秀丽隐杆线虫-泛耐药鲍曼不动杆菌感染模型用于外排泵抑制剂逆转环丙沙星耐药的研究

目的建立秀丽隐杆线虫-泛耐药鲍曼不动杆菌感染模型,用于外排泵抑制剂(EPIs)逆转泛耐药鲍曼不动杆菌(XDR-AB)对于环丙沙星耐药的研究。方法建立秀丽隐杆线虫-泛耐药鲍曼不动杆菌感染模型,选用6种EPIs(CCCP、PAβN、NMP、奥美拉唑、利血平和维拉帕米)与氟喹诺酮类药物环丙沙星联合使用,记录秀丽隐杆线虫生存率以评价体内药效,同时进行毒性试验及体外药敏试验。结果不同浓度XDR-AB对秀丽隐杆线虫的致死情况不同,选择5×10~(6 )CFU/mL作为XDR-AB感染秀丽隐杆线虫浓度。秀丽隐杆线虫生存实验显示,XDR-AB感染线虫3 h后线虫组与加入多粘菌素B的对照组生存曲线比较,差异无统计学意义(χ~2=3.154,P0.05),感染线虫6、9 h,与对照组比较,差异均有统计学意义(均P0.001),但感染6 h与9 h组的生存曲线比较,差异无统计学意义(χ~2=0.669,P0.05),最终选择6 h作为感染时长,36 h为合适的抗菌药物治疗时长。环丙沙星联合EPIs应用于感染模型实验中,低浓度的PAβN、NMP、奥美拉唑、利血平可将线虫存活率分别提高30%~40%、15%~20%、20%~30%、20%,高浓度的维拉帕米可将感染线虫的存活率提高30%左右。体外药敏试验和毒性试验结果显示,环丙沙星分别与CCCP、奥美拉唑和维拉帕米联合可降低MIC至原来的1/4,分别联合PAβN,NMP和利血平可降低MIC至原来的1/2,其中CCCP体外联合抑菌效果最佳,但毒性较大不适于体内药效研究。结论首次成功构建了秀丽隐杆线虫-泛耐药鲍曼不动杆菌感染模型,得到6种EPIs逆转环丙沙星耐药性的初步研究。     

新型饮用水氯化消毒副产物二氯苯醌对秀丽隐杆线虫的毒性

目的 研究饮用水氯化消毒副产物二氯苯醌对秀丽隐杆线虫的毒性作用.方法 以秀丽隐杆线虫为模式生物,分别进行二氯苯醌的急性致死作用实验[0(溶剂对照)～5 000 μmol/L暴露24、48 h]、发育毒性实验[0(溶剂对照)～1 000μmol/L暴露60 h]、生殖毒性实验[0(溶剂对照)～50 μmol/[].检测秀丽隐杆线虫的24、48 h死亡率、体长和产卵数目.结果 与溶剂对照组比较,31.25～1 000 μmol/L二氯苯醌暴露组秀丽隐杆线虫体长均较小,各浓度二氯苯醌暴露组秀丽隐杆线虫的24、48 h死亡率均较高,6.25～50 μmol/L二氯苯醌暴露组秀丽隐杆线虫产卵数目均较少,差异均有统计学意义(P＜0.05,P＜0.01);且随着二氯苯醌暴露浓度的升高,秀丽隐杆线虫体长呈缩短趋势,24、48 h的死亡率均呈上升趋势,产卵数目呈下降趋势.二氯苯醌对秀丽隐杆线虫24 h的LC50为660.34 μmol/L,95％C1为498.93～887.09 μmol/L;48 h的LC50为458.88 μmol/L,95％CI为324.04～624.00 μmol/L.结论 新型饮用水氯化消毒副产物二氯苯醌对秀丽隐杆线虫的生长发育以及生殖系统都有不良影响.     

