幽门螺杆菌的球形变异及其特征和意义

幽门螺杆菌 (H elicobacter pylori,简称 Hp)在不利于其生长繁殖的环境中易发生球形变异 ,如延长培养时间、进入无营养成分的水中、改变环境氧浓度、接触抗生素等均可使Hp转变为球形菌。球形 Hp在体外常规培养条件下不能繁殖 ,但具有活力 ,具有低代谢活性 ,在水中可存活较长时间 ,进入动物体内可致动物模型胃炎 ,推测球形 Hp在体内适宜的环境下可回复转变为螺旋菌 ,从而导致胃炎等消化性疾病的发生 ,因而认为球形菌可能在 Hp感染的传播中起重要作用。临床化学治疗剂的应用 ,使 Hp在化学治疗压力作用下转化为球形 ,并潜伏于机体内 ,成为日…     

C57BL/6小鼠幽门螺杆菌感染动物模型的建立

目的：建立幽门螺杆菌（Helicobacter pylori,Hp）小鼠感染模型。方法：建立Hp经口感染SPF级小鼠的动物模型,取小鼠胃粘膜组织,利用PCR技术、尿素酶实验、细菌培养等方法检测接种小鼠,对结果进行判定。结果：Hp可感染C57BL／6小鼠并在小鼠胃部定植。     

幽门螺杆菌致人胃病的小鼠模型研究

目的建立幽门螺杆菌致人胃病的小鼠模型.方法用Ⅰ型幽门螺杆菌(Helicobacter pylori,Hp)对三种SPF级小鼠(BALB/c、NIH、 KM)采用循环滴喂攻击等方法处理,从菌体定值、抗体水平、病理变化三个方面分14、39、69、105 d进行测试.结果 Hp可持续定植于各供试小鼠胃粘膜上,并刺激Hp抗体(IgG)维持一较高水平,Hp在小鼠上主要引起以胃粘膜变性坏死为主,伴有淋巴细胞浸润的炎症反应,这为Hp致人胃病的症状相似.结论为Hp的致病机理,治疗药物和疫苗研究提供了良好的小动物模型.     

介绍一种简易的幽门螺杆菌分离培养法

自 198 3年 Warren等首先从人胃粘膜分离培养出幽门螺杆菌 (Helicobacter pylori,Hp)以来 ,Hp与胃炎、消化性溃疡以及胃癌之间的关系也越来越受到人们重视。从胃粘膜分离 Hp是研究 Hp最基本的方法 ,同时又是诊断 Hp感染、评价新的诊断方法和疗效、体外筛选抗菌药物等的金标准。虽然 ,各国学者已相继研究出各种培养 Hp的含血和不含血的培养基 ,但其培养环境均采用抽气换气的微氧混合气体 ,而使得 Hp的培养不易在基层推广。本文进一步改进 Hp培养基成分 ,采用简便的蜡烛培养法获得了较好的临床分离效果。材料和方法1.培养基配制　按说明称…     

幽门螺旋杆菌ATCC 43504感染BALB/c小鼠动物胃炎模型的建立及分析

利用幽门螺旋杆菌标准菌株建立稳定可靠的幽门螺旋杆菌(Helicobacter pylori,Hp)感染小鼠胃炎模型对Hp疫苗研制、Hp致病机制的研究及抗Hp药物的筛选具有重要意义。通过灌胃国际标准菌株幽门螺旋杆菌Hp ATCC 43504,构建了BALB/c小鼠动物胃炎模型。利用小鼠胃部Hp尿素酶活性检测、Hp的定量培养、PCR检测、组织病理学等多种方法鉴定BALB/c小鼠动物胃炎模型。通过Hp诊断试剂盒检测,造模组小鼠的胃组织能使Hp尿素酶试剂变色,呈现玫瑰红色,而健康小鼠的胃组织不能使Hp尿素酶试剂变色,依旧呈现黄色;通过小鼠胃组织匀浆液培养Hp,造模组小鼠的胃组织匀浆液均可在BHI血平板长出Hp菌落,而对照组小鼠的胃组织匀浆液不能培养出Hp菌落;利用PCR对造模组和对照组BALB/c小鼠的胃组织进行Hp检测,造模组小鼠胃组织可扩增出150 bp的DNA产物,而对照组小鼠胃组织无扩增产物;通过HE染色法观察小鼠胃部病理变化和炎症情况,与健康BALB/c小鼠比较,造模组小鼠胃粘膜和粘膜下层有大量白细胞浸润,胃部炎症明显。利用国际标准菌株Hp ATCC 43504菌株成功构建了BALB/c小鼠胃炎模型,为评价防治Hp感染药物的效果奠定了实验基础。     

