2015年2月全国突发公共卫生事件及需关注的传染病风险评估

目的评估2015年2月国内外突发公共卫生事件及需要关注的传染病风险。方法根据国内外突发公共卫生事件报告及重点传染病监测等各种资料和部门通报信息,采用专家会商法,并通过视频会议形式邀请各省(直辖市、自治区)疾病预防控制中心专家参与评估。结果预计2月份将是全年突发公共卫生事件报告数最少的月份。2015年2月,西非埃博拉出血热病例输入我国的风险依然存在,但在我国发生较大规模扩散的可能性极低;我国内地将继续出现人感染H7N9禽流感散发病例,不排除发生其他可感染人类的禽流感散发病例;近期全球多个国家及地区动物间禽流感疫情活跃;流行性感冒等呼吸道传染病将出现季节性升高;诺如病毒所致的腹泻病23月仍可能继续出现暴发疫情;猩红热疫情高于2014年同期,但较2014年12月已出现下降,学校和托幼机构陆续放假,预计病例数将会继续减少;麻疹疫情高于2014年同期,且较2014年12月继续上升,部分省份发生暴发疫情,形势不容乐观;中东呼吸综合征在沙特等地仍持续有散发病例报告,我国存在输入风险,但进一步播散的风险极低;非职业性一氧化碳中毒仍需进一步关注。结论 2015年2月我国的突发公共卫生事件及传染病疫情发生态势与往年相似,处于全年较低水平;需重点关注西非埃博拉出血热疫情,我国人感染H7N9禽流感疫情,流感,诺如病毒所致的腹泻病,同时关注猩红热、麻疹及中东呼吸综合征输入我国的风险。     

耐多药结核分枝杆菌中embB基因突变与乙胺丁醇耐药的相关性研究

目的 研究耐多药结核分枝菌中embB基因突变与乙胺丁醇耐药的相关性. 方法 比例法检测84株耐多药结核分枝杆菌的乙胺丁醇(EMB)耐药性,基因测序检测embB基因的突变,2检验分析二者之间的相关性. 结果 84株耐多药结核分枝杆菌中有43株(51.2%)对EMB耐药,41株(48.8%)对EMB敏感,57株耐多药菌株(67.9%)的embB基因发生突变.在43株EMB耐药菌株中,embB基因突变的菌株为40株(93.0%),而41株EMB敏感菌株中,embB基因突变的菌株为17株(41.5%),embB基因在耐药菌株中的突变频率远高于敏感菌株(2=25.58,P=0.00).embB306是最常见的突变位点,其在耐药菌株的突变率也高于敏感菌株(2=12.37,P=0.00),embB基因和embB306位点检测EMB耐药的敏感度、特异度和准确性分别为93.0%和65.1%,58.5%和73.2%,76.2%和69.0%. 结论 EMB耐药的产生与embB基因和embB306突变有关,二者用于检测EMB耐药有一定的参考意义.     

潜在致病性的弗氏枸橼酸杆菌的筛查

目的 筛查具有潜在致病性的弗氏枸橼酸杆菌。方法 对从河南省睢县分离到的36株弗氏枸橼酸杆菌进行黏附HEp-2细胞的检测,以及与HEp-2细胞(MOI: 100)作用10 h后的乳酸脱氢酶(LDH)释放情况分析。同时比较弗氏枸橼酸杆菌CF74(Citrobacter freundii 74)、CF72(Citrobacter freundii 72)、肠聚集性大肠埃希菌(Enteroaggregative E. coli,EAEC)、肠致病性大肠埃希菌(Enteropathogenic E. coli,EPEC)2348/69和HB101的黏附和细胞毒性差异。结果 16株弗氏枸橼酸杆菌几乎没有黏附性,黏附指数1;18株弗氏枸橼酸杆菌具有中等强度的黏附性,黏附指数100;2株弗氏枸橼酸杆菌CF74和CF65(Citrobacter freundii 65)具有强的黏附性。与HEp-2细胞作用10 h后,除了CF74(24.4%),其余的35株弗氏枸橼酸杆菌具有低的LDH释放量,LDH释放量与阴性对照HB101(5.02%)相似。说明除了CF74,其余的弗氏枸橼酸杆菌不具有细胞毒性。CF74具有和EAEC042一样的聚集性黏附类型,并且 CF74引起的LDH释放率明显高于CF72、2348/69和HB101(P0.01)而低于EAEC17-2。结论 作为潜在的致病菌,CF74具有强的黏附性和细胞毒性。     

