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旨在获得产气荚膜梭菌β毒素（CPB）的重组突变体,并评价其毒力及免疫保护性。对已知的产气荚膜梭菌CPB编码基因进行优化设计,同时引入4个氨基酸突变位点,分别是第212位的精氨酸突变为谷氨酸,第268位的亮氨酸突变为甘氨酸,266位的酪氨酸和275位的色氨酸突变为丙氨酸。此外,在该基因5'端添加Th细胞表位（T）和鞭毛蛋白（flagellin）N末端的编码序列,经人工合成获得重组基因片段（GTFNCPBm4）。将GTFNCPBm4克隆至原核表达载体pET-30a（＋）中进行表达与纯化,获得重组蛋白rTFNCPBm4。利用Western blot方法检测rTFNCPBm4与C型产气荚膜梭菌毒素抗血清的反应性,并检测rTFNCPBm4对小鼠的毒力。随后,以rTFNCPBm4免疫家兔,按照《中华人民共和国兽药典》（2015年版）规定的方法检测家兔血清对C型产气荚膜梭菌毒素的中和抗体效价。结果表明,rTFNCPBm4主要以包涵体的形式表达且能与C型产气荚膜梭菌毒素抗血清反应。小鼠安全性试验显示,50 μg的rTFNCPBm4对小鼠仍无致死性;免疫rTFNCPBm4后,每毫升家兔二免抗血清可中和10~20个小鼠最小致死量（MLD）的C型产气荚膜梭菌毒素;1个家兔MLD的C型产气荚膜梭菌毒素攻毒后,对照组家兔4/4死亡,免疫组家兔得到了100%（4/4）的保护。以上结果说明,rTFNCPBm4在丧失毒力的同时保留了良好的免疫原性,从而为C型产气荚膜梭菌病基因工程疫苗的研制提供了重要的数据。 相似文献
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DU Jige ZHU Zhen XU Zhongqing LI Qianlin YAO Wensheng LI Qihong YIN Chunsheng YANG Liu FU Lizhi CHEN Xiaoyun LIU Ying XUE Qi 《畜牧兽医学报》1956,51(11):2794-2801
This study was conducted to obtain the Clostridium perfringens β toxin (CPB) derivative and to evaluate its virulence and immunoprotection. Based on the known sequence, four amino acid mutations, R212E, L268G, Y266A and W275A, were introduced into the gene of Clostridium perfringens CPB. Meanwhile, genes of Th cell and N-terminal of flagellin were added to 5' of the CPB gene, respectively. Then the gene GTFNCPBm4 was optimized and synthesized, and was subsequently cloned into the prokaryotic expression vector pET-30a (＋) for expression and purification to get the recombinant protein, rTFNCPBm4. Reactivity of rTFNCPBm4with antiserum of Clostridium perfringens type C crude toxins was detected by Western blot. Meanwhile, the toxicity of rTFNCPBm4 to mice was evaluated. According to the method prescribed in Chinese Veterinary Pharmacopoeia (2015), rabbits were immunized with rTFNCPBm4 to prepare antiserum and detect the neutralizing titer against Clostridium perfringens type C crude toxins. Results showed that rTFNCPBm4 was presented predominantly in an insoluble form (inclusion bodies), and it could react with the antiserum of Clostridium perfringens type C crude toxins. rTFNCPBm4 with an injection volume of 50 μg was still not fatal to mice. Sera from rabbits immunized with rTFNCPBm4can neutralize 10-20 mouse minimum lethal doses (MLD) of Clostridium perfringens type C crude toxins after twice immunization. Moreover, rabbits immunized with rTFNCPBm4 can fully resist 1 rabbit MLD of Clostridium perfringens type C crude toxins challenge, whereas all of the rabbits died (4/4) in the control groups. These data suggest that rTFNCPBm4 is a potential vaccine candidate for the subunit vaccine of Clostridium perfringens type C. 相似文献
