红茶菌发酵液抑菌作用研究

目的 研究不同pH值下红茶菌发酵液及其蛋白提取液的抗菌作用,为探寻新的抗菌物质奠定基础. 方法 采用K-B纸片扩散法检测不同pH值下红茶菌发酵液及不同量的蛋白提取液分别对大肠埃希菌、金黄色葡萄球菌和白色念珠菌的抑菌作用. 结果 红茶菌发酵液在酸性条件下对金黄色葡萄球菌和大肠埃希菌的生长具有明显的抑制作用,而在碱性条件下均未表现出抑制作用;红茶菌蛋白提取液对金黄色葡萄球菌和大肠埃希菌有抑菌活性,红茶菌发酵液及蛋白提取液对白色念珠菌无明显抑菌作用. 结论 红茶菌发酵液具有明显的抑制金黄色葡萄球菌和大肠埃希菌生长的作用.红茶菌发酵产生的蛋白质类物质是红茶菌液中的抑菌活性成分之一,具有用作食品抑菌剂的潜在价值.     

复方银翘散对五种常见耐药菌的体外敏感性研究

目的探讨复方银翘散对五种临床上常见抗生素耐药菌株的抑菌效果及机制。方法采用MH琼脂稀释法制备复方银翘散药液,分别对来自临床的产β-内酰胺酶（ESBLs）（＋）大肠埃希菌、ESBLs（-）大肠埃希菌、甲氧西林耐药的金黄色葡萄球菌（MRSA）、甲氧西林敏感的金黄色葡萄球菌（MSSA）、泛耐药铜绿假单胞菌各30株（剔除同一患者相同部位的重复菌株）进行敏感性实验,测定最低抑菌浓度（MIC）,并采用透射电镜观察细菌超微结构变化。结果复方银翘散作用后MRSA、MSSA及大肠埃希菌细胞壁、细胞膜破坏,细胞质内含物减少或消失。复方银翘散对五种菌株均有较强的抑菌作用,其中金黄色葡萄球菌〉泛耐药铜绿假单胞菌〉大肠埃希菌（P均〈0．01）;且对于金黄色葡萄球菌和大肠埃希菌,无论是否产酶抑菌作用相似。结论复方银翘散对金黄色葡萄球菌、泛耐药铜绿假单胞菌、大肠埃希菌均有较强的抑制作用,机制可能为破坏细菌细胞壁、细胞膜及细胞内含物等。     

富血小板血浆与抗生素联合应用在抑制大肠埃希菌中的作用

目的:探究富血小板血浆(platelet-rich plasma, PRP)及其与抗生素头孢呋辛钠联合应用在体外对大肠埃希菌的作用。方法:从六安市中心血站获取健康志愿者捐献的血小板作为PRP来源。将一定浓度的大肠埃希菌质控菌株与PRP及抗生素头孢呋辛钠共同培养，观察PRP单独应用及与抗生素头孢呋辛钠联合应用时的抑菌情况。结果:2 mg/L头孢呋辛钠在12 h内无抑菌作用，4 mg/L头孢呋辛钠可在24 h内发挥抑菌作用，8 mg/L头孢呋辛钠可在48 h内发挥较强抑菌作用。PRP单独应用可以在24 h内发挥抑菌作用，与2 mg/L头孢呋辛钠联合应用在12 h内可抑制大肠埃希菌生长，与4 mg/L头孢呋辛钠联合应用在24 h内可抑制大肠埃希菌生长，与8 mg/L头孢呋辛钠联合应用在36 h内可抑制大肠埃希菌生长。结论:PRP单独应用在体外可抑制大肠埃希菌的生长，与抗生素联合应用可发挥抑菌作用，并减轻抗生素的使用剂量。     

细菌性腹泻致病菌及耐药变迁情况分析

目的了解近10年细菌性腹泻致病菌及耐药情况的变迁。方法调查分析了我院10年间住院1068例腹泻患者的临床资料，选择麦康凯培养基和SS培养基，并对培养阳性进行血凝集试验及系列生化反应对细菌分类。药敏试验采取纸玻片法。结果1068例腹泻患者有323例培养为阳性，主要的致病菌为志贺菌属、福氏痢疾杆菌、大肠埃希菌、沙门菌、枸橼酸杆菌、阴沟杆菌、粪链球菌等。药敏结果显示随着年代的变迁耐药情况越来越普遍，且呈多重性。结论致病菌多样性，耐药菌日益严重，且呈多重性，因此合理诊治、合理用药是治疗关键。     

