工作场所空气中丁酸和异丁酸的溶剂解吸-气相色谱测定法

目的建立工作场所空气中丁酸和异丁酸的气相色谱测定法。方法以硅胶管采集工作场所中的丁酸和异丁酸,用丙酮解吸,经毛细管色谱柱分离,以火焰离子化检测器检测。结果丁酸和异丁酸的检出限均为0.45 mg/L。丁酸的线性范围为1.92～1 920 mg/L,回归方程为y=1.951 29x+2.767 12,r=0.999 98,最低检出浓度为0.30 mg/m~3(空气体积以1.5 L计算),批内精密度为0.73%～2.34%,批间精密度为1.99%～3.06%,解吸效率为91.95%～93.20%。异丁酸的线性范围为1.90～1 900 mg/L,回归方程为y=2.020 50x+3.296 35,r=0.999 99,最低检出浓度为0.30 mg/m~3(空气体积以1.5 L计算),批内精密度为0.69%～2.23%,批间精密度为2.02%～3.77%,解吸效率为94.31%～95.17%。样品在室温下至少可保存10 d。结论该方法精密度好,灵敏度高,操作简单,适用于工作场所空气中丁酸和异丁酸的同时测定。     

直接涂片法、乳胶免疫层析法检测淋球菌效果比较

目的：比较直接涂片法、乳胶免疫层析检测淋球菌效果。方法：收集2017年8月-2022年8月本院就诊临床疑似淋球菌感染的患者216例标本,其中男性尿道分泌物标本115例、女性宫颈分泌物标本101例。以细菌培养法检测为金标准,比较直接涂片法和乳胶免疫层析法检测淋球菌效果。结果：细菌培养法显示,216例临床样本中,淋球菌阳性173例(80.1%)、阴性43例(19.9%),115例男性标本中淋球菌阳性96例(83.5%)、阴性19例(16.5%),101例女性标本中,淋球菌阳性77例(76.3%)、阴性24例(23.8%)。与金标准比较,直接涂片法216例样本检出淋球菌阳性154例(71.3%),115例男性样本中检出淋球菌阳性85例(82.6%),101例女性样本中检出淋球菌阳性59例(58.4%);乳胶免疫层析法216例样本中检出淋球菌阳性177例(81.9%),115例样本中检出淋球菌阳性96例(87.8%),101例女性样本中检出淋球菌阳性76例(75.3%)。乳胶免疫层析法对所有样本、男性样本、女性样本中检出淋球菌的灵敏度、特异度、阳性预测值、阴性预测值、准确度均高于直接涂片法。直...     

2012年-2013年综合性三甲医院血培养病原菌分布及耐药性分析

目的研究2012年-2013年综合性三甲医院血培养病原菌分布及药敏分析,以指导临床合理有效地使用抗生素。方法收集2012年1月1日-2013年12月31日宁波市第一医院门诊及住院患者血培养标本,用美国BD公司BACTEC9120型全自动血培养仪及其配套成人树脂需氧瓶和厌氧瓶进行培养,检出的阳性菌株用法国梅里埃VITEK-2 COMPACT细菌鉴定仪进行鉴定和药敏分析,耐药性分析用WHONET 5.5软件统计。结果 2012年1月1日-2013年12月31日送检的血培养标本中分离到病原菌1 319株,其中革兰阳性菌511株,占38.7%,未检出耐万古霉素的葡萄球菌;革兰阴性菌771株,占58.5%,其中ESBL阳性大肠埃希菌145株,ESBL阳性肺炎克雷伯菌32株;真菌37株,占2.8%。未检出专性厌氧菌。结论血培养病原菌分布较广泛,耐药问题较严重并且有多重耐药菌出现,为临床合理控制和使用抗生素提供重要依据。     