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青海省互助县某羊场藏系绵羊患病死亡,伴有腹泻、神经症状,为快速确诊发病原因,及时防控和治疗,采集病羊样品5份,通过镜检、细菌分离培养、分子生物学试验及致病性试验进行病原鉴定分析。结果证明此次病原菌为羊致病性D型魏氏梭菌,毒素基因分析显示该菌同时含有α和ε两种毒素基因,动物致病性试验结果表明该菌对昆明系小鼠具有较强的致病性,并从试验致死的小鼠中分离到与藏羊病原相一致的细菌。三种基因的遗传进化树显示,该菌具有较强的多样性。研究确定了本次藏羊致死的主要病原为D型魏氏梭菌,结果可为该羊场梭菌病的治疗和预防提供科学依据。 相似文献
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circRNAs在病原菌感染宿主的肠道疾病发展中具有重要的调控作用。C型产气荚膜梭菌（C.perfringens type C）是引起仔猪腹泻及相关肠道炎症的主要细菌之一,对产业造成了严重的经济损失。然而,目前有关circRNAs如何调控仔猪C型产气荚膜梭菌性腹泻的全面且系统的研究未见报道。本研究通过RNA高通量测序研究分析了C型产气荚膜梭菌感染的7日龄仔猪回肠组织circRNAs的表达谱,筛选差异表达circRNAs,并进行差异表达基因GO和KEGG功能富集分析,利用miRanda等软件预测circRNA的microRNA靶点,构建circRNA-miRNA-mRNA的互作网络,并进行qPCR验证。结果显示,在C型产气荚膜梭菌感染的处理组（TI组）和对照组（CI组）中共鉴定出3 162个circRNAs,其中差异表达circRNAs有694个,上调表达circRNAs有404个,下调表达circRNAs有290个。功能富集分析结果表明,差异表达circRNAs的亲本基因主要富集在细胞周期、TGF-β信号通路、赖氨酸降解、Wnt信号通路、T细胞受体信号通路、MAPK信号通路等,调节仔猪对产气荚膜梭菌感染的抗性反应。此外,本研究构建了与C型产气荚膜梭菌感染致仔猪腹泻相关的circRNA-miRNA-mRNA互作网络,发现8 circRNAs-5 miRNAs-12 mRNAs组成的ceRNA网络与产气荚膜梭菌感染性疾病密切相关。本试验可为深入研究circRNA调控仔猪C型产气荚膜梭菌性腹泻疾病及猪抗腹泻病品系培育提供参考。 相似文献
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本研究自陕西省富平县某规模化关中奶山羊养殖场腹泻奶山羊肛门拭子中分离到5株产气荚膜梭菌,命名为21-D-1~21-D-5。毒素基因检测表明,其均为携带etx的D型产气荚膜梭菌,且21-D-5携带食源性致病毒素基因cpe。全基因组序列测定显示,5株D型产气荚膜梭菌基因组大小、GC含量和基因数量稳定;单核苷酸多态性（SNPs）分析显示,21-D-1和21-D-2以及21-D-3和21-D-4之间的SNPs差异极低（<25）,表明其大概率属于相同的产气荚膜梭菌菌株。分离的D型产气荚膜梭菌基因组中共检测到15种毒素基因,其中,毒素基因etx在分离的D型菌株中高度保守、基因环境相似,且在菌株21-D-5中毒素基因cpe位于etx下游。此外,包括噁唑烷酮类耐药基因optrA在内的9种耐药基因也在分离株中被检测到,并且erm（A）、optrA和fexA具有共同传播的可能性。本研究为国内首次对D型产气荚膜梭菌进行全基因组序列测定分析,结果对产气荚膜梭菌疾病的防治和基因组的进一步研究具有参考价值。 相似文献
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【目的】 查明引起福建省龙岩市某豪猪养殖场致豪猪腹泻死亡的病原菌及其特征,为该病的科学防控及合理用药提供参考依据。【方法】 分离腹泻死亡豪猪的病原,并结合形态特征、生理生化试验、16S rRNA基因扩增、种系发育分群鉴定分离菌株;通过毒力基因检测、动物致病性试验及药敏试验对分离菌株的致病性和耐药性进行研究。【结果】 从发病死亡豪猪肝脏组织中分离到1株大肠杆菌,命名为Fj/Porcupine2018,该分离菌株与22株不同来源的参考菌株16S rRNA序列之间的相似度为97.4%~99.8%,其中与禽源分离株（登录号：MN022583）和人源分离株（登录号：MW881377）的序列相似度高达99.8%;种系发育分群证实该分离菌株属于B1群。毒力基因检测结果显示,该分离菌株除检出肠侵袭型大肠杆菌毒力基因EinV外,还检出papC、iroC、Afa、luxs、stx2f及ompA 6种毒力相关基因。动物致病性试验显示,该分离菌株对小鼠具有较强的致病性,小鼠在攻毒后31 h内全部死亡,且肝脏、脾脏、肺脏及肠道等器官组织均有明显的病理损伤;在对常见抗菌药物的药敏试验中,该分离菌株对大环内酯类、四环素类、喹诺酮类、磺胺类、头孢类、氨基糖苷类、青霉素类7类11种药物表现出不同程度的耐药,耐药率为25%~100%,仅对头孢曲松和头孢西叮2种药物表现敏感。【结论】 本研究分离获得了1株腹泻死亡豪猪的病原菌大肠杆菌,通过一系列生物学特性研究证实该分离菌为1株具有较强致病力且呈现多重耐药性的B1群肠侵袭型大肠杆菌,为豪猪等野生动物大肠杆菌病的防控提供了重要的参考依据。 相似文献