库伦驴血液白细胞抗菌肽提取及其对牛乳腺炎主要致病菌的抗菌活性研究

目的验证库伦驴血液白细胞抗菌肽对牛乳腺炎无乳链球菌、金黄色葡萄球菌及大肠埃希菌的体外抗菌活性。方法利用乙酸萃取法提取库伦驴血液白细胞抗菌肽,制备药敏试纸片,用平皿药敏纸片法检测其抗菌活性。结果库伦驴血液白细胞抗菌肽对无乳链球菌、金黄色葡萄球菌及大肠埃希菌具有抑菌效果,43.60mg/ml抗菌肽作用24h抑菌环直径分别为14、15和17mm。结论库伦驴白细胞抗菌肽对无乳链球菌、金黄色葡萄球菌、大肠埃希菌有抑菌活性,可用于上述致病菌感染所致奶牛乳腺炎的治疗。     

大肠埃希菌O157:H7环介导等温扩增可视化检测方法的建立

目的建立肠出血性大肠埃希菌O157︰H7环介导等温扩增(LAMP)可视化快速检测方法。方法针对肠出血性大肠埃希菌(EHEC)O157︰H7编码脂多糖rfbE基因保守区设计LAMP引物及环引物,反应体系加入染料羟基萘酚蓝(HNB)作为LAMP扩增的指示剂,结合LAMP浊度仪优化扩增条件,根据HNB的颜色变化进行结果判定,评价LAMP方法的特异性和灵敏性。结果建立的LAMP法对O157︰H7rfbE基因的最低检出限约为100copy/反应管,检测肠产毒性大肠埃希菌(ETEC)、肠致病性大肠埃希菌(EPEC)、肠侵袭性大肠埃希菌(EIEC)、肠聚集性大肠埃希菌(EAEC)、宋内志贺菌、福氏志贺菌均为阴性。体系的扩增效率较高,可在40min内出结果。结论建立的基于颜色判定的EHEC O157︰H7LAMP检测方法具有特异、灵敏,设备要求简单等特点,适用于EHEC O157︰H7的快速检测。     

长春地区致儿童腹泻大肠埃希菌的分离鉴定与耐药分析

目的了解长春地区致儿童细菌性腹泻的病原菌类型、病原学特征和抗生素耐药模式,为临床合理用药提供参考。方法采集2019年长春市儿童医院和长春中医药大学附属医院儿童腹泻样品50份,进行16s rDNA扩增子高通量测序分析和大肠埃希菌的分离鉴定;E-test法测定细菌的耐药谱与抗生素最小抑菌浓度;ERIC-PCR检测细菌的同源性,并测定13种毒力基因,进行系统分群和血清型鉴定。结果通过16S rDNA扩增子组学测序分析,排除志贺菌、沙门菌等感染的可能,确定致儿童腹泻粪便样品中大肠埃希菌为优势病原菌。分离获得110株大肠埃希菌,系统进化分群以A群、B2群和D群为主。检测到O抗原血清型23种,其中优势血清型为O119,检出13株大肠埃希菌EAST1基因PCR阳性,7株eae基因PCR阳性,其中1株同时携带EAST1基因和eae基因。分离株对21种抗生素的耐药率为4.3%～68.1%,多药耐药菌菌株比例高达63.8%。49.3%的菌株为ESBL表型,喹诺酮类抗生素的耐药率约为50%,阿米卡星和碳青霉烯类抗生素耐药率较低(5.8%和4.3%)。结论长春地区致泻性大肠埃希菌是引起儿童腹泻的重要病原菌之一,存在非典型肠致病性大肠埃希菌和肠集聚性大肠埃希菌的流行。目前临床常用的β-内酰胺类和喹诺酮类抗生素已不能达到良好的治疗效果,ESBL菌株对12种抗生素有较高的耐药水平,儿童感染性腹泻大肠埃希菌的耐药形势严峻,应进一步加强耐药性监测与抗生素应用管理。     