ICU医院感染病原菌分布及控制研究

目的对三亚地区ICU医院感染的病原菌现状进行调查分析,并提出相应的预防控制措施,为降低该地区ICU医院感染率提供可靠的依据。方法回顾性分析2012年1月-2013年3月三亚地区4所综合性医院ICU患者临床资料,共收集标本3 251份,对送检标本进行培养及细菌鉴定,所有数据采用SPSS统计软件进行分析。结果 3 251份标本中有1 893份标本检出病原菌,以呼吸道标本为主占88.80%;检出病原菌共1 893株,以革兰阴性杆菌为主占81.25%,其中铜绿假单胞菌629株占33.23%,不动杆菌属284株占15.00%;革兰阳性球菌占13.15%,检出金黄色葡萄球菌85株占4.49%;检出真菌中白色假丝酵母菌91株占4.81%。结论三亚地区ICU医院感染的病原菌以革兰阴性杆菌为主,应严格规范医院对标本培养结果报告后再选择使用抗菌药物,严格掌握侵入性诊疗手段的使用指征,加强抗菌药物的管理等。     

需氧厌氧瓶配对在血与体液病原菌培养中的临床价值

目的探讨需氧和厌氧培养方式的选择对不同种属病原菌检出率、检测时间的影响及常规使用的临床价值。方法使用mini VITAL或BacT/ALERT 3D血培养仪,及VITEK-32自动细菌鉴定仪对1999年1月-2009年12月38 839份血液与体液临床标本需氧和厌氧配对培养的检测结果作回顾性分析。结果 38 839份标本培养阳性7241例占18.64%,共分离出各种细菌56属171种7327株;在需氧和厌氧培养瓶中的阳性检出率差异有统计学意义(2χ=7.14,P<0.01),非发酵菌、微球菌属、真菌、厌氧菌阳性检出率差异有统计学意义(P<0.01),葡萄球菌属、棒杆菌属阳性检出率差异有统计学意义(P<0.05),沙门菌属和棒杆菌属细菌在需氧和厌氧培养两种瓶子的阳性检测速度差异有统计学意义(P<0.01)。结论采用需氧和厌氧瓶配对培养,既解决了培养结果的早期快速问题,又可提高阳性检出率,是一种理想的组合,在临床上有良好的应用价值。     

16S rDNA检测在口腔厌氧菌鉴定中的应用

[目的]探讨厌氧菌16S rDNA保守序列及特异性序列在口腔厌氧菌感染诊断中的应用价值。[方法]采集2007年7月至2008年10月山东大学齐鲁医院口腔科门诊就医的病人临床标本18份,采用PCR技术扩增口腔厌氧菌16S rDNA保守序列和7种口腔感染常见厌氧菌特异性序列,同时采用厌氧菌标准菌株作对照;应用琼脂糖凝胶电泳方法检测PCR扩增产物。[结果]标准菌株和标本中厌氧菌16S rDNA保守序列检出率均为100.0%(标准菌株为7/7,标本为18/18),标准菌株鉴定准确率为7/7,标本厌氧菌16S rDNA特异性序列检出率为66.67%(12/18)。[结论]厌氧菌16S rDNA保守序列及特异性序列在口腔厌氧菌感染检出和鉴定方面具有较高的应用价值。     

环介导等温扩增法诊断初诊肺结核病研究

目的:初步评价环介导等温扩增法(Lamp)检测痰中结核分枝杆菌的准确性,探讨临床诊断初诊肺结核病人的应用价值。方法:选取249例初诊疑似肺结核病人的痰标本,同时进行Lamp、直接涂片抗酸染色法和改良罗氏培养基培养法检测。结果:剔除培养失败和非结核杆菌的标本,共检测了739份痰标本,其中直接涂片抗酸染色法检出阳性标本70份,阳性率9.47%;培养检出阳性标本118份,阳性率15.97%;Lamp检出阳性标本99份,阳性率13.40%。以培养法为标准,涂片法的灵敏度57.63%,特异度99.68%,符合率为94.30%;Lamp的灵敏度77.12%,特异度98.71%,符合率为96.61%。结论:Lamp在检测初诊疑似肺结核病人中有较高的灵敏度和特异性,适用于基层结核病工作中初诊肺结核病人的诊断。     

