鼠伤寒沙门氏菌噬菌体分型及药敏试验

鼠伤寒沙门氏菌噬菌体分型及药敏试验苏州市卫生防疫站任德生林建国鼠伤寒沙门氏菌是引起食物中毒和腹泻，特别是引起婴幼儿院内感染的重要病原菌。为摸清我市鼠伤寒沙门氏菌噬菌体型别分布及药敏情况，我们收集了２７株鼠伤寒沙门氏菌进行噬菌体分型及耐药性试验，现将结...     

甘肃省部分地区鼠伤寒沙门氏菌噬菌体分型、耐药性及质粒检测

我们于1990年7月～1991年8月从食物中毒、腹泻病患者排泄物中分离出276株鼠伤寒沙门氏菌,并进行了噬菌体分型、耐药性测定、质粒检测试验。现报告如下。材料与方法:(1)测试菌株:276株鼠伤寒沙门氏菌是从本省兰州市、武威市、白银市、临夏4市搜集。(2)标准菌株:大肠ATCC25922、绿脓杆菌ATCC27853、金萄菌ATCC25923;质粒检测用标准E·Coli V517;均由中国预防医学科学院流行病学微生物学研究所提供。(3)鼠伤寒沙门氏菌噬菌体:由中国医学细菌保藏     

辽宁省鼠伤寒沙门氏菌噬菌体分型及耐药谱监测

辽宁省自１９８８年以来从不同地区、不同来源标本中分离到１５１株鼠伤寒 沙门氏菌,可分为１４个菌体型,分型率为９７．３５％,其中４７７４为我省优势噬菌体型,占暴发株的５７．８０％。１５１株鼠伤寒沙门菌耐药谱复杂,所有菌株匀呈三耐以上。     

福建省鼠伤寒沙门氏菌病原学特征变迁趋势

目的：了解福建省鼠伤寒沙门氏菌的病原学特征变迁情况。方法：采用噬菌体分型、质粒谱分析及耐药性测定的方法,对福建省１９８０～１９９５年１５年鼠伤寒沙门氏菌的病原学特征进行动态监测。结果：福建省鼠伤寒沙门氏菌的噬菌体流行型别存在明显的变迁与更迭;质粒谱型有逐渐增多且分散趋势;菌株耐药率逐年大幅度上升,耐药谱逐年迅速增宽,多重耐药菌株逐年急剧增多,耐药现象日趋严重。结论：噬菌体分型、质粒谱分析及耐药性测定是监测福建省鼠伤寒沙门氏菌病原学特征变迁趋势的有效方法。     

杭州地区伤寒沙门氏菌Vi噬菌体分型及药物敏感试验

为了解本地区伤寒Vi噬菌体型别分布以及伤寒沙门氏菌对抗菌药物的耐药程度,收集了1982～1989年杭州地区127株伤寒沙门氏菌,经系统生化反应及血清学鉴定后,对其中114株Vi抗原丰富的菌株在北京市卫生防疫站的协助下,进行了96个     

应用耐药谱,质粒谱和噬菌体分型分析医院内鼠伤寒沙门氏菌感…

１９８８年鞍山市中心医院及鞍钢铁东医院婴儿室、新生儿室同时发生了一起急性腹泻暴发。经流行病学调查，病原菌分离确定为一起鼠伤寒沙门氏菌引起的院内感染暴发，对从患儿粪便、病房外环境中分离出的４５株菌进行血清学、耐药性，质粒图谱和噬菌体分型测定，并以同年散发菌株为对照，发现此次暴发菌株抗原结构完全相同，对常用抗生素耐药，耐药谱基本一致，具有相同的质粒谱，噬菌体分型６０．４２％属４７７４型，与散发菌株有明     

不同来源鼠伤寒沙门氏菌噬菌体,质粒图谱的分型及药敏试验

鼠伤寒沙门氏菌是严重危害人民健康的人畜共患疾病,感染和死亡率均居之高首。为摸清自流行中收集的菌种是否属于同一来源,并探讨彼此间的关系。我们对腹泻病人的血液和大便中、甘棠湖水和生活在湖中的铜锈环棱螺体内共分离出１３９株鼠伤寒沙门氏菌,通过噬菌体分型、质粒图谱分型和耐药谱测定等方法进行了追踪监测,现将结果报告如下：１　材料与方法１１　菌株来源：从某医院腹泻病人血液和粪便中获得５８株鼠伤寒沙门氏菌（简称病人株）;自市内甘棠湖水中分离得２０株鼠伤寒沙门氏菌（简称湖水株）;在湖水中生长的铜锈环棱螺体内检…     