蓝藻球形体的分离,培养及再生

在高渗溶液中,用0.05%溶菌酶和2—5mmol·1~(-1)EDTA 处理蓝藻柱孢鱼腥藻、多变鱼腥藻和组囊藻细胞。5—8h 后,70—90%的细胞转为对渗透压敏感的球形体(Spheroplast),又称原生质球。研究了藻的不同培养条件对球形体形成率的影响。测定了 EDTA 处理藻纽胞后外膜脂多糖的释放量。在高渗溶液中,藻细胞和经酶处理获得的球形体的光合放氧活性明显下降,固氮种类的固氮活性失去。饲养层法、固体混合法和含有0.5mg·1~(-1)BA 的液体悬滴培养的柱孢鱼腥藻的球形体,9天后出现再生藻落;在固体混合法培养中获得了组囊藻球形体的再生藻落。在第4天的悬滴培养物中,可以看到球形体发生第一次细胞分裂。再生藻细胞和酶处理物中残留细胞的抗溶菌酶特性有差异。     

利用雌激素构建小鼠淋病奈瑟菌感染模型

目的探讨用雌激素构建淋病奈瑟菌感染小鼠模型的方法。方法淋病奈瑟菌WHO-A接种经皮下注射苯甲酸雌二醇和真皮下埋植尼尔雌醇片（雌三醇）预处理的雌性ICR小鼠,小鼠阴道拭子接种T-M选择培养基培养分离淋病奈瑟菌,取小鼠阴道分泌物涂片染色观察淋病奈瑟菌感染情况,比较两种雌激素对小鼠淋病奈瑟菌感染的差异。结果与对照组相比,苯甲酸雌二醇小鼠体内淋病奈瑟菌有短时间的定植,而尼尔雌醇组与对照组无差异。结论雌激素（尤其是雌二醇）有利于淋病奈瑟菌在小鼠阴道内的定植。     

幽门螺杆菌(SS1)感染及其胃炎的小鼠模型

目的 :建立感染幽门螺杆菌 (Helicobacterpylori,H pylori)SS1株BALB/c小鼠感染模型 ,研究H pylori胃内定植及胃黏膜病理变化。 方法 :BALB/c小鼠胃内分别接种体外培养的H pyloriSS1株 (实验组 )或PBS(对照组 ) ,组织学方法评价H pylori定植及胃黏膜病理变化。结果 :所有对照组小鼠胃组织未见H pylori定植 ,胃组织也未见明显的炎症反应 ;而所有实验组小鼠在感染H pylori 12周后 ,胃黏膜表面的黏液层及胃小凹顶端可见大量H pylori,胃体及胃窦交界处、胃体及胃底交界处最多 ;胃组织可见到不同程度的炎性反应 ,感染H pylori 2 4周后 ,胃组织炎性反应加重。结论 :用胃内接种方法建立了小鼠H pylori感染及其相关性胃炎的模型。     

幽门螺杆菌感染Beagle犬动物模型的建立

建立幽门螺杆菌感染Beagle犬动物模型 ,为进行临床治疗及预防Hp感染研究提供实验基础。对Beagle犬进行一定程序的预处理后 ,口服灌喂Hp液体培养悬液。在以后不同时间段通过胃镜观察、组织培养、酶试验、粪便全菌ELISA检测、14 C 尿素呼气试验、PCR以及抗体检测等方法对Hp感染Beagle犬情况进行检测 ,观察细菌所引起的病理改变及定植时间。Beagle犬感染Hp数月后胃镜观察动物大体标本仍有病理改变 ;组织培养、酶实验、全菌检测及其它检测试验均阳性。Hp可以长时间定植于犬胃粘膜上并引起相应的病理改变 ,Beagle犬可以作为Hp感染动物模…     

