The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Dušan Benčina - One of the best experts on this subject based on the ideXlab platform.
-
Multilocus sequence analysis for Mycoplasma synoviae molecular genotyping
British Poultry Science, 2015Co-Authors: Ivanka Cizelj, Mojca Narat, Rebeka Lucijana Berčič, Brigita Slavec, Peter Dovč, Dušan BenčinaAbstract:Abstract The aim of this study was to identify molecular techniques which enable clear discrimination between Mycoplasma synoviae isolates for improved epidemiology.Multilocus sequence analysis (MLSA) of 6 M. synoviae loci was conducted for genotyping of isolates with previously determined 5ʹ-vlhA sequences.Sequencing of three polymorphic genes (5ʹ-vlhA, cysP and nanH) enables good discrimination between isolates with different genotypes. Such a genotyping scheme revealed 10 distinct genotypes, which were confirmed by sequencing of an additional three loci of the M. synoviae genome. Epidemiologically linked strains formed clusters with the same genotypes which clearly differed between clusters.MLSA used in this study is a promising tool for epidemiology of M. synoviae isolates, but it should be evaluated by further investigations using a much higher number of M. synoviae strains.
-
Phenotypic Characterization of Mycoplasma synoviae Induced Changes in the Metabolic and Sensitivity Profile of In Vitro Infected Chicken Chondrocytes
BioMed Research International, 2014Co-Authors: Daliborka Dušanić, Dušan Benčina, Mojca Narat, Irena OvenAbstract:In infectious synovitis caused by Mycoplasma synoviae chicken chondrocytes (CCH) may come into direct contact with these bacteria that are also capable of invading CCH in vitro. In this study, phenotype microarrays were used to evaluate the influence of Mycoplasma synoviae on the global metabolic activity of CCH. Therefore, CCH were cultured in the presence of 504 individual compounds, spotted in wells of 11 phenotype microarrays for eukaryotic cells, and exposed to Mycoplasma synoviae membranes or viable Mycoplasma synoviae. Metabolic activity and sensitivity of normal cells versus infected cells were evaluated. Metabolic profiles of CCH treated with viable Mycoplasma synoviae or its membranes were significantly different from those of CCH alone. CCH treated with Mycoplasma synoviae membranes were able to use 48 carbon/nitrogen sources not used by CCH alone. Treatment also influenced ion uptake in CCH and intensified the sensitivity to 13 hormones, 5 immune mediators, and 29 cytotoxic chemicals. CCH were even more sensitive to hormones/immune mediators when exposed to viable Mycoplasma synoviae. Our results indicate that exposure to Mycoplasma synoviae or its membranes induces a wide range of metabolic and sensitivity modifications in CCH that can contribute to pathological processes in the development of infectious synovitis.
-
diacylated lipopeptide from Mycoplasma synoviae mediates tlr15 induced innate immune responses
Veterinary Research, 2013Co-Authors: Irena Oven, Dušan Benčina, Daliborka Dusanic, Calvin L Keeler, Mojca NaratAbstract:Avian-specific toll like receptor 15 (TLR15) is functionally equivalent to a group of TLR2 family proteins that the mammalian innate immune system utilizes to recognize a broad spectrum of microbe-associated molecular patterns, including bacterial lipoproteins. In this study we examined the role of chicken TLR2 family members in the innate immune response to the avian pathogenic bacterium, Mycoplasma synoviae. We found that Mycoplasma synoviae, and specifically the N-terminal diacylated lipopeptide (MDLP) representing the amino-terminal portion of its mature haemagglutinin protein, significantly induces the expression of TLR15, but not TLR1 and TLR2 in chicken macrophages and chondrocytes. TLR15 activation is specific and depends on diacylation of the lipopeptide. Activation of TLR15 after stimulation with Mycoplasma synoviae and MDLP triggers an increase in the expression of transcription factor nuclear factor kappa B and nitric oxide production. Moreover, transfection of avian macrophage cells with small interfering RNA reduces the expression of TLR15 after stimulation with MDLP. This leads to decreased activation of the innate immune response, as measured by nitric oxide production. Additionally, pretreatment of cells with neutralizing anti-TLR15 antibody results in a notable attenuation of MDLP-driven release of nitric oxide. This positive correlation may constitute a mechanism for stimulating the innate immune response against avian Mycoplasmas in chicken cells via TLR15.
