上海市鼠伤寒沙门菌流行特征及分子分型研究

[目的]研究上海市2006—2007年鼠伤寒沙门菌腹泻病例株的分子流行病学特征。[方法]追溯2002—2007年食品中分离的鼠伤寒沙门菌来源,比较鼠伤寒沙门菌食源株与腹泻株的抗生素耐药性;对全球沙门菌监测(GSS)病例和食品中分离的鼠伤寒沙门菌进行血清、耐药表型和脉冲凝胶电泳(PFGE)分子分型。[结果]经培养确认的鼠伤寒沙门菌腹泻病例数,在2006—2007年本市非伤寒沙门菌型病例构成中仅次于肠炎沙门菌,食品菌株多源于禽(64.4%)和畜肉制品(17.8%),其多重耐药菌株显著高于腹泻株(P0.05)。PFGE将7株食品株和44株腹泻株分为23种带型,优势型为1型(8株)、2型(6株)、29型(4株)、49型(8株)和6型(4株),与食源菌株完全匹配的仅有49型、6型共7个病例(15.9%,7/44)。PFGE-1型腹泻株在2006和2007年分别为2例和6例,2型分别为4例和2例。[结论]上海市鼠伤寒沙门菌腹泻病例存在高度散发和分散爆发的流行特征,没有与本地食品菌株相匹配的优势克隆型分别是PFGE 2型和1型,与市售生鲜类肉食品污染株之间的遗传同源性低。推测传染源可能由输入性传染源对食品等媒介形成二次污染所致。建议加强流行病学调查,以揭示潜在的传染源和传播途径。     

辽宁省肠炎沙门菌耐药性及分子分型特征

目的分析近年辽宁省腹泻病例中检出的肠炎沙门菌血清型、耐药性及分子分型。方法对辽宁地区50株沙门菌临床分离株进行血清型分型;采用微量肉汤法,进行16种抗菌药物的药敏试验;采用脉冲场凝胶电泳(PFGE)方法对选取的16株肠炎沙门菌株进行基因分型。结果肠炎沙门菌是沙门菌中的优势血清型。所有菌都对链霉素耐药。16株肠炎沙门菌分成7种型别,其中6个PFGE型别间仅有1条~3条带的差异,相似度在78.68%~100%,菌株间具有很近的亲缘关系。结论辽宁省感染性腹泻病例中沙门菌感染率较低。PFGE分子分型较多,无明显聚集性。     

一类罕见硫化氢阴性山夫登堡沙门菌腹泻株的分子溯源

[目的]研究一类罕见硫化氢阴性山夫登堡沙门菌腹泻菌株遗传克隆特征。[方法]收集、分析本地区参加全球沙门菌监测(GSS)腹泻病例中分离的山夫登堡沙门菌生化、编码SPI-1毒力岛基因(hilA、invA)和耐药特征;应用Riboprinter(r)(RP)DNA指纹图谱系统比较表型典型与不典型菌株的核糖体分型;通过Pluse Net China数据库中同型菌株的脉冲凝胶电泳(PFGE)图谱聚类比较分子型谱。[结果]2006年长宁区GSS监测病例分离出19株山夫登堡沙门菌,其中10株属于硫化氢阴性和SPI-1毒力岛缺失的表型变异菌株。RP分型证实发生变异的山夫登堡沙门菌与典型菌株间分属2个不同的克隆。Pluse Net China数据库将包括长宁区19株山夫登堡沙门菌在内的36株山夫登堡腹泻株共分18种PFGE带型。长宁区的表型变异株优势型分属4型(2株)和6型(6株),典型菌株的优势型分属11型(1株)、17型(4株)和23型(2株)。聚类分析显示,表型变异株的克隆在遗传相似度上高于典型株。[结论]分子溯源证实,SPI-1毒力岛缺失的山夫登堡沙门菌变异菌株与典型菌株同样具有引发局部爆发的致病性。2006年长宁区分离的硫化氢阴性山夫登堡沙门菌变种腹泻株与2002年深圳市的1例食物中毒案例分离的2株SPI-1毒力岛缺失株存在同源性。     

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。     

上海市长宁区2017年肠炎沙门菌多重耐药和分子分型研究

【目的】了解上海市长宁区2017年肠炎沙门菌的分子分型结果及抗菌药物耐药情况。【方法】对2017年上海市长宁区的感染性食源性病原菌监测标本进行沙门菌的分离鉴定、血清分型,检出33株肠炎沙门菌,运用国家致病菌识别网技术手册(2017年)的分子分型方法进行脉冲场凝胶电泳(PFGE)分子分型,使用微量肉汤稀释法进行抗菌药物耐药性的测定。【结果】33株肠炎沙门菌共分为11种带型,优势带型集中在Clade1中,共计30株。耐2种及2种以上抗菌药物的有22株,耐6种及6种以上抗菌药物的19株,并出现2株四代头孢全耐药。【结论】长宁区肠炎沙门菌多重耐药现象比较普遍,PFGE型别差异较小,相同PFGE型别的菌株多重耐药表型相近。     