充气和搅动对球形棕囊藻生长及囊体形成的影响

球形棕囊藻生活史中包含游离单细胞和球形囊体两种生活形态,但是实验室中培养的球形棕囊藻经常无法形成囊体。研究通过向培养基中泵入过滤空气,以及给培养基提供不同程度的搅动,研究了充气和搅动对球形棕囊藻生长及囊体形成的影响。充气和搅动均显著提高了囊体的数量,并且提高了囊体内细胞的生长速率。但是充气对于囊体直径及囊体内细胞密度并无显著影响。搅动则明显的提高了囊体直径和囊体内细胞数量。然而,尽管充气以及搅动有利于球形棕囊藻囊体的形成,但是培养的囊体直径依然小于自然海区中囊体的大小。     

两株乳酸菌在小鼠体内对幽门螺杆菌抑制作用的初探

成功地建立了小鼠幽门螺杆菌感染模型,并对两株在体外对幽门螺杆菌有显著抑制作用的乳酸菌,进行了体内预防与治疗作用的初步验证。通过尿素酶反应、细菌培养、病理组织切片检验三种指标测试,证明J16发酵乳能够有效预防幽门螺杆菌感染;小鼠胃中乳酸菌数量和幽门螺杆菌数量相反。     

Helicobacter pylori: A Fickle Germ

The morphologic changes from bacillary to coccoid forms of Helicobacter pylori were studied. These form changes were analyzed by bacterial growth in Brucella broth plus 2% fetal calf serum. The coccoid forms were observed at five days of incubation and a rapid decrease of CFU/ml was recorded. At two weeks of microaerophilic incubation, all coccoid forms observed were not culturable in vitro. The coccoid morphology was observed earlier when the culture of H. pylori was incubated in aerobic conditions and with subinhibitory concentrations of omeprazole and roxithromycin. To evaluate the possibility of resistance of coccal forms, before plating, the cultures were heated to 80 C for 10 min and sonicated. In the absence of these treatments the cultures did not show growth in vitro. The proteic patterns of the same strains of two different morphologies were studied revealing significant differences.     

Micronuclei in mucose cells and colonization of human stomach epithelium with coccoid forms of Helicobacter pylori

International Agency for Research on Cancer recognized as sufficient the evidence of Helicobacter pylori (HP) infection carcinogenicity and placed it into the 1 st group of carcinogens. Micronucleus level in gastric epithelial cells of antral stomach region of patients with chronic non-atrophy gastritis (n = 62) was studied. 40 patients of 62 had HP-associated gastritis. The HP-bacterium exists in a spiral and coccoid form. Both morphological forms were examined using immunocytochemistry. Significantly increased micronucleus number was observed in the cells of HP-infected patients compared with non-infected person (P < 0.05). The frequency of stomach epithelium cells with micronuclei was enhanced considerably in the patients infected with the coccoid HP form. Therefore the patients with HP-associated chronic gastritis caused by the coccoid form with high degree of colonization must be considered as a group of enhanced risk of gastric carcinogenesis.     

Formation of nonculturable Mycobacterium tuberculosis and their regeneration

Nonculturable cells were found to occur in populations of Mycobacterium tuberculosis cells during the long post-stationary phase. These cells were small (0.6-0.8 micron) ovoid and coccoid forms with intact cell walls and negligible respiratory activity, which allows them to be regarded as dormant cells. Nonculturable cells were characterized by low viability after plating onto solid medium; a minor part of the population of these cells could be cultivated in liquid medium. Cell-free culture liquid of an exponential-phase Mycobacterium tuberculosis culture or the bacterial growth factor Rpf exerted a resuscitating effect, increasing substantially the growth capacity of the nonculturable cells in liquid medium. During resuscitation of nonculturable cells, a transition from ovoid to rodlike cell shape occurred. At early stages of resuscitation, ovoid cells formed small aggregates. The recovery of culturability was associated with the formation of rod-shaped cells in the culture. The data obtained demonstrate the in vitro formation of dormant cells of Mycobacterium tuberculosis, which do not grow on solid media but can be resuscitated in liquid medium under the effect of substance(s) secreted by actively growing cells.     