应用耐药谱、质粒谱和噬菌体分型分析医院内鼠伤寒沙门氏菌感染的暴发

１９８８年３月鞍山市中心医院及鞍钢铁东医院婴儿室、新生儿室同时发生了一起急性腹泻暴发．经流行病学调查、病原菌分离确定为一起鼠伤寒沙门氏菌引起的院内感染暴发。对从患儿粪便、病房外环境中分离出的４５株菌进行血清学、耐药性、质粒图谱和噬菌体分型测定，并以同年散发菌株为对照，发现此次暴发菌株抗原结构完全相同，对常用抗生素耐药，耐药谱基本一致。具有相同的质粒谱，噬菌体分型６０．４２％属４７７４型，与散发菌株有明显差别．分析结果表明，两所医院分离菌株具有同源性，传播途径为院内交叉感染．     

绍兴县伤寒流行菌株噬菌体定型及药敏实验结果

我们对1987～1989年搜集的70株伤寒菌株进行了噬菌体定型和耐药谱的检定。其中8株分离自带菌者粪便,10株分离自患者粪便,52株分离自住院伤寒患者的血液、骨髓和胆汁。全部菌株经生化反应及血清学鉴定,符合Ka-uffmann 伤寒沙门氏菌特性,质控菌株为ATCC25922。噬菌体定型用96型噬菌体定型法;耐药谱测定采用Kivby-Bauev 纸片法,试验菌液浓度8.4×10~7CFu/ml。抑杀菌试验采用试管两倍稀释法,试验菌液浓度为8.4×10~7CFu/ml;试验药物浓度起始为128μg 或u/ml,最终为0.03μg 或u/ml。     

我国伤寒沙门氏菌的分子流行病学特征:Ⅱ.部分伤寒沙门氏菌的16S rRNA基因多态性

利用PCR扩增标记的Dig-dUTP-16S rRNA基因为探针,分析我国不同时间和地区分离的119株伤寒沙门氏菌和1株鼠伤寒沙门氏菌染色体经PstI消化后的16S rRNA基因限制性图谱。结果发现,各菌株的杂交片段范围为7.0~26.5kb,每个菌株有5~10条杂交带不等。通过对每个菌株的杂交结果进行数值分类,119株伤寒沙门氏菌可分为38个RTs,其中新疆伊犁1991年流行菌株和大连1990年爆发菌株大部分(13/20)为同一RT;从国内各高发省份分离的一些流行株也有相同的RT;而一些地区的散发菌株具有独特的RT;鼠伤寒沙门氏菌的RT则更为特别。对39个RTs进行聚类分析发现:国内的一些流行菌株,爆发菌株在遗传距离0.55处聚成一大类;而散发菌株,非流行菌株则在0.70处聚成另一类。此外,从健康带菌者分离的菌株251所具有的RT单成一类。鼠伤寒沙门氏菌的距离更远。     

Molecular characterization of trimethoprim resistance in salmonellas isolated in Sicily, 1985–1988

The occurrence of trimethoprim (Tp) resistance in salmonellas isolated from humans and water samples in Sicily between 1985 and 1988 has been investigated and the Tp resistance mechanisms have been further characterized on the basis of hybridization with probes for the dihydrofolate reductase (DHFR) genes types I, II, IV and V. Of 765 strains examined, high level (>1000 mg/1) resistance to Tp was identified in 23 strains (3%). In 22 of these strains, such resistance was associated with resistance to sulphonamides. Six serovars with Tp-resistant strains were identified,Salmonella typhimurium (14 strains),S. enteritidis (2),S. agona (2),S. mbandaka (2),S. virchow (2),S. Indiana (1). In all strains with high level Tp resistance, resistance to this antimicrobial was plasmid-encoded, in most strains by plasmids with MWs ranging from 70–100 MDa. On the basis of restriction endonuclease analysis, four different categories of Tp resistance plasmids were identified in Tp-resistant strains ofS. typhimurium. Hybridization with the DHFR I probe was observed in three strains of Tp-resistantS. typhimurium and two strains of Tp-resistantS. enteritidis; in contrast, in none of the strains tested was there any detectable hybridization with the probes for DHFR types II, IV and V. It is concluded that the DHFR type I resistance mechanism, common in Tp-resistant enterobacteria in many European countries, is relatively uncommon in Tp-resistant salmonellas isolated in Sicily. Furthermore, the DHFR V resistance mechanism, previously identified in strains ofShigella sonnei isolated in Sicily and associated with travellers from Sri Lanka, has not yet appeared in salmonellas in Sicily.     