海南省某医院103株鲍曼不动杆菌复合群-内酰胺类耐药性与碳青霉烯酶携带情况分析

目的 鲍曼不动杆菌复合群细菌是临床可造成感染的重要条件性致病菌,本研究旨在调查和分析我国海南省临床来源鲍曼不动杆菌复合群细菌对常用-内酰胺类药物的耐药性及菌株碳青霉烯酶携带情况,探讨其耐药流行性特点。方法 采用微量肉汤稀释法对103株采集自2012-2013年海南省三亚市人民医院的非重复鲍曼不动杆菌复合群细菌进行7种抗菌药物的药敏检测;应用聚合酶链反应(PCR)对收集的鲍曼不动杆菌复合群细菌进行9种碳青霉烯酶编码基因的筛查。结果 103株鲍曼不动杆菌复合群细菌对哌拉西林、头孢他啶、头孢噻肟的耐药率较高(接近50%),对头孢吡肟、哌拉西林/他唑巴坦的耐药率为40%,对亚胺培南和美罗培南的耐药率均在20%左右;PCR检测显示有38株携带blaOXA-58基因,62株blaOXA-66基因,其中25株同时携带有这两种基因;其余7种碳青霉烯酶编码基因筛查结果为阴性。结论 本研究中鲍曼不动杆菌复合群细菌对-内酰胺类药物耐药性较高,菌株携带的blaOXA-58和blaOXA-66基因编码的碳青霉烯酶对菌株的耐药表型有一定贡献意义,但仍有其他耐药机制参与到碳青霉烯酶耐药表型的贡献中。     

针对gyrA基因突变的反向斑点杂交技术快速检测结核分枝杆菌喹诺酮耐药性的研究

目的 建立快速检测结核分枝杆菌喹诺酮耐药性的反向斑点杂交(reverse dot blot hybridization,RDBH)技术,并观察其效果。方法 针对结核分枝杆菌gyrA基因序列及常见的突变位点,分别设计1条野生型和7条突变型探针,建立RDBH技术,对临床分离结核分枝杆菌菌株进行喹诺酮耐药性检测,以比例法药敏试验和DNA测序做对照。结果 应用比例法药敏试验、DNA测序、RDBH三种方法分别检测59株喹诺酮耐药株和51株喹诺酮敏感株,与比例法相比,RDBH试验灵敏度和特异度分别为69.49%(41/59)、100%(51/51),符合度为83.63%;而RDBH与DNA测序结果比较,敏感度和特异度分别为97.56%(40/41),98.55%(68/69),符合度达98.18%。结论 RDBH技术检测结核分枝杆菌喹诺酮耐药具有良好的灵敏度、特异度和符合度。     

Genetic Diversity,Antimicrobial Resistance,and Virulence Genes of Aeromonas Isolates from Clinical Patients,Tap Water Systems,and Food

Objective This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of Aeromonas isolates from clinical patients, tap water systems, and food.Methods Ninety Aeromonas isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing(MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated gyr B-cpn60 sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.Results The 90 Aeromonas isolates were divided into 84 sequence types, 80 of which were novel,indicating high genetic diversity. The Aeromonas isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes act, aer A, alt,and ast found in 47(52.2%), 13(14.4%), 22(24.4%), and 12(13.3%) of the isolates, respectively. The majority of the isolates(≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol,gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new mcr-3 variant.Conclusions Sequence type, virulence properties, and antibiotic resistance vary in Aeromonas isolates from clinical patients, tap water systems, and food.     

Multispacer Typing (MST) of Spotted Fever Group Rickettsiae Isolated from Humans and Rats in Chengmai County,Hainan Province,China

Spotted fever caused by spotted fever group rickettsiae (SFGR) is found throughout China. During 2007–2008, 28 human SFGR isolates and 34 rat SFGR isolates including 15 isolates from Rattus fulvescens, 5 isolates from R. edwardsi, 7 isolates from Callosciurus erythraeus roberti and 7 isolates from Dremomys rufigenis) were obtained from L929 cell culture. Previous research indicated that the 62 strains of SFGR mentioned above shared not only the same serophenotype but also 100% of identity sequences of 16S rRNA, gltA, ompA, groEL and 17KD, which enabled us to apply multispacer typing (MST) to the 62 SFGR isolates in the study. Six primer pairs, which were used for typing of Rickettsia rickettsii and Rickettsia conorii, were chosen, and the results exhibited greater nucleotide polymorphisms among the 62 isolates tested. A total of 48 distinct genotypes were identified. The dominant genotype, represented by h3 isolates, accounted for 21.7% (13/60) of the isolates tested, and the remaining 47 genotypes were all unique. Phylogenetic analysis showed that all the 48 genotypes could be classified in the same clade, while the genetically related strain, R. heilongjiangensis, was close but not the same as the cluster. We concluded that the genetically diverse of spotted fever group rickettsiae strains are endemic in Chengmai County, Hainan Province, China.