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PENG Xiao-bing TIAN Dong-qing LI Xu-ni PENG Guo-rui WANG Meng JIANG Yu-wen 《中国畜牧兽医》2015,42(8):1950-1955
One pair of primers had been designed and synthesized based on the α-toxin gene of Clostridium perfringens.The complete α-toxin gene fragment was amplified by polymerase chain reaction (PCR), and then was cloned into pGEM-T Easy vector to construct pGEM-T-α.Digested with EcoRⅠ and Hind Ⅲ, a fragment of 1125 bp was cloned into the expression plasmid vector pET-28a(+).The recombinant plasmid was transformed into the BL21(DE3)plys and induced by 1.0 mmol/L IPTG at 37 ℃.The expression product was found to be 46.1 ku as expected one identified by SDS-PAGE, and confirmed by Western blotting with Clostridium perfringens type A antisera, indicating similar reactivity with native α-toxin.Recombinant α-toxin protein was simultaneously found in culture supernatant, postsonic supertanant and inclusion bodies, most protein was expressed in inclusion bodies, which indicated recombinant α-toxin protein was expressed in the extracellular, periplasm and cytoplasm.Recombinant α-toxin protein in postsonic supertanant could not make mice die, indicating its non-toxicity.Toxin-antitoxin neutralization test showed that antisera of recombinant α-toxin protein were specific to α-toxin.Upon immunization of rabbit with the recombinant α-toxin protein, antisera with high antibody titer neutralizing 100 MLD toxin per 1 mL were prepared. 相似文献
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本试验通过设计并合成1对引物,PCR扩增B型产气荚膜梭菌C58-2株α毒素完整成熟肽序列,并将其插入到pGEM-T Easy载体中,构建克隆载体pGEM-T-α。对克隆载体pGEM-T-α进行EcoRⅠ和Hind Ⅲ的双酶切,将得到的1125 bp片段以正确的阅读框架定向克隆于pET-28a(+)中,然后将重组质粒转化大肠杆菌BL21(DE3)plys宿主菌中,37 ℃、1.0 mmol/L IPTG诱导该片段获得良好表达。经SDS-PAGE分析,其表达的蛋白约为46.1 ku,与预期大小一致。Western blotting结果显示,该重组α毒素蛋白可被A型产气荚膜梭菌定型血清识别,表明该重组α毒素蛋白具备与天然毒素相似的反应原性。重组α毒素蛋白在菌液上清、超声波裂解上清和超声波裂解沉淀中均有分布,且以包涵体表达为主,表明重组α毒素蛋白可同时在胞外、周质和胞浆表达。小鼠毒力试验结果表明,重组α毒素蛋白不具有毒性。毒素—抗毒素中和试验结果表明,该抗血清具有α毒素特异性。以重组α毒素蛋白作为抗原免疫家兔制备血清,效价测定结果表明每1 mL重组α毒素蛋白抗血清可以中和100 MLD的A型毒素。 相似文献
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为探究羊源尸毒梭菌的生物学基本特性，进行生理生化分析、16S rDNA基因扩增、动物回感试验、耐药表型和耐药基因检测等试验。结果显示，菌株LJH-1为革兰阳性菌。PCR扩增获得长度为1 023 bp的片段。LJH-1与尸毒梭菌C4菌株聚类，从而判定LJH-1为尸毒梭菌。试验组小鼠全部死亡。小鼠肝中央静脉充盈大量红细胞，炎性细胞浸润，肾间质血管充血，肠黏膜上皮细胞脱落。LJH-1对头孢噻肟、氨苄西林等敏感，对头孢拉定、阿莫西林等耐药，并检出ant（3″）-Ia、aac（3）-IIa、aph（3'）-IIa、Sul2、Sul3和TEM耐药基因。这为该细菌性疾病的检测和防治提供了科学资料。 相似文献