壬基酚对秀丽隐杆线虫的生殖毒性

目的研究壬基酚(nonylphenol,NP)对秀丽隐杆线虫的生殖毒性。方法将秀丽隐杆线虫暴露于终浓度分别为含0(溶剂对照)、0.01、0.1、1、10、100mg/LNP的培养基24 h,并设空白对照。检测NP对线虫的半数致死浓度(LC50)、后代数目、世代时间和精子发生相关基因spe-10、spe-15、folt-1、fer-1 mRNA的表达水平。结果 NP对线虫的LC50远高于100 mg/L。与溶剂对照组比较,各浓度NP暴露组秀丽隐杆线虫世代时间延长,差异均有统计学意义(P0.05);而后代数目无明显改变;且随着NP暴露浓度的升高,秀丽隐杆线虫世代时间呈延长趋势,后代数目呈下降趋势。与溶剂对照组比较,仅1、100 mg/L NP暴露组秀丽隐杆线虫spe-10 mRNA的表达水平降低,差异均有统计学意义(P0.05);而各浓度NP暴露组秀丽隐杆线虫spe-15、folt-1、fer-1 mRNA的表达水平均无明显改变;且随着NP暴露浓度的升高,秀丽隐杆线虫spe-10、folt-1、fer-1 mRNA的表达水平呈下降趋势。结论 NP抑制线虫精子发生相关基因spe-10的表达,对后代数目和世代时间影响较小,本实验结果表明运用线虫模型评价NP的生殖毒性,其基因表达的改变先于表型指标。     

秀丽隐杆线虫-泛耐药肺炎克雷伯菌感染模型的建立

目的建立泛耐药肺炎克雷伯菌（XDRKP）感染秀丽隐杆线虫感染模型。方法在液体条件下,利用临床分离的XDRKP菌株感染秀丽隐杆线虫,观察线虫存活及体内细菌数量变化情况。结果线虫感染XDRKP后活动明显迟缓,不同浓度的XDRKP对线虫的致死情况不同。log-rank检验显示,1.5×10⁶ CFU/mL XDRKP组与E.coli OP₅₀对照组的生存曲线差异无统计学意义（χ2=0.08,P>0.05）;1.5×10⁷、1.5×10⁸ CFU/mL组与E.coli OP50对照组的生存曲线差异均有统计学（χ²值分别为229.37、275.98,均P<0.001）,1.5×108与1.5×10⁷ CFU/mL XDRKP组线虫的生存率低于对照组。实验获得上清悬液,经细菌纯培养后进行细菌鉴定和药敏测试,证实为XDRKP。XDRKP感染线虫4、6、12、24 h后,线虫体内细菌总量分别为（0.28±0.02）×10⁵、（0.50±0.38）×10⁵、（1.73±0.56）×10⁵、（2.62±0.53）×10⁵ CFU/mL,不同时间线虫体内细菌总数存在统计学差异（F=1 363.39,P<0.001）。结论成功建立了秀丽隐杆线虫-XDRKP感染模型。     

山楂提取物延缓秀丽隐杆线虫衰老作用的研究

目的以秀丽隐杆线虫(Caenorhabditis elegans,C.elegans)为对象研究山楂提取物(haworth fruit extract,HFE)延缓衰老作用及其可能的作用机制。方法将秀丽隐杆线虫饲喂于含有不同浓度(0、25、50、100μg/ml)山楂提取物的NGM培养基,用计数法统计线虫的平均、最高寿命及繁殖能力,用荧光法观察脂褐素的自发荧光强度,DCFDA探针法检测ROS水平,试剂盒法测定SOD活力,用PCR法检测抗氧化相关基因mRNA表达量。结果饲喂HFE后,线虫表寿命明显延长,繁殖能力显著下降。线虫的脂褐素自发荧光明显减弱,并且与HFE浓度呈剂量依赖效应。线虫的体内ROS水平也显著减少,50、100μg/ml组线虫体内SOD活力显著提高,let-60、cat-1、daf-16、cdc-42、sir-2.1 mRNA的表达水平显著上调,daf-2 mRNA表达水平显著下调。结论山楂提取物可有效延缓衰老,其机制主要涉及提高线虫抗氧化防御系统功能、调控体内内源性抗氧化基因mRNA的表达水平。     

氯化甲基汞对秀丽隐杆线虫运动和感觉功能的影响

目的分析神经毒物氯化甲基汞对模式生物秀丽隐杆线虫运动和感觉行为的影响,初步探讨利用秀丽隐杆线虫研究氯化甲基汞神经毒性的可能性。方法采用氯化甲基汞对L1期、L4期幼虫分别急性(30 min)染毒[终浓度分别为0(溶剂对照)~202.5μmol/L和0~1 200μmol/L]和慢性(24 h)染毒[终浓度分别为0(溶剂对照)~80μmol/L和0~150μmol/L]。测定半数致死浓度(LC50)及行为学指标。结果氯化甲基汞致L1期、L4期秀丽隐杆线虫的LC50(30 min)分别为(65.93±8.89)μmol/L和(206.71±35.43)μmol/L,LC50(24 h)分别为(11.59±0.79)μmol/L和(24.89±4.88)μmol/L,L1期秀丽隐杆线虫对氯化甲基汞的毒性较L4期敏感。随着氯化甲基汞暴露剂量的升高,急性和慢性染毒L1期、L4期秀丽隐杆线虫的弯曲频率和头部摆动频率均呈下降的趋势,基本运动能力呈减弱趋势,触碰反应呈迟钝的趋势。结论氯化甲基汞可抑制运动和感觉功能,秀丽隐杆线虫可用于氯化甲基汞神经毒性的研究。     

