上海市2014年腹泻患者弯曲菌分离、毒力基因检测及分子分型结果

[目的]了解上海市2014年腹泻患者中弯曲菌感染现状,并分析弯曲菌的毒力基因及分子分型特征。[方法]采用膜过滤法对2014年上海市2 235例腹泻患者肛拭标本进行弯曲菌检测,并用常规生化试验和PCR方法鉴定分离菌株。采用PCR检测弯曲菌分离株的6种毒力相关基因,包括鞭毛蛋白基因fla A,细胞溶涨毒素cdt基因簇cdt A、cdt B、cdt C,p Vir质粒vir B同源性基因vir B11,外膜蛋白基因cad F。采用脉冲场凝胶电泳(PFGE)法对弯曲菌分离株进行分子分型。[结果]2 235例腹泻患者的肛拭标本中共检出弯曲菌43株,阳性率为1.9%。其中空肠弯曲菌占95.3%(41/43),结肠弯曲菌占4.7%(2/43)。毒力相关基因检测显示,100.0%(43/43)的弯曲菌菌株fla A基因和cad F基因阳性,93.0%(40/43)的弯曲菌菌株cdt A基因和cdt B基因阳性,88.4%(38/43)的弯曲菌菌株cdt C基因阳性,只有7.0%(3/43)的弯曲菌菌株vir B11基因阳性。43株弯曲菌经PFGE分型,共分为6个聚类。[结论]上海市腹泻患者中分离的弯曲菌普遍存在fla A和cad F基因,cdt A、cdt B、cdt C基因携带率高,vir B11携带率略低。弯曲菌分子分型呈多样化和复杂化特征,其引起的腹泻以散发为主。     

肺炎链球菌毒力基因表达差异性及对大环内酯类耐药性分析

目的探讨临床分离各表型肺炎链球菌毒力基因表达的差异性并分析其对青霉素和大环内酯类抗菌药物的耐药性。方法收集2012年12月-2016年12月不同来源的肺炎链球菌111株,分为侵袭性组和非侵袭性组,采用荚膜肿胀实验进行血清学分型,聚合酶链反应(PCR)和荧光定量PCR检测psaA、ply、lytA、cbpA、nanA毒力基因,最低抑菌浓度(MIC)法检测药物敏感性并用PCR检测相关耐药基因(PBP1A、PBP2B、PBP2X,ermB、mefA)。结果 111株肺炎链球菌共检出24个血清型/群,流行血清型为:19F、19A、14、23F、6A、6B。所有菌株5个毒力基因的携带率基本均接近100%;侵袭性菌株nanA、lytA、psaA、ply 4个毒力基因在转录水平高于非侵袭性菌株,此外19F和6A/B血清型中侵袭性菌株这4个毒力基因转录水平也高于非侵袭性组;nanA、psaA、cbpA和ply在3型中的转录水平高于其他血清型。血液与痰液标本来源的肺炎链球菌毒力基因转录水平有一定差异但无统计学意义,脑脊液来源与血液,痰液比较,转录水平增高;脑膜炎肺炎链球菌青霉素非敏感率为70.00%(7/10),非脑膜炎肺炎链球菌青霉素非敏感率为18.81%(19/101),90.09%(100/111)菌株同时对红霉素和克林霉素耐药,主要携带ermB基因。结论常见5种毒力基因在肺炎链球菌中普遍存在,但不同致病类型、不同血清型和不同来源菌株基因表达水平存在差异,侵袭性3型和脑脊液来源的菌株毒力较强,且该地区肺炎链球菌对青霉素、红霉素和克林霉素耐药率较高,尤其是脑膜炎肺炎链球菌,应引起临床重视。     