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湖北某奶牛场牛群爆发体温升高、呼吸困难、流涎及颈胸皮下气肿等症状的疾病,部分发病牛衰竭死亡,为确诊牛场牛群发病原因并提出防控方案,本试验采集死亡牛的心脏、肝脏、肺脏及气管组织进行病原菌的分离纯化及PCR鉴定,并对鉴定的病原菌进行生化特性鉴定、致病性试验和药物敏感性分析;同时提取患牛血清RNA,开展牛流行热病毒的RT-PCR鉴定。结果显示,病料在类胸膜肺炎固体培养基上不生长,生化特性鉴定显示能形成靛基质、不发酵肝糖和肌醇;牛流行热病毒RT-PCR扩增阴性;所分离的病原菌经16S rRNA及牛A型多杀性巴氏杆菌特异性引物PCR扩增阳性;致病性试验显示该病原可致死小鼠,且能从死亡小鼠体内分离到感染菌;药敏试验结果显示该病菌对头孢哌酮、左氧氟沙星敏感,其他20种临床常见药物表现耐药。综上所述,该牛场患病牛确诊为牛A型多杀性巴氏杆菌感染,建议根据药敏试验结果选择敏感药物,对患病牛进行隔离治疗,疑似患病牛隔离观察,同时加强通风,及时清理污物并消毒,改善饲养管理,避免拥挤、寒冷及长途运输等应激因素。 相似文献
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XIE Qian-ru TONG Sheng-tao SHAO Yong-xuan JIANG Peng PENG Qing-jie CHEN Ying-yu HU Chang-min GUO Ai-zhen 《中国畜牧兽医》2016,43(3):837-843
The assay was aimed to clarify the reasons why dairy cattle became ill with the symptoms including fever,breathing difficulty,salivation and subcutaneous emphysema at neck or chest in a dairy cow farm at Hubei province,even part of dairy cows were dead for exhaustion.The disease was diagnosed by laboratory methods,and treatment scheme was proposed.The samples from heart,liver,lung or trachea tissues were collected,then M.bovis and pathogenic bacteria were isolated,respectively.Biochemical characteristics,pathogenicity test and drug sensitivity analysis were performed on the isolated pathogenic bacteria.RNA was extracted from bovine serum,then bovine ephemeral fever virus was identified by RT-PCR.The results showed that nothing grew in PPLO medium,and the isolated bacteria could form indole,but did not ferment glycogen and inositol in the biochemical tests.The isolated pathogenic bacteria was conformed as serotype A P.multocida by PCR while bovine ephemeral fever virus of RT-PCR result was negative.The pathogen could kill mice and the pathogenic bacteria could be isolated from heart blood of the dead mice in pathogenicity test.The isolated bacteria was sensitive to cefoperazone or levofloxacin in drug sensitivity analysis.In conclusion,the disease was diagnosed as bovine serotype A P.multocida infection.Some treatments including choosing sensitive antibiotic drugs based on the drug sensitivity tests,holding sick cattle under quarantine treatment and isolating suspected cattle should be taken.Moreover,some complex measures such as keeping the air flowing,cleaning up in time,improving the management,and preventing stress from congestion,cold and long distance transport were very important to prevent and control serotype A P.multocida infection in dairy cows. 相似文献