二氯苯醌对秀丽隐杆线虫胚胎细胞DNA的损伤作用

目的研究新型饮用水氯化消毒副产物二氯苯醌对秀丽隐杆线虫胚胎细胞的DNA损伤作用。方法提取秀丽隐杆线虫的胚胎细胞,分别暴露于0(溶剂对照)、0.781 25、3.125、12.5、50、200、800μmol/L含二氯苯醌的L-15液体培养基染毒1 h,并设阳性对照(含300μmol/L过氧化氢的L-15液体培养基染毒15 min)。采用单细胞凝胶电泳技术测定DNA损伤情况。结果 3.125~800μmol/L二氯苯醌暴露组彗星实验Olive尾矩值均高于溶剂对照组,差异有统计学意义(P0.05,P0.01);且随着二氯苯醌暴露浓度的升高,秀丽隐杆线虫胚胎细胞Olive尾矩呈上升趋势。结论二氯苯醌对秀丽隐杆线虫胚胎细胞的DNA具有损伤作用。     

秀丽隐杆线虫模型评估威尼斯不动杆菌的致病性

目的应用秀丽隐杆线虫模型评估可能用作环境修复剂的威尼斯不动杆菌(Av)的致病性。方法分别在铺有大肠杆菌OP50和Av的培养基上培养秀丽隐杆线虫,通过观察秀丽隐杆线虫的发育、运动、消化功能、寿命和繁殖能力评估Av致病性;同时按照NY 1109—2017 《微生物肥料生物安全通用技术准则》进行Av致病性试验,比较两种方法的评估结果。结果应用秀丽隐杆线虫模型发现,Av组与OP50组成年秀丽隐杆线虫的体长、体宽、头部摆动频率和身体弯曲频率差异均无统计学意义(P0.05);Av组平均排便循环时间缩短(P0.05);Av组和OP50组线虫的生存曲线基本重合,平均寿命分别为(13.5±0.4) d和(13.7±0.4) d,差异无统计学意义(P0.05);Av组后代总数比OP50组增加了18.7%。NY 1109—2017 《微生物肥料生物安全通用技术准则》评估体系发现,雌性、雄性小鼠急性经口LD50均10 g/kgbw,属实际无毒;急性腹腔注射致病性试验结果显示动物未出现中毒体征及死亡,大体解剖未见异常;Av对家兔破损皮肤和眼均为无刺激性;溶血试验结果为阴性;Av对7种不同类别的抗菌药物均敏感,对1种抗菌药物中介。结论 Av无致病性;采用秀丽隐杆线虫模型评价环境修复剂的致病性具有可行性,可考虑作为致病性评价体系的筛选方案。     

纳米二氧化钛毒性线虫模式生物评价

目的 利用模式生物--秀丽隐杆线虫探讨二氧化钛(TiO2)纳米颗粒的毒性作用,为建立线虫作为毒理学评价模型提供试验依据.方法 采用5,35,300 nm等3种粒径的二氧化钛对秀丽隐杆线虫以0.1,1.0,10.0 g/L等3个浓度染毒24 h,应用世代时间、后代数目、头部摆动频率和身体弯曲频率及体长等生殖、运动和发育的相关指标对纳米二氧化钛毒性作用进行综合评价.结果 与对照组比较,暴露于5 nm TiO2的线虫在中高浓度暴露组均出现生殖、运动和发育等多系统的异常(P<0.05);而暴露于35 nm TiO2的线虫仅在高浓度暴露组出现生殖、运动等指标的异常(P<0.05);暴露于300 nmTiO2时高浓度暴露组的线虫出现身体弯曲频率降低(P<0.05),其他浓度组未出现差异有统计学意义的改变.结论 纳米TiO2暴露可影响秀丽隐杆线虫运动、生殖和发育等多种系统,并与粒径和暴露浓度有关.     

