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1.
Vaccine ; 42(8): 1868-1872, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38365481

RESUMO

Vaccination is the most cost-effective tool to control contagious bovine pleuropneumonia. The vaccines currently used in Africa are derived from a live strain called T1, which was attenuated by passage in embryonated eggs and broth culture. The number of passages is directly correlated to the degree of attenuation of the vaccinal strains and inversely correlated to their immunogenicity in cattle. Current quality control protocols applied to vaccine batches allow the assessment of identity, purity, and titers, but cannot assess the level of genetic drift form the parental vaccine strains. Deep sequencing was used to assess the genetic drift generated over controlled in vitro passages of the parental strain, as well as on commercial vaccine batches. Signatures of cloning procedures were detected in some batches, which imply a deviation from the standard production protocol. Deep sequencing is proposed as a new tool for the identity and stability control of T1 vaccines.


Assuntos
Doenças dos Bovinos , Mycoplasma mycoides , Pleuropneumonia Contagiosa , Pleuropneumonia , Animais , Bovinos , Vacinas Bacterianas/genética , África , Vacinas Atenuadas/genética , Controle de Qualidade , Sequenciamento de Nucleotídeos em Larga Escala , Pleuropneumonia Contagiosa/prevenção & controle , Mycoplasma mycoides/genética
2.
Microbiology (Reading) ; 170(1)2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38193814

RESUMO

Mycoplasma capricolum subspecies capripneumoniae (Mccp) is the causative agent of contagious caprine pleuropneumonia (CCPP), a devastating disease listed by the World Organisation for Animal Health (WOAH) as a notifiable disease and threatening goat production in Africa and Asia. Although a few commercial inactivated vaccines are available, they do not comply with WOAH standards and there are serious doubts regarding their efficacy. One of the limiting factors to comprehend the molecular pathogenesis of CCPP and develop improved vaccines has been the lack of tools for Mccp genome engineering. In this work, key synthetic biology techniques recently developed for closely related mycoplasmas were adapted to Mccp. CReasPy-Cloning was used to simultaneously clone and engineer the Mccp genome in yeast, prior to whole-genome transplantation into M. capricolum subsp. capricolum recipient cells. This approach was used to knock out an S41 serine protease gene recently identified as a potential virulence factor, leading to the generation of the first site-specific Mccp mutants. The Cre-lox recombination system was then applied to remove all DNA sequences added during genome engineering. Finally, the resulting unmarked S41 serine protease mutants were validated by whole-genome sequencing and their non-caseinolytic phenotype was confirmed by casein digestion assay on milk agar. The synthetic biology tools that have been successfully implemented in Mccp allow the addition and removal of genes and other genetic features for the construction of seamless targeted mutants at ease, which will pave the way for both the identification of key pathogenicity determinants of Mccp and the rational design of novel, improved vaccines for the control of CCPP.


Assuntos
Mycoplasma , Vacinas , Animais , Cabras , Mycoplasma/genética , Serina Proteases
3.
ACS Synth Biol ; 12(11): 3252-3266, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37843014

RESUMO

The genetic engineering of genome fragments larger than 100 kbp is challenging and requires both specific methods and cloning hosts. The yeast Saccharomyces cerevisiae is considered as a host of choice for cloning and engineering whole or partial genomes from viruses, bacteria, and algae. Several methods are now available to perform these manipulations, each with its own limitations. In order to extend the range of yeast cloning strategies, a new approach combining two already described methods, Fusion cloning and CReasPy-Cloning, was developed. The CReasPy-Fusion method allows the simultaneous cloning and engineering of megabase-sized genomes in yeast by the fusion of bacterial cells with yeast spheroplasts carrying the CRISPR-Cas9 system. With this new approach, we demonstrate the feasibility of cloning and editing whole genomes from several Mycoplasma species belonging to different phylogenetic groups. We also show that CReasPy-Fusion allows the capture of large genome fragments with high efficacy, resulting in the successful cloning of selected loci in yeast. We finally identify bacterial nuclease encoding genes as barriers for CReasPy-Fusion by showing that their removal from the donor genome improves the cloning efficacy.


