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。     

广西人群DNA修复基因XRCC3多态性与肝细胞癌遗传易感性关联分析

目的 探讨DNA修复基因X线修复交叉互补因子3(X-ray cross-complementing group 3,XRCC3)基因Thr241Met多态性与黄曲霉毒素B1(aflatoxin B1,AFB1)相关性肝细胞癌(hepatocellular carcinoma,HCC)遗传易感性的相关性.方法 应用PCR技术对AFB1高污染区广西地区257例HCC患者和711名对照人群的XRCC3基因多态性进行检测,进行的病例对照研究.结果 (1)XRCC3 3种基因型(Thr/Thr、Thr/Met、Met/Met)中带有Met者与HCC的易感性相关,且这种相关性与Met数量呈正相关(校正风险值OR分别为2.20和8.56);(2)XRCC3突变基因型多态与血白细胞AFB1-DNA加合物水平在HCC发生过程中存在协同作用(校正OR:2.34～20.44,P＜0.01).结论 XRCC3多态性与HCC易感性相关,且这种多态性与AFB1暴露水平在HCC发生中存在协同作用.     

Effects of low, subinhibitory concentrations of antibiotics on expression of a virulence gene cluster of pathogenic Escherichia coli by using a wild-type gene fusion

S fimbrial adhesins (Sfa) represent virulence factors of E. coli wild-type strains causing urinary tract infections and meningitis of the new born. In order to determine the influence of subinhibitory concentration of antibiotics on the expression of the sfa gene cluster, a wild-type strain carrying the lacZ gene, coding for the enzyme β-galactosidase fused to the sfa determinant was used. The expression of lacZ which was under the control of the sfa wild-type promoters, was now equivalent to the sfa gene expression of wild-type strain 536. With this strain the influence of subinhibitory concentrations of 28 antibiotics on the expression of the sfa determinant was studied. The expression was strongly suppressed by a treatment of the wild-type fusion strain by aztreonam, gentamicin, clindamycin and trimethoprim; the latter had a dramatic effect on sfa expression. It was further shown for clindamycin and trimethoprim that the reduction of sfa gene expression was dependent on the concentration of the antibiotics. In contrast imipinem, amphotericin B and rifampicin weakly stimulated sfa expression. We conclude that gene fusions between virulence-associated loci and indicator genes in wild-type pathogens are useful to study virulence modulation due to subinhibitory concentration of antibiotics on the genetic level.     

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.     

Experimental antitumor activity of BMY-28175 a new fermentation derived antitumor agent

Summary BMY-28175 is a novel antitumor antibiotic produced in fermentation by Actinomadura verrucosospora. The cytotoxic effects of BMY-28175 were determined using murine and human tumor cell lines in vitro. Following 72 hour exposure, the drug had IC50 values 1.5 to 13.5 ng/ml in a microtiter assay. BMY-28175 was evaluated for antitumor activity against several experimental murine and human tumor models. The drug administered ip was active against ip implanted P388 leukemia, L1210 leukemia, B16 melanoma, M109 lung carcinoma, C26 colon carcinoma, M5076 sarcoma and Lewis lung carcinoma. In addition, BMY-28175 administered iv was active against iv implanted P388 and L1210 leukemias. BMY-28175 was active against sc implanted B16 melanoma (increased lifespan and/or inhibition of primary tumor growth) in about 60% of the tests. The growth of sc implanted M109 was inhibited by BMY-28175 in a single experiment. BMY-28175 was also active against the MX-1 human mammary xenograft implanted in the subrenal capsule of nude mice. The optimal dose for BMY-28175 in these various studies ranged from 0.16 g/kg per injection with consecutive daily (qd1-9) administration, to 51.2 g/kg with single dose administration. The results of these studies indicate that BMY-28175 is one of the most potent antitumor agents yet observed, with a broad spectrum of activity against tumors of murine and human origin and activity against tumors located distal to the site of drug administration.     