-
Mycoplasma synoviae invades non phagocytic chicken cells in vitro
Veterinary Microbiology, 2009Co-Authors: Daliborka Dusanic, Mojca Narat, Ivanka Cizelj, Rebeka Lucijana Berčič, Simona Salmic, Dušan BenčinaAbstract:Abstract Mycoplasma synoviae and Mycoplasma gallisepticum are major poultry pathogens, but their strains differ significantly in invasiveness and pathogenicity. Recent studies have demonstrated that M. gallisepticum invades chicken erythrocytes (CER) and chicken embryonic fibroblasts. The aim of this study was to determine whether M. synoviae also invades chicken cells. Using the gentamicin invasion assay, relative invasion frequency (RIF) of four M. synoviae strains was determined for CER, chicken embryonic cell line (CEC-32) and/or primary chicken chondrocytes (CCH). All tested strains of M. synoviae were capable of invading chicken cells within 24 h after infection. The type strain WVU 1853 showed significantly higher invasiveness in CER (RIF 7.5 ± 1.5%) and CEC-32 (RIF 7.0 ± 0.3%) than field strain ULB 02/T6 and M. gallisepticum strain R low . Surprisingly, WVU 1853, which is capable of causing synovitis and arthritis in chickens, was less invasive for CCH with a RIF (1.2 ± 0.3%) similar to that of R low (1.1 ± 0.1%). This is the first study documenting the invasiveness of M. synoviae strains for non-phagocytic chicken cells.
-
infection of turkeys with ornithobacterium rhinotracheale and Mycoplasma synoviae
Avian Diseases, 2000Co-Authors: Olga Zormanrojs, Dušan Benčina, Irena Zdovc, Ivan MrzelAbstract:: Within 1 mo, two separate outbreaks of respiratory disease occurred in two flocks on the multiage market turkey farm in Slovenia. More severe dinical signs and higher mortality were observed in male birds. Ornithobacterium rhinotracheale (ORT) was isolated in pure culture from tracheas of the affected birds in both outbreaks. Commercial enzyme-linked immunosorbent assay test showed the presence of antibodies to ORT in sera of birds from both clinically affected flocks and also in two flocks of younger birds without clinical sings. Immunoblotting with ORT culture isolated during the outbreak as an antigen confirmed the presence of antibodies to ORT in sera of turkeys of all four flocks examined. In addition, three different serologic assays also detected antibodies to Mycoplasma synoviae (MS) in three out of four flocks. The concomitant infection with MS did not show an obvious effect on mortality rates nor on the antibody response against ORT. Younger birds appeared to be less susceptible to ORT pathogenicity because in those flocks the infection was subclinical.
Mojca Narat - One of the best experts on this subject based on the ideXlab platform.
-
Multilocus sequence analysis for Mycoplasma synoviae molecular genotyping
British Poultry Science, 2015Co-Authors: Ivanka Cizelj, Mojca Narat, Rebeka Lucijana Berčič, Brigita Slavec, Peter Dovč, Dušan BenčinaAbstract:Abstract The aim of this study was to identify molecular techniques which enable clear discrimination between Mycoplasma synoviae isolates for improved epidemiology.Multilocus sequence analysis (MLSA) of 6 M. synoviae loci was conducted for genotyping of isolates with previously determined 5ʹ-vlhA sequences.Sequencing of three polymorphic genes (5ʹ-vlhA, cysP and nanH) enables good discrimination between isolates with different genotypes. Such a genotyping scheme revealed 10 distinct genotypes, which were confirmed by sequencing of an additional three loci of the M. synoviae genome. Epidemiologically linked strains formed clusters with the same genotypes which clearly differed between clusters.MLSA used in this study is a promising tool for epidemiology of M. synoviae isolates, but it should be evaluated by further investigations using a much higher number of M. synoviae strains.
-
Phenotypic Characterization of Mycoplasma synoviae Induced Changes in the Metabolic and Sensitivity Profile of In Vitro Infected Chicken Chondrocytes
BioMed Research International, 2014Co-Authors: Daliborka Dušanić, Dušan Benčina, Mojca Narat, Irena OvenAbstract:In infectious synovitis caused by Mycoplasma synoviae chicken chondrocytes (CCH) may come into direct contact with these bacteria that are also capable of invading CCH in vitro. In this study, phenotype microarrays were used to evaluate the influence of Mycoplasma synoviae on the global metabolic activity of CCH. Therefore, CCH were cultured in the presence of 504 individual compounds, spotted in wells of 11 phenotype microarrays for eukaryotic cells, and exposed to Mycoplasma synoviae membranes or viable Mycoplasma synoviae. Metabolic activity and sensitivity of normal cells versus infected cells were evaluated. Metabolic profiles of CCH treated with viable Mycoplasma synoviae or its membranes were significantly different from those of CCH alone. CCH treated with Mycoplasma synoviae membranes were able to use 48 carbon/nitrogen sources not used by CCH alone. Treatment also influenced ion uptake in CCH and intensified the sensitivity to 13 hormones, 5 immune mediators, and 29 cytotoxic chemicals. CCH were even more sensitive to hormones/immune mediators when exposed to viable Mycoplasma synoviae. Our results indicate that exposure to Mycoplasma synoviae or its membranes induces a wide range of metabolic and sensitivity modifications in CCH that can contribute to pathological processes in the development of infectious synovitis.
