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1.
杀钉螺微生物的筛选   总被引:2,自引:0,他引:2  
目的筛选有效杀钉螺菌株。方法从钉螺和钉螺孳生的土壤中分离具有杀钉螺作用的微生物。结果 153株中分离出YT28和LT129芽孢杆菌强毒株。室内浸泡杀螺,48h钉螺死亡率90%,72h达95%。结论 YT28和LT129菌株有较好的杀螺效果。  相似文献   

2.
目的了解麻风树籽甲醇提取物浸杀钉螺上爬现象对杀螺效果的影响。方法室内观察浸泡在不同浓度药液中的钉螺上爬及死亡情况。结果钉螺在药液中立即上爬 ,1 h达高峰 ,上爬率 86%~ 92 % ,48h自由上爬组各浓度药液中钉螺死亡率与人为干涉组相应浓度中钉螺死亡率比较差异有非常显著性 (P<0 .0 1 )。结论该植物杀螺剂对钉螺有激动作用 ,短时间内钉螺大量上爬 ,减少了接触药物时间 ,严重影响杀螺效果。  相似文献   

3.
目的评价50%杀螺胺乙醇胺盐悬浮剂的实验室和现场杀螺效果。方法在实验室和现场采用50%杀螺胺乙醇胺盐悬浮剂浸杀、喷洒法灭螺,并与50%氯硝柳胺乙醇胺盐可湿性粉剂进行效果比较。结果室内浸杀,50%杀螺胺乙醇胺盐悬浮剂24、48 h和72 h LC_(50)值分别为0.092 6、0.062 9 mg/L和0.054 9 mg/L;室内0.25 mg/L浸杀24、48 h和72h,钉螺死亡率均为100%;室内喷洒,0.25 g/m~2 3 d后钉螺死亡率即可达100%。江陵现场,除0.5 g/m~3浸杀24 h钉螺死亡率为96.67%外,其余浓度组钉螺死亡率均为100%。公安现场,0.5 g/m~3及以上浓度组浸杀钉螺2 d后,钉螺死亡率可达100%;江陵现场,0.5 g/m~2喷洒1、3 d和7 d后钉螺死亡率分别为87.5%、92.82%和97.40%。公安现场,0.5 g/m~2喷洒1、3 d和7 d后钉螺死亡率分别为85.94%、86.78%和94.21%,且1.0 g/m~2组钉螺死亡率均高于实验对照组WPN。结论 50%杀螺胺乙醇胺盐悬浮剂具有较好的实验室和现场杀螺效果,为新型高效、使用方便的灭螺药物剂型。  相似文献   

4.
金钱松内生真菌JJ18(Aspergillus)分别接种到固体培养基(A)、灭菌土壤(B)和未灭菌土壤(C)中,按照WHO的杀螺剂浸泡试验法观察各培养基浸出液的发酵产物对钉螺的杀灭作用,以及JJ18在土壤中的存活时间,并设不接种内生真菌JJ18的未灭菌空白土壤组(D)、去氯离子水阴性对照组(E)和氯硝柳胺阳性对照组(F)。采用WHO推荐的浸泡法,用卤虫(Artemia salina)模型观察其急性毒性,以人工海水为对照组,观察A~D组对卤虫的杀灭情况。结果显示,浸泡钉螺24、48、72 h,B组灭螺率分别为(36.67±7.56)%、 (63.33±4.65)%、 (90±0)%, 明显高于D组(30±6.87)%、 (33.33±5.68)%、 (56.67±8.55)% (P<0.05, P<0.01)。内生真菌JJ18在土壤中至少可存活30 d。B组对卤虫的杀虫率为(25.24±3.74)%, 显著低于A组(57.15±8.90)% (P<0.01)。  相似文献   

5.
5种天南星植物水浸液的杀螺效果研究   总被引:1,自引:0,他引:1  
目的了解不同天南星植物的杀螺效果,为研制高效低毒植物杀螺剂提供依据。方法室温(25±1)℃条件下将5种天南星植物以水浸法进行杀螺实验,并设清水对照作比较。结果5种天南星植物具有不同的杀螺效果,其中一把伞南星和螃蟹七的杀螺效果最好,1.0%的一把伞南星块茎和叶处理72h后,钉螺死亡率分别为100.0%和90.0%,螃蟹七块茎和叶都为93.3%;最弱为异叶南星的叶,72h钉螺死亡率为37.4%。一把伞南星不同器官中,块茎的杀螺效果最好,0.1%浓度处理72h的钉螺死亡率达93.3%;花序的杀螺效果最差,1.0%浓度处理的死亡率只有10.0%。结论一把伞南星和螃蟹七具有较强的杀螺效果,且一把伞南星的块茎部位杀螺效果最强。  相似文献   