肿瘤医院血流感染患者病原菌分布与耐药性分析

目的了解肿瘤医院血流感染患者的病原菌分布及耐药性,为临床治疗选择合理的抗菌药物提供依据。方法采用BacT/Alert 3D全自动血培养仪对2010年1月-2013年12月4 796份血标本进行检测,对阳性血培养使用VITEK-2Compact全自动鉴定系统进行鉴定和药敏试验,使用WHONET5.6软件进行分析。结果 4 796份血液标本中共检出病原菌613株,检出率为12.3%,其中革兰阴性菌344株占56.2%、革兰阳性球菌211株占34.4%、厌氧菌32株占5.2%、真菌26株占4.2%,检出最多的病原菌分别为大肠埃希菌、凝固酶阴性葡萄球菌、肺炎克雷伯菌,分别占19.1%、15.2%、12.1%;按疾病种类分,胃癌、肠道肿瘤和淋巴癌为前3位,分别占17.0%、16.2%和11.5%;未发现耐亚胺培南、厄他培南肠杆菌科细菌,未发现耐万古霉素和利奈唑胺葡萄球菌。结论肿瘤患者血培养临床分离菌对常用抗菌药物存在不同程度的耐药性,应合理使用抗菌药物,降低血流感染的病死率。     

临床标本细菌分布及耐药性分析

目的了解细菌分布变迁及耐药情况。方法使用K-B纸片法进行药物敏感性试验。结果临床标本检出的阳性率为44.87%,菌株以痰、尿液和分泌物标本分离为主要来源,铜绿假单胞菌、大肠埃希菌、金黄色葡萄球菌、表皮葡萄球菌、肺炎克雷伯菌和不动杆菌属为常见菌;MRSA和MRCNS对临床药物的耐药率远比MSSA和MSCNS高,屎肠球菌对药物的敏感性普遍比粪肠球菌低,肠杆菌科细菌对亚胺培南的耐药性较低,产ESBLs的大肠埃希菌和肺炎克雷伯菌的检出率依次为23.9%、25.4%,铜绿假单胞菌对抗菌药物都表现出较高的耐药性。结论革兰阳性球菌有上升趋势,细菌的耐药性和抗菌药物的广泛使用有密切关系。     

烧伤患者不动杆菌属感染分布及耐药性分析

目的分析烧伤患者不动杆菌属感染分布特点及耐药性,为临床合理用药提供依据。方法选取2009年1月-2013年8月治疗的400例烧伤患者送检标本,按照常规方法分离不动杆菌属,采用纸片扩散法测定细菌耐药性;采用SPSS18.0统计软件进行分析。结果共检出不动杆菌属182株,其中119株来自创面分泌物,占65.38%,其次为痰液、导管、血液及其他标本,分别占17.03%、8.79%、5.50%及3.30%;不动杆菌属对常见抗菌药物的平均耐药率为47.52%,对美洛西林的耐药率最高为81.87%,对亚胺培南的耐药率最低为1.17%,对头孢他啶、头孢噻肟、头孢哌酮、哌拉西林、庆大霉素及阿米卡星的耐药率均较高。结论不动杆菌属感染主要见于烧伤患者的创面,对常见抗菌药物耐药率高,对其进行分离鉴定有助于指导临床合理应用抗菌药物。     

