一起沙门菌爆发的菌株鉴定和分子溯源研究

[目的]1起沙门菌爆发的菌株鉴定和分子溯源研究。[方法]收集2007年上海市黄浦区1起食源性沙门菌爆发病例的菌株,使用3种不同产地沙门菌分型血清进行菌株比对鉴定,测试菌株耐药性并对部分菌株进行多位点基因序列分型(MLST)。通过Pluse Net China非伤寒沙门菌数据库聚类分析上海市与重庆市爆发菌株的脉冲凝胶电泳(PFGE)图谱。[结果]发生在上海市黄浦区某工地爆发的1起食源性菌株,经血清学和MLST鉴定为汤卜逊沙门菌ST26型;菌株对6种抗生素(四环素、阿莫西林/克拉维酸、氨苄西林、氯霉素、萘啶酸、磺胺异恶唑)的耐药率均为100%。2007年重庆市报告多起食源性爆发案例中的C群沙门菌,经鉴定亦为汤卜逊沙门菌ST26型,与上海市的菌株间存在高度遗传同源性。[结论]兰州生物制品研究所和泰国S&A的沙门菌分型血清的H因子"c"和"k"间存在交叉凝集。2007年上海市黄浦区发生的食源性爆发病例可能为输入性汤卜逊沙门菌ST26型的多重耐药克隆株引起。     

我国秋季型恙虫病地方特点及流行状况分析

恙虫病是由恙虫病东方体引起的自然疫源性疾病,根据其流行的季节特征大致分为夏季型、秋季型和冬季型3种类型,各种类型的恙虫病流行特征存在较大的差异。本文根据我国文献报道秋季型恙虫病疫情资料进行分析,归纳总结了我国秋季恙虫病的一些主要的流行特征,为制定秋季型恙虫病预防控制措施提供参考和依据。     

Characterization of the tick-pathogen interface by quantitative proteomics

Ticks are vectors of pathogens that affect human and animal health worldwide. Ticks and the pathogens they transmit have co-evolved molecular interactions involving genetic traits of both the tick and the pathogen that mediate their development and survival. Proteomics and genomics studies of infected ticks are required to understand tick-pathogen interactions and identify potential vaccine antigens to control tick infestations and pathogen transmission. In this paper, the application of quantitative proteomics to characterize differential protein expression in ticks and cultured tick cells in response to pathogen infection is reviewed. Analyses using (a) two-dimensional differential in gel electrophoresis (DIGE) labeling and (b) protein one-step in gel digestion, peptide iTRAQ labeling, and isoelectric focusing fractionation, both followed by peptide and protein identifications by mass spectrometry resulted in the identification of host, pathogen, and tick proteins differentially expressed in response to infection. Although at its infancy, these results showed that quantitative proteomics is a powerful approach to characterize the tick-pathogen interface and demonstrated pathogen and tick-specific differences in protein expression in ticks and cultured tick cells in response to pathogen infection.     

HIV-1 superinfection can occur in the presence of broadly neutralizing antibodies

