O157 and O113:H21 belonged to subtype IgM. The ascetic titers of the antibody was 1:1x10(6). No cross-reactivity of the MAb was observed with strains of Salmonella spp, Yersinia enterocolitica, Shigella dysenteriae, etc. The purified polyclonal antibody had a titer of 1:1x10(5) with E. coli O157. The detection limit of this sandwich ELISA was 10(3)-10(4) cfu E. coli O157/mL in pure culture with a high specificity, which was characterized by every non-O157 strain with negative response. With 10h enrichment procedure, E. coli O157:H7 recovered well from inoculated ground poultry meat and pasteurized milk at levels of 0.1 cfu/g and 0.1 cfu/mL.</p><p><b>CONCLUSION</b>MAb 3A5 specific for E. coli O157 and O113:H21 can be produced by immunizing BALB/c mice with a strain of E. coli O157:H7. Then a sandwich ELISA can be developed with the polyclonal antibody as the capture antibody and the MAb 3A5 as the detection antibody. The method is proved to be a sensitive and specific technique to detect low number of E. coli O157 in food.</p>

Application of green fluorescence protein in the detection of E. coli O157:H7 in food / 中华预防医学杂志

<p><b>OBJECTIVE</b>To introduce green fluorescence protein (GFP) into E. coli O157:H7 and improve the detection methods for this bacteria, and to study the kinetics of E. coli O157:H7.</p><p><b>METHODS</b>The plasmid pGFP was transferred into E. coli O157:H7. The characteristic of the new built O157:H7-pGFP strain was evaluated. Some food samples were inoculated with the recombinant strain under certain temperature to imitate different storage circumstances. The contaminated E. coli O157:H7 were counted after certain time.</p><p><b>RESULTS</b>The pGFP was stable in E. coli O157:H7. The E. coli O157:H7-pGFP inoculated in ground poultry meat and pasteurized milk were enriched to 35 000 approximately 200 000 times in 12 h under higher storage temperature (37 degrees C), whereas the quantity decreased slowly under lower temperature (4 degrees C).</p><p><b>CONCLUSION</b>The recombinant strain with the characters of ampicillin resistance and green fluorescence under UV 365 nm was a useful tool in detection methods improvement and bacteria survival studies.</p>