广州市136株沙门菌耐药表型与分子分型研究

目的研究广州市2013年腹泻患者感染的沙门菌的血清型分布、耐药情况以及分子流行特征。方法用传统血清学方法鉴定沙门菌的血清型,并用纸片扩散法进行抗菌药物敏感性试验,用脉冲场凝胶电泳(PFGE)对斯坦利沙门菌、肠炎沙门菌、鼠伤寒沙门菌和Ⅰ4,5,12:i:-沙门菌进行分子分型研究。结果 136株沙门菌被鉴定为29种血清型,数量居前三位的血清型为斯坦利沙门菌(19.9%)、肠炎沙门菌(15.4%)和鼠伤寒沙门菌(15.4%)。所有沙门菌菌株对四环素和萘啶酸耐药率最高,分别达到44.8%和39.7%,对环丙沙星的敏感率仅为19.9%;对头孢他啶、头孢噻肟和头孢曲松的耐药率均为7.4%。对3类及以上抗生素耐药的多重耐药菌有56(41.2%)株。27株斯坦利沙门菌和21株肠炎沙门菌分别可分为25个PFGE型和15个PFGE型。结论在广州市引起腹泻的沙门菌主要以斯坦利沙门菌、肠炎沙门菌和鼠伤寒沙门菌为主,分成多种PFGE型,呈高度散发。本地区沙门菌菌株的多重耐药现象严重,对于氟喹诺酮类和头孢类药物的耐药性升高。     

广东省2009-2013年沙门菌对环丙沙星耐药特征分析

目的了解广东省2009—2013年腹泻病例分离沙门菌对环丙沙星的耐药状况。方法采用纸片扩散法测定广东省通过全球沙门菌加强监测系统(ESS)收集的腹泻病例分离沙门菌对环丙沙星的耐药性,对耐药和中度敏感菌株的病例进行描述性流行病学分析,并对耐药菌株的脉冲场凝胶电泳(PFGE)进行分型。结果广东省2009—2013年间通过ESS监测系统共分离到沙门菌2939株,其中耐环丙沙星菌253株(8.61%),中度敏感菌665株(22.63%)。7岁以下携带耐药菌株的病例占总携带耐药菌株的病例的73.52%(186/253),携带中度敏感菌株的病例则为总携带中度敏感菌株的病例的76.84%(511/665)。2009—2012年环丙沙星耐药率呈升高趋势(P0.01)。东莞、佛山、广州、中山及珠海地区分离到的耐药菌株占全省的86.96%(220/253)。253株耐药菌株涵盖34种血清型,鼠伤寒沙门菌、I4,5,12:i:-、肠炎沙门菌、斯坦利沙门菌、德尔卑沙门菌为主要血清型。PFGE结果显示同一血清型中有部分相同的克隆系,呈现高多态性。结论广东省沙门菌对环丙沙星总体耐药率低,2009—2012年间逐步升高。耐药菌株PFGE型别多样,呈现遗传多态性。     

广东省2007年度非伤寒沙门菌监测及病原学特征分析

目的 了解广东省腹泻病患者中非伤寒沙门菌感染情况和菌株的血清型别、分布、耐药性变化.方法 对纳入研究的腹泻病患者进行非伤寒沙门菌检测,对分离到的菌株进行血清分型、药物敏感性试验和脉冲场凝胶电泳(PFGE)分型.结果 2007年度共检测1128份腹泻粪便标本,分离到71株沙门菌,阳性检出率为6.29%;共分得29种血清型,肠炎和鼠伤寒沙门菌居多;大多数沙门菌对常用的头孢类和喹诺酮类抗生素敏感,鼠伤寒沙门菌的耐药率普遍较肠炎和斯坦利沙门菌高;除肠炎沙门菌外,其余的血清型没有同一PFGE型别的菌株;用Xba Ⅰ酶切17株肠炎沙门菌可分为PFGE-XbaⅠ 1～8型,其中PFGE-XbaⅠ 4型为优势型别.用Sfi Ⅰ和Not Ⅰ酶对12株肠炎沙门菌进行再分型,综合用Xba Ⅰ/Sfi Ⅰ/Not Ⅰ三种酶的结果 发现仍有三组菌的PFGE图谱是完全一致的.结论 2007年度广东省非伤寒沙门菌的感染多数为散发病例,头孢类和喹诺酮类抗生素是治疗非伤寒沙门菌感染的首选药物.     