肺炎链球菌的耐药性及其血清型分布调查

目的 了解中山市肺炎链球菌的耐药性及其血清型分布情况，比较正常人群肺炎链球携带株与临床分离株的耐药性与血清型分布关系，探讨肺炎链球菌的耐药性和血清型分布特点。方法 肺炎链球菌的培养、分离和鉴定按《全国临床检验操作规程》进行；药敏试验根据美国临床实验室标准委员会(NCCLS)有关抗生素敏感性试验法规进行试验并对结果进行判定；肺炎链球菌分型使用Quellung反应方法。结果 266株肺炎链球菌中耐青霉素肺炎链球菌占26．7％；耐青霉素肺炎链球菌对红霉素、四环素、氯霉素、克林霉素、利福平和复方新诺明的耐药率高达97．1％、100％、56．3％、84．5％、42．5％、78．9％；在所有菌株中排在前9位(占所有血清型的65．9％)的常见血清型是23F(13．2％)、6A(12．4％)、19F、(10．9％)、6B(7．1％)、14(6．4％)、1．5B(5．3％)、NT(5．3％)、19A(3．0％)、22F(2．3％)。而71株对青霉素不敏感的菌株中排在前9位的常见血清型分别为19F、23F、14型、不能分型、6B、22F、、9V、19B和33F。目前推荐使用的23价肺炎球菌多糖疫苗(1，2，3，4，5，6B，7F，8，9N，9V，10A，11A，12F，14，15B，17F，18C，19A，19F，20，22F，23F，33F、)能覆盖所有分离菌株血清型71．9％。结论 在携带者中，肺炎链球菌对青霉素耐药率已处于较高水平，耐青霉素肺炎链球菌同时对其它常用抗生素普遍耐药，且已发现对三代头孢菌素耐药菌株，对红霉素、四环素、氯霉素、克林霉素材复方新诺明耐药已非常严重；建议对小儿和体弱老人使用23价肺炎球菌多糖疫苗预防接种以减少抗生素的使用和降低耐药菌株出现的压力。     

苏云金杆菌对淡色库蚊幼虫抗氧化酶的影响

目的 测定苏云金杆菌(Bacillus thuringiensis,Bt)对淡色库蚊幼虫的毒力,以及Bt浸渍后淡色库蚊幼虫体内抗氧化酶浓度的变化。方法 采用浸渍法测定Bt溶液对淡色库蚊幼虫的毒力;应用酶联免疫吸附法(ELISA)测定4 mg/ml Bt处理24 h后未致死组(A)、致死组(B)和对照组(C)的抗氧化酶浓度。结果 2、4和8 mg/L Bt溶液对淡色库蚊幼虫均有一定的毒力。A组、B组和C组的过氧化氢酶(CAT)浓度分别为(123.75±1.09)、(112.83±1.46)和(108.17±3.26)ng/ml,差异具有统计学意义(F=41.182,df=2,P<0.000 1);超氧化物歧化酶(SOD)的浓度分别为(12.10±0.10)、(10.12±0.46)和(10.04±0.62)ng/ml,差异具有统计学意义(F=20.447,df=2,P=0.002);谷胱甘肽过氧化物酶(GSH-PX)浓度分别为(64.33±4.41)、(58.90±4.30)和(55.53±0.72)ng/ml,差异没有统计学意义(F=4.617,df=2,P=0.061)。结论 ...     

奇异变形杆菌毒力基因检测和药物敏感性分析

目的了解不同来源奇异变形杆菌毒力基因分布特点及对抗生素的敏感性特点。方法收集分离自2011年-2014年食品和食物中毒样品的44株奇异变形杆菌,采用PCR方法检测常见的毒力基因hpm A、hpm B、hly A、rpo A、mrp A、fli L和zap A;利用BD Phoenix全自动药敏系统测定菌株对20种抗生素的敏感性。结果除hly A基因未检出外,其余6种毒力基因在所有菌株中均有检出,这些毒力基因在不同来源菌株中的分布无特异性;食品分离株对19种抗生素的敏感性明显低于食物中毒分离株;食源性奇异变形杆菌对四环素和多粘菌素的敏感率最低(4.5%)。结论奇异变形杆菌常见的毒力基因不能区分致腹泻株和非致腹泻株;食品分离株对抗生素处于较高的耐药水平。     