BackgroundSuperinfection of individuals already infected with HIV-1 suggests that pre-existing immune responses may not adequately protect against re-infection. We assessed high-risk female sex workers initially infected with HIV-1 clades A, D or A/D recombinants, to determine if HIV-1 broadly neutralizing antibodies were lacking prior to superinfection.MethodsSix superinfected female sex workers previously stratified by HIV-1 high-risk behavior, infecting virus clade and volunteer CD4 counts were evaluated at baseline (n = 5) and at 350 days post-superinfection (n = 6); one superinfected volunteer lacked pre-superinfection plasma. Retrospective plasmas were assessed for neutralization of a multi-clade panel of 12 HIV-1 viruses before superinfection, and then at quarterly intervals thereafter. Similarly stratified singly infected female sex workers were correspondingly assessed at baseline (n = 19) and 350 days after superinfection (n = 24). Neutralization of at least 50% of the 12 viruses (broad neutralization), and geometric means of the neutralization titers (IC₅₀) were compared before and after superinfection; and were correlated with the volunteer HIV-1 superinfection status, CD4 counts, and pseudovirus clade.ResultsPreexisting broad neutralization occurred in 80% (4/5) of the superinfected subjects with no further broadening by 350 days after superinfection. In one of the five subjects, HIV-1 superinfection occurred when broad neutralization was lacking; with subsequent broadening of neutralizing antibodies occuring within 9 months and plateauing by 30 months after detection of superinfection. Clade B and C pseudoviruses were more sensitive to neutralization (13; [87%]); and (12; [80%]) than the locally circulating clades A (10; [67%]) and D (6; [40%]), respectively (p = 0.025). Low antibody titers correlated with clade D viruses and with >500 CD4 T cell counts, but not with the superinfection status.ConclusionThese data demonstrate that HIV-1 superinfection can occur both in the presence, and in the absence of broadly neutralizing antibodies.     

Novel trimeric human cytomegalovirus glycoprotein B elicits a high-titer neutralizing antibody response

Human cytomegalovirus (HCMV) is a major cause of disability in congenitally infected infants and in the immunosuppressed. There is currently no licensed prophylactic HCMV vaccine. The HCMV envelope glycoprotein B (gB) is considered a major vaccine target antigen based on its critical role in mediating viral-host cell fusion and thus viral entry. The natural conformation of HCMV gB within the viral envelope is a trimer, but there has been no reported success in producing a recombinant trimeric gB suitable for vaccine use. Phase II clinical trials of a monomeric recombinant gB protein demonstrated 50% efficacy in preventing HCMV infection in seronegative women of reproductive age, and in reducing viremia in solid organ transplantation recipients. We now report the production of a uniformly trimeric recombinant HCMV gB protein in Chinese ovary cells, as demonstrated by Western blot analysis under modified non-reducing conditions and size exclusion chromatography with multi-angle scattering. Immunization of mice with trimeric HCMV gB induced up to 11-fold higher serum titers of total gB-specific IgG relative to monomeric HCMV gB using Alum + CpG as adjuvants. Further, trimeric HCMV gB elicited 50-fold higher complement-independent and 20-fold higher complement-dependent HCMV neutralizing titers compared to monomeric HCMV gB using the fibroblast cell line, MRC-5, and up to 6-fold higher complement-independent and –dependent HCMV neutralizing titers using the epithelial cell line, ARPE-19. The markedly enhanced HCMV neutralizing activity in response to trimeric HCMV gB was also observed using an additional four distinct clinical HCMV isolates. These data support a role for trimeric HCMV gB as an important component for clinical testing of a prophylactic HCMV vaccine.     

Estimating primary care attendance rates for fever in infants after meningococcal B vaccination in England using national syndromic surveillance data

BackgroundIn September 2015, the United Kingdom became the first country to introduce the multicomponent group B meningococcal vaccine (4CMenB) into a national infant immunisation programme. In early clinical trials 51–61% of infants developed a fever when 4CMenB was administered with other routine vaccines. Whilst administration of prophylactic paracetamol is advised, up to 3% of parents may seek medical advice for fever following vaccination. We used research-level general practitioner consultations to identify any increase in attendances for all-cause fever in vaccine-eligible infants following 4CMenB introduction in England.MethodsConsultations for infant all-cause fever in the year following the vaccine introduction were identified from The Phoenix Partnership (TPP) ResearchOne general practice database using Read (CTV3) codes. Average daily consultation rates and incidence rate ratios (IRRs) were calculated for vaccine-eligible age groups and compared to the two years preceding vaccine introduction. The difference between pre- and post-vaccine all-cause fever consultations was estimated.ResultsAll-cause fever consultations in vaccine-eligible 7–10 week olds were 1.6-fold higher (IRR, 1.58; 95% CI, 1.22–2.05) compared to the two previous years and 1.5-fold higher (IRR 1.47; 95% CI, 1.17–1.86) in 15–18 week-olds. There were no significant differences in 0–6 or 11–14 week-olds. Applying the difference between pre- and post-vaccine consultation rates to the 4CMenB vaccine-eligible age groups across England estimated 1825 additional fever consultations in the year following 4CMenB introduction.ConclusionsWe found a small but significant difference in all-cause fever consultation rates in vaccine-eligible infants who would have received 4CMenB with other vaccines.     

