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1.
Goren E 《The Veterinary quarterly》1979,1(3):158-162
Summary Colonies of the avian mycoplasma strains Mycoplasma gallisepticum S6 and Mycoplasma synoviae WVU 1853 and two Mycoplasma synoviae isolates from this laboratory were shown to be haemadsorption positive for chicken erythrocytes. Three Mycoplasma synoviae isolates from this laboratory proved to be haemadsorption and haemagglutination negative. The haemadsorption of the mycoplasma colonies mentioned above was inhibited with specific antisera of either high or low titre. No cross-inhibition was observed. It is suggested that this test could be used for a quick tentative identification of the two avian mycoplasmas on primary solid-medium cultures. 相似文献
2.
The two avian pathogens Mycoplasma gallisepticum and Mycoplasma synoviae were found, by Southern blot hybridization of their digested DNAs, to share genomic nucleotide sequences additional to those of the highly conserved ribosomal RNA genes. The assumption that some of the shared sequences encode for antigens or epitopes common to both mycoplasmas was supported by Western immunoblot analysis of cell proteins of one mycoplasma with specific antiserum to the other mycoplasma. Interestingly, the band patterns of reactive antigens were different for some of the M. gallisepticum strains, supporting the concept that the species is genotypically variable. The results of the present study may explain the cross-reactivity of the two mycoplasmas noted previously in a variety of routine serological tests. 相似文献
3.
Hong Y García M Leiting V Bencina D Dufour-Zavala L Zavala G Kleven SH 《Avian diseases》2004,48(3):606-616
Mycoplasma synoviae is a major pathogen of chickens and turkeys, causing economic losses to the poultry industry worldwide. In this study, we validated and applied polymerase chain reaction (PCR) and DNA sequence analysis on the N-terminal end of the hemagglutinin encoding gene vlhA as an alternative for the detection and initial typing of field strains of M. synoviae in commercial poultry. PCR primers were tested against isolates of M. synoviae from various sources along with other avian mycoplasma and other bacterial species. The vlhA gene-targeted PCR assay was highly specific in the identification of M. synoviae, with a detection limit of 4.7 x 10(2) color changing units/ml. DNA sequence analysis of amplified products was also conducted to validate the potential for typing M. synoviae strains using the N-terminal region of the vlhA gene. To evaluate the test, we applied the PCR assay to tracheal swabs collected from chickens challenged with M. synoviae strain K1968 and compared the results to the serologic detection. The PCR assay was also evaluated directly on tracheal samples collected from commercial layers. Overall, this vlhA gene-targeted PCR is a useful tool for detection and initial typing of M. synoviae and can be applied in the preliminary identification of M. synoviae isolates directly from clinical samples. 相似文献
4.
Monitoring of susceptibility to antibiotics in field isolates of pathogenic avian mycoplasmas is important for appropriate choice of treatment. Our study compared in vitro susceptibility to enrofloxacin and difloxacin in recent (2005-2006) isolates of Mycoplasma gallisepticum and Mycoplasma synoviae from meat-type turkey flocks with archived (1997-2003) isolates and reference strains. Comparison of minimal inhibitory concentration (MIC) values determined by microtest, agar dilution and commercial Etest showed good agreement, but underscored the need for standardized methods for testing. Notably, while the commercial Etest was convenient and accurate for determining MICs for enrofloxacin in the range 0.002-0.094mug/ml, the endpoint of inhibition for M. gallisepticum and M. synoviae strains with MIC values >/=1.0mug/ml could not be determined. A decrease in susceptibility to both fluoroquinolones was detected in archived strains but to a greater degree in recent isolates, most of which had MICs above the NCCLS susceptibility breakpoint for these antibiotics (相似文献
5.
Two hemagglutination (HA) antigens produced from Mycoplasma synoviae isolates WVU-1853m and FMT grown in Frey's mycoplasma broth were lyophilized for HA preservation. Some increase in the HA titer occurred following lyophilization. 相似文献
6.