254株志贺菌血清分型与耐药性和致病因子分析

目的了解宁波市志贺菌血清型变化、耐药性及菌株毒力,为预防控制菌痢提供实验依据。方法从腹泻患者中分离菌株;鉴定采用API生化条;血清分型采用玻片凝集法;药敏采用VITEK 2 Compact GPS-16卡片和K-B法;5种毒力基因检测采用PCR法。结果 254株志贺菌中分出福氏志贺菌(B群)170株(占66.93%),宋内志贺菌(D群)83株(32.68%),鲍氏志贺菌(C群)1株(0.39%),其生化结果典型与ATCC标准株一致。志贺菌ipa H、set1A、set1B、sen、ial和vir A毒力基因携带率分别为100.00%、80.71%、75.20%、85.04%、94.49%和88.98%。耐药率前3位的是奎诺酮类的萘啶酸、四环素类的四环素和青霉素类的氨苄西林,部分菌株对三代头孢菌素中的头孢他啶、四代头孢菌素中的头孢吡肟等耐药,未检出耐碳青霉烯类抗生素的志贺菌。结论宁波市志贺菌流行株的血清型正在变迁中,形成F2a血清型、Fc亚型和D群志贺菌新格局。菌株耐药严重,多为ESBLs菌株,携带多种毒力基因,有较强的致病力,应引起关注。     

多药耐药肺炎克雷伯菌毒力基因研究

目的了解多药耐药肺炎克雷伯菌(MDRKP)中5种毒力基因存在情况,为临床治疗提供参考依据。方法收集2008年8月-2010年5月杭州市和湖州市6所医院共47株MDRKP,采用PCR及序列分析方法检测5种毒力基因(arr、magA、rmpA、hofA和ompT)。结果 47株MDRKP中检测到arr和magA两种毒力基因,检出率分别为29.8%和17.0%;6所医院A、B、C、D、E、F的MDRKP分离株中毒力基因arr的检出阳性率分别为26.7%、81.8%、0、14.3%、0、0,6所医院A、B、C、D、E、F的MDRKP分离株中毒力基因magA的检出阳性率分别为0、0、0、0、0、88.9%。结论 MDRKP中毒力基因arr和magA具有一定的携带率,在MDRKP中检出毒力基因arr和magA为国内首次报道。     

大肠埃希菌O157∶H7特异基因检测与毒力基因分析

目的 :对江苏省 2 0 0 0和 2 0 0 1年分离的经血清玻片凝集试验初筛为大肠埃希菌O15 7∶H7(E .coliO15 7∶H7)的菌株进行O15 7O抗原及H 7抗原特异性基因检测 ,了解 2 0 0 0年监测点宿主动物分离O15 7菌株毒力基因携带率及毒力基因图谱。方法 :用聚合酶链反应法检测O15 7特异基因、H 7特异基因 ,多重引物聚合酶链反应法检测VT1、VT2、eaeA、hly等毒力基因并进行分析。结果 :13 4株血清玻片凝集试验初筛为E .coliO15 7∶H7的菌株经特异基因检测确定为E .coliO15 7的占 72 .4% (97 13 4) ,E .coliO15 7∶H 7的仅为 2 9.1% (3 9 13 4) ;非O15 7菌株占 2 6.9% (3 6 13 4) ,有44 .3 % (5 8 13 4)的O15 7菌株鞭毛抗原不是H7。 2 0 0 0年宿主动物分离菌株 ,经特异基因检测为非O15 7的不携带毒力基因 (0 18) ;为E .coliO15 7∶H ?的菌株 ,毒力基因携带率为 10 .7% (3 2 8) ;确定为E .coliO15 7∶H 7的菌株 ,毒力基因携带率高达 93 .1% (2 7 2 9) ,且毒力基因型以VT2 eaeA hly为主。 结论 :特异性基因检测鉴定E .coliO15 7∶H7,可大大减少血清玻片凝集试验的误判 ,结合毒力基因检测 ,可分析E .coliO15 7∶H 7菌株毒力基因型的变化 ,对制定切实有效的防制对策控制E .coliO15 7∶H7流行具有重要意义     