蒽醌暴露对秀丽隐杆线虫的毒性作用

目的 研究蒽醌暴露对模式生物秀丽隐杆线虫的毒性作用,观察其对秀丽隐杆线虫急性致死效应、寿命、生殖能力及抗氧化酶的影响。方法 根据蒽醌的溶解度及急性毒性试验结果确定本研究剂量为0、8、20、50、125 μmol/L,另设1%二甲基甲酰胺（DMF）溶剂对照组,对同步化至L4期的秀丽隐杆线虫分别进行处理,测定其致死率、寿命、子代数目及抗氧化酶的变化。结果 蒽醌24 h急性暴露后,随剂量的增加,秀丽隐杆线虫致死率增加,20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比差异均有统计学意义（P<0.05或P<0.01）;8、20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比,超氧化物歧化酶（SOD）活力增加（均P<0.01）。蒽醌长期暴露后,125 μmol/L剂量组与1%DMF溶剂对照组相比子代数目减少（P<0.05）;20、50、125 μmol/L剂量组与1%DMF溶剂对照组相比平均寿命明显减少（P<0.05或P<0.01）。结论 秀丽隐杆线虫暴露于蒽醌可对其致死率、寿命、生殖能力产生影响,并可激活其体内抗氧化酶,启动氧化防御系统。     

Coding and non-coding polymorphisms in VDR gene and susceptibility to pulmonary tuberculosis in tribes, castes and Muslims of Central India

Vitamin D receptor (VDR) plays an important role in activating immune response against various infectious agents. This study was aimed to investigate the association between VDR gene polymorphisms and different clinical forms of pulmonary tuberculosis (TB) in different population groups. Four common polymorphisms (TaqI, ApaI, BsmI and FokI) of VDR gene were studied in clinically diagnosed TB patients and healthy controls from Sahariya tribe (n = 377), Bhil tribe (n = 95), Chhattisgarh tribe (n = 33), general population from North-Central (NC) (n = 1021) and South-Eastern (SE) region (n = 646) and Muslims (n = 217). Genotyping was carried out using PCR-RFLP method and re-confirmed by direct sequencing. The haplotype analysis was performed on Haploview 4.1 and statistical analysis was done using SPSS 13.0 software. We found that bb genotype of BsmI polymorphism conferred significant risk to smear positive and multiple drug resistant (MDR) TB in tribes [OR (CI) = 3.7 (1.5–9.2), p = 0.002], SE population [OR (CI) = 2.1 (1.4–3.3), p = 0.0004] and Muslims [OR (CI) = 6.7 (1.1–39), p = 0.01]. The subjects with FF genotype of FokI polymorphism appeared less likely (p = 0.004) to develop MDR TB in NC population, whereas, those with Ff [OR (CI) = 2.5 (1.3–5.0), p = 0.004] and ff [OR (CI) = 3.4 (1.2–9.3), p = 0.01] genotypes were at high risk of MDR and smear positive disease, respectively. Similarly, tt genotype of TaqI polymorphism was found associated with high risk of smear positive TB in NC [OR (CI) = 3.6 (0.9–14.2), p = 0.05] as well as in SE [OR (CI) = 4.7 (1.8–12.3), p = 0.00003] population. Interestingly, tt genotype appeared strongly associated [OR (CI) = 8.9 (2.7–29), p = 0.00001] with high bacillary load outcome. In conclusion, genetic polymorphisms in VDR gene, alone or in combination (haplotypes) are associated with different clinical outcomes in pulmonary TB.     

成人灰色小克银汉霉侵袭性毛霉菌病1例并文献复习

目的 探讨灰色小克银汉霉感染导致成人毛霉菌病患者的临床特点及诊治方案。方法 总结某院血液内科收治的1例灰色小克银汉霉感染致成人侵袭性毛霉菌病患者的临床诊疗过程,并检索数据库相关文献进行复习。结果 患者男性,54岁,因“反复乏力1年余,加重伴发热1周”入院,肺组织病理检查可见宽大、不规则、无分隔的菌丝,形态学鉴定为毛霉菌,肺泡灌洗液及外周血宏基因组二代测序(mNGS)检测示灰色小克银汉霉,诊断为灰色小克银汉霉感染致侵袭性毛霉菌病,给予脂质体两性霉素B联合泊沙康唑、卡泊芬净治疗后感染获得控制。检索出符合条件的文献37篇,加上本病例,共纳入44例患者,其中男性26例,女性18例,中位年龄52.5(18～79)岁;基础疾病主要为血液系统疾病(65.9%,29例),进行造血干细胞或实体器官移植者14例;最常见的侵犯部位为肺、脑及皮肤,分别为36、9、9例;组织病理学、真菌培养、直接镜检及分子学检测阳性者分别为28、37、29、17例。41例患者接受了抗真菌治疗,其中8例联合手术治疗;30例死亡,病死率为68.2%,抗真菌治疗联合手术者生存率(62.5%,5/8)高于单独抗真菌治疗者(24.2%,...     