北京市40株肠炎沙门菌多重耐药和分子分型研究

目的分析2009-2010年北京市肠炎沙门菌多重耐药和脉冲场凝胶电泳(pulsed-field gel electropho-resis,PFGE)分子分型。方法对2009-2010年北京市肠道门诊监测系统分离到的40株肠炎沙门菌进行生化鉴定、血清分型并运用纸片法进行药敏检测,并采用PFGE进行分子分型。结果发现40株肠炎沙门菌中,32株多重耐药菌株,其中4～5种抗生素耐药27株(84.38%),10种抗生素耐药1株(3.13%);可分为14个PFGE带型,其中4个PFGE型的菌株数超过1株。结论北京市肠炎沙门菌分离株多重耐药性比较严重,PFGE分子型别较多,且存在差异明显的多个克隆系,但同一PFGE型菌株的多重耐药谱较为接近。     

上海市虹口区2010—2012年腹泻病例沙门菌监测及分子型特征

[目的]研究基于公共卫生实验室主动监测哨点医院沙门菌腹泻及优势菌型的耐药性和分子型特征。[方法]选择辖区内2家医院作为主动监测哨点,甄别食源性感染性腹泻的病例并采集粪便标本进行沙门菌培养、血清型鉴定和抗菌药物耐药性试验,通过脉冲场凝胶电泳（ PFGE ）分析优势菌型的遗传同源性。[结果]2010—2012年,共检测2579份标本,分离沙门菌185株（年度阳性率分别为9．1％、6．8％、5．1％,总阳性率为7．2％）,涵盖23种不同血清型,最常见的为肠炎和鼠伤寒沙门菌。所有沙门菌感染病例的男女性别比为0．9∶1;肠炎和鼠伤寒沙门菌感染均以21～60岁（68．9％）和60岁以上（21．4％）者居多。肠炎和鼠伤寒沙门菌对萘啶酸、磺胺异噁唑、链霉素、甲氧嘧啶、庆大霉素、四环素等6种抗菌药物的耐药率分别为27．7％～96．9％和2．6％～63．2％,且肠炎沙门菌的耐药率显著高于鼠伤寒沙门菌（P值均＜0．05）。22株肠炎和20株鼠伤寒沙门菌经PFGE各自分为11个和6个分子型。[结论]肠炎和鼠伤寒是区域内最常见的沙门菌腹泻菌型,分子分型提示存在优势克隆的聚集性爆发和分散爆发,应警惕多重耐药的肠炎沙门菌克隆株形成潜在爆发的风险。加强以实验室为基础的主动监测对控制食源性感染性腹泻具有重要的公共卫生意义。     

The role of roof rats ( Rattus rattus) in the spread of Salmonella Enteritidis and S. Infantis contamination in layer farms in eastern Japan

The prevalence of Salmonella in four layer farms in eastern Japan was investigated between 2004 and 2006 to determine the role of roof rats (Rattus rattus) in the epizootology of Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis). Persistent S. Enteritidis and S. Infantis contamination of the environment and pooled egg samples were detected in three out of four layer farms. A total of 113 (13.3%) and 158 (18.6%) out of 851 rats examined were positive for S. Enteritidis and S. Infantis, respectively. By pulsed-field gel electrophoresis, only one indistinguishable pulsed-field pattern was yielded by S. Enteritidis strains from rats, eggs and environmental samples from each of the two contaminated layer farms. Although, a variety of pulsed-field patterns were generated by S. Enteritidis isolates from rats, eggs, and the environment of the other contaminated farms, there are, however, some S. Enteritidis strains that are closely related clones. These results suggest that roof rats are carriers of S. Enteritidis and S. Infantis and that persistent S. Enteritidis and S. Infantis infections in a rat population may play an important role in the spread and maintenance of these pathogens inside the layer premises.     