Ogino S Munakata Y Ohashi S Fukui M Sakamoto H Sekiya Y Noormohammadi AH Morrow CJ 《Avian diseases》2011,55(2):187-194
Mycoplasma synoviae is an important causative agent of avian mycoplasmosis. In the present study the conserved domain of the variable lipoprotein and hemagglutinin (vlhA) gene of M. synoviae was sequenced and analyzed for 19 field strains of M. synoviae isolated from chickens across Japan. This analysis revealed that there were at least nine genotypes of M. synoviae present in Japan. Furthermore, we found a single nucleotide polymorphism (SNP) within this region in all the Japanese isolates, and based on this finding, we established a PCR method with cycling probe technology to differentiate between these field isolates and the live M. synoviae vaccine strain Mycoplasma synoviae-H (MS-H). 相似文献
7.
The ability of Mycoplasma synoviae, an avian pathogen, to persist despite fluoroquinolone treatments was investigated in hens. Groups of Mycoplasma-free hens were experimentally infected with the M. synoviae 317 strain and treated twice with enrofloxacin at the therapeutic dose. The results show that the two treatments did not have any influence on this strain of M. synoviae recovery from tracheal swabs. Mycoplasmas were isolated from tracheal swab cultures, but not from inner organs such as the liver or spleen, suggesting that this strain of M. synoviae was not able to cross the mucosal barrier to disseminate throughout the host. A significant increase of the resistance level to enrofloxacin of five re-isolated mycoplasma clones, was observed after the second treatment. This increase was associated in two clones to a Ser81-->Pro substitution, found in the ParC quinolone-resistance determining region (QRDR) of DNA topoisomerase IV. This is the first time that a mutation in a gene coding for topoisomerase IV is described in M. synoviae after in vivo enrofloxacin treatments in experimentally infected hens. 相似文献
8.
9.
We have previously identified species-specific DNA fragments, referred to as MS2/28 and Mm14, of Mycoplasma synoviae and Mycoplasma meleagridis, respectively. In the present study, we extended our analysis of the MS2/28 fragment that was found to encode a species-specific antigenic site, and we demonstrated the specificity of the Mycoplasma gallisepticum hemagglutinin protein encoded by pMGA1.2 (a member of the vlhA gene family). Then, we combined the Escherichia coli-expressed products of MS2/28, Mm14, and pMGA1.2, to develop a recombinant antigen-based enzyme-linked immunosorbent assay (recELISA), for the simultaneous and specific detection of antibodies to the three aforementioned major avian mycoplasma species. For comparative purposes, a novel in-house crude antigen capture ELISA (capELISA) was developed in parallel. In the latter protocol, the microtiter wells were enriched in species-specific antigens by capturing sonicated crude antigens on coated rabbit polyclonal antibodies that had been extensively adsorbed with the whole antigen of the heterologous species. With regard to rapid serum agglutination, both ELISA tests were highly specific, and they showed a significant correlation when field sera from naturally infected birds were tested. recELISA proved to be highly specific because absorbance values, with the heterologous species, were significantly lower (P < 0.001) than those obtained with capELISA. Given its cost-effectiveness and simplicity, the recombinant antigen-based ELISA seems to represent a valid tool for the specific screening of the three major avian mycoplasma species. recELISA will be particularly useful with regard to trade control because a large number of samples from various fields could be rapidly processed. 相似文献
10.
The diseases caused by mycoplasmas are generally chronic and persistent and apparently occur notwithstanding a host immune response. The ability to evade the host immune response is facilitated by phenotypic variation in the mycoplasma surface components. The avian mycoplasmas Mycoplasma gallisepticum and Mycoplasma synoviae have both been previously described to be able to switch their surface antigens, and recent evidence indicates that M. gallisepticum could switch surface antigens under natural conditions in vivo. In this work we present data to support that Mycoplasma iowae is also capable of phenotypic variation as detected by reactions with the monoclonal antibody MAb MI1 on colony immunoblots. This phenomenon is suggested to occur spontaneously or in response to normal serum and tissue components and may play an important role in the evasion of the host immune response. 相似文献
11.
