Carba NP法用于产碳青霉烯酶菌株快速检测的研究

目的探讨将Carba NP法用于产碳青酶烯酶肠杆菌科及假单胞菌属细菌的检测。方法将8株产碳青霉烯酶菌株作为研究对象,采用Carba NP法进行碳青霉烯酶检测,并将其与改良Hodge试验比较。结果 Carba NP法能够特异、灵敏地检测产碳青霉烯酶菌株。Carba NP试验Ⅰ能检测菌株是否产碳青霉烯酶,Carba NP试验Ⅱ能进一步判定产碳青酶烯酶菌株的组别。其检测方法较改良的Hodge试验更简单、快速。结论 Carba NP法操作快速、简单,有助于提高产碳青酶烯酶菌株的检出率及医院内感染的控制。     

Molecular Epidemiological Characteristics of Streptococcus pyogenes Strains Involved in an Outbreak of Scarlet Fever in China, 2011

Objective To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Methods Seventy-four 5treptococcol pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis （PFGE）, superantigen （SAg） genes and antimicrobial susceptibility profiling were analyzed for these isolates. Results A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12（79.7%） and emml （14.9%） accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emml isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. Conclusion Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.     

Multicenter Research on the BACTEC MGIT 960 system for the second-line drugs susceptibility testing of Mycobacterium tuberculosis in China

The reliability of the BACTEC MGIT 960 system for the second-line drugs (capreomycin [CPM], kanamycin [KAN], ofloxacin [OFX] and ethionamide [ETH]) susceptibility testing (DST) of Mycobacterium tuberculosis (M. tuberculosis) was compared to that of traditional Lowenstein-Jensen (L-J) proportion method (PM) among four different sites in China. After resolution of discrepant results by retesting the strains using both methods in the National Reference Laboratory of tuberculosis, the overall concordance values between the 2 systems were 99.7% (kappa value: 0.97) for CPM, 99.7% (kappa value: 0.97) for KAN, 100.0% (kappa value: 1.00) for OFX, and 98.6% (kappa value: 0.95) for ETH. The average turnaround time with BACTEC MGIT 960 system among four sites was 8.9 ± 1.7 days, significantly shorter than 28 days with the traditional L-J PM. Therefore, the BACTEC MGIT 960 system is a reliable and rapid method for the second-line drug susceptibility testing of tuberculosis in China. Notably, a stricter quality control program should be routinely carried out when clinical laboratories perform the second-line DST with BACTEC MGIT 960 system.     

利用脉冲场凝胶电泳筛选质粒方法的建立和应用

目的 改良及优化常规脉冲场凝胶电泳(pulsed-field gel electrophoresis,PFGE)方法,建立基于PFGE技术筛选细菌质粒方法,并用于军团菌质粒的筛选。 方法 使用含有质粒的杜莫氏军团菌及其质粒消除株对常规PFGE方法进行条件优化,调整细菌菌悬液浓度,蛋白酶K用量及作用时间,胶块清洗时间和次数,胶块不经过酶切直接进行PFGE,染色成像后选择能形成条带清晰脱尾较少的最优条件。 结果 去除常规PFGE方法中酶切步骤并优化裂解和清洗条件能使细菌DNA完整保留在胶块中,经过PFGE后,质粒DNA和染色体DNA在琼脂糖凝胶上能被很好的区分。 结论 该方法较常规方法更为快速可靠,可用于细菌质粒图谱的快速筛选。     

青海省2005-2019年人间布鲁氏菌病流行特征及分子特征分析

目的 分析青海省人间布鲁氏菌病（布病）流行规律与趋势,对2005-2019年布鲁氏菌分离株进行分子分型,为制定青海省布病预防控制策略提供依据。方法 收集中国疾病预防控制信息系统青海省2005-2019年布病报告数据,描述和分析其时间、地区和人群三间分布。采用BCSP31聚合酶链式反应（BCSP31-PCR）、AMOS聚合酶链式反应（AMOS-PCR）和多位点串联重复序列分析（MLVA-16）方法鉴定布鲁氏菌分离株,进行聚类分析。结果 2005-2019年青海省累计报告病例577例,平均发病率为0.07/10万,不同年份差异有统计学意义。一年四季均可发病,集中在每年的3-10月。577例病例分布在6个自治州（市）的31个县（市、区）中,病例数位居前5位的是门源回族自治县（22.88%,132/577）、天峻县（10.57%,61/577）、西宁市（10.57%,61/577）、河南蒙古族自治县（10.51%,58/577）和海晏县（9.53%,55/577）。年龄范围8～82岁,男女性别比为1.8：1（374/203）,职业分布以牧民为主（47.83%,276/577）。从人全血中分离的10株菌株均为羊种Ⅲ型布鲁氏菌,分为5种基因型（2种基因型为单基因型,3种基因型为相同基因型）,MLVA-16分型和聚类分析结果显示,同青海省已发表文献的26株羊种Ⅲ型布鲁氏菌的遗传关系较近。结论 青海省布病疫情呈回升趋势,应加强人群监测和疫情通报,MLVA-16分型呈基因多态性,提示MLVA-16可用于遗传多样性分析和分子流行病学溯源调查,以提高布病监测能力。     

Streptococcus suis sequence type 7 outbreak, Sichuan, China

An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described.     