2004—2007年某医院1885株临床病原菌的分布与耐药分析

目的了解新乡市第一人民医院2004—2007年1885株临床常见病原菌分布及耐药情况。方法菌株鉴定采用复星公司FORTUNE.2000和珠海黑马生物工程有限公司全自动微生物鉴定系统,药敏试验用纸片扩散法（K-B法）。结果在1885株病原菌中革兰阴性杆菌60.3%,革兰阳性球菌35.7%,真菌4.0%。对革兰阴性杆菌耐药率较低的抗菌药物为亚胺培南、头胞他啶、阿米卡星、呋喃妥因等。某些常见抗菌药物,如头孢他啶、哌拉西林、左氧氟沙星、四环素等2004、2005、2006年耐药率逐年提高,2007年明显降低。对革兰阳性球菌耐药率较低的抗菌药物为万古霉素、亚胺培南、利福平等,青霉素、苯唑西林等2004、2005、2006年耐药率逐年提高,2007年明显降低。红霉素、阿奇霉素、复方新诺明、环丙沙星2006年已开始降低,亚胺培南、头孢唑林、克林霉素、利福平、四环素等有耐药率升高的趋势。结论开发抗菌药物、加强细菌的耐药性检测及强调抗菌药物的合理使用等,依然是今后抗感染界控制细菌耐药性蔓延的主要措施。     

Demographic risk factors and incidence of Salmonella enteritidis infection in Michigan

Salmonella Enteritidis is a major cause of foodborne disease worldwide. In the United States, this serotype has been associated with significant morbidity and mortality accounting for about 17% of all human Salmonella infections. Data on risk factors associated with serotype-specific Salmonella infections have not been reported in Michigan before. We carried out this study using surveillance data to identify high-risk groups and regions for S. Enteritidis infection in Michigan. Results of this study may be used to develop better control and prevention measures against this common foodborne pathogen. We analyzed data on Salmonella infections collected by the Michigan Department of Community Health's surveillance system (1995-2001). We computed age, gender, and place of residence-specific incidences of S. Enteritidis infection in Michigan using population-based denominators. We used Poisson regression analysis to study the associations between S. Enteritidis infection and certain predictor demographic variables, while controlling for confounders and covariates. We found an overall 1.87/100,000 average annual S. Enteritidis incidence with 1.91/100,000 in females and 1.81/100,000 in males. A higher incidence of S. Enteritidis infection was associated with Michigan children<5 years old when compared with average national estimates (p<0.01). The final adjusted Poisson model revealed that children<1 year of age [RR: 9.75, CI: 7.99-11.90] and children 1-4 years of age [RR: 3.37, CI: 2.83-4.02] are at higher risk for S. Enteritidis infection compared to adults aged 15-39 years. No significant differences in incidence of S. Enteritidis infections were found between urban and rural dwellers or between genders (p>0.05). The incidence rate of S. Enteritidis infection in the Michigan pediatric population (<5 years) was found to be significantly higher than average national estimates, meriting immediate public health attention. Risk factors for S. Enteritidis infection in Michigan children should be identified in order to devise effective control and prevention measures.     

Molecular and epidemiological trend of rotavirus infection among infants and children in Japan

This study investigated the prevalence of group A, B, and C rotavirus (RAV, RBV, RCV) and adenovirus (AdV) infections in infants and children with acute gastroenteritis in Japan from July 2006 to June 2007. A total of 628 fecal specimens collected from infants and children with acute gastroenteritis in five different places (Maizuru, Tokyo, Sapporo, Saga and Osaka) in Japan during the period of July 2006–June 2007 were examined for RAV, RBV, RCV and AdV by RT-multiplex PCR. RAV was further characterized to G-typing and P-typing by RT-multiplex PCR and sequencing method. It was found that 123 (19.6%) fecal specimens were positive for RAV followed by AdV of 4.5%. RBV and RCV could not be detected in this study. Serotype G1 (58.5%) was identified at high levels followed by G9 (20.3%), G2 (11.4%), and G3 (7.3%). P genotyping revealed P[8] as predominant (84.6%) followed by P[4] (13.8%) and P[6] (1.6%). During the 2006/2007 rotavirus season, G1P[8] strains were most common with G9P[8], G2P[4], G3P[8], G1P[4] and G9P[6] also detected. It is clear from this study that RAV is still the cause of diseases in Japan. To our knowledge, this is the first report of RV P[6] strain in humans in Japan.     

2003～2007年山东省集贸市场食品李斯特氏菌污染状况调查

[目的]了解山东省市售食品单核细胞增生李斯特氏菌污染状况。[方法]2003-2007年夏秋季,在山东省部分地区集贸市场、超市采样检测。[结果]2003-2007年,合计检测各种食品1 502份,检出单增李斯特氏菌133份,检出率为8.85%。单增李斯特氏菌检出率,生鸡肉为9.54%,生羊肉为3.35%,生牛肉为14.47%,生猪肉为24.85%,散装熟肉为6.84%,生食蔬菜为1.34%（P〈0.01）;2003年为5.13%,2004年为3.63%,2005年为19.22%,2006年为3.52%,2007年为12.86%（P〈0.01）;济南市为9.34%,烟台市为3.77%,菏泽市为11.01%,莱芜市为7.51%,德州市为11.20%,潍坊市为4.61%（P〉0.05）。小鼠毒力试验显示检出的菌株均具有较强的致病性。[结论]山东省部分地区集贸市场食品摊点销售的食品李斯特氏菌污染较为严重。     