The Mycoplasma synoviae haemagglutinin gene, vlhA, encodes two major immunodominant and surface-exposed membrane proteins, MSPB and MSPA. Both products are antigenically variable but only MSPA mediates binding to erythrocytes. Previously we have shown that M. synoviae type strain WVU 1853 could express a variant vlhA gene, referred to as MS2/28.1, with a considerably shorter and divergent MSPA region. A finding that prompted detailed characterization of its antigenic and functional properties. Here we mutagenized each of the six opal codons of the variant MS2/28.1 vlhA member into tryptophan, thus allowing its expression in Escherichia coli as well as its cleavage products, MSPB and MSPA. In addition, we expressed 5 contiguous regions of MS2/28.1 extending from the last part of MSPB to the C-terminus of MSPA. Colony immunostaining with region-specific antisera mapped antigenic variation to the N-terminal half of MS2/28.1 MSPA. No haemagglutinating activity was observed for MSPB, but consistent haemadsorption inhibition was mapped to the region extending from amino acid 325 to 344. Inhibition of both haemagglutination and haemadsorption activities were obtained with sera directed against the C-terminal region of MSPA, with the highest titers (1/320 and 1/160, respectively) being recorded for its last 60 residues. Importantly, antibodies to this region also yielded the highest metabolic inhibition titer of 1/1280. Overall, aside from mapping the functional domains of a M. synoviae highly divergent haemagglutinin gene, this study shows that the C-terminal half of its MSPA region induced the highest titers of antibodies inhibiting haemagglutination, haemadsorption, and metabolism. 相似文献
12.
The aim of the study was to analyse experimental transmission of Mycoplasma synoviae, an avian pathogen. Three experiments using specific pathogen-free day-old chicks placed in isolators were conducted. In the first experiment, the birds were introduced in an isolator previously contaminated with a M. synoviae broth culture. After 34 days, these birds were eliminated and, for the second trial, the chicks were introduced in the same isolator without disinfecting. In the third assay, the chicks were placed in an isolator containing a mixture of food, feathers and dust collected less than an hour earlier from a M. synoviae infected laying hen flock. In the second and third experiments in order to exacerbate the M. synoviae infection, the birds were inoculated with infectious bronchitis (IB) virus. The presence of M. synoviae in the environment and in tracheal swabs was monitored by culture, a multiplex PCR (mPCR) detecting M. synoviae and Mycoplasma 16S rDNA and a multiplex RT-PCR (mRT-PCR) detecting the M. synoviae mRNA coding for a membrane protein and Mycoplasma 16S rRNA. In in vitro experimental conditions, M. synoviae mRNA and 16S rRNA were detected up to 20 min and 23 h respectively after mycoplasma death. In the first assay, the first infected bird was detected on the 13th day. In the second trial, culturable M. synoviae or viable M. synoviae were detected in the isolator for 3 or 4 to 5 days respectively after depopulation of the birds of the first assay whereas the first culture positive tracheal swabs were detected on the 33rd day, after IB inoculation. In the third experiment, the first infected birds were detected on the 54th day. Thus, the different assays showed that M. synoviae contaminated material (dust, feathers and food) can infect chicks, sometimes after remarkably long silent periods. 相似文献
13.