Assuntos
Sistemas CRISPR-Cas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Sistemas CRISPR-Cas/genética , Filogenia , Genoma Bacteriano/genética , DNA , Clonagem Molecular , Edição de Genes/métodos
4.
Vet Res ; 53(1): 92, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376915

RESUMO

Multi-Locus Sequence Analysis (MLSA) of Mycoplasma capricolum subsp. capripneumoniae (Mccp) strains from Asia revealed unforeseen diversity and a central position for genotyping groups representing strains from Central/East Asia, suggesting a possible origin of contagious caprine pleuropneumonia in this continent. A better assessment of the emergence, diversity and distribution of Mccp in Asia and Africa calls for renewed efforts to dramatically enlarge the sample of strains. Availability and affordability in the field, added to superior typeability (directly from poor samples) and high stability, discriminatory power and concordance with epidemiological and phylogenetic analyses, make MLSA an excellent tool for such investigations.


Assuntos
Doenças das Cabras , Mycoplasma capricolum , Pleuropneumonia Contagiosa , Animais , Pleuropneumonia Contagiosa/epidemiologia , Filogenia , Cabras/genética , Doenças das Cabras/epidemiologia , Análise de Sequência/veterinária , Variação Genética , Mycoplasma capricolum/genética
5.
Heliyon ; 6(10): e05146, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33083610

RESUMO

Contagious caprine pleuropneumonia is an infectious and contagious disease affecting goats and wildlife ruminants, mostly in Africa and Asia. It is caused by a mycoplasma, Mycoplasma capricolum susbp. capripneumoniae, which is very fastidious. This may be the reason why there are few reports of its isolation and characterization. This study describes the development of a whole genome typing strategy based on sequencing reads assemblies on a reference genome (Abomsa, GenBank accession LM995445) and extraction of informative single nucleotide polymorphism. FASTA sequences inferred from the variant calling files were used to establish a comprehensive phylogenetic tree based on 2880 SNPs. This tree included a total of 34 strains originating from all the regions where CCPP has been detected, as well as strains isolated from wildlife. A recent isolate from West-Niger was positioned closely to another 1995 East-Niger isolate, an indication that CCPP may be extending westward in Africa. Six 2013 Tanzanian isolates had identical sequences in spite of diverse geographical origins. This could be explained by the clonal expansion of a virulent strain at that time in East Africa. Although all strains isolated from wildlife in the Middle East were in the same phylogenetic group, this may not sign an adaptation to new hosts. The most probable explanation for wildlife contamination remains the contact with goats. This strategy will easily accommodate new data in the near future and should become a gold-standard high-resolution typing procedure for the surveillance of contagious caprine pleuropneumonia.

6.
Appl Environ Microbiol ; 85(23)2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31540994

RESUMO

Many mycoplasma species are isolated from the ruminant lungs as either saprophytes or true pathogens. These wall-less bacteria possess a minimal genome and reduced metabolic capabilities. Accordingly, they rely heavily on their hosts for the supply of essential metabolites and, notably, peptides. Seven of 13 ruminant lung-associated Mycoplasma (sub)species were shown to possess caseinolytic activity when grown in rich media and assessed with a quantitative fluorescence test. For some species, this activity was detected in spent medium, an indication that proteases were secreted outside the mycoplasma cells. To identify these proteases, we incubated concentrated washed cell pellets in a defined medium and analyzed the supernatants by tandem mass spectrometry. Secreted-protease activity was detected mostly in the species belonging to the Mycoplasma mycoides cluster (MMC) and, to a lesser extent, in Mycoplasma bovirhinis Analyzing a Mycoplasma mycoides subsp. capri strain, chosen as a model, we identified 35 expressed proteases among 55 predicted coding genes, of which 5 were preferentially found in the supernatant. Serine protease S41, acquired by horizontal gene transfer, was responsible for the caseinolytic activity, as demonstrated by zymography and mutant analysis. In an M. capricolum mutant, inactivation of the S41 protease resulted in marked modification of the expression or secretion of 17 predicted surface-exposed proteins. This is an indication that the S41 protease could have a role in posttranslational cleavage of surface-exposed proteins and ectodomain shedding, whose physiological impacts still need to be explored.IMPORTANCE Few studies pertaining to proteases in ruminant mycoplasmas have been reported. Here, we focus on proteases that are secreted outside the mycoplasma cell using a mass spectrometry approach. The most striking result is the identification, within the Mycoplasma mycoides cluster, of a serine protease that is exclusively detected outside the mycoplasma cells and is responsible for casein digestion. This protease may also be involved in the posttranslational processing of surface proteins, as suggested by analysis of mutants showing a marked reduction in the secretion of extracellular proteins. By analogy, this finding may help increase understanding of the mechanisms underlying this ectodomain shedding in other mycoplasma species. The gene encoding this protease is likely to have been acquired via horizontal gene transfer from Gram-positive bacteria and sortase-associated surface proteases. Whether this protease and the associated ectodomain shedding are related to virulence has yet to be ascertained.