2012—2022年肠道绦虫感染患者的临床表现和流行病学特征

目的 探讨肠道绦虫病病例的临床表现及流行病学特征。方法 对北京市某医院2012年1月—2022年7月就诊的35例肠道绦虫病患者临床特点进行总结,并分析患者流行病学特征。结果 35例肠道绦虫病患者均有绦虫节片排出,经鉴定牛带绦虫病18例(51.43%),阔节裂头绦虫病17例(48.57%)。临床表现为腹痛、腹胀症状11例(31.43%),肛周瘙痒及头晕各2例(各占5.71%),恶心及呕吐、腹泻、发热、体重下降各1例(各占2.86%),无症状16例(45.71%)。21例(60.00%)北京市本地病例,其余患者来自北京市以外省份。31例(88.57%)患者有食用生或半生可疑食物病史。结论 肠道绦虫病患者多无临床症状或有轻微消化道症状,易被误诊、漏诊,重视流行病学史的询问可提高该疾病的诊断率。     

Leishmania species identification using FTA card sampling directly from patients' cutaneous lesions in the state of Lara, Venezuela

A molecular epidemiological study was performed using FTA card materials directly sampled from lesions of patients with cutaneous leishmaniasis (CL) in the state of Lara, Venezuela, where causative agents have been identified as Leishmania (Viannia) braziliensis and L. (Leishmania) venezuelensis in previous studies. Of the 17 patients diagnosed with CL, Leishmania spp. were successfully identified in 16 patients based on analysis of the cytochrome b gene and rRNA internal transcribed spacer sequences. Consistent with previous findings, seven of the patients were infected with L. (V.) braziliensis. However, parasites from the other nine patients were genetically identified as L. (L.) mexicana, which differed from results of previous enzymatic and antigenic analyses. These results strongly suggest that L. (L.) venezuelensis is a variant of L. (L.) mexicana and that the classification of L. (L.) venezuelensis should be reconsidered.     

Acute toxicity of widely used pharmaceuticals in aquatic species: Gambusia holbrooki, Artemia parthenogenetica and Tetraselmis chuii

Pharmaceuticals are continuously dispersed into the environment as a result of human and veterinary use, posing relevant environmental concerns. This study evaluated the acute toxicity of three therapeutic agents (diazepam, clofibrate, and clofibric acid) and a detergent (sodium dodecyl sulfate; SDS) in three aquatic species, namely the euryhaline fish Gambusia holbrooki, the hypersaline crustacean Artemia parthenogenetica, and the marine algae Tetraselmis chuii. The ranking of 50% lethal concentrations (LC50) for the two animal species and 50% inhibitory concentration (IC50) for the algal species was, in decreasing order, clofibric acid > SDS > diazepam > clofibrate for G. holbrooki, clofibric acid > clofibrate > SDS > diazepam for A. parthenogenetica, and clofibric acid > clofibrate > SDS > diazepam for T. chuii. These differences show that the intrinsic nature of test organisms must be considered when evaluating the toxicity of these agents to aquatic ecosystems.     

Kinetoplastid genomics: The thin end of the wedge

The completion of the genome sequencing projects for major pathogens Trypanosoma brucei, Trypanosoma cruzi and Leishmania major has enabled numerous studies that would have been difficult or impossible to perform otherwise. New technologies in sequencing and protein analyses promise further rapid expansion in our capabilities. The keys to successful use of these new tools are recognizing the power and limitations of studies performed thus far, grasping the unrealized potential of new and developing technologies, and creating access to a multidisciplinary set of skills that will facilitate research, particularly in the bioinformatic analysis of the reams of data that will be forthcoming. In this Discussion, we will provide an overview of kinetoplastid genomics studies with emphasis on studies advanced through genomic data, and a preview of what may come in the near future.     