16S rDNA多重PCR检测牙周组织感染菌及混合感染与慢性牙周炎病变程度关系的研究

目的　建立多重 16SrDNAPCR检测慢性牙周炎 (CP)标本中牙龈卟啉单胞菌 (Pg)、伴放线杆菌 (Aa)和齿垢密螺旋体 (Td) ,了解不同感染情况与CP严重程度的关系。方法　将轻、中和重度15 2例CP患者牙周袋标本和 30名牙周健康者龈沟标本置于 2 0 0 μl裂解缓冲液中 ,10 0℃水浴 10min后取 10 μl上清液作为聚合酶链反应 (PCR)模板。常规酚 氯仿法提取的PgATCC332 77株、AaY4株、TdFM株和E .coliDH5α株DNA分别作为PCR阳性和阴性对照。采用Pg、Aa和Td 16SrDNA特异性引物 ,建立多重PCR检测上述标本。 3例Pg、Aa和TdPCR结果均阳性标本的目的扩增片段T A克隆后测序。采用 χ2 检验分析不同混合感染情况与牙周炎严重程度之间的关系。结果所建立的多重 16SrDNAPCR最低可检出 10个Pg、2 0个Aa和 2 0个Td细胞。Pg、Aa和Td 16SrDNA扩增片段与已报道的序列比较 ,相似性分别高达 99.4 5 %、97.0 8%和 96 .5 9%。 30名牙周健康者龈沟标本中 ,仅有 1名Pg(3.3% )、2名Aa(6 .7% )的 16SrDNA扩增结果阳性 ,其余标本均阴性。 15 2例CP患者牙周袋标本中 ,14 7例 (96 .7% )检出Pg、Aa和 /或Td的 16SrDNA ,5例 (3.3% )扩增结果均阴性。Pg的PCR检测阳性率 (91.5 % ,139 15 2 )明显高于Aa(72 .4 % ,110 15 2 )或Td(80 .9% ,12 3 15     

Isovaleric acid in stool correlates with human depression

Objective: Human depression is a major burden, both on the individuals who suffer from the disease and on society at large. Traditionally, depression has been linked to psychological and biological causes, but there has been increasing interest in the gut–brain axis. In this regard, we have recently shown that specific bacteria are correlated with human depression, and we hypothesize that volatile fatty acids (VFAs) are mediators.

Methods: Here, we analyzed the direct correlation between VFAs, depression and cortisol in a cohort consisting of 34 depressed patients and 17 controls.

Results: We found statistically significant correlations between depression and the VFA isovaleric acid, as well as between isovaleric acid and cortisol. Furthermore, bacteria that previously have been identified as being correlated with depression were also correlated with isovaleric acid. Isovaleric acid showed a bimodal distribution in which the depressed patients were overrepresented in the high level group (P < 0.00005, binominal test).

Discussion: It has recently been shown that gut-derived VFAs can cross the blood–brain barrier, where isovaleric acid interferes with synaptic neurotransmitter release. The multiple correlation patterns, in addition to a potential mechanistic model, point towards a potential causal relationship between depression and isovaleric acid.     

Anaerobic bacteria in tropical ulcer--the application of a new transport system for their isolation

The successful isolation of anaerobes largely depends on adequate transportation of the specimens after collection. We are investigating the role of anaerobes in the pathogenesis of tropical ulcer and have used Hungate tubes with pre-reduced peptone yeast broth and agar as a transportation system. The medium included 0.05% cysteine and 0.03% sodium formaldehyde sulphoxylate as an Eh buffer. Resazurin 1 microgram/ml seved as an Eh indicator. We found the tubes convenient to use and very reliable at maintaining anaerobiasis.     

水中还原亚硫酸盐厌氧芽胞菌的检测

目的 检测水中还原亚硫酸盐厌氧芽胞菌。方法 先进行胞子形成试验,再进行还原性培养观察颜色变化,培养基颜色变黑则表示亚硫酸钠被还原,可判定厌氧芽胞菌阳性。结果 对纯净水、矿泉水、二次供水、水源水、游泳池水以及空调冷凝水54份水样中进行了测定,在检测的7份水源水中有5份检出还原亚硫酸盐厌氧芽胞菌,其他均未检出,检出率为9．2％。结论 开展还原哑硫酸盐厌氧芽胞菌的检测,可有助于及时预测各种水质污染情况,为预防和控制水质污染提供依据。     