6.
目的 了解麻风树籽甲醇提取物浸杀钉螺上爬现象对杀螺效果的影响。方法 室内观察浸泡在不同浓度药液中的钉螺上爬及死亡情况。结果 钉螺在药液中立即上爬,1h达高峰,上爬率86%-92%,48h自由上爬组各浓度药液中钉螺死亡率与人为干涉组相 浓度中钉螺死亡率比较差异有非常显著性(P<0.01)。结论 该植物杀螺剂对钉螺有激动作用,短时间内钉螺大量上爬,减少了接触药物时间,严重影响杀螺效果。  相似文献   

7.
杀虫丁室内和现场杀螺效果观察   总被引:1,自引:0,他引:1  
目的评价杀虫丁实验室和现场杀螺效果,探索有效灭螺剂量及影响灭螺效果的有关因素.方法以杀虫丁为实验组、氯硝柳胺为实验对照组和清水为空白对照组,捕捉野外钉螺在室内进行浸杀和喷洒实验,并选择有螺滩地进行现场浸杀和喷洒实验,观察比较不同浓度、作用时间和温度下钉螺校正死亡率.结果室内浸杀,杀虫丁1.0mg/L浓度组浸杀72h后钉螺校正死亡率为54.55%,显著低于同浓度的氯硝柳胺组(P<0.01);室内喷洒,杀虫丁1.0g/m2浓度组喷洒72h后钉螺校正死亡率为80.0%,杀螺效果也不及氯硝柳胺(P<0.05);现场浸杀,杀虫丁杀螺效果与室内相似,但现场喷洒1.0g/m2浓度组15d后钉螺校正死亡率达77.10%,与氯硝柳胺组相比差异无统计学意义(P>0.05),而1.25g/m2浓度组钉螺校正死亡率高于相应的氯硝柳胺组.杀虫丁杀螺效果受温度和作用时间影响较明显,但杀虫丁具有较强抑制钉螺爬动作用.结论杀虫丁适合现场喷洒灭螺,浓度以1.00~1.25g/m2、气温在25C为宜.  相似文献   

8.
醉鱼草内生真菌LL3026杀螺作用实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
目的研究醉鱼草(Buddleia lindleyana)内生真菌LL3026(Colletotrichum sp.)发酵液的杀螺作用、活性部位及其热稳定性和光照稳定性。方法采用烧杯浸杀法,观察不同时间、不同浓度LL3026发酵液醇浸膏水溶液对湖北钉螺的杀灭作用,同时设1mg/L氯硝柳胺水溶液和去氯离子水为对照。采用溶剂系统分离法分离LL3026发酵液的不同极性部位,并比较各极性部位的杀螺活性。该菌发酵液醇浸膏水溶液于不同温度(30~100℃)、不同时间(30~150min)处理后,进行杀螺试验,检测其热稳定性。在25℃、不同光照强度(分别照射1~9d)条件下,测定其光照稳定性。结果施药后24、48和72h的半数致死浓度(LC50)分别为50.11、3.43和1.55mg/L。分离LL3026发酵液,获得石油醚、乙醚、乙酸乙酯、正丁醇和水相等不同极性部位,其低极性部位的乙醚相杀螺效果最好,24、48和72h杀螺率均为100%。在80℃加热120min后,发酵液活性物质热稳定性好,杀螺率为100%。3600lx强度光照9d的发酵液的杀螺活性较强,其48h杀螺率为86.7%。结论醉鱼草内生真菌LL3026具有较好的杀螺活性。  相似文献   

