Isolation and Identification of a Pathogenic E.coli Strain Causing Diarrhea in Foxes

[Objectives] The study aimed to identify the pathogenic E. coli strain that caused diarrhea in foxes and to analyze its drug sensitivity.[Methods] A pathogenic E. coli strain was isolated from dead foxes with diarrhea. By conventional bacterial isolation and culture, morphological observation, pathogenicity test and K-B disc method, the isolated strain was identified as pathogenic E. coli .[Results] The isolated pathogen was highly sensitive to ceftriaxone, cefotaxime, ciprofloxacin and lincomycin, moderately sensitive to enrofloxacin, neomycin, gentamycin, spectinomycin, florfenicol, amikacin and polymyxin, and resistant to ampicillin, amoxicillin and doxycycline.[Conclusions] This study provided reference for the prevention and control of diarrheal diseases in foxes in Qinhuangdao region.

Solar photocatalytic pathogenic disinfection:Fundamentals to state-of-the-art

It is necessary to treat pathogen-infected water before its utilisation.Of conventionally used treatment methods,solar photocatalysis has gained considerable momentum owing to its operational simplicity and capacity to use freely and abundantly available solar energy.This article systematically reviewed the disinfection of water with photocatalysis.It addressed the concerns of microbial infection of water and the fundamentals behind its treatment with photocatalysis.It presented an in-depth description of pathogenic deactivation with powerful reactive oxygen species.Special emphasis was given to process intensification as it is an attractive technique that provides multifunctionality and/or equipment miniaturisation.Solar reactor design regarding mobilised/immobilised photocatalysts and compound parabolic concentrators were elucidated.Finally,key parameters governing photoperformance,corresponding trade-offs,and the need for their optimisation were discussed.Overall,this article is a single point of reference for researchers,environmentalists,and industrialists who address the ever-severing challenge of providing clean water whilst also maintaining energy sustainability.

戊型肝炎的肝外表现及其致病机制研究进展

[背景]戊型肝炎属于病毒性人畜共患传染病,由戊型肝炎病毒(HEV)引起,主要通过粪-口途径传播.HEV感染不仅可导致肝脏疾病,还可引起多种肝外表现,如神经系统疾病、泌尿系统疾病、血液系统疾病等.目前HEV相关的肝外表现机制研究主要关注HEV感染可能引发宿主的多种防御机制,或HEV可能在肝外组织中的复制,但确切的潜在病理生理学机制尚未得到充分证实.[进展]本文系统综述了HEV的肝外临床表现及其致病机制的研究进展.通过分析神经系统疾病(包括神经性肌萎缩症和脑膜脑炎等)、泌尿系统疾病(如肾小球肾炎)以及血液系统疾病(如血小板减少症)等HEV引发的肝外疾病相关流行病学特征及其临床表现,进一步总结了HEV感染与这些疾病之间的潜在联系和可能作用机制.[展望]尽管目前已取得一定的研究进展,但关于HEV感染与肝外疾病之间复杂关联的认识仍有限,未来研究需开展更多流行病学研究评估不同人群、不同基因型HEV感染对肝外疾病的影响,并深入探索HEV肝外疾病的致病机制,尤其是如何通过免疫介导机制或直接效应影响肝外器官.同时,基于研究结果发展有效的戊型肝炎及相关疾病的预防、诊断和治疗策略,以应对这一日益重要的公共卫生挑战.

Genetic characteristics and pathogenicity of human hepatitis E virus in Nanjing,China

AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.

Detection of High Pathogenicity Island(HPI) in Pathogenic Escherichia coli of Mink by PCR

[Objective] The paper was to analyze the carrying status of high pathogenicity island （HPI） in pathogenic Escherichia coli of mink. [Method] Eight strains of E. coli were isolated from dead mink, and conducted pathogenicity test of artificial infection. The carrying status of HPI （irp2, fyuA） was detected by PCR. [Result] Eight strains of E. coli were pathogenic E. coli, and the carrying rate of HPI （irp2, fyuA） was 100%, positively correlated with the pathogenicity. [Conclusion] The results lay a foundation for further exploring the pathogenic mechanism of E. coli..