The nutrient content of five traditional South African dark green leafy vegetables—A preliminary study

The nutrient content (proximate composition, vitamin B₂, ß-carotene, iron, zinc, magnesium, calcium and phosphorus) of 5 traditional dark green leafy vegetables, traditionally consumed by rural inhabitants of South Africa (SA), was determined in this study. The nutritional dilemma in SA, with many children and adults suffering from micronutrient deficiencies, is a strong motivation for determining the nutritional composition of traditional foods. The moisture, protein, ash and fat content in the raw leaves per 100 g ranged from 81.0 to 89.9 g/100 g, 3.49 to 5.68 g/100 g, 1.42 to 3.23 g/100 g and 0.12 to 0.36 g/100 g respectively. There was an increase in moisture content in the cooked leaves, while the protein, fat and ash decreased during the cooking process. Raw misbredie (Amaranthus tricolor), pumpkin leaves (Curcubita maxima) and cat's whiskers (Cleome gynandra) had a high iron content compared to cowpea leaves (Vigna unguiculata) and wild jute (Corchorus olitorius), which in nutritional terms might play a role in combating iron deficiency in SA. The zinc content ranged from 0.5 to 1.0 mg/100 g, while the magnesium ranged from 54.7 mg to 146 mg/100 g. As expected, the minerals decreased during cooking. Cowpea leaves was the poorest source of minerals compared to the other leafy vegetables but had a good index of nutritional quality for protein. Raw and cooked pumpkin leaves had the highest index of nutritional quality for protein. Both raw and cooked leafy vegetables contained high levels of beta-carotene (with total beta-carotene levels in the range of 796–6134 μg/100 g) but low levels of vitamin B₂ (0.01–0.12 mg/100 g).     

Toxicity of four nitrogen-heterocyclic polyaromatic hydrocarbons (NPAHs) to soil organisms

The aims of this study were: (i) to investigate the toxicity of N-heterocyclic polyaromatic hydrocarbons (NPAHs) quinoline, acridine, phenazine, and 1,10-phenanthroline to the soil invertebrates Eisenia fetida, Enchytraeus crypticus, Folsomia candida, and Caenorhabditis elegans, (ii) to compare the toxicity of four NPAHs and the species sensitivity, and (iii) to discuss possible risks of these compounds in soils. Different toxicities were found for the tested NPAHs which might be partially explained by their structure and properties. Effect concentrations expressed as soil pore-water concentrations were related to log K_ow, which indicated narcosis as the most probable mode of toxic action. The species sensitivity decreased in the rank: springtails >enchytraeids=earthworms> nematodes. Predicted no-effect concentration (PNEC) values were calculated for all tested species giving values from 0.5 to 6.8 mg/kg. It is unlikely that there is a risk for soil organisms in natural soils where lower NPAHs concentrations are expected.     

Monitoring of Cryptosporidium and Giardia in the Vantaa river basin, southern Finland

We compared two sampling methods to assess the contamination of the Vantaa river basin by Giardia cysts and Cryptosporidium oocysts: 10-1 grab samples, the common river mussel Anadonta piscinalis, were analysed for concentration of (oo)cysts from river water. The samples were collected 2-5 times in autumn 2001 from four wastewater treatment plants and four river water sites located downstream of the plants, and six times from raw water of a drinking water plant using the river as water source. The presence of Giardia and Cryptosporidium was analysed by IF microscopy and PCR. Both cysts and oocysts were detected at all sampling sites, but oocysts were more common than cysts in river water samples. In contrast, cysts were more common in A. piscinalis. Most Cryptosporidium-positive samples were of genotype 2 and Giardia were assemblage B. In river water, MPN of Escherichia coli did not correlate to the presence of (oo)cysts. In conclusion, low (oo)cyst counts were regularly identified in the Vantaa river basin which is contaminated by discharges of treated wastewater of human origin. In general, both methods to appropriate to detect (oo)cysts, but grab samples yielded more positive results. Grab sampling is also more practical and less expensive than analysis of A. piscinalis.     

肺炎克雷伯菌、类肺炎克雷伯菌和变栖克雷伯菌的研究进展

肺炎克雷伯菌临床分离株是一种有荚膜的革兰阴性粗短杆菌,是临床上重要的机会致病菌。肺炎克雷伯菌临床分离株基因间存在差异,依据系统发育树可分为肺炎克雷伯菌(Klebsiella pneumoniae, KpⅠ)、类肺炎克雷伯菌(Klebsiella quasipneumoniae, KpⅡ)和变栖克雷伯菌(Klebsiella variicola, KpⅢ),三者生态分布、基因型、耐药性、毒力特征以及致病性存在显著差异,为感染性疾病精准治疗带来新的挑战。本文对KpⅠ、KpⅡ、KpⅢ的鉴定、流行特点及致病特点的最新研究进展进行综述。