9.
目的评价杀虫丁实验室和现场杀螺效果,探索有效灭螺剂量及影响灭螺效果的有关因素.方法以杀虫丁为实验组、氯硝柳胺为实验对照组、清水为空白对照组,捕捉野外钉螺在室内进行浸杀和喷洒实验,并选择有螺滩地进行现场浸杀和喷洒实验,观察比较不同浓度、作用时间和温度下钉螺校正死亡率.结果室内浸杀杀虫丁1.0mg/L浓度组浸杀72h后钉螺校正死亡率为54.55%,显著低于同浓度的氯硝柳胺组(P<0.01);室内喷洒杀虫丁1.0g/m2浓度组喷洒72h后钉螺校正死亡率为80.0%,杀螺效果也不及氯硝柳胺(P<0.05);现场浸杀杀虫丁杀螺效果与室内相似,但现场喷洒1.0g/m2浓度组15d后钉螺校正死亡率达77.10%,与氯硝柳胺组相比差异无统计学意义,而1.25g/m2浓度组钉螺校正死亡率高于相应的氯硝柳胺组.杀虫丁杀螺效果受温度和作用时间影响较明显,但杀虫丁具有较强抑制钉螺爬动作用.结论杀虫丁适合现场喷洒灭螺,浓度以1.0~1.25g/m2、气温在25℃为宜.  相似文献   

10.
目的 目的 比较螺威 (TDS) 和四聚?杀螺胺 (MNSC) 的现场杀螺效果。方法 方法 选择有钉螺孳生的小型有螺沟渠环境为 试区, 分别采用浸杀法和喷洒法对TDS和MNSC的杀螺效果进行评价。TDS和MNSC浸杀试验浓度分别为2.5 g/m3 和2ml/m3 , 喷洒试验剂量分别为3 g/m2 和2 ml/m2 ; 设50%氯硝柳胺乙醇胺盐可湿性粉剂 (WPN) 为对照组, 浸杀浓度和喷洒剂量为2 g/ m3 和2 ml/m2 。结果 结果 TDS浸杀24 h钉螺死亡率为90.70%, 喷洒7 d 死亡率为81.40%, 各观察时点杀螺效果差异均无统计 学意义 (P均>0.05)。喷洒后1 d , TDS组钉螺死亡率低于MNSC组 (P<0.01), 喷洒3 d后两组死亡率相近 (P>0.05)。MN? SC浸杀24 h钉螺死亡率为99.17%, 喷洒1 d 为66.07%;WPN浸杀24 h钉螺死亡率为97.51%, 喷洒1 d 为71.43%, 两者差异 均无统计学意义 (P均>0.05)。结论 结论 TDS具有良好的杀螺活性和药效稳定性, 现场杀螺效果与MNSC相近, 但杀螺敏感 性低于MNSC。  相似文献   

11.
Growth, survival, and resistance of the Legionnaires' disease bacterium   总被引:13,自引:0,他引:13  
The Legionnaires' disease (LD) bacterium can now be readily cultured on artificial media. Studies were done to define the growth and survival of the LD bacterium in these media and ascertain its susceptibility to disinfecting agents. Growth-curve studies of the Philadelphia 1 strain using Mueller-Hinton broth with ferric pyrophosphate and L-cysteine (Feeley-Gorman broth) showed a lag phase of less than 24 h, a generation time of 3.8 h during the logarithmic phase, a plateau of 2 x 10(7) organisms per millilitre, and continued viability for as long as 110 d. Viability on chocolate agar with 1% hemoglobin and 2% IsoVitaleX added reached 150 d. This strain was susceptible to a variety of commonly recommended hospital and laboratory disinfectants, often in low concentrations. These investigations suggest that prolonged survival may occur in natural as well as artificial milieus and that low concentrations of phenolics, quaternary ammonium compounds, glutaraldehyde, formaldehyde, and hypochlorite could eradicate potential reservoirs for human infection.  相似文献   

12.

Background

A survey was carried out to estimate the point prevalence of bacteriologically positive pulmonary tuberculosis (PTB) among persons ≥15 years of age residing in Jhuggi–Jhopri (JJ) colonies – urban slums in Delhi, India implementing Directly Observed Treatment strategy since 1998.

Methods

Among 12 JJ colonies selected by simple random sampling, persons having persistent cough for ≥2 weeks at the time of the survey or cough of any duration along with history of contact/currently on ant-TB treatment/known HIV positive were subjected to sputum examination – 2 specimens, by smear microscopy for Acid Fast Bacilli and culture for Mycobacterium tuberculosis. Persons with at least one specimen positive were labelled as bacteriologically confirmed PTB. Prevalence was estimated after imputing missing values to correct bias introduced by incompleteness of data and corrected for non-screening by X-ray by a multiplication factor derived from recently conducted surveys.