山西省2015-2016年食源性疾病主动监测的病原学特征分析

目的 了解山西省食源性疾病主动监测中沙门菌、志贺菌、副溶血性弧菌、致泻性大肠埃希菌(包括粘附性大肠埃希菌EAEC、致病性大肠埃希菌EPEC、侵袭性大肠埃希菌EIEC、产毒性大肠埃希菌ETEC)的病原谱、耐药情况及分子分型。方法 对2015-2016年山西省食源性疾病主动监测病例中分离到的沙门菌、志贺菌、副溶血性弧菌、致泻性大肠埃希菌进行血清学分型、药物敏感性试验以及PFGE分型。结果 2015-2016年共采集腹泻病人标本2 505例,检出目标菌数157例,检出率为6.27%,其中致泻性大肠埃希菌82例(3.27%)、沙门菌51例(2.04%)、志贺菌14例(0.56%)、副溶血性弧菌10例(0.40%)。致泻性大肠埃希菌中,分离率最高的是EPEC。在对15种常见抗生素药敏实验中,致泻性大肠埃希菌对亚胺培南全部敏感(100%),对头孢他啶和甲氧苄啶\磺胺甲恶唑敏感率大于90%。沙门菌以肠炎沙门菌和鼠伤寒沙门菌2个血清型为主,沙门菌对亚胺培南全部敏感(100%),对头孢西丁和头孢他啶敏感率大于90%。副溶血性弧菌毒力基因全部为tdh阳性。结论 山西省2015-2016年食源性疾病主动监测中,检出率最高的是致泻性大肠埃希菌,其次为沙门菌,志贺菌,副溶血性弧菌。     

碳青霉烯类抗生素对重症监护病房老年患者耐药菌的体外抑菌效果

目的监测该院重症监护病区老年患者革兰阴性菌的耐药情况及比较不同碳青霉烯类抗生素针对耐药革兰阴性菌体外抑菌效果。方法临床搜集重症监护老年患者标本分离的革兰阴性细菌菌株,进行分离、培养,按照CLSI2010标准,采用K-B纸片扩散法测定比阿培南、美罗培南、亚胺培南-西司他丁及头孢吡肟的体外抑菌效果。结果大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌对4代头孢菌素耐药率分别为46.8%,18.8%,47.8%,79.0%;大肠埃希菌对比阿培南、美罗培南、亚胺培南-西司他丁的耐药率均为0,肺炎克雷伯菌的耐药率分别为4.3%,2.9%,4.3%,铜绿假单胞菌的耐药率分别为57.8%,54.4%,63.3%,鲍曼不动杆菌的耐药率均为67.9%。三种碳青霉烯类抗生素针对四种病原菌的抗菌活性无统计学差异。结论肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、鲍曼不动杆菌对4代头孢具有不同程度的耐药性。大肠埃希菌、肺炎克雷伯菌对碳青霉烯类仍保持较高敏感性,铜绿假单胞菌、鲍曼不动杆菌对碳青霉烯类已经产生了较高耐药性;三种碳青霉烯类抗生素针对四种革兰阴性病原菌的抗菌活性无统计学差异。     

单耐氧氟沙星的结核分枝杆菌耐药机制研究

目的探讨单耐氧氟沙星的结核分枝杆菌中耐药相关基因突变及外排泵基因风坦两种不同耐药机制的作用。方法从国家结核病参比实验室2007年全国耐药基线调查菌株库中挑选单耐氧氟沙星的菌株17株。采用直接测序法检测利福平耐药相关基因删似和gyrB突变情况。提取gyrA和gyrB无突变菌株的RNA后反转录并采用Real—timePCR方法检测20个药物外排泵基因的表达量，对比菌株最低抑菌浓度（MIC）试验结果，筛选可能与氧氟沙星药物外排泵的相关基因，并选用大肠埃希菌为模式生物构建表达载体，检测过表达目的外排泵蛋白的大肠埃希菌对氧氟沙星的耐药程度加以验证。结果在17株单耐氧氟沙星的菌株中，有4株（4／17）检测到gyrA突变，其中包括90位点突变1株及94位点突变3株，上述突变均表现为高浓度耐药，其MIC均不低于4μg/ml。在gyrA和gyrB未突变菌株中，通过real-timePCR检测发现在高浓度耐药的2株菌株中，Rv0933和Rv2938的转录水平显著高于其他低浓度耐药菌株，较对照株H37Rv转录水平高16倍和5倍。在对照组和转入pEASY-E1-Rv2938的大肠埃希菌中MIC均小于0．125μg／ml，而转入pEASY-E1-Rv0933的大肠埃希菌的MIC为2μg／ml。结论本研究结果显示，gyrA耐药决定区基因突变与氧氟沙星高浓度耐药相关，PstB可能是氧氟沙星特异性的药物外排泵基因，其高水平表达与氧氟沙星高浓度耐药相关。     

Glucose and insulin concentration in amniotic fluid and in maternal blood in early and in late pregnancy

Glucose concentration in the amniotic fluid decreases towards the end of gestation, whereas the insulin concentration increases. The ratio between fetal (amniotic fluid) glucose to maternal glucose is reduced by about 50% at the end of pregnancy, whereas the ratio of C peptide is increased four times. The higher glucose concentration in amniotic fluid in early pregnancy could be explained by a lower fetal metabolic rate in the early stage of development and a low insulin activity of the fetus.     