芬吗通和雌三醇软膏分别联合生物反馈治疗围绝经期妇女压力性尿失禁的效果比较

目的探讨芬吗通和雌三醇软膏分别联合生物反馈治疗围绝经期妇女压力性尿失禁的治疗疗效,为临床治疗提供理论依据。方法选取苏州大学附属第二医院2014年10月-2017年10就诊于妇科门诊,围绝经期妇女伴轻中度压力性尿失禁患者120例。将随机分为A、B、C 3组,各组40例,A组患者仅接受生物反馈电刺激治疗,B组患者接受口服芬吗通+生物反馈电刺激治疗,C组患者接受雌三醇软膏+生物反馈电刺激治疗。对比3组患者临床疗效、压力性尿失禁频率、压力性尿失禁评分及血雌二醇(E_2)和卵泡生成激素(FSH)的变化情况。结果 (1)临床疗效比较,其中C组总有效率明显高于A、B组,B组明显高于A组,比较差异均有统计学意义(χ~2=19. 863,χ~2=21. 683,χ~2=26. 841,均P0. 001);(2)3组患者压力性尿失禁评分随着时间推移而降低(P0. 05);与A、B组比较,C组治疗3、6个月时压力性尿失禁评分明显较低(t=5. 934,t=6. 183,均P0. 001); A、B两组比较B组压力性尿失禁评分明显低于A组(t=6. 517,P0. 001);(3)3组患者压力性尿失禁频率随着时间推移而降低(P0. 05); C组治疗3、6个月时压力性尿失禁频率明显低于A、B组(t=5. 934,t=6. 183,均P0. 001); A、B两组比较,B组压力性尿失禁频率明显低于A组(t=6. 517,P0. 001);(4)3组患者治疗后血清E_2水平明显升高,FSH水平明显降低(P0. 05);其中B、C组治疗后血E_2水平明显高于A组(t=5. 962,t=6. 453,均P0. 001),FSH水平明显低于A组(t=6. 582,t=5. 837,均P0. 001),C组治疗后FSH水平明显低于B组(t=5. 862,P0. 001),但B、C组治疗后血清E_2水平比较差异无统计学意义(t=0. 183,P=0. 381)。结论雌三醇软膏联合生物反馈治疗是一种安全、有效治疗围绝经期妇女压力性尿失禁的方法。     

241株肺炎链球菌血清分型及耐药性研究

目的了解肺炎链球菌（Streptococcus pneumoniae,S．p）对常用抗菌药物的敏感性及血清型构成。方法采用纸片扩散法检测241株S．P对6种常用抗菌药物的敏感性;采用荚膜肿胀试验对菌株进行血清学分型。结果241株s．p对利福平、米诺环素、氧氟沙星、复方新诺明、阿奇霉素、氯霉素的耐药率分别为0．41％、77．18％、0％、78．00％、95．44％、22．00％。229株S．P可分为24个血清型／群,主要的流行血清型／群为19F、6B、19A、23F、15、14、6A、3、6C;12株s．p未能分型。多重耐药菌株分布在6B、19A、19F、23F血清型。结论S．P的耐药情况严重,大多数菌株呈多重耐药特征。     

从4例肝炎病人分离的输血传播病毒基因分析

[目的 ]测定从 4例肝炎病人分离的输血传播病毒的 (TTV)基因序列 ,观察其临床特点。[方法 \〗利用 PCR技术提取 1 999～ 2 0 0 1年检出的 4例 TTV患者血清中 DNA,进行基因分型。 [结果 ] H1 、H2 株与 TX0 1 1 同源性较大 ,H3 、H4株与 TA2 78、N2 2 、CHN1 、TX0 1 1 、TS0 0 3 、NA0 0 4的序列差异均较大 ,H3 与 H4之间的差异也较大。 4例患者的丙氨酸氨基转移酶 (ALT)均升高。 [结论 ] H1 、H2 属 1 b型 ,具有一定毒性 ;H3 、H4为新的基因型或变异株 ,二者亦不同型 ,均具有较强的毒性。     