-
diacylated lipopeptide from Mycoplasma synoviae mediates tlr15 induced innate immune responses
Veterinary Research, 2013Co-Authors: Irena Oven, Dušan Benčina, Daliborka Dusanic, Calvin L Keeler, Mojca NaratAbstract:Avian-specific toll like receptor 15 (TLR15) is functionally equivalent to a group of TLR2 family proteins that the mammalian innate immune system utilizes to recognize a broad spectrum of microbe-associated molecular patterns, including bacterial lipoproteins. In this study we examined the role of chicken TLR2 family members in the innate immune response to the avian pathogenic bacterium, Mycoplasma synoviae. We found that Mycoplasma synoviae, and specifically the N-terminal diacylated lipopeptide (MDLP) representing the amino-terminal portion of its mature haemagglutinin protein, significantly induces the expression of TLR15, but not TLR1 and TLR2 in chicken macrophages and chondrocytes. TLR15 activation is specific and depends on diacylation of the lipopeptide. Activation of TLR15 after stimulation with Mycoplasma synoviae and MDLP triggers an increase in the expression of transcription factor nuclear factor kappa B and nitric oxide production. Moreover, transfection of avian macrophage cells with small interfering RNA reduces the expression of TLR15 after stimulation with MDLP. This leads to decreased activation of the innate immune response, as measured by nitric oxide production. Additionally, pretreatment of cells with neutralizing anti-TLR15 antibody results in a notable attenuation of MDLP-driven release of nitric oxide. This positive correlation may constitute a mechanism for stimulating the innate immune response against avian Mycoplasmas in chicken cells via TLR15.
-
Mycoplasma synoviae invades non phagocytic chicken cells in vitro
Veterinary Microbiology, 2009Co-Authors: Daliborka Dusanic, Mojca Narat, Ivanka Cizelj, Rebeka Lucijana Berčič, Simona Salmic, Dušan BenčinaAbstract:Abstract Mycoplasma synoviae and Mycoplasma gallisepticum are major poultry pathogens, but their strains differ significantly in invasiveness and pathogenicity. Recent studies have demonstrated that M. gallisepticum invades chicken erythrocytes (CER) and chicken embryonic fibroblasts. The aim of this study was to determine whether M. synoviae also invades chicken cells. Using the gentamicin invasion assay, relative invasion frequency (RIF) of four M. synoviae strains was determined for CER, chicken embryonic cell line (CEC-32) and/or primary chicken chondrocytes (CCH). All tested strains of M. synoviae were capable of invading chicken cells within 24 h after infection. The type strain WVU 1853 showed significantly higher invasiveness in CER (RIF 7.5 ± 1.5%) and CEC-32 (RIF 7.0 ± 0.3%) than field strain ULB 02/T6 and M. gallisepticum strain R low . Surprisingly, WVU 1853, which is capable of causing synovitis and arthritis in chickens, was less invasive for CCH with a RIF (1.2 ± 0.3%) similar to that of R low (1.1 ± 0.1%). This is the first study documenting the invasiveness of M. synoviae strains for non-phagocytic chicken cells.
Hernan Terenzi - One of the best experts on this subject based on the ideXlab platform.
-
extracellular proteins of Mycoplasma synoviae
International Scholarly Research Notices, 2012Co-Authors: Manuel Sebastian Rebollo Couto, Catia Silene Klein, Daiane Vossrech, Hernan TerenziAbstract:Mycoplasma synoviae is a Gram positive bacteria lacking of cell wall that affects chickens and turkeys causing infection in the upper respiratory tract and in some cases arthritis, with economical impact to broiler breeders. Treatment and prevention of avian synovitis depend on knowledge of the infectious process. Secreted or surface-exposed proteins play a critical role in disease because they often mediate interactions between host and pathogen. In the present work, we sought to identify possible M. synoviae secreted proteins by cultivating the bacteria in a modified protein-free Frey medium. Using this approach, we were able to detect in the cell-free fraction a number of proteins that have been shown in other organisms to be secreted, suggesting that they may also be secreted by M. synoviae.