UV-TiO_2 photocatalytic disinfection and photoreactivation of pathogenic bacterium in municipal wastewater

The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivation of Escherichia coli(E.coli) and Enterococcus faecalis(E.faecalis) in secondary effluents which were disinfected respectively by pure UV and UV-TiO_2 was investigated.The results show that the disinfection efficiency of UV-TiO_2 is much higher than that of the pure UV disinfection.The photoreactivation rate of E.coli is much higher in pure UV disinfection than in UV-TiO_2 photocatalytic disinfection.Under high light intensity in UV-TiO_2 disinfection,high resurrection rate can be induced.However,a higher resurrection rate can be introduced even under low light intensity in pure UV disinfection alone.Meanwhile,UV-TiO_2 disinfection has a strong inhibition effect on E.faecalis photoreactivation.When the light intensity is lower than 21 μW/cm^2,nearly no resurrection of E.faecalis occurs after 72 h resurrection irradiation,and a little resurrection rate is observed only under a strong photoreactivating light intensity.

Pathogenicity of Escherichia coli O_(123) from Rex Rabbit on White Mice

[Objective]The paper was to analyze the pathogenesis of Escherichia coli O123 from rex rabbit. [Method]E. coli O123 isolated from rabbit liver with diarrhea symptom in scale rex rabbit farm was intraperitoneally injected into 18- 22 g Kunming mice,and its pathogenicity was determined by clinical symptoms and pathological examination. [Result]When the inoculation concentration was about 8. 5 × 107 CFU /mL,Kunming mice appeared the clinical symptoms of drooping spirit,diarrhea and gathering,and the mortality reached 50%. Anatomical examination found that intestinal wall was thinning and intestinal mucosa was bleeding. [Conclusion]E. coli from rex rabbit has strong pathogenicity,and establishing animal model with Kunming mice to study its pathogenesis is of great reference significance for diagnosis and prevention of E. coli disease of rex rabbit.

A Comparative Investigation on Growth of Three Food Born Pathogenic Bacteria Inoculated with Withania somnifera:an Invitro Experimental Study

Background:Withania somnifera(WS)is proposed as one of the alternatives instead of the antibiotic.This study is aimed to evaluate the inhibitory potency of enzymatic extract of the fruits of the WS.Methods:As an invitro experimental study,the growth rate of Shigella dysenteriae,Salmonella typhimurium,and Escherichia coli inoculated in different concentrations(25%,12.5%,6.25%and 3.125%)of the extract were assessed.A microtitre plate method was conducted.ANOVA was applied to identify statistical differences with p-value<0.05.Results:Different concentrations of extract,in comparison with control,declined the growth rate of all tested bacteria.All concentrations inhibited the growth of S.typhimurium(p<0.05).Compared to the microorganism control,effective concentration of the extract inhibiting the growth of E.coli was 12.5%,and 6.25%,while it was 12.5%,and 6.25%for Sh.dysenteriae(p<0.05).A dose-dependent response of E.coli was observed.The antibacterial activity of the extract tested was found mainly against E.coli and Sh.dysenteriae.The most resistant microorganism compared to E.coli and Sh.dysenteriae was S.typhimurium(p<0.05).25%of the concentration of the extract showed the different inhibitory effect among three tested bacteria(p<0.05).Conclusions:The extract was labeled as an antibacterial agent against the representative of three foodborne bacteria,Invitro.The common effective concentrations of the extract(12.5,and 6.25%)is recommended for further research,as food additive,to remedy digestive ailments related to E.coli,S.typhimurium and Sh.dysenteriae.

