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1.
鸡源大肠埃希氏菌某些生物学特性 总被引：4，自引：1，他引：3
对鸡源大肠埃希氏菌的某些生物学特性进行了研究,包括对１日龄鸡的致病性、溶血性、菌毛的表达、血凝性、对鸡胚成纤维细胞（ＣＥＦ）的粘附特性、体内外与鸡气管粘膜的粘附特征、质粒特征、全菌蛋白ＳＤＳ－ＰＡＧＥ电泳及免疫转印等。结果表明,鸡源大肠埃希氏菌的溶血性、质粒特征、对ＣＥＦ的粘附特性与其致病性无关;菌毛与致病性有关,大部分菌株表达Ⅰ型菌毛;血凝能被Ｄ－甘露糖抑制,不同菌株血凝谱具有差异;体内外与气管粘膜的粘附特性与菌株致病性有关;在全菌蛋白ＳＤＳ－ＰＡＧＥ电泳中,相对分子质量约为４０７００的多肽仅存在于具有致病性的菌株中,经免疫转印证实,该多肽为致病性大肠埃希氏菌所特有 相似文献
2.
大肠杆菌新菌毛抗原的研究Ⅰ．菌毛抗原及其血凝活性测定 总被引：3，自引：0，他引：3
Ｎｏ．１和Ｎｏ．２两株大肠杆菌产生一种新菌毛抗原（暂定名Ｆ１９８７），并有性菌毛形成；菌毛直径３．６３６ｎｍ，性菌毛直径４．２ｎｍ。抗Ｄ－甘露糖血凝试验（ＭＲＨＡ）表明：本菌毛抗原具有独特的血凝谱，能稳定地凝集人（Ａ、Ｂ、ＡＢ、Ｏ）及貂的红血球，不凝集豚鼠、绵羊、山羊、马、牛、家兔、犬、貉子、小白鼠、鸡、鸽、鹌鹑等动物的红血球，对猪红血球凝集不稳定；血凝作用仅能被相应菌毛因子血清所抑制，不被Ｋ＿８８、Ｋ＿９９、Ｆ＿４１，及ＣＦＡ／Ⅰ、ＣＦＡ／Ⅱ等菌毛因子血清所抑制。血凝作用存在４℃－３７℃－４℃的凝集－解脱－复凝集现象。用Ｍｉｎｃａ培养基做３７℃培养１８～２４ｈ，可使菌毛抗原良好表达。在玻片凝集反应、反向间接血凝及反向间接血凝抑制试验中，本菌毛抗原与动物中常见的Ｋ＿８８、Ｋ＿９９、９８７Ｐ、Ｆ＿４１，及人源ＣＦＡ／Ⅰ、ＣＦＡ／Ⅱ等菌毛抗原不存在类属反应。 相似文献
3.
禽大肠杆菌菌毛粘附特性的研究 总被引：5，自引：0，他引：5
用透射电镜观察了鸡大肠杆菌的３个致病菌株ＧＬ７（Ｏ５０）、ＨＢ５（Ｏ７８）及ＴＧ１８（Ｏ８８），发现在营养肉汤中于３７℃培养均表达菌毛，但在１８℃培养不表达菌毛，用３７℃培养的大肠杆菌对鸡气管粘膜做粘附试验，并用扫描电镜观察，发现它们对体内体外的鸡气管均可粘附，但１８℃培养的大肠杆菌均缺乏这种粘附作用。采用粘附抑制试验测定这３种菌株对体外鸡气管节段粘附的特异性，结果是抗这３种细菌菌毛的抗体能显著抑制各自相应的菌株对气管上皮的粘附；Ｏ７８株和Ｏ８８株对气管上皮的粘附作用可被甘露糖显著抑制，表明甘露糖对介导菌体对气管粘膜上皮细胞受体起重作用。用甘露糖不能抑制Ｏ５０菌株对气管上皮的粘着，表明该菌体的粘附作用不由甘露糖介导。用高碘酸钠处理能抑制所有菌株的粘附作用，再次表明细菌对气管上皮的粘附作用是由单糖介导的 相似文献
4.