B Ben Abdelmoumen R S Roy R Brousseau 《Journal of veterinary diagnostic investigation》1999,11(2):162-169
A genomic library of Mycoplasma synoviae (MS) was generated by using bacteriophage lambda gt11 as a cloning and expression vector. Identification of recombinant clones highly specific to MS was achieved by screening the library for expression of MS proteins with polyclonal antiserum that had been preadsorbed with 6 heterologous avian mycoplasma species antigens. Expression of the recombinant clones in Escherichia coli followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the total cell lysates and immunoblot yielded a predominant reactive fusion protein of 165 kD. Two clones (MS2/28 and MS2/12) that yielded inserts of different size were selected. The 2 MS DNA inserts were subcloned in a plasmid vector, labeled with digoxigenin, and used as probes for the specific recognition of several MS strains. A high degree of conservation was demonstrated for the MS2/12 and MS2/28 genes in tested MS strains. In addition, neither DNA fragment recognized any other avian mycoplasma species (M. gallisepticum, M. meleagridis, M. gallinarum, M. iners, M. anatis, and M. iowae), thus indicating their high specificity to MS. The sensitivity of the slot blot hybridization method using digoxigenin-labeled MS2/12 and MS2/28 probes for direct detection of MS from broth cultures of field isolates was 10(5) colony-forming units/ml. These results demonstrate the effectiveness of adsorbed antisera for the isolation of species-specific mycoplasma DNA and the potential for its use as probes for the specific and direct detection of MS from broth cultures of field isolates. 相似文献
14.
为了解宁夏及其周边不同地区蛋鸡场中的鸡滑液囊支原体的种类及其致病力,采用改良Frey氏鸡滑液囊支原体培养基,从疑似感染鸡滑液囊支原体的不同蛋鸡群中分离出病原株,设计鸡滑液囊支原体vlhA基因特异性引物,对分离到的病原进行基因序列扩增并测序,使用MEGA6.0软件中的邻接法(Neighbor-joining,NJ)构建分离株系统发育树并进行遗传进化分析,采用从临床症状最明显的鸡体分离的菌株进行动物感染试验,制作石蜡切片,HE染色,病理组织学观察。结果表明,所分离到的病原菌均为鸡滑液囊支原体,部分菌株之间极其相似;鸡滑液囊支原体不仅可以使鸡只关节肿胀、生长缓慢,也可引起鸡只的肝脏轻微肿大,肝细胞部分坏死、间质增生;脾脏结缔组织增生,出血。 相似文献
15.
Mycoplasma gallisepticum (MG) has repeatedly emerged as a serious problem in U.S. broiler, layer, and turkey industries. Tracing the source of an outbreak is essential if MG control is to be accomplished. Amplified fragment length polymorphism (AFLP), random amplification of polymorphic DNA (RAPD), and restriction fragment length polymorphism (RFLP) are valuable tools used to study MG epidemiology, allowing diagnosticians to determine the source of MG infections. In some past outbreaks, AFLP, RAPD, and RFLP fingerprinting, which require pure MG cultures, were not successful because of contaminating nonpathogenic mycoplasmas from field samples. The objective of this research was to develop a method to separate rapidly growing nonpathogenic avian mycoplasma species from slower-growing MG field strains. Mixtures of MG and three separate nonpathogenic avian mycoplasmas were inoculated onto chick embryo fibroblasts cells (CEF) allowing MG to penetrate the CEF cells. Later, gentamicin sulphate was added to the culture, eliminating the nonpathogenic mycoplasmas and allowing MG to be isolated in pure culture. Mixtures of Mycoplasma synoviae (MS) and MG could not be separated in this assay. However, removal of nicotinamide adenine dinucleotide and cysteine hydrochloride during serial passage in Frey broth medium successfully eliminated growth of MS. 相似文献
16.