Results

Of 40,756 persons registered, 40,529 (99.4%) were screened. Of them, 691 (2%) were eligible for sputum examination. Spot specimens were collected from 659 (99.2%) and early morning sputum specimens from 647 (98.1%).Using screening by interview alone, prevalence of bacteriologically positive PTB in persons ≥15 years of age was estimated at 160.4 (123.7–197.1) per 100,000 populations and210.0 (CI: 162.5–258.2) after correcting for non-screening by X-ray.

Conclusion

Observed prevalence suggests further strengthening of TB control program in urban slums.  相似文献   

13.
OBJECTIVES: We report the cases of two patients, brother and sister, both with pulmonary tuberculosis. Both patients complied poorly with treatment. One developed multi-drug resistant disease, whilst the other did not. We aimed to show that the two infecting strains were the same, and then to compare the fitness of the resistant strain to that of the sensitive strain. METHODS: The isolates were typed by RFLP. The fitness of the multi-drug resistant tuberculosis strain was determined by calculating the ratio of generation produced by the drug-resistant and a drug-susceptible strain in a mixed culture. The number of bacteria present in this broth culture was estimated using the Miles and Misra technique. The number of drug-resistant bacteria present was determined by inoculating aliquots of broth onto Middlebrook 7H10 agar with 5mg/l rifampicin. RESULTS: The infecting strain of Mycobacterium tuberculosis was shown to be the same on RFLP typing in both cases. It was found that the multi-drug resistant organism had decreased fitness compared to the sensitive organism. CONCLUSION: The decreased relative fitness of the resistant strain implies a physiologic cal cost for the development of drug resistance.  相似文献   

14.
AIM:To establish a stable and reliable model of Helicobacter pyloriinfection model in Mongolian gerbils and to observe pathological changes in gastric mucosa in infected animals.METHODS:Mongolian gerbils were randomly divided into 18 groups;6 groups were infected with Hpylori clinical strain Y06 (n=6, groups Y), 6 groups were infected with Hpylori strain NCTC11637 (n=6, roups N),and 6 uninfected groups as negative controls (n=4,groups C).Hpylori suspensions at the concentrations of 2&#215;10^8 and 2&#215;10^9CFU/mL of strain NCTC11637 and strain Y06 were prepared. The animals in three groups N and in three groups Y were orally challenged once with 0.5 mL of the low concentration of the bacterial suspension.The animals in another three groups N and in another three groups Y were orally challenged with 0.5mL of the high concentration of the bacterial suspension for 3 times at the intervals of 24 h,respectively.For the negative controls,the animals in six groups C were orally given with the same volume of Brucella broth at the corresponding inoculating time.The animals were killed after 2nd, 4^th and 6^th week after the last challenge and the gastric mucosal specimens were taken for urease test,bacterial isolation, pathological and immunohistochemical examinations.RESULTS:Positive isolation rates of Hpyloriin the animals of groups Y at the 2nd, 4^th and 6^th week after one challenge were 0%, 16.7% and 66.7%, while in the animals of groups N were 0%, 0% and 16.7%, respectively.Positive isolation rates of Hpyloriin the animals of groups Y at the 2nd, 4^th and 6^th week after three challenges were 66.7%,100% and 100%,while in the animals of groups N were 66.7%,66.7% and 100%, respectively. In animals with positive isolation of Hpylori, the bacterium was found to colonized on the surface of gastric mucosal cells and in the gastric pits,and the gastric mucosal lamina propria was infiltrated with inflammatory cells.CONCLUSION:By using H pylori suspension at high concentration of 2&#215;10^9 CFU/mL for multiple times,the orally challenged Mongolian gerbils can be used as a stable and reliable H pylori infection model.The 2 strains of H pylori can colonize in gastric mucosa of the infected animals and cause mild inflammation reaction.  相似文献   

15.

Background

Old, stationary cultures of Mycobacterium tuberculosis contain a majority of bacteria that can grow in broth cultures but cannot grow on solid medium plates. These may be in a non-replicating, dormant growth phase. We hypothesised that a similar population might be present in chronic, murine tuberculosis.