2005-2006年河北省流感病毒监测与毒株变异分析

目的分析2005～2006年河北省流感病毒的流行与毒株变异情况。方法将采集的咽拭子标本用MDCK（Madin—Darby Canine Kidney）细胞培养分离流感病毒，血凝抑制试验鉴定病毒型别；在分离得到的3种型别流感病毒中分别以不同时间点选取分离株，进行血凝素重链（HA1）区核苷酸序列测定，并进行基因进化特性分析。结果2005～2006年分离到流感病毒92株，甲1亚型57株，甲3亚型6株，乙型29株。HA1区核苷酸和氨基酸序列分析表明，甲1亚型流感病毒与A／New Caledonia／20／99比较，1株有5个位点（173V〉A、259W〉R、260Y〉F、281 E〉K、322V〉A）发生氨基酸替换，2株有7个位点（90T〉K、102Y〉H、153R〉K、173V〉A、216R〉K、259W〉R、274T〉N）发生替换。3株甲3亚型与A圯alfornia／7／2004比较3个位点（188N〉D、193S〉F、225D〉N）氨基酸发生同样的替换。3株乙型流感病毒与B／HongKong／330／2001比较有7个位点（48K〉E、80K〉R、116R〉H、121N〉T、129K〉N、164E〉D、197S〉N）发生了相同的氨基酸替换。结论2005～2006年河北省流行甲1、甲3亚型和乙型流感病毒。流行株的基因特性发生了一定程度的变异，但乙型毒株变异更明显。     

Host range of Clostridium bifermentans serovar. malaysia, a mosquitocidal anaerobic bacterium.

Clostridium bifermentans serovar. malaysia (C.b.m.) is toxic to mosquito larvae. In this study, we quantified its toxicity to the mosquitoes, Aedes aegypti, Ae. albopictus, Ae. caspius, Ae. detritus, Anopheles stephensi, An. gambiae, Culex pipiens and Cx. quinquefasciatus. Anopheles larvae are the most susceptible, followed by Ae. detritus and Ae. caspius, then Culex and other Aedes larvae. According to mosquito species, the LC50 varies from 7 x 10(3) to 1.3 x 10(6) cells/ml. Three concentrations (10(7), 10(6) and 10(5) cells/ml) of C.b.m., Bacillus thuringiensis var. israelensis (B.t.i.) and Bacillus sphaericus were tested on Ae. aegypti, An. stephensi and Cx. pipiens larvae in order to determine the time necessary for each concentration to kill 50 and 90% of the population. Ninety percent of the 3 mosquito populations are killed within 4-15 h by the C.b.m. concentrations. Whatever the concentrations, C.b.m. kills at least 10 times less rapidly than B.t.i. but always quicker than B. sphaericus. Bioassays of C.b.m. bacterial cells or final whole culture were not toxic to Musca domestica and Drosophila melanogaster (Diptera) as well as to Phaedon cochleariae (Coleoptera) and Spodoptera littoralis (Lepidoptera).     