Differentiation pathways in carcinogenesis and in chemo- and radioresistance

Cancer stem cells (CSCs) share many features with embryonic stem cells (ESCs) such as the ability for self-renewal and differentiation. Signaling pathways that are involved in these processes are also involved in chemo- and radioresistance (e.g. Wnt, Notch and Hedgehog pathways). This review is focused on the influence of three important differentiation pathways on carcinogenesis and on chemo- and radioresistance in ESCs and CSCs.     

Nitrite and thiocyanate in the fasting and secreting stomach and in saliva.

The concentrations of nitrite and thiocyanate in fasting and pentagastrin stimulated gastric juice and in saliva have been examined. Nitrite was found in all of 17 samples of fasting gastric juice, mean 4-9 +/- 1-1 muM. Stimulation of gastric secretion with pentagastrin caused no significant change in nitrite concentration. Thiocyanate was detected in all of 21 samples of fasting gastric juice and the difference in concentration between smokers and non-smokers probably reflects similar differences in saliva. In contrast to the nitrite data there was a significant drop in thiocyanate concentration of gastric juice after pentagastrin from 0-9 +/- 0-1 mM to 0-3 +/- 0-04 mM, suggesting a salivary origin for the thiocyanate in gastric juice. Thiocyanate is a powerful catalyst of nitrosation, which, together with small amounts of nitrite and naturally occurring amines could lead to the intragastric formation of carcinogenic nitrosamines and in certain circumstances be a factor in the aetiology of gastric cancer.     

Osteoporosis in celiac disease and in endocrine and reproductive disorders

As the increase in lifespan brings to light diseases that were previously not clinically detectable, osteoporosis has become an issue of worldwide significance. The disease is marked by a loss of bone mass; the bones become less dense, fragile and more prone to fracturing. Because it is regulated by endocrine and environmental factors, osteoporosis presents a multifactorial etiopathogenesis, with the genetic component accounting for 70% of an individual variation in bone mass density （BMD）, the principal determinant, with age, of fracture risk. Pathological conditions such as celiac disease （CD） exacerbate the process of bone loss, so that the occurrence of osteoporosis in celiac subjects is of particular note： indeed, the screening of osteoporosis patients for this disease is advisable, since it may be the only sign of undiagnosed CD. An increase in interleukin IL-1β, of the IL-1 system, in the relatives of celiac patients confirms the genetic predisposition to osteoporosis and its presence is evidence of an association between the two conditions. The direct effect on the bones of CD is secondary to poor absorption of calcium and vitamin D. In women osteoporosis is indirectly associated with early menopause and amenorrhea, and it may follow prolonged breast-feeding and frequent pregnancies, while in men it is associated with hypogonadism and GH deficit. These endocrine and non-endocrine factors exert their effects on bones by modulating the RANK/RANK-L/OPG system. An appropriate lifestyle from adolescence onwards, together with early diagnosis of and treatment for CD and primaryand secondary endocrine pathologies are important for the prevention of damage to the bones.     

Salmonellosis in children in developing and developed countries and populations

PURPOSE OF REVIEW: The present review addresses recent developments that relate to the clinical management and prevention of childhood salmonellosis in developed and developing countries. RECENT FINDINGS: Invasive disease due to serovar Typhi as well as nontyphoidal salmonellae (NTS) is common in children younger than 5 years old in developing countries, and multidrug resistance is an increasingly difficult problem to manage. A new conjugate vaccine was found to be very effective in preventing typhoid fever in young Vietnamese children and was well tolerated, showing great promise for the future. Antibiotic use in the food animal industry is an important source of disease with multidrug resistant NTS strains in the developed world. Efforts for prevention are aimed at immunization of animals, control of antibiotic use in the food animal industry and careful monitoring of food-borne outbreaks. On the other hand, although the burden of NTS disease in children is far greater in developing countries, especially in tropical Africa, knowledge of even basic epidemiology is lacking. Importantly, it may be that, as spp. acquire increasing resistance, they also acquire increasing virulence that will lead to even greater morbidity and mortality. SUMMARY: Recent developments include a better knowledge of clinical aspects of invasive salmonellosis, an increasing response to the problem of multiple antibiotic resistance (including quinolones), and excellent results from the use of a recently developed conjugate vaccine for typhoid fever in children as young as 2 years old.