Methods

Estimates of the numbers of viable M. tuberculosis, strain H37Rv, in the spleens and lungs of mice in a 7-day acute infection and in a 10-month chronic infection were made by conventional plate counts and, as broth counts, by noting presence or absence of growth in serial replicate dilutions in liquid medium.

Results

Plate and broth counts in 6 mice gave similar mean values in the acute infection, 7 days after infection. However, the broth counts were much higher in 36 mice with a chronic infection at 10 months. Broth counts averaged 5.290 log10 cfu /organ from spleens and 5.523 log10 cfu/organ from lungs, while plate counts were 3.858 log10 cfu/organ from spleens and 3.662 log10 cfu/organ from lungs, indicating that the total bacterial population contained only 3.7% bacilli in spleens and 1.4% bacilli in lungs, capable of growth on plates.

Conclusion

The proportion growing on plates might be a measure of the "dormancy" of the bacilli equally applicable to cultural and animal models.
  相似文献   

16.
We attempted to isolate TDH-producing Vibrio parahaemolyticus O3:K6 from shellfish. Asari samples were incubated with TSB supplemented with 2% (w/v) NaCl for 6 h, and then the 6-h cultures were incubated with salt polymyxin broth for 18 h. After the two-step enrichment, a 1 ml portion of the culture was treated with magnetic beads coated with K6 antibody for immunoconcentration of V. parahaemolyticus O3:K6. The immunoconcentrated and untreated cultures were plated onto a chromogenic agar and TCBS agar media for isolation of V. parahaemolyticus. TDH-producing V. parahaemolyticus O3:K6 was isolated from 3 out of 66 lots (4.5%) of naturally contaminated Asari. Six of 4,265 colonies suspected as V. parahaemolyticus (0.14%) were TDH-producing V. parahaemolyticus O3:K6.  相似文献   

17.
目的应用超声二维斑点追踪技术评价二维整体收缩期峰值应变在判断左室收缩功能中的价值。方法心功能不全患者52例和健康对照者30例,应用二维斑点追踪技术分别测量左室各节段收缩期纵向峰值应变、径向峰值应变和圆周峰值应变,并分别取其平均值做为左室收缩期整体纵向应变(GLS)、整体径向应变(GRS)和整体圆周应变(GCS),同时应用Simpson双面法计算左室射血分数(LVEF)。对各指标绘制受试者工作特性曲线(ROC)并获得界值。结果心功能不全患者GLS、GRS和GCS均显著低于正常对照组(P0.05);ROC评价显示GLS、GCS的曲线偏左上角,其曲线下面积分别为0.950、0.939,对应的界值分别为-13.12%、-13.86%,其诊断心功能不全的灵敏度和特异度分别为90.0%/94.4%,93.3%/83.3%,GRS的曲线下面积0.170.5,诊断左室收缩功能不全意义不显著。结论二维整体收缩期应变可较好地评价左室的收缩功能,其中GLS和GCS具有较高的诊断心功能不全的价值。  相似文献   

18.
The aim of this study was to determine synergistic effects of meropenem and ciprofloxacin against Pseudomonas aeruginosa and Acinetobacter strains isolated from intensive care unit (ICU) infections. A total of 18 P. aeruginosa and 17 Acinetobacter strains were tested. MICs were determined using the broth microdilution method. The synergy of meropenem and ciprofloxacin was investigated in glass tubes using time-kill methodology. The synergistic effect of meropenem and ciprofloxacin in combination was found to be 22% at 0.5 x the MIC and 61% at 1 x the MIC in P. aeruginosa strains. Two strains (11%) showed synergy at both 0.5 and 1 x the MIC. Of the 18 P. aeruginosa strains, 1 strain (6%) did not show a synergistic effect at either 0.5 or 1 x the MIC. In Acinetobacter strains, the synergistic effect of meropenem and ciprofloxacin in combination was found to be 29% at 0.5 x the MIC and 18% at 1 x the MIC. One strain (6%) showed synergy at both 0.5 and 1 x the MIC. Of the 17 Acinetobacter strains, 8 strains (47%) did not show a synergistic effect at either 0.5 or 1 x the MIC. According to the results of this study, the combination of meropenem and ciprofloxacin is more effective than either antibiotic alone in ICU infections due to P. aeruginosa strains.  相似文献   

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