2019年内蒙古包头市细菌耐药监测

目的 监测2019年包头市11所三级医院所有临床分离菌株的构成及对常用抗菌药物的耐药情况,为临床科室选择抗菌药物提供可靠依据。方法 对上述医院的临床分离菌采用纸片扩散法（KB法）或全自动药敏仪法进行药敏试验,按CLSI 2018年版 M - 100标准判读药敏结果,采用WHONET 2019软件进行数据分析。结果 2019年共收集上述医院非重复临床分离菌8 430株,其中革兰阳性菌2 278株,占比27.0%,革兰阴性菌6 152株,占比73.0%。葡萄球菌属中耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）和耐甲氧西林金黄色葡萄球菌 (MRSA）检出率分别为65.5%和12.8%,未检出利奈唑胺、万古霉素和替考拉宁耐药菌株。粪肠球菌（EFA）对多数抗菌药物的耐药率均低于屎肠球菌（EFM）,EFA中检出2株利奈唑胺耐药菌株,EFM中检出1株替考拉宁耐药菌株、2株万古霉素耐药菌株。产超广谱β- 内酰胺酶（ESBLs）大肠埃希菌（ECO）和ESBLs（+）克雷伯菌属菌株的检出率分别为46.0%和16.8%。耐碳青霉烯大肠埃希菌（CREC）和耐碳青霉烯肺炎克雷伯菌（CRKP） 的检出率分别为0.5%和1.1%,CREC对左旋氧氟沙星的耐药率为100%,远高于CRKP的29.4%。结论 本地区ECO对喹诺酮类抗菌药物耐药率较高,应继续做好耐药监测工作,加强抗菌药物的合理使用,预防耐药菌的产生与传播。     

In vitro susceptibility of mycelial and yeast forms of Penicillium marneffei to amphotericin B,fluconazole, 5-fluorocytosine and itraconazole

The mycelial (25°C) and yeast-like (37°C) forms of Penicillium marneffei clinical and type strains were investigated for their in vitro susceptibility to amphotericin B (AmB), 5-fluorocytosine (5-FC), fluconazole (FLU) and itraconazole (ITZ), using Bacto antibiotic medium 3, yeast-nitrogen, Sabouraud's dextrose (pH 5.7) and high resolution (pH 7.1) broth media (1ml/tube), respectively. Results indicated that the minimal inhibitory and minimal fungicidal concentrations (MICs and MFCs) for the mycelial cultures of P. marneffei to AmB were in the range 0.78–1.56 and 0.78–3.125 g/ml, respectively, as against 3.125–25 g (MICs) for the yeast form cultures. The MFCs to AmB for the yeast form were one dilution higher. The MICs to FLU were generally lower for the yeast form (6.25–25 g) than the mycelial form (25–50 g/ml), whereas MFCs for the mycelial cultures were > 100 g as compared to 6.25–100 g for their yeast form. The MICs for the mycelial form to 5-FC ranged from < 0.195–0.39 g. Higher MICs (6.25 g) were recorded for their yeast form. The MFCs to 5-FC for the yeast form were 25–100 g/ml. The MICs for the mycelial form to ITZ ranged from < 0.195 to 3.125 g/ml. Higher values (< 0.195–50 g) were recorded for their yeast-like form. The MFCs to ITZ for mycelial and yeast forms ranged from < 0.195–0.39 and 25–100 g/ml, respectively. Results indicate that P. marnefei's yeast form is more sensitive to FLU and ITZ (8 of 10 strains) while the mycelial form displayed greater susceptibility to AmB and 5-FC. The MICs for ITZ remained steady in SD medium, pH 5.7 to 7.1. However, some strains gave higher MIC values (0.39–1.56 g/ml) when tested in the HR.     

Salmonella serovars identified at the centre for enterobacteriaceae of palermo over the 5-year period 1983-87

Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area.This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983–1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.     

Accounting for susceptibility in risk assessment: The need for full disclosure

Many Environmental Laws create the unrealistic expectation that science can be used to determine ‘safety'. The many uncertainties surrounding environmental risks, as well as individual, group and societal differences about what is considered ‘safe', make it inevitable that policy decisions must be made. It is appropriate that such decisions be shaped by politics and social issues, as well as be informed by science and economics, but care should be taken to distinguish between policy and fact. Not much is known about the nature and magnitude of environmental susceptibilities. Credible environmental decisions require that scientists, risk assessors and decision-makers acknowledge this, and that they take care to distinguish policy calls from scientific fact.     

HBV无症状携带者与ABO血型关系的探讨

目的：探讨ＨＢＶ无症状携带者与ＡＢＯ血型间关系。方法：采用Ｗｏｏｌｆ统计方法与卡方（ｘ＾２）检验方法对１７４例ＨＢＶ无症状携带者的ＡＢＯ血型分布以及男女性别的关系进行系统分析。结果：男性携带者血型呈Ｂ〉Ｏ〉Ａ〉ＡＢ型分布,女性携带者呈Ｂ〉Ａ〉Ｏ〉ＡＢ型分布。Ａ、Ｂ、Ｏ和ＡＢ血型人相对危险率分别是０．４８７０、２．０４１４、０．９６６８和１．７９５０。结论：ＨＢＶ无症状携带者与ＡＢＯ血型间存在一定关     

Antimicrobial susceptibility and serogroups of Salmonella isolates from Riyadh, Saudi Arabia