嗜水气单胞菌粘附特性的研究 总被引：7，自引：1，他引：6
不同来源的６株嗜水气单胞菌（Ａｅｒｏｍｏｎａｓｈｙｄｒｏｐｈｉｌａ）对１０种不同红细胞的血凝试验表明，Ｊ－１株能凝集所有的１０种红细胞，而与其他菌株的血凝谱有所不同。血凝图式有２种：人、鸡、麻雀的红细胞凝集快，呈大小不等的絮状；而鲫鱼、绵羊、猪、小鼠、兔、鸭、犬的红细胞凝集慢，且呈均匀颗粒状。这两种血凝均能被Ｄ－甘露糖抑制，但不能被Ｊ－１株Ｒ菌毛抑制。组织粘附试验显示，Ｊ－１株能粘附小鼠和鲫鱼的肠组织和肠绒毛。将提纯的Ｒ菌毛预处理肠组织，或用Ｄ－甘露糖或木瓜蛋白酶消化的Ｒ菌毛抗血清Ｆａｂ片段预处理菌体，都不能抑制上述的粘附作用。Ｊ－１株对ＨＥｐ－２细胞显示强粘附，菌体随机粘附在细胞上，有少数侵入细胞浆内。其余５株菌的粘附特性与Ｊ－１株不尽相同。所有６株菌对草鱼肠组织及肠绒毛、ＥＰＣ细胞（鲤鱼乳头状上皮瘤细胞系）均无粘附性。 相似文献
5.
应用８株鸡病原性大肠杆菌研究了菌毛作为分型抗原和共粘附特性,以抗Ⅰ型菌毛单克隆抗体（单抗）ｂＧ５和甘露糖进行了抑制作用试验。在血凝试验中、单抗和甘露糖都能抑制血凝反应,说明这些株都属于Ⅰ型,通过以单抗或甘露糖的粘附抑制程序这些Ｅｃｏｌｉ株对鸡气管上皮都不能特异粘附。 相似文献
6.
7.
从福建省几个大肠杆菌病较严重的大型养鸡场分离到的８５株大肠埃希氏菌,从致病性试验、生化试验、药敏试验及生物学我试验结果表明,其中有５２株为致病菌,致病菌分离率６１．１％;分离菌株的生化特性符合大肠埃希氏菌的生化特性;所有菌株均能凝集鸡的红细胞,并能被Ｄ－甘露糖所抑制;对人、猪、山羊、乳牛、兔、犬、豚鼠、鸽和鱼的红的细胞表现为不同的血凝（ＨＡ）和Ｄ－甘露糖血凝抑制特性;２４株强致病菌中有７９．２％的表现为盐凝集试验（ＳＡＴ）阳性：所有菌株对丁胺卡那霉素（ＡＫＮ）和菌必治敏感,对氯霉素（ＣＭＰ）、先锋霉素（ＣＴＮ）、卡那霉素（ＫＡＮ）、呋喃妥因（ＮＩ）、氟嗪酸（ＯＦＬ）、壮观霉素（ＳＰＴ）、妥布霉素（ＴＯＢ）、新霉素（ＮＥＯ）、氟哌酸（ＮＯＲ）、复合磺胺（ＳＸＴ）和强力毒素（ＤＯＸ）有较高敏感性,而对红霉素（ＥＲＹ 相似文献
8.
对243株禽源大肠杆菌分离株进行血清耐受试验、菌毛化大肠杆菌血凝试验和温度敏感性血凝素试验.在这些分离株中,高度血清耐受、中等血清耐受、轻度血清耐受和血清敏感菌株分别占受试菌株的57.2%(139/243)、28.8%(70/243)、10.3%(25/243)和3.7%(9/243).在37℃细菌培养物与鸡红细胞凝集试验中,甘露糖敏感血凝(MSHA)和甘露糖耐受血凝(MRHA)菌株分别占受试菌株的64.6%(157/243)和5.8%(14/243);与豚鼠红细胞凝集试验中,MSHA和MRHA菌株分别占受试菌株的74.9%(182/243)和2.9%(7/243),其中与鸡红细胞凝集试验MSHA菌株中,MSHA阳性菌株占高致病株的69.5%(132/190),MRHA阳性菌株占低致病株的22.2%(2/9),两者差异极显著(p<0.01).在温度敏感性血凝素试验中,MRHA菌株为112株,占分离株的46.1%,其中O1、O2和O78血清型的高致病株占所在血清型分离株的83%～100%,而其它血清型的高致病株仅占57%左右,差异显著(p<0.05).结果显示禽源大肠杆菌的致病性与其血清耐受能力、鸡红细胞MSHA菌毛的表达和温度敏感性血凝素的表达呈一定的相关关系. 相似文献
9.