Bercic RL Slavec B Lavric M Narat M Bidovec A Dovc P Bencina D 《Veterinary microbiology》2008,127(1-2):147-154
Mycoplasma synoviae isolates differ in patterns of immunogenic proteins, but most of them have not been identified yet. The main aim of this study was their identification in two closely related M. synoviae isolates, ULB 02/P4 and ULB 02/OV6, recovered recently from chickens in Slovenia. N-terminal sequencing identified 17 M. synoviae proteins. Amongst them were 14 major, highly expressed but previously unidentified proteins, including enzymes, chaperones and putative lipoproteins. ULB 02/P4 proteins with increasing molecular weight (M(w)) in the region above the lipoprotein MSPB (approximately 40 kDa) were elongation factor EF-Tu, enolase, NADH oxidase, haemagglutinin MSPA, ATP synthase beta chain, trigger factor, pyruvate kinase and chaperone DnaK. Enolase (approximately 47 kDa) seemed to be immunogenic for chickens infected with M. synoviae, whereas EF-Tu, which might cross-react with antibodies to the P1 adhesin of Mycoplasma pneumoniae, was not. ULB 02/OV6 synthesized several immunogenic proteins and those with M(w) of approximately 70, 78, 82, 90, 110 and 160 kDa, cross-reacted with antibodies to Mycoplasma gallisepticum. They remain to be identified, because besides putative lipoproteins, protein bands of 78, 82, 85 and 110 kDa contained also dehydrogenase PdhD, elongation factor EF-G, enzyme PtsG and putative neuraminidase, respectively. 相似文献
17.
为调查不同地区鸡滑液囊支原体的耐药情况,从河南、江苏、安徽、河北和广东五省204份疑似鸡滑液囊支原体感染鸡的病料中分离到20株鸡滑液囊支原体,每省随机取1株进行了12种常用抗菌药物的敏感性测定。结果表明,5株鸡滑液囊支原体均对泰乐菌素较为敏感,而对恩诺沙星、氧氟沙星、盐酸环丙沙星具有不同程度的耐受性。本实验可为临床合理用药提供参考。 相似文献
18.
应用多重套式PCR检测鸡毒支原体和鸡滑液囊支原体 总被引：2，自引：0，他引：2
根据已发表的鸡毒和鸡滑液支原体血凝素基因序列pMGA和vlhA各设计两对引物,建立鉴别诊断两种支原体的多重套式PCR方法,对其进行温度条件、Ⅱ步模板浓度优化及特异性、敏感性实验。该方法在两步PCR后能特异性地扩增出MG(408 bp)和MS(688 bp)两个目的片段。应用于临床样品检测,与支原体分离、SPA检测比较结果PCR灵敏度高于病原分离。 相似文献
19.
Mycoplasma synoviae infection occurs worldwide in commercial poultry flocks and may result in severe economic losses. The prevalence of this mycoplasma in standard layers older than 60 weeks was studied in a French department and the characteristics of infected or free flocks were compared. The genomic profiles of isolates from 36 infected flocks were studied by pulsed-field gel electrophoresis and random amplified polymorphic DNA methods in order to investigate possible routes of transmission. The minimum inhibitory concentrations of antibiotics were determined. Results showed that infection was more frequent in multi-age farms. Egg production and mortality of infected flocks were respectively lower and higher than in non-infected flocks but the differences were not statistically significant. The genomic profiles of isolates were quite homogeneous, a feature which does not facilitate the understanding of routes of transmission. All isolates were susceptible to tetracyclines, macrolides (except erythromycin), spectinomycin and fluoroquinolones. 相似文献
20.
Pulsed-field gel electrophoresis (PFGE) analysis was developed and compared with random amplified polymorphic DNA (RAPD) method to type 18 Mycoplasma synoviae (MS) strains. All analysed strains were typeable by RAPD but only 89% of MS strains were typeable by PFGE because of DNA degradation. The discriminatory power of RAPD was greater than that of PFGE but the two techniques had a discriminatory index superior to 0.95, the threshold value for interpreting typing results with confidence. The in vitro, in ovo and in vivo reproducibility of both typing techniques was 100%. However, the interpretation of RAPD patterns was complicated because of inconsistent band intensity. Thus, these molecular typing techniques should be helpful for epidemiological studies of avian mycoplasma infections. 相似文献