蒙古族人ACE基因和代谢综合征与高血压关系

目的探讨蒙古族人血管紧张素转换酶（ACE）基因多态性和高血脂、胰岛素抵抗与高血压的关系.方法在现况调查的基础上,分别对获得知情同意的450名高血压者和590名血压正常者采集血标本,进行血脂、血糖、胰岛素和ACE基因多态性的检测.结果高血压组的ID基因型频率显著高于血压正常组（P＜0.05）.Ⅱ在ID基因型人群中,胰岛素敏感指数＜-2.81与≥-2.81相比,OR值分别为2.23和1.94.结论蒙古族人群胰岛素敏感性低下可能是高血压的危险因素,且具有ID基因型者和胰岛素敏感性低下之间可能产生协同作用.     

Prevention of meningococcal disease at mass gatherings: Lessons from the Hajj and Umrah

Meningococcal disease is a serious public health threat given the seriousness of the illness, its disabling sequelae and its potential for epidemic spread. The disease is a concern during mass gatherings which provide conditions that facilitate transmission of infectious agents including Neisseria meningitidis. Implementation of appropriate meningococcal disease preventive measures during at-risk mass gatherings is crucial to prevent illness and outbreaks which may result in significant morbidity and mortality as well as local and international spread of the disease. These preventive measures should be informed by comprehensive risk assessments of the disease at those events and may include the use of vaccination, chemoprophylaxis and health awareness and educational campaigns, supported by efficient disease surveillance and response systems. The Hajj and Umrah religious mass gatherings in the Kingdom of Saudi Arabia are examples of how the implementation of such preventive measures was successful in reducing the incidence of meningococcal disease during these events as well as controlling and preventing outbreaks. Lessons learned from the Hajj and Umrah experience can inform meningococcal disease preventive strategies for other mass gatherings worldwide.     

The 2015–2016 influenza epidemic in Beijing,China: Unlike elsewhere,circulation of influenza A(H3N2) with moderate vaccine effectiveness

BackgroundWhile the 2015–2016 influenza season in the northern hemisphere was dominated by A(H1N1)pdm09 and B/Victoria viruses, in Beijing, China, there was also significant circulation of influenza A(H3N2) virus. In this report we estimate vaccine effectiveness (VE) against influenza A(H3N2) and other circulating viruses, and describe further characteristics of the 2015–2016 influenza season in Beijing.MethodsWe estimated VE of the 2015–2016 trivalent inactivated vaccine (TIV) against laboratory-confirmed influenza virus infection using the test-negative study design. The effect of prior vaccination on current VE was also examined.ResultsOf 11,000 eligible patients included in the study, 2969 (27.0%) were influenza positive. Vaccination coverage was 4.2% in both cases and controls. Adjusted VE against all influenza was 8% (95% CI: −16% to 27%): 18% (95% CI: −38% to 52%) for influenza A(H1N1)pdm09, 54% (95% CI: 16% to 74%) for influenza A(H3N2), and −8% (95% CI: −40% to 18%) for influenza B/Victoria. The overall VE for receipt of 2015–2016 vaccination only, 2014–2015 vaccination only, and vaccinations in both seasons was −15% (95% CI: −63% to 19%), −25% (95% CI: −78% to 13%), and 18% (95% CI: −11% to 40%), respectively.ConclusionsOverall the 2015–2016 TIV was protective against influenza infection in Beijing, with higher VE against the A(H3N2) viruses compared to A(H1N1)pdm09 and B viruses.