-
first partial proteome of the poultry pathogen Mycoplasma synoviae
Veterinary Microbiology, 2010Co-Authors: Angela C O Menegatti, Catia Silene Klein, Carolina Tavares, Javier Vernal, Luciano F Huergo, Hernan TerenziAbstract:Mycoplasma synoviae is responsible for respiratory tract disease and synovitis in chickens and turkeys. In an attempt to identify the most prominent proteins expressed by this microorganism, a proteome map of M. synoviae was developed by using two-dimensional gel electrophoresis in combination with mass spectrometry. Based on the genome sequence of M. synoviae, a total of 30 different coding DNA sequences, including one hypothetical and one conserved-hypothetical protein, were experimentally verified with the identification of the corresponding protein products by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). The identified proteins were assigned according to the Clusters of Orthologous Groups of proteins functional classification. M. synoviae has 694 predicted CDSs. Overall, in this work 416 proteins spots were resolved in Coomassie Blue stained 2DE gels and were analyzed by mass spectrometry (MS). Altogether, we have achieved by MS the identification of 78 protein spots, corresponding to 30 different proteins. This is the first proteome map to be described in M. synoviae, and it is expected to be useful as a reference for comparative analysis.
S. H. Kleven - One of the best experts on this subject based on the ideXlab platform.
-
sialidase activity in Mycoplasma synoviae
Avian Diseases, 2007Co-Authors: S. H. Kleven, Daniel R BrownAbstract:Abstract Eleven strains of the avian pathogen Mycoplasma synoviae were evaluated for the presence of sialidase activity with the use of the fluorogenic substrate 2′-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid and the sialidase inhibitor 2-deoxy-2,3-didehydro-N-acetylneuraminic acid. The kinetics of in vitro growth in modified Frey medium were also assessed for each strain. Five strains had been isolated from clinically symptomatic chickens, and strains WVU1853T and K3344 have been demonstrated to be capable of reproducing disease in specific-pathogen-free chickens. All strains exhibited sialidase activity, although the amount varied 65-fold among strains (P < 0.0001) from 1.3 × 10−7 to 2.0 × 10−9 activity units per colony-forming unit. Strains originally isolated from clinically symptomatic birds had more (P < 0.05) sialidase activity than strains from asymptomatic birds. Strain WVU1853T exhibited the most sialidase activity (P < 0.0001) and grew to the highest culture density (P < 0.0001) among st...
-
virulence of recent isolates of Mycoplasma synoviae in turkeys
Avian Diseases, 2002Co-Authors: M S Kang, P Gazdzinski, S. H. KlevenAbstract:SUMMARY. Systemic Mycoplasma synoviae (MS) infection was induced experimentally in commercial turkeys with recent MS isolates (K4822D and K4774J) from turkey breeder flocks that exhibited no clinical signs typical of MS infection except for a low incidence of swollen footpads. The virulence of each strain was compared by evaluating gross and microscopic lesions, serologic responses, and MS isolation rates at 10 and 21 days postchallenge and by comparing these results with those obtained from a known virulent isolate (K1968), another previously characterized field isolate (K4463B), and unchallenged controls. All strains induced lesions typical of infectious synovitis but showed distinct differences in the extent of the gross and microscopic lesions and in the isolation rates from the tissues in turkeys. K1968 induced the most extensive lesions in hock and stifle joints and footpads, but strains K4822D, K4774J, and K4463B all induced synovitis and were similar in virulence for synovial tissues. Very mild re...
-
poor serologic response to upper respiratory infection with Mycoplasma synoviae in turkeys
Avian Diseases, 2001Co-Authors: S. H. Kleven, G N Rowland, M C KumarAbstract:SUMMARY. Mycoplasma synoviae (MS) was isolated from a flock of commercial tom turkeys in which a small percentage of the birds exhibited clinical signs and lesions typical of MS synovitis. However, serologic testing of such flocks revealed poor to inconsistent reactivity by agglutination, enzyme-linked immunosorbent assay (ELISA) or hemagglutination inhibition; isolation of MS from such flocks proved to be very difficult. Turkeys were challenged with one of the isolates (K4463B) either by aerosol or systemically by a combination of intravenous, foot pad, and eyedrop routes. Turkeys challenged by the systemic route responded normally to all serologic tests, whereas those challenged by aerosol either responded very poorly on all serologic tests or were seronegative up to 6 wk postchallenge even though they were positive for MS by tracheal culture. These results suggest that turkeys may harbor an upper respiratory infection with MS while remaining serologically negative. RESUMEN. Nota de Investigacion-Respuesta serologica pobre a la infecci6n del tracto respiratorio superior con Mycoplasma synoviae en pavos.