肠炎沙门菌食物中毒的病原学检测分析

目的 对一起食物中毒事件进行病原学分析和流行病学调查,探讨其中毒原因、传染源及传播途径。方法 通过现场流行病学调查对数据资料进行Fisher确切概率检验,对患者肛拭子、剩余食品、原材料等28份样品进行实时荧光PCR检测及分离培养;对分离菌株进行生化鉴定和血清分型,用改良K-B法进行药敏试验,应用脉冲场凝胶电泳（PFGE）分型技术进行同源性分析。 结果 从可疑食品蛋糕和6个患者中共分离到7株肠炎沙门菌,生物学性状、血清型和药敏试验结果一致, PFGE条带聚类分析显示所有菌株属同一克隆株。结论 这是一起肠炎沙门菌污染引起的食物中毒事件。食品卫生监督部门应加强网购食品卫生管理,减少食物中毒的发生。     

Emergence of Salmonella enteritidis outbreaks in broiler chickens in the Lebanon: epidemiological markers and competitive exclusion control

This study investigates the first emergence of Salmonella Enteritidis outbreaks among chickens in the Lebanon and identifies the epidemiological markers of selected recovered Enteritidis strains. In addition, the authors evaluate a competitive exclusion approach to control infection in broiler chickens by Enteritidis organisms which possess the prevalent identified markers. The basic procedure in this investigation involved recording signs and lesions in eleven broiler chicken flocks on eleven farms, and culturing livers, spleens, and caeca of ten randomly selected birds per flock for Salmonella isolation and serotyping. Furthermore, culturing for Salmonella and serotyping was attempted from the livers, spleens, caeca and oviduct swabs of ten hens in four broiler breeder flocks which provided hatching eggs for the broilers under study. The identification of epidemiological markers in recovered S. Enteritidis included the determination of drug-resistance patterns and plasmid profiling. The competitive exclusion was evaluated by spraying the microflora on day-old broilers in the hatchery, followed by a controlled oral challenge at three days of age, with 2.85 x 10(5) colony-forming units of S. Enteritidis organisms per bird. Exclusion was evaluated by culturing for S. Enteritidis in anal swabs, spleens, livers, and caeca of individual challenged birds treated with the microflora and in untreated challenged birds. A total of 112 invasive S. Enteritidis strains were recovered on eleven farms from individual organs of broiler chickens with typical signs and lesions of salmonellosis. The prevalent resistance to drugs in such strains was to furaltadone and gentamycin, a marker identified in 93 strains (83%), recovered from nine out of eleven farms. The same resistance pattern was present in S. Enteritidis strains recovered from breeders on one out of four farms. The prevalent plasmid profile in nine S. Enteritidis organisms selected randomly from a pool of 93 strains (one per each of the nine broiler farms) was 14.1 kilobases (kb) and approximately 50.0 kb, a typical pattern to that identified in S. Enteritidis organisms recovered from oviducts of breeders on one out of four breeder farms. The exclusion significantly reduced cumulative mortality in birds of up to 45 days of age by 3.93%, in comparison to that observed in untreated challenged birds (P < 0.05). At 45 days of age, exclusion resulted in a 15.6% reduction in the percentage infection rate by S. Enteritidis in spleens or livers and a 34.4% reduction in the percentage infection rate of the caeca (P < 0.05).     

上海市沙门菌病流行特征分析

[目的]了解上海市沙门菌病发病特征、菌型分布、抗生素耐药情况及初步估计相关的疾病负担。[方法]在上海市4个区的监测点医院采集监测病例的粪便标本进行沙门菌培养，菌株的血清分型及耐药监测，并对病人开展流行病学调查及沙门菌疾病负担估算。[结果]腹泻病人沙门菌阳性率3．13％，监测病例沙门菌阳性率高于非监测病例（X^2=68．212，P〈0．001）；流行季节在7．10月份；73．47％的病例发病前一周有可疑不洁饮食史；本市主要的沙门菌血清型为肠炎、山夫登堡、鼠伤寒和阿伯丁及德比。分离到的沙门菌存在不同程度的耐一种或多种抗生素现象；估计本市每年发生沙门菌病约13561例。[结论]监测结果提示上海市沙门菌病发病水平较高，应加强监测；防制措施上应重视食品安全、健康教育。