Toxicity-metabolism relationship of the photoisomers of certain chlorinated cyclodiene insecticide chemicals

Photoaldrin, photodieldrin, and photoheptachlor are more toxic than their corresponding parent compounds (aldrin, dieldrin, and heptachlor) to freshwater invertebrates and vertebrates, and to adult houseflies. The increase in toxicity is very significant in the case of the amphipod,Gammarus (1.5–12 times), bluegill fry (3.6–5.7 times), mosquito larvae,Aedas (2.3–6 times), minnow fry (2.5 times), and the isopid,Asellus (2 times). The greatest increases occur with photodieldrin which is 12 and 5 times more toxic than dieldrin, respectively, toGammarus, and to blue-gill fry, and with photoaldrin which is 6 and 4 times more toxic than aldrin, respectively, to mosquito larvae and bluegill fry. The toxicities of the photoisomers of isodrin and chlordene are generally less than those of their parent compounds to all the organisms tested. The basis of the differences in toxicities of the chlorinated cyclodiene photoisomers appears to be related to their chemical structure which possibly affects their action at the site(s) of toxic action and/or detoxication. The acidic proton present at the secondary chloride in photoaldrin, photodieldrin, and photoheptachlor possibly is responsible for the formation of charge-transfer complexes between components of the nerve and the mixed-function oxidase; the latter enzyme apparently dehydrochlorinates these photo products to their corresponding, more toxic ketones. The absence of such protons in photoisodrin and photochlordene renders them incapable of forming such ketones. The inhibition of these reactions by sesamex in house flies increases the stability of the chlorinated cyclodiene insecticides and, thus, significantly affects their toxicity. The conversion of photoaldrin, photodieldrin, and photoheptachlor to more-toxic and lipophilic ketones warrants additional studies of their accumulation and subsequent concentration by the food chain.     

Dynamics of Escherichia coli O157:H7 outbreak detection and investigation, Minnesota 2000-2008

We determined characteristics of Escherichia coli O157:H7 pulsed-field gel electrophoresis clusters that predict their being solved (i.e. that result in identification of a confirmed outbreak). Clusters were investigated by the Minnesota Department of Health (MDH) using a dynamic iterative model. During 2000-2008, 19 (23%) of 84 clusters were solved. Clusters of ≥3 isolates were more likely to be solved than clusters of two isolates. Clusters in which the first two case isolates were received at MDH on the same day were more likely to be solved than were clusters in which the first two case isolates were received over ≥8 days. Investigation of clusters of ≥3 E. coli O157:H7 cases increased the success of cluster investigations.     

Toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid on freshwater macroinvertebrates (Daphnia magna and Moina macrocopa) and fish (Oryzias latipes)

Because of their global distribution, persistence, and tendency to bioaccumulate, concerns about perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are growing. We determined the toxicity of PFOS and PFOA in several freshwater organisms, including two cladocerans, Daphnia magna and Moina macrocopa, and the teleost Oryzias latipes. In general, PFOS is approximately 10 times more toxic than PFOA in these organisms. In M. macrocopa, the median lethal concentration (LC50) was 17.95 mg/L for PFOS and 199.51 mg/L for PFOA. Moina macrocopa exhibited greater sensitivity than D. magna to both perfluorinated compounds in both acute and chronic exposures. In the 48-h acute toxicity test, M. macrocopa was approximately two times more sensitive than D. magna. In the 7-d chronic toxicity test, M. macrocopa showed significant reproductive changes at 0.31 mg/L for PFOS, which was approximately seven times lower than the effect concentrations observed over the 21-d exposure in D. magna. Two-generation fish toxicity tests showed that parental exposure to both compounds affected the performance of offspring. Unexposed progeny-generation (F1) fish exhibited elevated mortality and histopathological changes that were correlated with exposure in the parental generation (F0). Continuous exposure from F0 through F1 generations increased the extent of adverse effects. Considering the persistent nature of PFOS and PFOA, more research is required to determine potential consequences of long-term exposure to these compounds in aquatic ecosystems.     

Serotype competence and penicillin resistance in Streptococcus pneumoniae

From 2003 to 2005, we prospectively collected 118 isolates of pneumococci belonging to 7 serotypes to investigate their competence under the influence of the synthetic competence-stimulating peptides. The degree of competence of the various serotypes differed significantly. Serotype 6B had the highest competence, followed by serotypes 14, 19F, 9V, 23F, 3, and 18C. Isolates belonging to serotype 6B had greater genetic diversity than isolates belonging to serotype 3, which has high genetic clustering. Isolates belonging to serotypes 3 and 18C that were 100% sensitive to penicillin were significantly less competent than isolates belonging to serotypes 6B, 14, 19F, 9V, and 23F, which were frequently resistant to penicillin. Under the 7-valent pneumococcal conjugate vaccine program, enhanced molecular surveillance of virulent clones with higher competence to detect serotype switching will become more important.     