Dietary supplementation with beta-glucan enriched oat bran increases faecal concentration of carboxylic acids in healthy subjects

BACKGROUND/OBJECTIVE: Carboxylic acids (CAs), especially butyric acid, have been suggested to counteract colonic diseases, such as ulcerative colitis and colon cancer. Colonic formation of CAs can be influenced by the diet, but the concentrations and pattern formed need to be evaluated for different food products in humans. To elucidate how the colonic concentration of CAs in healthy subjects is influenced by dietary supplementation with oat bran, and whether the concentration varies over time and during consecutive days. SUBJECTS/METHODS: Twenty-five healthy subjects (age 24+/-1.3) were recruited to the study. The subjects were given 40 g beta-glucan enriched oat bran per day, corresponding to 20 g dietary fibre, in 4 slices of bread. CAs were analysed in faeces during three consecutive days after 0, 4, 8 and 12 weeks on this diet. RESULTS: The concentration of acetic, propionic, butyric, isobutyric and isovaleric acid was higher (P<0.05-0.001) after 8 weeks on the oat bran diet as compared with values at entry, whereas that of lactic acid was lower (P<0.05). After 12 weeks, the concentrations of acetic, propionic and isobutyric acid were still higher and that of lactic acid lower. The variation between individuals was considerable, whereas in the same individuals there was little variation. CONCLUSIONS: Oat bran increased the faecal concentration of CAs after 8 weeks, indicating an increased concentration also in the distal colon. The concentration of all main acids increased, except for lactic acid, which decreased. Oat bran may therefore have a preventive potential adjunct to colonic diseases.     

Influences of dietary adaptation and source of resistant starch on short-chain fatty acids in the hindgut of rats

The effect of adaptation time on the concentration and pattern of short-chain fatty acids (SCFA) formed in the hindgut of rats given resistant starch (RS) in the form of raw potato starch (RPS) or high-amylose maize starch (HAS) was evaluated. Each starchy material was tested in diets containing 100 g indigestible carbohydrates/kg DM, and fed for 13, 28 and 42 d. At the end of each period, the content of SCFA was determined in caecum, distal colon and faeces. The caecal concentration of total and individual SCFA increased for both diets with increasing adaptation time. The concentration of butyric acid was higher in the group fed RPS than in that fed HAS at all adaptation times. The caecal proportion of butyric acid was low both in rats fed RPS and HAS (6 and 4 %, respectively) following 13 d of adaptation. However, after 28 d of adaptation, the proportion of butyric acid had increased to 19 % in rats given RPS. A longer adaptation period (42 d) did not increase the proportion of butyric acid further. With HAS, there was also a significant (P<0.01) increase in the proportion of butyric acid with longer adaptation time. However, the increase was much slower and the proportion of butyric acid reached 6 and 8 % after 28 and 42 d respectively. It is concluded that the pattern of SCFA formed from RS in rats is dependent on adaptation time. It cannot be excluded that the different patterns of SCFA reported in the literature for RS may be due to the time of adaptation.     