柴防止咳方治疗小儿风邪犯肺型变应性咳嗽的临床观察

【目的】观察柴防止咳方(由北柴胡、防风、黄芩、清半夏、党参、乌梅、五味子等中药组成)治疗小儿风邪犯肺型变应性咳嗽的临床疗效。【方法】将60例风邪犯肺型变应性咳嗽患儿随机分为治疗组和对照组,每组各30例。治疗组给予自拟的柴防止咳方免煎颗粒口服治疗,对照组给予氯雷他定片联合苏黄止咳胶囊口服治疗。1周为1个疗程,连续治疗2个疗程。观察2组患儿治疗前后咳嗽症状评分、外周血嗜酸性粒细胞计数(EOS)和血清总免疫球蛋白E(IgE)水平的变化情况,并评价2组患儿的临床疗效。【结果】(1)临床疗效方面,治疗2周后,2组患儿的总有效率均为93.33%(28/30),组间比较(χ2检验),差异无统计学意义(P>0.05);但治疗组的总体疗效(秩和检验)优于对照组(P<0.05)。(2)咳嗽症状评分方面,治疗后,2组患儿的日间咳嗽症状评分和夜间咳嗽症状评分均较治疗前降低(P<0.05),且治疗组的降低程度均优于对照组(P<0.05)。(3)实验室指标方面,治疗后,2组患儿的外周血EOS和血清总IgE水平均较治疗前降低(P<0.05),且治疗组的降低程度均优于对照组(P<0.05)。【结论】柴防止咳方治疗小儿风邪犯肺型变应性咳嗽疗效显著,能有效减轻患儿咳嗽症状,纠正免疫失衡状态。

Prevalence and Seroprevalence of Non-SARS Human Coronaviruses 229E and OC43 in East Tyrol/Austria

The recent SARS-CoV-2 pandemic renewed interest in other previously discovered human coronaviruses—the non-severe acute respiratory syndrome human coronavirus (non-SARS hCoVs) and this study is a starting point for a closer investigation of those. With the pandemic behind us we believe it to be important to also examine the current and past respiratory pathogen landscape in the patient population in our care. Therefore, 954 nasopharyngeal swabs of patients with respiratory diseases collected between October 2018 and March 2020 were tested against the pathogens Mycoplasma pneumoniae, Bordetella pertussis, Influenza A and virus, Human metapneumovirus, respiratory syncytial virus, Parainfluenza virus, human Adenovirus and Polyoma virus BK/JC. Swabs negative against these pathogens were further tested for OC43 and 229E by RT-qPCR. Human coronaviruses 229E and OC43 were proven as the causative agents in a considerable number of cases, confirmed by PCR. Overall, our results show that those two non-SARS hCoVs were responsible for 13.9% (11 of 79) of infections with flu-like symptoms of unknown etiology in the study area. In the subsequent seroprevalence study, it was shown that the seroprevalence rate of IgG antibodies against 229E and OC43 was over 50%, indicating that a big part of the population in our study area has been in contact with these non-SARS-CoVs and has built the specific humoral immune response accordingly.

不同地理株鸡柔嫩艾美耳球虫致病性的研究

采用盲肠病变记分、每克粪便含有的卵囊数、粪便记分、肉鸡增重等检查方法对来自山东、吉林、黑龙江、北京4个不同地区的鸡柔嫩艾美耳球虫的致病性进行了研究。将上述各株球虫分别接种10日龄AA肉鸡,并于接种后5d开始进行各项指标的检测。结果表明:山东株(S株)的致病性最强,黑龙江株(H株)和吉林株(J株)的致病性次之,北京株(B株)最弱。