The antimicrobial susceptibility and serogroups of 153 Salmonella strains isolated during a period of 22 months from both children and adults at a major teaching hospital in Riyadh, Saudi Arabia were studied. Antimicrobial susceptibility testing by comparative disc method and MIC determination by E-test method were performed on selected antimicrobial agents. For nalidixic acid and trimethoprim only the comparative disc method was used. Discrepancy between the two methods were noticed only in 1.3% of isolates. The majority of isolates from children (41%) were serogroup B, while those from adults (43%) were serogroup C1. The overall resistance was 16% to ampicillin and ampicillin/sulbactam, 13% to nalidixic acid, and 11% to chloramphenicol and trimethoprim/sulphamethoxazole. The resistance of Salmonella isolates to the so-called first line anti-Salmonella agents, i.e. ampicillin, chloramphenicol and trimethoprim/sulphamethoxazole, has increased compared to that reported 4 years ago from this Institution. Almost all isolates were susceptible to the second, and third generation cephalosporins, fluoroquinolones, aztreonam, mecillinam and gentamicin. Multiple drug resistance to two or more drugs was noticed in 16% of isolates, most of which were serogroup B. The majority of these multiple drug resistant isolates (96%) were ampicillin resistant and β-lactamase producers. Although these isolates showed reduced MICs to ampicillin/sulbactam, their MICs were still higher than the susceptibility breakpoint for this combination. The nalidixic acid-resistant isolates showed higher MICs to the fluoroquinolones compared to the nalidixic acid-sensitive isolates. Isolates from children showed higher resistance to some of the antimicrobial agents compared to those from adults.     

High-speed black blood imaging of vessel stenosis in the presence of pulsatile flow.

Stenosis phantoms were created to study the ability of "black blood" methods to image a vessel stenosis in the presence of pulsatile flow. Black blood images were acquired with a modified TurboFLASH (fast low-angle shot) method that eliminates flow signal by applying a set of prepulses before segmented data acquisition. With this high-speed approach, imaging can be completed within 16 seconds. This technique was compared with conventional spin-echo black blood, gradient-echo black blood, and gradient-echo bright blood methods. Loss of flow signal, which extended beyond the site of the stenosis, was seen on the gradient-echo bright blood images. The pattern of signal loss varied with the type of stenosis. Flow voids were achieved with spin-echo black blood imaging; however, substantial ghosting artifacts were seen. With gradient-echo black blood imaging, it was difficult to eliminate all flow signal, particularly for in-plane flow. The modified TurboFLASH method produced high-quality black blood images in a fraction of the time needed for spin-echo imaging. It showed no ghosting artifacts even in the presence of pulsatile flow.     

药敏纸片的质量控制研究

目的：探讨和研究药敏纸片质量控制的方法。方法：以克拉霉素药敏纸片为例，参照美国临床实验室标准化委员会(NCCLS)和联邦法规全书(CFR)的方法，建立一套药敏纸片质量控制的指标，包括鉴别、检查及含量测定。结果：采用专属性较强、灵敏度较高的TLC法进行鉴别，最低检出量为50μg；制订纸片的的直径、重量差异、含量均匀性及干燥失重作为检查项，采用短小芽孢杆菌(Bacillus pumilus)[CMCC(B)63202]作为检定菌，进行含量测定。结论：建立的克拉霉素药敏纸片质量标准能够控制其质量，可作为其他抗生素药敏纸片建立质量标准的参考。     

Variations in Prkdc and susceptibility to benzene-induced toxicity in mice.

Benzene, a carcinogen that induces chromosomal breaks, is strongly associated with leukemias in humans. Possible genetic determinants of benzene susceptibility include proteins involved in repair of benzene-induced DNA damage. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), encoded by Prkdc, is one such protein. DNA-PKcs is involved in the nonhomologous end-joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here we compared the toxic effects of benzene on mice (C57BL/6 and 129/Sv) homozygous for the wild-type Prkdc allele and mice (129/SvJ) homozygous for a Prkdc functional polymorphism that leads to diminished DNA-PK activity and enhanced apoptosis in response to radiation-induced damage. Male and female mice were exposed to 0, 10, 50, or 100 ppm benzene for 6 h/d, 5 d/week for 2 weeks. Male mice were more susceptible to benzene toxicity compared with females. Hematotoxicity was evident in all male mice but was not seen in female mice. We observed similar, large increases in both micronucleated erythrocyte populations in all male mice. Female mice had smaller but significant increases in micronucleated cells. The p53-dependent response was induced in all strains and genders of mice following benzene exposure, as indicated by an increase in p21 mRNA levels in bone marrow that frequently corresponded with cell cycle arrest in G2/M. Prkdc does not appear to be a significant genetic susceptibility factor for acute benzene toxicity. Moreover, the role of NHEJ, mediated by DNA-PK, in restoring genomic integrity following benzene-induced DSB remains equivocal.     

细胞色素P450 3A4基因多态性及与肝癌易感性研究

目的 探讨细胞色素P450 3A4(CYP3A4)基因的多态性与肝癌的关系。方法 应用聚合酶链反应（PCR）、变性梯度凝胶电泳（DGGE）、单链构象多态（SSCP）和DNA测序技术，对84例肝癌患者和144例健康对照的CYP3A4基因的多态性进行了研究。结果 通过对CYP3A4基因10个外显子的检测，发现2例肝癌患者的第7外显子第15742位核苷酸发生了A→G转换，使得第183位氨基酸残基由天冬酰胺转变为丝氨酸；发现第10内含子存在一单核苷酸多态，表现第20338位核苷酸发生了G→A转换。病例组G／G、G／A和A／A基因型频率分别为59.52％,36.90%和3.58%；对照组则为59.72%，33.33%和6.95％。两组比较没有统计学差异。结论 CYP3A4基因可能高度保守，虽有突变，但属罕见。