Studies on staphylococci from toxic shock syndrome in France, 1981-1983.

Staphylococci from 22 cases of toxic shock syndrome with onsets between 1981 and March 1983 have been studied. Another four cases were detected by abstract surveillance. Three of these patients died. The case histories show that the syndrome occurs in women during menstruation as well as in males and in children, and is associated with Staphylococcus aureus infections. The production of enterotoxins (A, B, C) and toxic shock toxin by S. aureus isolates from toxic shock syndrome was investigated. Twenty-two of the 23 isolates were found to be toxigenic: 7 produced enterotoxin A, 8 produced enterotoxin B, 3 produced enterotoxin C and 13 produced toxic shock toxin. The latter was found with enterotoxin A in five cases, and with enterotoxins A and B in only one case. Sixty-three percent of 46 S. aureus strains isolated from the vagina of patients with diseases other than toxic shock syndrome produced toxin; eight of these strains produced toxic shock toxin.     

Studies on staphylococci from toxic shock syndrome in France, 1981-1983

Staphylococci from 22 cases of toxic shock syndrome with onsets between 1981 and March 1983 have been studied. Another four cases were detected by abstract surveillance. Three of these patients died. The case histories show that the syndrome occurs in women during menstruation as well as in males and in children, and is associated with Staphylococcus aureus infections. The production of enterotoxins (A, B, C) and toxic shock toxin by S. aureus isolates from toxic shock syndrome was investigated. Twenty-two of the 23 isolates were found to be toxigenic: 7 produced enterotoxin A, 8 produced enterotoxin B, 3 produced enterotoxin C and 13 produced toxic shock toxin. The latter was found with enterotoxin A in five cases, and with enterotoxins A and B in only one case. Sixty-three percent of 46 S. aureus strains isolated from the vagina of patients with diseases other than toxic shock syndrome produced toxin; eight of these strains produced toxic shock toxin.     

Stage-dependent differences in effects of carbaryl on population growth rate in Japanese medaka (Oryzias latipes)

Fish embryo toxicology is important because embryos are considered more susceptible than adult fish to the effects of toxic chemicals. Recently, fish embryo bioassay was proposed to replace the conventional fish acute toxicity chemical test of the Organization for Economic Cooperation and Development guidelines because it offers the advantages of fewer reagents, easy handling, and efficient data production. To accelerate the establishment of a chemical toxicity database for the protection of environmental and human health, we need to determine whether the conventional toxicity test can safely be replaced by such fish embryo toxicity tests. For instance, it is unclear how the presence of the chorion moderates the toxic effects of some chemicals. If such chemical toxicities do differ between embryos and, for example, the larval stage, then different toxic effects should appear in later life. We tested the later-life effects of the neurotoxic insecticide carbaryl at sublethal concentrations (0 [control] and 5 and 10 mg/L) in embryos and posthatch larvae of the freshwater fish medaka, Oryzias latipes. Although embryos exposed until hatching showed multiple developmental malformations and reductions in subsequent survival rates over three months, no significant reduction was observed in tolerance to starvation for 7 d and in intrinsic population growth rate (r). Exposure of larvae for 96 h resulted in dose-responsive vertebral fracture, significant reduction in tolerance to starvation for 7 d, and reduced three-month survival rate; r was reduced significantly and consistently. These results suggested that posthatch larvae were more susceptible than embryos to carbaryl exposure and that the toxic cascades may differ between larvae and embryos. The influences of carbaryl exposure on population growth rate differed significantly with developmental stage.