SEASONALITY OF MICROBIAL FOULING ON ASCOPHYLLUM NODOSUM (L.) LEJOL., FUCUS VESICULOSUS L., POLYSIPHONIA LANOSA (L.) TANDY AND CHONDRUS CRISPUS STACKH1

The nature and seasonal extent of microbial fouling on Ascophyllum nodosum (L.) LeJol., Fucus vesiculosus L., Polysiphonia lanosa (L.) Tandy and Chondrus crispus Stackh. were observed by scanning electron microscopy. Bacterial filaments and smaller rod and coccoid forms dominated the fouling communities on all species, with pennate diatoms constituting a minor component in contrast to results with plastic substrates on which pennate diatoms dominated and preceded bacterial colonization. The total percent microbial coverage on the surfaces of all four seaweed species was determined by monthly stereological analyses of representative composite micrographs. These showed a simultaneous decline between April and May which could represent the die-off of the cold water bacterial flora when water temperature increased past the threshold for obligate psychrophiles. Microbial colonization patterns were directly correlated (P = 0.005) with maximum coverage in April and November–December and reduced levels from May to October. Significant inverse (P < 0.041) correlations between total percent coverage and water temperature indicate distinct seasonal cycles, however, the patterns of dominance by filamentous bacteria and rod and coccoid forms were markedly different. Total coverage patterns of both rhodophytes showed no apparent seasonal cycle and were not related to water temperature. Rod and coccoid bacteria were apparently suppressed year round on P. lanosa relative to the other species. These interspecific differences in seasonal fouling patterns are discussed in light of possible modes of regulation, especially algal antibiosis.     

Digital image analysis of growth and starvation responses of a surface-colonizing Acinetobacter sp.

Surface growth of an Acinetobacter sp. cultivated under several nutrient regimens was examined by using continuous-flow slide culture, phase-contrast microscopy, scanning confocal laser microscopy, and computer image analysis. Irrigation of attached coccoid stationary-phase Acinetobacter sp. cells with high-nutrient medium resulted in a transition from coccoid to bacillar morphology. Digital image analysis revealed that this transition was biphasic. During phase I, both the length and the width of cells increased. In contrast, cell width remained constant during phase II, while both cell length and cell area increased at a rate greater than in phase I. Cells were capable of growth and division without morphological transition when irrigated with a low-nutrient medium. Rod-shaped cells reverted to cocci by reduction-division when irrigated with starvation medium. This resulted in conservation of cell area (biomass) with an increase in cell number. In addition, the changes in cell morphology were accompanied by changes in the stability of cell attachment. During phase I, coccoid cells remained firmly attached. Following transition in high-nutrient medium, bacillar cells displayed detachment, transient attachment, and drifting behaviors, resulting in a spreading colonization pattern. In contrast, cells irrigated with a low-nutrient medium remained firmly attached to the surface and eventually formed tightly packed microcolonies. It is hypothesized that the coccoid and bacillar Acinetobacter sp. morphotypes and associated behavior represent specialized physiological adaptations for attachment and colonization in low-nutrient systems (coccoid morphotype) or dispersion under high-nutrient conditions (bacillar morphotype).     

Formation of Nonculturable Cells of Mycobacterium tuberculosis and Their Resuscitation

Nonculturable cells were found to occur in populations of Mycobacterium tuberculosis cells during the long poststationary phase. These cells were small (0.6–0.8 m) ovoid and coccoid forms with intact cell walls and negligible respiratory activity, which allows them to be regarded as dormant cells. Nonculturable cells were characterized by low viability after plating onto solid medium; a minor part of the population of these cells could be cultivated in liquid medium. Cell-free culture liquid of an exponential-phase Mycobacterium tuberculosisculture or the bacterial growth factor Rpf exerted a resuscitating effect, increasing substantially the growth capacity of the nonculturable cells in liquid medium. During resuscitation of nonculturable cells, a transition from ovoid to rodlike cell shape occurred. At early stages of resuscitation, ovoid cells formed small aggregates. The recovery of culturability was associated with the formation of rod-shaped cells in the culture. The data obtained demonstrate the in vitro formation of dormant cells of Mycobacterium tuberculosis, which do not grow on solid media but can be resuscitated in liquid medium under the effect of substance(s) secreted by actively growing cells.     