大肠杆菌菌毛油乳剂苗的实验研究 总被引：2，自引：0，他引：2
利用加热法对一株用牛心琼脂培养的当地产肠毒素性大肠杆菌（ETEC）进行了宿主特异性菌毛的提取，并用该菌毛制成的油乳剂苗进行了家兔免疫试验。用甘露糖抵抗血凝反应（MRHA）及血凝抑制试验（HI）检测了菌毛的表达效果及抗体含量。结果显示，菌毛的血凝价为1：512，抗体滴度为1：64。 相似文献
10.
大肠杆菌新菌毛抗原的研究：I.菌毛抗原及其血凝活性测定 总被引：1，自引：1，他引：0
Ｎｏ．１和Ｎｏ．２两株大肠肝菌产生一种新菌毛抗原（暂定各Ｆ１９８７），并有性菌毛形成；菌毛直径３．６３６ｎｍ，性菌毛直径４．２ｎｍ。抗Ｄ－甘露糖血凝试验（ＭＲＨＡ）表明：本菌毛抗原具有独特的血凝谱、能稳定地凝集人（Ａ、Ｂ、ＡＢ、Ｏ）及貂的红血球，不凝集豚鼠、绵羊、山羊、马、牛、家兔、犬、貉子、小白鼠、鸽、鹌鹑等动物的红血球，戏猪红血球凝集不稳定；血凝作用仅能被相应菌毛因子血清所抑制，不被Ｋ８８、Ｋ 相似文献
11.
Adherence of Bordetella avium to tracheal mucosa of turkeys: correlation with hemagglutination 总被引：4，自引：0，他引：4
Adherence to turkey tracheal mucosa and agglutination of guinea pig erythrocytes were determined for 20 strains of Bordetella avium. Ten type-I strains, 7 type-II strains, 2 transposon-induced mutants, and 1 revertant were evaluated. All type-I strains adhered readily to tracheal mucosa and agglutinated erythrocytes, whereas no type-II strains adhered to trachea or caused hemagglutination (HA). Two mutants selected for loss of HA activity were less adherent to tracheal mucosa, compared with the parent strain. Reversion of one mutant to HA-positive status was accompanied by reconstitution of much of its adherence capacity. Results of this study provide preliminary evidence that tracheal adherence and HA of B avium are closely related. 相似文献
12.
Mycoplasma gallisepticum (MG) strains showing marked variation in pathogenicity were examined for virulence in ovo. No correlation was found between in ovo pathogenicity and other in vivo or in vitro methods for pathogenicity evaluation. For certain highly pathogenic strains, there was a clear relationship between the titer of MG inoculated and the embryo mortality and time of death; an LD50 for these strains could be calculated by yolk-sac inoculation. However, not every strain that caused lesions in the respiratory tract in vivo caused embryo mortality. Less pathogenic strains that grow well and colonize the respiratory tract usually caused embryo mortality during the later stages of incubation, and there was no strict correlation between titer of inoculum and embryo mortality. It appeared that embryo death in these cases may have resulted from generalized stress due to mass multiplication of the MG. Embryo mortality due to virulent MG was completely blocked in eggs containing maternal antibody to MG, although the mycoplasma could be reisolated from the yolk-sac membrane of the live embryonated egg after 17 days of incubation. Attempts to mimic the effect of maternal antibody by injecting exogenous MG antiserum were not successful. 相似文献
13.
A quantitative study of single and mixed infection of the chicken trachea by Mycoplasma gallisepticum 总被引：2，自引：0，他引：2
The interaction between Mycoplasma gallisepticum (MG) and the tracheal mucosa of the young chicken was studied. The use of a selective plating method permitted differentiation between a pathogenic tylosin-resistant strain (227) and a less pathogenic tylosin-sensitive vaccine strain (F). Both MG strains adhered to the tracheal mucosa and colonized equally well. In mixed infection, the presence or absence of the second strain did not change the efficiency of colonization by either strain. When chickens were exposed to the vaccine strain 24 hr or 2 weeks before superinfection by the pathogen, there was no significant reduction in the efficiency of superinfection, despite the presence of 10(6) colony-forming units of MG strain F in the trachea. However, chickens had an increased ability to resist superinfection 5 weeks after exposure via the air sac. These results suggest that the biological mechanism underlying protection of F-strain-vaccinated chickens against adventitious infection by the homologous species does not involve competition for adherence sites or blockage by prior colonization. 相似文献
14.