Features of breast cancer in developing countries,examples from North-Africa

Epidemiological features of breast cancer appear to be different in developing countries compared to Western countries, with notably large proportions of young patients, male patients and aggressive forms of the disease. Using North-Africa (Morocco, Algeria, Tunisia, Libya and Egypt) as an example, we document the magnitude and explore possible explanations for such patterns. Articles and reports published since the seventies were reviewed.Results show that breast cancer incidence in females is 2–4 times lower in North-Africa than in Western countries while incidence in males is similar. Consequently, the relative proportion of male breast cancer is high (≈2% of all breast cancers). Similarly, the incidence of aggressive forms of the disease, like inflammatory or triple negative breast cancer (in females), is not higher in North Africa than in Western countries, but their relative proportion in case series (up to 10% for inflammatory and 15–25% for triple negative) is significantly higher because of low incidence of other forms of the disease.In North Africa, the incidence among women aged 15–49 is lower than in Western countries, but the very low incidence among women aged more than 50, combined to the young age pyramid of North-Africa, makes the relative proportions of young patients substantially higher (50–60% versus 20% in France).Such epidemiological features result mainly from peculiar risk factor profiles, which are typical for many developing countries and include notably rapid changes in reproductive behaviours. These features have important implications for breast cancer control and treatment.     

2019年中国克–雅病监测网络病例特征分析

  目的  了解2019年中国克–雅病（CJD）监测网络中12个省（自治区、直辖市）的发病情况、流行病学和临床特征。  方法  对我国CJD监测网络获得的可疑CJD病例的临床及流行病学资料进行分析,收集患者脑脊液及血液样品,采用Western blot检测脑脊液中14-3-3蛋白,提取全血基因组DNA并利用聚合酶链式反应（PCR）及测序方法对朊蛋白基因（PRNP）进行129位和219位氨基酸多态性及基因突变的分析。   结果  2019年共监测CJD病例520例,其中临床诊断病例190例（36.54％）,疑似诊断病例8例（1.54%）,遗传型病例25例（4.81%）,致死性家族型失眠症5 例（0.96%）,格斯特曼综合征（GSS）1例（0.19%）。 病例报告无季节聚集性,长久居住地呈散在分布,职业分布广泛。 确诊诊断和临床诊断病例年龄中位数为63（40, 84）岁,男女性别比为0.96∶1;疑似诊断病例年龄中位数为64.5（45, 76）岁,男女性别比例为1∶1。 快速进行性痴呆为最常见的首发症状。 508份血液样品PRNP的检测结果显示,其中491份129位氨基酸为M/M纯合子,497份219位氨基酸为E/E纯合子。   结论  2019年我国监测到的CJD病例的报告时间、长久居住地、职业、性别比例以及年龄分布均符合散发型克–雅病的发病特点。     

dndC基因在脉冲场凝胶电泳基因组降解中的作用及降解处理方法

  目的  了解大肠埃希菌和弗格森埃希菌dndC基因的携带情况,以及该基因与脉冲场凝胶电泳（PFGE）基因组降解表型之间的关系,探讨PFGE中菌株基因组降解的原因及处理方法。  方法  使用PFGE对450株大肠埃希菌和弗格森埃希菌进行分析,设计引物检测dndC基因的携带情况并进行序列测定。 通过dndC基因序列比对和进化树的构建,获得dndC基因型别以及其在不同型别大肠埃希菌中的分布。 通过添加硫脲和消毒电泳仪研究基因组降解的处理方法。  结果  450株大肠埃希菌和弗格森埃希菌中,降解的菌株为40株（8.89%）。 dndC基因阳性菌株33株（7.33%）,均出现了降解。 大肠埃希菌携带的dndC基因可分为8个群。 不同型别大肠埃希菌中均存在dndC基因阳性菌株,且阳性率存在差异。 添加硫脲可以有效缓解PFGE分析中dndC基因导致的降解,电泳仪消毒可以缓解全胶降解的情况。  结论  dndC基因会导致大肠埃希菌和弗格森埃希菌PFGE分析中基因组降解,添加硫脲可以缓解此降解。     

2018－2021年湖南省人源非O1/非O139群霍乱弧菌药物敏感性及基因组特征

  目的  了解2018—2021年间湖南省从病例分离到的非O1/非O139群霍乱弧菌的药物敏感性及基因组特征。  方法  选取2018—2021年间湖南省腹泻病例肠道标本分离的非O1/非O139群霍乱弧菌分离株4株和非腹泻病例血液标本分离的非O1/非O139群霍乱弧菌分离株3株,进行药物敏感性测试以及基因组序列测定,分析其药物敏感性及基因组特征。  结果  3株血液样品分离株对氨苄西林、诺氟沙星、头孢曲松、美罗培南、米诺环素、复方磺胺甲恶唑、庆大霉素、头孢噻肟、萘啶酸、环丙沙星全部敏感,1株对四环素中介,1株对氯霉素耐药;4株粪便样品分离株对诺氟沙星、头孢曲松、美罗培南、米诺环素、复方磺胺甲恶唑、庆大霉素、头孢噻肟全部敏感,1株对四环素、氯霉素中介,1株对氯霉素耐药,2株对氨苄西林、环丙沙星、萘啶酸耐药;其中1株对氨苄西林、萘啶酸、环丙沙星二重耐药;1株对氨苄西林、萘啶酸、环丙沙星、氯霉素多重耐药。 7株非O1/非O139群霍乱弧菌的基因组序列表现出明显的多样性,但是部分菌株在核心基因组和泛基因组都高度相似。 基因组序列中均未检出ctxAB基因、VPI-1和VSPII基因组岛。 分离自粪便的菌株携带耐药基因的数量是4～8个,分离自血液的菌株携带耐药基因的数量是1～2个。  结论  湖南省非O1/非O139群霍乱弧菌基因组表现出明显的多样性,菌株对多种抗菌药物耐药,需加强腹泻病例、食品及环境水体中非O1/非O139群霍乱弧菌的菌株型别变异及药物敏感性监测。