注射用阿奇霉素治疗细菌性感染临床观察

目的 :评价国产注射用阿奇霉素治疗细菌性感染的临床疗效和安全性。方法 :采用随机对照方法 ,将 43例下呼吸道感染和 33例泌尿道感染分验证组和对照组。 43例验证组给予注射用阿奇霉素 0 .2 5 g静脉滴注 ,每天 1次 ;33例对照组给予注射用头孢呋辛 1.5g静脉滴注 ,每天 2次 ,两组疗程均为 5天。结果 :验证组有效率为 83.7% ,细菌清除率为 72 .5 % ,药物敏感率为 80 .8% ;对照组有效率为 81.8% ,细菌清除率为 77.4% ,药物敏感率为 82 .2 % ,两组差异均无显著性 (P >0 .0 5 )。两组不良反应轻微。结论 :注射用阿奇霉素是一种有效、安全的治疗细菌性感染的抗生素     

Dengue determinants: Necessities and challenges for universal dengue vaccine development

Dengue illness can range from mild illness to life-threatening haemorrhage. It is an Aedes-borne infectious disease caused by the dengue virus, which has four serotypes. Each serotype acts as an independent infectious agent. The antibodies against one serotype confer homotypic immunity but temporary protection against heterotypic infection. Dengue has become a growing health concern for up to one third of the world's population. Currently, there is no potent anti-dengue medicine, and treatment for severe dengue relies on intravenous fluid management and pain medications. The burden of dengue dramatically increases despite advances in vector control measures. These factors underscore the need for a vaccine. Various dengue vaccine strategies have been demonstrated, that is, live attenuated vaccine, inactivated vaccine, DNA vaccine, subunit vaccine, and viral-vector vaccines, some of which are at the stage of clinical testing. Unfortunately, the forefront candidate vaccine is less than satisfactory, and its performance depends on serostatus and age factors. The lessons from clinical studies depicted ambiguity concerning the efficacy of dengue vaccine. Our study highlighted that viral structural heterogeneity, epitope accessibility, autoimmune complications, genetic variants, genetic diversities, antigen competition, virulence variation, host-pathogen specific interaction, antibody-dependent enhancement, cross-reactive immunity among Flaviviruses, and host-susceptibility determinants not only influence infection outcomes but also hampered successful vaccine development. This review integrates dengue determinants allocated necessities and challenges, which would provide insight for universal dengue vaccine development.     

Clinical manifestations and outcome of nocardiosis and antimicrobial susceptibility of Nocardia species in southern Taiwan, 2011–2021

Background/PurposeNocardiosis is an uncommon infectious disease. This study aimed to assess the clinical outcome of patients with nocardiosis and examine the antimicrobial susceptibility profiles of Nocardia spp. isolated.MethodsWe retrospectively reviewed the medical records of all inpatients diagnosed with nocardiosis between 2011 and 2021. The identification of Nocardia spp. at the species level was performed with the use of MALDI-TOF and 16S rRNA assays. The antimicrobial susceptibility of Nocardia spp. was performed using the microbroth dilution method. Factors associated with 90-day all-cause mortality were identified in multivariate logistic regression analysis.ResultsOf 60 patients with nocardiosis in the 11-year study period, the lungs (55.0%) were the most common site of involvement, followed by the skin and soft tissue (45.0%). Twenty-two patients (36.7%) died within 90 days following the diagnosis. All of the Nocardia isolates were susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin, whereas more than 70% of the isolates were not susceptible to ciprofloxacin, imipenem-cilastatin, moxifloxacin, cefepime, and clarithromycin. Nocardiosis involving the lungs (relative risk [RR], 9.99; 95% confidence interval [CI], 1.52–65.50; p = 0.02), nocardiosis involving the skin and soft tissue (RR, 0.15; 95% CI, 0.02–0.92; p = 0.04), and treatment with trimethoprim-sulfamethoxazole (RR, 0.14; 95% CI, 0.03–0.67; p = 0.01) were independently associated with 90-day all-cause mortality.ConclusionsNocardia spp. identified between 2011 and 2021 remained fully susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin. Nocardiosis of the lungs, skin and soft tissue infection, and treatment with trimethoprim-sulfamethoxazole were independently associated with 90-day all-cause mortality.     

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.