Virulence properties of Escherichia coli isolated from ostriches with respiratory disease 总被引：2，自引：0，他引：2
Knöbl T Baccaro MR Moreno AM Gomes TA Vieira MA Ferreira CS Ferreira AJ 《Veterinary microbiology》2001,83(1):71-80
Eight Escherichia coli isolates from ostriches with respiratory disease were investigated for the presence of genes encoding the following adhesins: type 1 pili (fim), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afaI), temperature regulated adhesin, curli (crl, csgA) and temperature-sensitive hemagglutinin (tsh). Genes for heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf), alpha-haemolysin (hly) and aerobactin (aer) production were also investigated. Other characteristics investigated were the presence of hemagglutination activity, growth on an iron-deficient medium, aerobactin production, serum resistance, adherence to chicken tracheal cells, pathogenicity for day-old chicks, and serogroup. Serogrouping showed that four isolates belonged to serogroup O2, two to serogroup O78, one to serogroup O9, and one to serogroup O21. The virulence genes found were: fim in all eight isolates, csgA in seven, aer in six, and pap, crl and tsh in one isolate each. All isolates analyzed were positive for mannose-resistant hemagglutination, adhered in vitro to ciliated tracheal epithelium, grew on iron-deficient medium, and showed serum resistance. Pathogenicity tests on day-old chickens revealed one highly pathogenic isolate, three of low pathogenicity and four isolates with intermediate pathogenicity. 相似文献
15.
Selection and comparison of Mycoplasma synoviae hemagglutinating and nonhemagglutinating variants 总被引：1，自引：0，他引：1
K R Rhoades 《Avian diseases》1985,29(4):1170-1176
Hemagglutinating (HA) and nonhemagglutinating (NHA) variants were selected from each of two strains of Mycoplasma synoviae, WVU-1853 and Neb-3S. The HA titers of antigens prepared by 100-fold concentration of broth cultures were 1:2560 and 1:5120 for the HA variants and less than 1:5 for the NHA variants. Adsorption of erythrocytes to colonies of the variants was directly correlated with HA activity. The HA and NHA characteristics were stable in vitro, and there was no change in HA titers after repeated transfers in broth medium. Comparisons of pathogenicity indicated differences between strains but not between variants of each strain. Air-sac lesions resulting from exposure to variants of strain Neb-3S were marked, whereas those resulting from exposure to variants of WVU-1853 were slight. The HA titers of isolates recovered from turkey air sacs exposed to the Neb-3S variants varied considerably, suggesting in vivo instability of the HA characteristic. 相似文献
16.
H9N2亚型禽流感病毒HA蛋白S145N变异株致病性及抗原特性 总被引：1，自引：0，他引：1
为确定近年来H9N2亚型禽流感病毒(AIV) HA蛋白S145N点突变对病毒毒力变化和抗原性变异的影响,笔者对从全国不同地区分离的12株H9N2亚型AIV HA蛋白S145N变异株和HP疫苗参考株进行了半数鸡胚感染量(EID50)、半数鸡胚致死量(ELD50)、平均鸡胚致死时间(MDT)、雏鸡脑内致病指数(ICPI)、鸡静脉致病指数(IVPI)和8周龄SPF鸡感染排毒试验,并与抗H9N2亚型AIV HP参考株HA蛋白单抗2A4和F6的血凝抑制(HI)和中和反应特性进行测定.结果发现,H9N2亚型AIV HA蛋白S145N变异株毒力偏强,能引起部分SPF鸡发病和死亡,感染8周龄SPF鸡排毒时间更早,排毒期更长.单抗2A4和F6不能抑制H9N2亚型AIV HA蛋白S145N变异株的血凝特性,也不能中和病毒感染CEF细胞.研究结果表明,H9N2亚型AIV呈现变异趋势,有毒力增强和抗原性变异毒株出现.S145为H9N2亚型AIV HA蛋白的1个抗原位点,是血凝抑制抗体结合的位点,但有该位点漂变导致抗原变异毒株出现,并可逃避免疫作用.这提示该病的防控面临着新的挑战. 相似文献
17.
This study investigated the in vitro adherence of Staphylococcus intermedius to canine corneocytes, collected from a healthy dog using double-sided adhesive tape. Adherence was shown to depend on duration (P < 0.001) and temperature of incubation (P < 0.001) and the concentration of bacteria (P < 0.001). Isolates of S. intermedius from lesions of pyoderma were not generally more adherent to healthy canine skin than were isolates from healthy dogs. Significant differences in adherence were demonstrated between individual isolates within both groups (P < 0.001). The study suggests that among S. intermedius there is no correlation between virulence and adherence to canine corneocytes in vitro. The finding may be important for the potential use of avirulent variants of S. intermedius as antagonistic strains against canine pyoderma. However, more studies are needed to compare the adherence of the isolates to skin cells obtained from dogs with diseases predisposed to pyoderma. 相似文献
18.