Lotharella reticulosa sp. nov.: a highly reticulated network forming chlorarachniophyte from the Mediterranean Sea

A new chlorarachniophyte Lotharella reticulosa sp. nov. is described from a culture isolated from the Mediterranean Sea. This strain is maintained as strain RCC375 at the Roscoff Culture Collection, France. This species presents a multiphasic life cycle: vegetative cells of this species were observed to be coccoid, but amoeboid cells with filopodia and globular suspended cells were also present in the life cycle, both of which were not dominant phases. Flagellate cells were also observed but remained very rare in culture. The vegetative cells were 9-16 μm in diameter and highly vacuolated, containing several green chloroplasts with a projecting pyrenoid, mitochondria, and a nucleus. The chloroplast was surrounded by four membranes possessing a nucleomorph in the periplastidial compartment near the pyrenoid base. According to ultrastructural observations of the pyrenoid and nucleomorph, the present species belongs to the genus Lotharella in the phylum Chlorarachniophyta. This taxonomic placement is consistent with the molecular phylogenetic trees of the 18S rRNA gene and ITS sequences. This species showed a unique colonization pattern. Clusters of cells extended cytoplasmic strands radially. Then, amoeboid cells being born proximately moved distally along the cytoplasmic strand like on a "railway track". Subsequently the amoeboid cell became coccoid near the strand. In this way, daughter cells were dispersed evenly on the substratum. We also observed that the present species regularly formed a structure of filopodial nodes in mid-stage and later-stage cultures, which is a novel phenotype in chlorarachniophytes. The unique colonization pattern and other unique features demonstrate that RCC375 is a new chlorarachniophyte belonging to genus Lotharella, which we describe as Lotharella reticulosa sp. nov.     

Improved Microscopy of Mycoplasma In Vitro

Techniques were developed for continuous microscopic observation of mycoplasmata growing in vitro in Rose chambers by using an inverted phase microscope. The methods permitted direct microscopic observation of undisturbed growth of mycoplasmata in liquid medium. Inocula of mycoplasmata were passed through 0.22-mum filters before culture to provide a suspension of discrete particles. The sequential growth of Mycoplasma pneumoniae was followed from points or single straight lines, with development of branching, a net-like confluence of filaments, large bodies occurring in the center of developing colonies, and finally coccoid forms. Other species of Mycoplasma which did not attach as readily to glass could be observed also by inverted phase microscopy. Umbonation of colonies (a "friedegg" appearance) occurred in liquid medium, indicating that this appearance was not due simply to interaction with the agar medium, but may reflect a qualitative difference in growth patterns between center and periphery. For growth on solid medium, direct observation of colonies in uncovered plates of agar medium was made by using inverted phase microscopy. This was found helpful in detecting small colonies and in observing relationships between colonies.     

Culturability of Mycobacterium tuberculosis cells isolated from murine macrophages: a bacterial growth factor promotes recovery

Very little is known about the culturability and viability of mycobacteria following their phagocytosis by macrophages. We therefore studied populations of the avirulent 'Academia' strain of Mycobacterium tuberculosis isolated from murine peritoneal macrophage lysates several days post-infection in vivo. The resulting bacterial suspensions contained a range of morphological types including rods, ovoid forms and coccoid forms. Bacterial viability measured using the MPN method (dilution to extinction in liquid medium) was often much higher than that measured by CFU (plating on solid medium). Viability in the MPN assay was further enhanced when the Micrococcus luteus protein, Rpf, was incorporated into the liquid culture medium at picomolar concentrations. Rpf is an example of a family of autocrine growth factors found throughout the high G+C cohort of Gram-positive bacteria including M. tuberculosis. M. tuberculosis cells obtained from macrophages had altered surface properties, as compared with bacteria grown in vitro. This was indicated by loss of the ability to adsorb bacteriophage DS6A, a reduced tendency to form clumps, acquisition of ethidium bromide stainability following heat treatment, and loss of Rpf-mediated resuscitation following freezing and thawing. These results indicate that a proportion of 'unculturable' M. tuberculosis cells obtained from macrophages is either injured or dormant and that these cells may be recovered or resuscitated using Rpf in liquid medium.