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旨在探索产气荚膜梭菌外毒素造成机体炎性损伤及免疫调控紊乱的毒性机制,为产气荚膜梭菌病的致病机理研究提供理论基础。将C型产气荚膜梭菌强毒株C59-2培养上清腹腔注射BALB/c小鼠,采集小肠样本进行转录组测序,筛选差异表达基因,并对其进行GO功能注释和KEGG通路富集分析。结果显示,共获得40.99 Gb有效碱基,筛选后共得到795个差异表达基因,其中,229个基因表达上调,566个基因表达下调,对随机选取的10个基因进行q-PCR验证,其相对表达量与转录表达谱一致。GO功能注释主要涉及G蛋白偶联核苷酸受体活性和G蛋白偶联嘌呤核苷酸受体活性等。KEGG通路富集分析发现,主要富集在TNF信号通路、IL-17信号通路、p53信号通路、FOXO信号通路、Toll样受体信号通路、NF-κB信号通路等。产气荚膜梭菌外泌毒素侵入机体,会激活TNF等炎性信号通路,进而造成肠道发生炎性损伤甚至坏死。 相似文献
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为确诊广西中医药大学瑶山亚种树鼩人工驯化养殖中心的瑶山亚种树鼩发病死亡原因,并调查分离菌株的致病性与耐药情况,试验通过平板划线分离获得病原菌,进一步对分离菌进行形态观察、培养特性、生化试验及16S rRNA序列分析,纯化获得一株致病性嗜水性气单胞菌;利用昆明小鼠的致病性试验测定了该分离菌株的半数致死量（LD50）,利用药敏纸片法分析该分离株对常用药物的敏感性,并应用PCR方法进行菌株耐药基因的检测。结果显示,从病死瑶山亚种树鼩分离到一株嗜水性气单胞菌,镜检显示为革兰氏阴性菌,形态呈短杆状。该菌16S rRNA序列与日本淡水湖源嗜水性气单胞菌SWCY-3.27株同源性高达100%,遗传进化关系最近。该分离菌对成年昆明小鼠的LD50为1×107 CFU,毒力高于模式菌株ATCC 7966,近似于中国流行株NJ-35和J-1等,致病性试验鉴定该菌为强毒力菌株。生化鉴定七叶苷、阿拉伯糖、氧化酶呈阳性,各种生化鉴定符合嗜水气单胞菌生化特性。药敏检测显示,该菌株对米诺环素、链霉素、妥布霉素等9种药物敏感,对四环素、红霉素、青霉素等10种药物耐药。以PCR扩增基因方法对分离菌进行6类12种耐药基因的检测,发现分离菌存在氨基糖苷类（Aph-（3）-lia）和β-内酰胺类（mecA）两类抗生素的耐药基因,与药敏试验结果基本吻合。本研究结果表明,引起此次树鼩死亡的病原菌为嗜水性气单胞菌,可用高敏药物进行针对性治疗,为防治嗜水性气单胞菌感染导致的树鼩疾病提供参考依据。 相似文献
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【目的】 查明江苏某鹅场鹅发病及死亡原因。【方法】 剖检病死鹅，运用细菌分离纯化、染色观察、生化试验、基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS）鉴定、16S rDNA测定方法进行病原菌分离鉴定，通过药敏试验和小鼠致病性试验探究分离菌株的特性。【结果】 从患病鹅肝脏分离到1株革兰氏阴性短杆状细菌；生化试验结果显示，此菌株可发酵葡萄糖、麦芽糖、枸橼酸盐、尿素；MALDI-TOF MS鉴定结果显示，此菌株为类志贺邻单胞菌；16S rDNA序列对比分析发现，分离菌与类志贺邻单胞菌相似性最高，达98%以上；药敏试验结果显示，分离菌对左氧氟沙星、美罗培南、头孢西丁、庆大霉素等10种抗菌药敏感，对四环素、头孢吡肟、头孢他啶、头孢唑林表现为中介，对阿奇霉素、复方新诺明、氨苄西林等6种药物表现为耐药，是典型的多重耐药菌；小鼠致病性试验结果显示，分离菌对小鼠的半数致死量为5.0×106.5 CFU。【结论】 本试验首次报道了从鹅体内分离到致病性类志贺邻单胞菌，通过药敏试验筛选了左氧氟沙星、美罗培南、头孢西丁等有效的临床常用抗菌药，分离株对小鼠致病性较强，提示其带来的潜在风险不可忽视。 相似文献
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旨在确定甘肃省天水市某林麝养殖场致死林麝的病原菌,并开展其致病性和耐药性研究及全基因组序列分析。采集病死林麝肺,通过细菌的分离纯化、生化鉴定和16S rRNA基因序列分析,对分离菌进行鉴定;随后对其致病性和药物敏感性进行分析,并在分离菌全基因组测序的基础上,对分离菌全基因组序列进行组装和注释,对毒力基因toxA和exoT进行遗传进化分析。结果表明,从病死林麝肺中分离到一株绿脓杆菌,命名为TS2019。致病性试验测得分离菌对小鼠的LD50为2.82×107CFU·mL-1;药敏试验结果表明,TS2019具有多重耐药性,但对环丙沙星、洛美沙星等药物敏感。基因组测序表明,TS2019基因组全长为6 308 327 bp,编码5 929个基因,其中有1 035个编码产物参与新陈代谢途径;全基因组中有毒力因子编码基因875个,产物有黏附蛋白、调控因子、毒性蛋白等;有四环素类、氨基糖苷类等抗生素耐药相关基因5 288个。遗传进化分析表明,TS2019毒力基因toxA、exoT与GenBank中绿脓杆菌众多菌株相应基因序列相似性均高于99%,其中eoxT基因与中国杭州人源分离株P33的遗传关系最近,但处于独立分支。本研究从病死林麝肺分离鉴定到一株绿脓杆菌,并证实该菌有较强致病性和多重耐药性,其毒力基因toxA和exoT与GenBank中绿脓杆菌相应基因序列具有高度相似性。研究结果为林麝绿脓杆菌感染相关疾病的防治提供了理论支持,也为绿脓杆菌致病机制和耐药机制的深入研究奠定了基础。 相似文献
17.