流感病毒咽拭子处理方式对其病毒分离率影响的研究

目的 通过采用咽拭子中加入青链霉素混合液或使用过滤器直接过滤标本的方式,对比两种处理方法对流感病毒分离率的影响。 方法 选择2017年10月1日至12月31日贵阳市哨点医院及各区、市、县疾控中心采集的流感样病例(ILI)咽拭子中PCR核酸检测阳性的标本200份,将同一份标本分为两份,一份加入青链霉素混合液（双抗）4℃过夜,另一份使用0.22μm的过滤器直接过滤标本,采用 MDCK 细胞进行流感病毒的分离培养,通过观察CPE（细胞病变效应）确定病毒收获时间进行HA（血凝）试验,并对病毒液进行无菌试验。 结果 （1）200份标本经两种方法分别处理后,双抗组病毒液受细菌污染数为37瓶,病毒液污染率为18.5%;过滤膜处理组病毒液受细菌污染数为4瓶,病毒液污染率为2%,双抗处理组污染率高于过滤膜处理组,差异有统计学意义（〖XC小五号.EPS;P〗=29.594, P=0.000<0.05）;（2）去除污染的毒株后,双抗处理组分离流感病毒97株,分离率为48.5%;过滤膜处理组成功分离流感病毒102株,则病毒分离率为51.0%,滤膜处理组病毒分离率与双抗处理组比较,差异无统计学意义（〖XC小五号.EPS;P〗=0.250,P=0.617>0.05）。 结论 两种方法处理流感病毒咽拭子标本后,病毒分离率无明显差异,但使用过滤器直接过滤标本的方式可显著降低病毒分离期间被细菌污染的风险。     

Comparison of immunofluorescence and immunoperoxidase methods for viral diagnosis at a distance: a WHO collaborative study.

Nasopharyngeal secretions collected in Newcastle were examined in both Newcastle and Stockholm for the presence of influenza virus type A and respiratory syncytial (RS) virus by immunofluorescence and immunoperoxidase techniques. A total of 139 specimens were examined in this way and the agreement between the two centres for immunofluorescence was 94% for influenza virus A, 95% for respiratory syncytial virus, and 95% for negative specimens. This technique can therefore be used for examining specimens taken at great distances from the collecting laboratory. The results of the immunoperoxidase technique were unsatisfactory mainly because of the presence of endogenous peroxidase. Measures taken to remove this also destroyed RS virus antigen. It is premature to introduce the immunoperoxidase technique for rapid virus diagnosis, but in due course, when the problems outlined in this article are solved, it could become a useful technique.     

Utilization of nitrogen from soybean meal, casein, zein, and urea by mature sheep.

The utilization of nitrogen contained in soybean meal, casein, zein, and urea was studied in 12 mature wethers. Net microbial synthesis rates during the 6-hour period after feeding corresponded to ruminal ammonia concentrations, suggesting that the ruminal ammonia level in these experiments was a limiting factor in microbiol protein synthesis. Maximum conversion of dietary nitrogen to microbial nitrogen in the rumen during a 24-hour period was estimated to be 62.5, 85.3, 40.9, and 90.1%, respectively, for soybean meal, casein, zein, and urea. Estimated production rates of acetic, propionic, butyric, isovaleric, and valeric acids during the first 6 hours after feeding suggested that zein supported the lowest microbial activity in the rumen, and that urea supplementation resulted in isovaleric and valeric acids production rates equivalent to or greater than rates when the other nitrogen supplements were present in the diet. Daily endogenous urinary and metabolic fecal nitrogen determined by regression analysis utilizing soybean meal as the only nitrogen supplement were 72 mg/kg body weight0.75 and 340 mg/100 g of dry matter intake. Biological values of 84.8, 78.3, 84.3, and 76.4 were obtained for soybean meal, casein, zein, and urea, respectively.     

标本因素对麻疹病毒分离率的影响

目的探讨不同的标本、不同的标本采集时间对麻疹病毒分离率的影响。方法采用B95a细胞培养法分离麻疹病毒,用逆转录-聚合酶链反应(RT-PCR)对分离出的麻疹病毒进行鉴定。结果对天津市2003~2004年采集的8份咽拭子和37份尿液标本进行了麻疹病毒检测。从8份咽拭子中分离到7株麻疹病毒,分离率为87.5%;从37份尿液中分离到8株麻疹病毒,分离率为21.6%。咽拭子麻疹病毒的分离率高出尿液3倍;出疹后4d之内可以从咽拭子中检出麻疹病毒;出疹后3d之内可以从尿液中检出麻疹病毒。结论为提高麻疹病毒的分离率应首先采集病人的咽拭子标本,标本采集以出疹4d内为宜。