规模化养鸭场鸭源大肠杆菌分离株的致病性及系统发育分析

为研究鸭源大肠杆菌(E.coli)的致病性,明确鸭病原性E.coli与人和其他动物E.coli的亲缘关系及O血清型与菌种间遗传关系的相关性,本研究从我国西南地区规模化养鸭场患典型E.coli败血症的雏鸭体内分离37个血清型共82个E.coli分离株(其中优势血清型32株,其他血清型50株),以每株0.2 mL(l09 cfu/mL)腿部肌肉接种7日龄健康鸭进行致病性试验;并对其中14个鸭源E.coli代表株进行16S rRNA基因克隆、测序及系统发育分析。结果表明:所有分离株全部为致病性E.coli,其中高致病株、中等致病株和低致病株分别占受试菌株的80.5%(66/82)、17.1%(14/82)和2.4%(2/82),4个优势血清型全部为高致病株和中等致病株,分别占受试菌株的84.4%(27/32)和15.6%(5/32);14个代表株鸭源E.coli的16S rRNA形成2个主要分支,3株新发现的血清型单独形成一个较远的分支,11株常见血清型与人及其他动物源E.coli形成另一个大的分支,其中有6株与人的O157亲缘关系较近,2株与出血性E.coli O157∶H7 sakai聚为一个小分支;从遗传进化的关系分析,这些菌株有可能是人类的潜在病原菌;同时还发现不同血清型的分离株可以聚为一支,而同一血清型的分离株可以处于不同的分支,常规的O血清学分型不能体现菌种间遗传关系的远近。

乌梅对308株临床菌株的抑菌效果

目的观察乌梅对临床菌株的抑菌效果。方法采用琼脂稀释法,对乌梅进行308株临床菌株的抑菌活性检测。结果乌梅对112株金黄色葡萄球菌、112株表皮葡萄球菌和28株肠球菌的MIC50分别为0.72、1.44、0.72mg/mL;其MIC90分别为1.44、1.44、0.72mg/mL。对肺炎克雷伯菌和大肠杆菌的MIC90分别为2.88、1.44mg/mL。结论乌梅对革兰阳性球菌和某些革兰阴性杆菌均有较好的抑菌活性。

规模化猪场致病性大肠杆菌、沙门氏菌药敏区系调查

从四川省 1 6个和广西 1个规模化猪场临诊发生典型仔猪黄、白痢猪只的肛试粪样及死亡猪只的心血和肝中分离出致病性大肠杆菌 2 45株 ,从四川省 1 2个规模化猪场临诊发生典型仔猪副伤寒猪只中分离出致病性沙门氏菌 2 7株。用 1 6种常用抗菌药物对分离菌株进行了药敏测定 ,结果表明 ,大肠杆菌、沙门氏菌存在广泛的耐药性 ,以多重耐药性为主。大肠杆菌菌株最为敏感的药物是头孢唑啉、新霉素 ,而对林可霉素、青霉素钾的敏感率极低。对沙门氏菌菌株最为敏感的药物是新霉素、磺胺、庆大霉素、妥布霉素等 ,而对红霉素、林可霉素几乎全部耐药。

仔猪感染粪肠球菌的病原鉴定及病原特性初报

旨在对引起河南省三门峡某猪场肥育仔猪发病死亡的病原菌进行鉴定,并对其病原特性进行初步分析。用常规手段分离纯化可疑病原菌,观察其形态染色特性和培养特性,然后利用Vitek-32全自动细菌鉴定系统进行生化特性鉴定,并进一步检测分离菌株的明胶酶和溶血素等毒力因子表型及其药物敏感性。结果表明:①经细菌分离纯化,得到2个呈链状排列的G+球菌分离株,分别命名为HE1和HE2株。②经Vitek-32全自动细菌鉴定系统鉴定,2株分离菌均为粪肠球菌(E. faecalis)。③毒力因子表型试验表明,HE1和HE2均具有溶解明胶的能力,且能裂解兔红细胞,其中HE1呈现β型溶血,HE2呈现α型溶血。④动物试验表明,分离菌株对小鼠具有致死作用,其中HE1毒力更强。家兔对上述分离株具有一定耐受性,仅表现出临床症状但不死亡。⑤药敏结果显示分离菌对万古霉素、替考拉宁、利富平和氨苄西林敏感,对诺氟沙星、红霉素、卡那霉素和四环素耐药。粪肠球菌感染可以导致仔猪发病死亡,但不同的粪肠球菌分离株对动物的致死能力有差异。