Characteristics of 2 encephalomyocarditis virus (EMCV) isolates (MN-25 and MN-30) recovered from aborted swine fetuses were examined along with 2 other swine isolates (NVSL-MDV and NVSL-PR) and a reference ATCC strain (VR-129). All 5 EMCV isolates were found to be serologically related by cross testing, using serum neutralization and fluorescent antibody assays. Hemagglutination (HA) properties of the 5 isolates were compared, using 5 diluents. The MN-25 and NVSL-MDV strains had HA activity with guinea pig RBC in all 5 diluents, whereas MN-30, NVSL-PR, and VR-129 had HA activity only in KCl-borate buffer. The HA ability with RBC of various animal species was examined, using KCl-borate diluent. All virus isolates had high HA titer (1:512 to 1:2,048) with guinea pig, rat, and horse RBC and lower HA titer (1:16 to 1:64) with sheep RBC. The MN-25 and NVSL-MDV isolates agglutinated dogs RBC, whereas MN-30, NVSL-PR, and VR-129 strains did not. Viral replication was evident in 8 of 10 cell lines tested, although infectivity titers of each virus varied by cell line used. Plaque-forming ability was similar for all 5 isolates, but plaque size was different by virus and cell culture used. Virus isolates were found to be stable after being heated at 56 C and subjected to a wide range of pH. A viral polypeptide pattern difference for all 5 isolates was not found by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
19.
Increasing use of Mycoplasma gallisepticum (MG) live vaccines has led to a need for a rapid test for differentiation of MG field strains from the live vaccine strains ts-11 and 6/85. We examined the differentiating potential of diagnostic polymerase chain reaction (PCR) primers targeted to the gene mgc2, encoding a cytadherence-related surface protein uniquely present in MG. The mgc2-PCR diagnostic primers are specific for MG in tests of all avian mycoplasmas or bacteria present in the chicken trachea and are sensitive enough to readily detect MG in tracheal swabs from field outbreaks. Differentiation of vaccine strain ts-11 was based on identification of restriction enzyme sites in the 300-base-pair (bp) mgc2-PCR amplicon present in ts-11 and missing in MG isolates from field outbreaks in Israel. Restriction sites for the enzymes HaeII and SfaN1 were identified in the amplified region in strain ts-11 and were not found in 28 field isolates of MG, comprising a representative cross section of all the MG isolates from the period 1997-2003. In practice, differential diagnosis of MG is achieved within 1 day of submission of tracheal swab samples by mgc2-PCR amplification and restriction of the amplicon with HaeII, giving a 270-bp fragment for ts-11 or no restriction for other MG strains tested. Application of the mgc2-PCR-restriction fragment length polymorphism (mgc2-PCR-RFLP) assay enabled differential diagnosis of both components of a mixture of ts-11 and non-ts-11 DNA, detecting the field strain in the presence of a large excess of ts-11. The test was successfully applied in vivo for monitoring vaccinates in a ts-11 vaccine trial. In principle, the test may also be used to identify the 6/85 vaccine strain, which yields a 237-bp product, readily differentiated from the approximately 300-bp PCR product of all other strains tested. Further testing of field isolates will be necessary to determine the applicability of this test in the United States and other countries. 相似文献
20.
Passive immunization versus adhesion of Bordetella avium to the tracheal mucosa of turkeys 总被引：2，自引：0，他引：2
Three-week-old turkeys were passively immunized with convalescent serum or treated with tracheal washings from turkeys infected with Bordetella avium. Western blot analysis of the convalescent serum and tracheal washings revealed at least two bands of interaction with outer membrane protein preparations of B. avium. Adherence of B. avium in vivo to tracheal mucosa was determined and compared in treated and untreated turkeys. Passive immunization with convalescent serum reduced adherence of B. avium to the tracheal mucosa in a dose- and time-dependent manner. Adherence was significantly inhibited (P less than 0.01) when turkeys were treated intravenously with 1 ml of undiluted serum either 1 or 6 hours previously. Incubation of the bacterial inoculum with convalescent tracheal washings or application of the washings to tracheal segments before adherence determination in vivo resulted in a significant (P less than 0.01) decrease in adherence. These results indicate that adherence of B. avium to tracheal mucosa is inhibited by substances (antibody) present in both serum and tracheal secretions of convalescent turkeys. 相似文献