We evaluated the ability of hen-egg antibodies (HEA) to reduce intestinal colonization by Clostridium perfringens in broiler chickens. Antibodies against C. perfringens or cholera toxin (negative control) were obtained from the eggs of laying hens hyperimmunized using a C. perfringens bacterin or cholera toxin. Eggs were collected, pooled, and egg antibodies were concentrated by polyethylene-glycol precipitation. An initial experiment was conducted to determine the in vivo activity of the administered antibody along the length of the intestine. Thereafter, two feeding trials were performed to assess the efficacy of feed amended with the egg antibodies in reducing the level of colonization of C. perfringens in challenged birds. Antibody activity declined from proximal to distal regions of the intestine but remained detectable in the cecum. In the first experiment there was no significant reduction in the number of C. perfringens in the birds fed the diet amended with the anti-C. perfringens egg antibody, compared to the birds that received the anti-cholera toxin egg antibody (n = 10), at any of the sampling times. In the second experiment there was a significant decrease in C. perfringens intestinal populations 72 h after treatment (n = 15) as assessed by culture-based enumeration, but there was no decrease as measured by quantitative PCR based on the C. perfringens phospholipase C gene. Intestinal-lesion scores were higher in the birds that received the anti-C. perfringens HEA. Our work suggests that administration of HEA did not reduce the level of C. perfringens intestinal colonization and conversely might exacerbate necrotic enteritis. 相似文献
18.
本研究探索了丁酸梭菌分离株的益生特性，旨在为其在仔猪日粮中的应用提供理论依据。利用常规方法分离丁酸梭菌并进行纯培养，经生化检测和16S rRNA基因测序，对分离菌株进行鉴定；采用活菌计数法和牛津杯法研究分离株培养上清对3种致病菌的抑制作用、分离株黏附猪小肠上皮细胞（IPEC-J2）的特性及其对致病菌黏附细胞的抑制作用；采用细胞计数法研究分离株对IPEC-J2生长的影响；采用ELISA检测分离株处理细胞后培养上清液中细胞因子水平。结果表明，本研究成功分离到一株丁酸梭菌。与对照组相比，丁酸梭菌培养上清对3种致病菌生长抑制效果均显著（P<0.05）；丁酸梭菌可黏附于IPEC-J2，并且黏附效果最佳的感染复数（MOI）为50，最适处理时长为3 h；丁酸梭菌对3种致病菌黏附IPEC-J2均具有显著抑制作用（P<0.05）；丁酸梭菌MOI为1、10和50时细胞生长正常、形态完好，MOI为100时IPEC-J2生长受到显著抑制，同时出现部分细胞死亡；MOI为1时细胞因子水平无差异，MOI为10、50和100时细胞因子水平均显著增高（P<0.05）。综上所述，本研究分离的一株丁酸梭菌具有较好的益生特性，为其在生产中的应用提供了理论依据。 相似文献
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20.
Eugenia Bezirtzoglou Charles Romond 《Comparative immunology, microbiology and infectious diseases》1990,13(4):217-221
Anaerobic flora plays a key role in preventing intestinal colonization with potential pathogens. Nowadays, the mechanisms involved in the colonization resistance provided by the anaerobic microflora are to be clarified. Numerous factors seem to intervene in the regulation of the intestinal flora.
The purpose of the present study was to correlate the presence or relative absence of Clostridium sp. and Bacteroides with the colonization by C. perfringens, which is involved in lethal infections in an immunologically compromised host.
The intestinal bacterial colonization of 20 newborns delivered by cesarian section was assessed sequentially over the first 14 days of life. C. perifringens is a strongly reducing microorganism and undoubtedly causes a decrease in the oxidoreduction potential of the newborn feces favouring the subsequent colonization by other putrefactive bacteria. C. perfringens seems to be the precursor for installation of putrefactive bacteria, as Bacteroides and other Clostridium sp. 相似文献