Surveillance of multidrug-resistant strains of Salmonella enterica serotype Typhimurium in southern Italy in the years 1992–1997

Spread of multidrug-resistant strains of Salmonella enterica serotype Typhimurium (S. typhimurium) is increasingly reported worldwide. The presence of a pattern of resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline (ACSSuT), in some cases associated to trimethoprim and infrequently to quinolones, is of particular concern. This resistance pattern appears to be chromosomally encoded and, in most epidemiological studies, closely related to definitive type 104 (DT104).In southern Italy multidrug-resistant isolates of S. typhimurium had been identified since 1980, but only during 1992 S. typhimurium strains with chromosomally encoded drug resistance were first isolated from domestic animals.One hundred fifty-five isolates – 52.5% of the multidrug-resistant strains identified in the years 1992–1997 – were submitted to phage typing and plasmid profile analysis. Ribotyping was also performed in comparison with a random sample of 150 strains susceptible or resistant to three or less antibiotics identified in the same interval of time.Four ribotypes (RTs) -1, 5, 8, and 48 – included approximately 90% of the multiresistant strains, RT8 accounting for 61.2%. Phage type (PT) 193 is the most prevalent phage type.Phage typing and ribotyping suggest that few bacterial clones are involved in spread of multi- drug-resistant S. typhimurium strains in southern Italy.     

Mutagenicity of urine from nurses handling cytostatic drugs,influence of smoking

Summary Mutagenicity towards Salmonella typhimurium TA 100 of urine from smoking nurses, who were occupationally involved in the treatment of patients with cytostatic drugs, was significantly increased in comparison with that of smoking control subjects. Mutagenicity towards Salmonella typhimurium TA 100 was not increased in exposed non-smokers when compared to control non-smokers. In smoking subjects urinary mutagenicity appeared increased towards Salmonella typhimurium TA 1538 in the presence of S-9 mix.Rats pretreated with Aroclor 1254 showed higher mutagenicity in their urine than untreated rats after cyclophosphamide administration. Therefore, the synergistic effect of smoking might be due in part to induction of enzymes involved in the mutagenic activation of cytostatic drugs. Further, the animal experiments showed that cyclophosphamide (the most frequently used mutagenic cytostatic drug) can be absorbed after oral or percutaneous administration. Therefore, it is not excluded that differences in working hygiene between smokers and non-smokers also play a role.Support by the General Directorate of Labour, Dutch Ministry of Social Affairs     

Mutagenicity of aerosols from the oxidative thermal decomposition of rigid polyurethane foam

Summary The aerosol fraction of the oxidative thermal decomposition products (700°C) of rigid polyurethane foam was collected on glass fiber filters and fractionated into ether-soluble neutral, acidic, and basic fractions and water-soluble compounds. The fractions showed mutagenic activity in a bacterial fluctuation test with Salmonella typhimurium TA 98 or Escherichia coli CM 891 as the tester strains. All the fractions induced mutations in both strains after metabolic activation with rat liver S-9 mix. The basic and the water-soluble fractions were mutagenic for S. typhimurium TA 98 even without activation.Thin-layer chromatography showed the presence of several primary aromatic amines in the aerosol. Polycyclic aromatic hydrocarbons were not detected by glass capillary gas chromatography.We thank the Finnish Academy and the Swedish Work Environment Fund (Grant 241 C/77) for financial aid     

Validity of mutagenic activity as an indicator of river water pollution

Objectives To investigate if mutagenicity could be expressed by known water pollution indicators, we determined the mutagenic activity of blue rayon extracts from sampled river water with the Ames test utilizing new strains of bacteria, and compared the results with those of known indicators of water pollution. Methods Water samples were collected by the blue rayon adsorption method at sixteen sites in six rivers in the North Kyushu district. The Assay of mutagenicity was carried out using the Ames test. The test strains wereSalmonella typhimurium TA100, YG1024, YG1041 and YG1042. B(a)P, Trp-P-1 and Trp-P-2 were quantified by HPLC. Determinations of SS, BOD, COD, T-N, T-P, DOC, and A₂₆₀/DOC were performed. Results The extracts from five sampling sites showed higher mutagenicity toward strain YG1024 with or without S9mix, and the extracts from two of these five sites showed higher mutagenicity toward strain YG1041 with and without S9mix. However, the water pollution indicators did not show specific trends that were consistent with the mutagenic activity. Conclusions Since the mutagenic activity of river water could not be predicted using known water pollution indicators, we recommend that biological examinations such as mutagenicity tests be added to the indicators that are currently in use.     