规模化猪场致病性大肠杆菌血清型鉴定

从四川省 1 6个规模化猪场临诊发生典型仔猪黄、白痢猪只的肛试粪样及死亡猪只的心血和肝中分离出致病性大肠杆菌 2 45株 ,用 35种大肠杆菌单价O抗原进行血清型鉴定。 2 45株分离菌有 1 72株能定型 ,分属 30种血清型 ,其中以O6 0、O89、O1 1 9、O1 41、O9、O2 0、O1 37和O1 0 1等 8种血清型为优势血清型 ,占定型菌株的 6 6 86 %。尚有 73株未能定型 ,占分离菌株的 2 9 80 % (73/2 45 )。

多位点序列分型(MLST)在艾伯特埃希菌鉴定中的应用

目的探讨多位点序列分型技术在新病原艾伯特埃希菌发现与鉴定中的应用。方法采用MLST技术对生鲜肉中分离的30株疑似艾伯特埃希菌的7个管家基因进行PCR扩增、测序、DNAstar软件分析,核酸序列上传至大肠杆菌MLST数据库进行比对,确定其等位基因编号及基因序列型(ST型),并利用MEGA6.0软件Neighbor-joining法构建遗传进化树,与大肠埃希菌、志贺氏菌、艾伯特埃希菌和伤寒沙门氏菌参考菌株进行亲缘性分析。结果 30株菌可分为7种新序列型(16株)和4种已知序列型(14株),N-J分析显示与艾伯特埃希菌参考菌株具有高度亲缘性,而与大肠埃希菌、志贺氏菌、弗格森埃希菌和鼠伤寒沙门氏菌存在较大差异。结论 MLST在管家基因水平上准确地确定艾伯特埃希菌的种属关系,首次在国内发现艾伯特埃希菌的存在。

辽宁地区奶牛乳房炎细菌性病原分离鉴定及大肠杆菌药敏试验

为了掌握辽宁地区奶牛乳房炎主要细菌性病原种类及致奶牛乳房炎大肠杆菌药物敏感性特征,本研究选取辽宁地区某大型奶牛场75头临床表现为乳房炎的奶样进行细菌培养与分离,通过生化方法对分离到的细菌进行鉴定,并对分离到的奶牛源大肠杆菌进行体外药物敏感性试验研究。结果发现,该场奶牛乳房炎细菌性病原主要为大肠杆菌、葡萄球菌和链球菌,其检出率分别为58.7%、64.0%和54.7%,存在二重感染和三重感染等混合感染的情况。大肠杆菌药物敏感性试验结果表明,该场分离株对磺胺类药物(耐药率>85%)及氯霉素类药物(耐药率>30%)耐药性较高,对氨苄西林(9.5%)、环丙沙星(9.5%)、头孢噻呋(7.1%)和氧氟沙星(4.8%)比较敏感。上述研究结果为该地区奶牛乳房炎的防制提供可靠的理论依据。

大肠杆菌外膜蛋白A研究进展

大肠杆菌病血清型众多、易继发、地域性强、耐药性突出、暴发率高。鸡大肠杆菌病已严重影响中国养禽业,在实践中主要以预防为主。文章综述了大肠杆菌及其致病因素外膜蛋白的基本概况和外膜蛋白A的研究现状。

肠球菌毒力岛基因的检测

目的探索肠球菌中毒力岛基因的存在情况。方法使用PCR和杂交方法对155株肠球菌进行毒力岛相关基因检测。结果155株肠球菌中,88.39%携带至少一个毒力岛基因,各基因阳性率由高至低依次为hyd(81.94%),psaA(78.06%)、nuc(57.42%)、esp(53.55%)、cylB(52.90%)和gls24-like(38.06%);除esp基因,其他5个基因的阳性率均是粪肠球菌高于屎肠球菌,其中nuc、cylB、gls24-like三个基因的阳性率有统计学差异。粪肠球菌中临床分离株各基因的阳性率和所携带的基因数均高于健康人分离株。结论肠球菌普遍携带毒力岛相关基因,粪肠球菌各基因阳性率高于屎肠球菌,粪肠球菌中临床分离株所携带的毒力基因、毒力岛基因数目均明显高于健康人分离株。