-
pathogenicity of Mycoplasma synoviae in broiler chickens
Veterinary Pathology, 1998Co-Authors: S B Lockaby, Frederic J. Hoerr, L H Lauerman, S. H. KlevenAbstract:Six isolates of Mycoplasma synoviae, identified as WVU 1853, K1968, K1858, 92D8034, F10–2AS, and FMT, were compared for pathogenicity in broiler chickens. Specific-pathogen-free chickens were inoculated, in two groups of 20, with each isolate by footpad or eyedrop inoculation at 1 day of age and were examined at necropsy 7, 14, 28, and 42 days postinoculation. Specimens were taken for histopathology, culture, polymerase chain reaction assay, and hemagglutination-inhibition serology. Isolates were grouped according to pathogenicity on the basis of differences in lesion development and tissue distribution in the respiratory system, other viscera, and the skeletal system. K1968 (pathogenic) induced lesions in all sites examined in both the footpad and eyedrop inoculation groups. It was detected in all sites following footpad inoculation and in all sites except viscera following eyedrop inoculation. WVU 1853, K1858, and 92D8034 (moderately pathogenic) induced lesions and were detected in all sites following f...
-
Serological detection of Mycoplasma synoviae infection in turkeys.
Avian Diseases, 1992Co-Authors: Ariel Ortiz, S. H. KlevenAbstract:SUMMARY. The antibody response of turkeys experimentally infected with Mycoplasma synoviae was determined by the serum plate agglutination (SPA), hemagglutination-inhibition (HI), and microagglutination (MA) tests and the enzyme-linked immunosorbent assay (ELISA). No antibody response was detected until 2 weeks postinfection (PI) with the MA test (17% positive), 3 weeks PI with the SPA test (11% positive), 4 weeks with the HI test (21% positive), and 5 weeks PI with the ELISA, and even then, only 16% of the birds were positive. Although at least 89% of the birds were positive by culture, only 58% of the turkeys developed a detectable antibody response.
Ivanka Cizelj - One of the best experts on this subject based on the ideXlab platform.
-
Multilocus sequence analysis for Mycoplasma synoviae molecular genotyping
British Poultry Science, 2015Co-Authors: Ivanka Cizelj, Mojca Narat, Rebeka Lucijana Berčič, Brigita Slavec, Peter Dovč, Dušan BenčinaAbstract:Abstract The aim of this study was to identify molecular techniques which enable clear discrimination between Mycoplasma synoviae isolates for improved epidemiology.Multilocus sequence analysis (MLSA) of 6 M. synoviae loci was conducted for genotyping of isolates with previously determined 5ʹ-vlhA sequences.Sequencing of three polymorphic genes (5ʹ-vlhA, cysP and nanH) enables good discrimination between isolates with different genotypes. Such a genotyping scheme revealed 10 distinct genotypes, which were confirmed by sequencing of an additional three loci of the M. synoviae genome. Epidemiologically linked strains formed clusters with the same genotypes which clearly differed between clusters.MLSA used in this study is a promising tool for epidemiology of M. synoviae isolates, but it should be evaluated by further investigations using a much higher number of M. synoviae strains.
-
Mycoplasma synoviae invades non phagocytic chicken cells in vitro
Veterinary Microbiology, 2009Co-Authors: Daliborka Dusanic, Mojca Narat, Ivanka Cizelj, Rebeka Lucijana Berčič, Simona Salmic, Dušan BenčinaAbstract:Abstract Mycoplasma synoviae and Mycoplasma gallisepticum are major poultry pathogens, but their strains differ significantly in invasiveness and pathogenicity. Recent studies have demonstrated that M. gallisepticum invades chicken erythrocytes (CER) and chicken embryonic fibroblasts. The aim of this study was to determine whether M. synoviae also invades chicken cells. Using the gentamicin invasion assay, relative invasion frequency (RIF) of four M. synoviae strains was determined for CER, chicken embryonic cell line (CEC-32) and/or primary chicken chondrocytes (CCH). All tested strains of M. synoviae were capable of invading chicken cells within 24 h after infection. The type strain WVU 1853 showed significantly higher invasiveness in CER (RIF 7.5 ± 1.5%) and CEC-32 (RIF 7.0 ± 0.3%) than field strain ULB 02/T6 and M. gallisepticum strain R low . Surprisingly, WVU 1853, which is capable of causing synovitis and arthritis in chickens, was less invasive for CCH with a RIF (1.2 ± 0.3%) similar to that of R low (1.1 ± 0.1%). This is the first study documenting the invasiveness of M. synoviae strains for non-phagocytic chicken cells.