Mutagenicity of a polar portion in the neutral fraction separated from organic extracts of airborne particulates

Six fractions were prepared from an organic extract of airborne particulate matter collected between June 1983 and May 1984 by liquid-liquid partition and silica gel column chromatography. These fractions were assayed for their mutagenicities by the AmesSalmonella and sister chromatid exchange tests, with and without metabolic activation. After metabolic activation, a moderately polar fraction had the greatest mutagenicity per weight inSalmonella typhimurium strains TA98 and TA100. Ten subfractions were subsequently obtained from this fraction by high-pressure liquid chromatography, which were subjected to capillary gas chromatography with a nitrogen-phosphorous selective detector, and gas chromatography-mass spectrometry, in addition to further investigation of their mutagenicities. The characterized components were classified into polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (containing ketones, quinones, coumarines and aldehydes), and azaarenes.     

Sanitizing alternatives for Escherichia coli and Salmonella typhimurium on bell peppers at household kitchens

Fresh fruits and vegetables are known to play an important role as carriers of disease-causing organisms in household kitchens. The aims of this study were to assess and compare the effectiveness of sodium hypochlorite, organic acid-based and silver-based products to reduce Escherichia coli and Salmonella typhimurium inoculated on individual bell pepper pieces. Inoculated bell pepper pieces (n = 5) were submerged in sodium hypochlorite, organic acid-based and silver-based product solutions, at the concentration specified in the product label for sanitization of fruits and vegetables. Sodium hypochlorite reduced E. coli and Salmonella typhimurium by 3.13 Log₁₀/25cm² and 2.73 Log₁₀/25cm², respectively. Organic-based and silver-based products reduced E. coli and S. typhimurium by 2.23 Log₁₀/25cm², 1.74 Log₁₀/25cm² and 2.10 Log₁₀/25cm², 1.92 Log₁₀/25cm², respectively. The results showed that greater attention is needed in selecting sanitizing products to kill or remove human pathogens from fresh produce to minimize risk of foodborne infections.     

Epidemiology of antibiotic resistance of human nontyphoidal salmonellae in Greece during an 8-year period (1990-1997)

The susceptibility patterns of 1027 nontyphoidal Salmonella strains of human origin, isolated in Greece between 1990 and 1997, were determined by broth microdilution. From 1990 to 1995, the overall incindence of resistance for both Salmonella enteritidis and S. typhimurium increased. From 1996 onwards, a decrease was observed, which was more evident for S. enteritidis. Regarding the other examined serotypes a substantial proportion of resistant isolates was found only for S. Virhow and S. Hadar.     

Antimicrobial antibodies in Danish slaughterhouse workers and greenhouse workers

Summary As a consequence of contact with animals and animal products slaughterhouse workers might be at risk of infection with pathogenic microorganisms. This hypothesis has been supported by some earlier studies. In this study 217 slaughtermen and a control group of 113 greenhouse workers were investigated for the prevalence of serum antibodies to Toxoplasma gondii, Campylobacter jejuni (IgA and IgG), Yersinia enterocolitica types 3 and 9, Yersinia pseudotuberculosis types I, II, III, IV, and V, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella typhimurium, and Borrelia burgdorferi. No significant differences were found concerning either frequency of positive tests or magnitude of titers. The prevalence of toxoplasma antibodies was remarkably high in both groups.     

Lack of mutagenic activity of white spirit

Summary The mutagenic potential of white spirit, a typical mixture of primarily aliphatic hydrocarbons used as a solvent, was investigated using a battery of test systems. The ability of this compound to induce gene mutations was assayed by the Ames' test with different strains of Salmonella typhimurium; its potential clastogenicity was tested in vivo on mouse bone marrow cells; in-vitro induction of sister chromatid exchanges was studied in human lymphocytes. Negative results were obtained in all test systems. It is concluded that, in spite of its evident toxicity, white spirit does not display mutagenic properties.