Assuntos
Pulmão/microbiologia , Mycoplasma/enzimologia , Peptídeo Hidrolases/metabolismo , Ruminantes/microbiologia , Animais , Proteínas de Membrana/metabolismo
7.
Int J Syst Evol Microbiol ; 69(11): 3650-3653, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31385780

RESUMO

The consensus of the members of the International Committee on Systematics of Prokaryotes' Subcommittee on the taxonomy of Mollicutes is that recently proposed sweeping changes to nomenclature of members of the Mycoplasmatales, specifically involving introduction of the names Malacoplasma gen. nov., Mesomycoplasma gen. nov., Metamycoplasma gen. nov., Metamycoplasmataceaefam. nov., Mycoplasmoidaceaefam. nov., Mycoplasmoidalesord. nov., Mycoplasmoides gen. nov., Mycoplasmopsis gen. nov., and all proposed species or subspecies comb. nov. placed therein, should be rejected because they violate one or more essential points of the International Code of Nomenclature of Prokaryotes.


Assuntos
Tenericutes/classificação , Filogenia , Terminologia como Assunto
8.
PLoS One ; 13(11): e0208160, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30485365

RESUMO

Release of extracellular vesicles (EV) by Gram-negative and positive bacteria is being frequently reported. EV are nano-sized, membrane-derived, non-self-replicating, spherical structures shed into the extracellular environment that could play a role in bacteria-host interactions. Evidence of EV production in bacteria belonging to the class Mollicutes, which are wall-less, is mainly restricted to the genus Acholeplasma and is scanty for the Mycoplasma genus that comprises major human and animal pathogens. Here EV release by six Mycoplasma (sub)species of clinical importance was investigated. EV were obtained under nutritional stress conditions, purified by ultracentrifugation and observed by electron microscopy. The membrane proteins of EV from three different species were further identified by mass spectrometry as a preliminary approach to determining their potential role in host-pathogen interactions. EV were shown to be released by all six (sub)species although their quantities and sizes (30-220 nm) were very variable. EV purification was complicated by the minute size of viable mycoplasmal cells. The proteins of EV-membranes from three (sub)species included major components of host-pathogen interactions, suggesting that EV could contribute to make the host-pathogen interplay more complex. The process behind EV release has yet to be deciphered, although several observations demonstrated their active release from the plasma membrane of living cells. This work shed new light on old concepts of "elementary bodies" and "not-cell bound antigens".


Assuntos
Proteínas de Bactérias/análise , Vesículas Extracelulares/metabolismo , Interações Hospedeiro-Patógeno , Infecções por Mycoplasma/metabolismo , Infecções por Mycoplasma/microbiologia , Mycoplasma/fisiologia , Proteínas de Bactérias/metabolismo , Fracionamento Celular , Vesículas Extracelulares/química , Vesículas Extracelulares/ultraestrutura , Humanos , Microscopia Eletrônica , Mycoplasma/química , Mycoplasma/ultraestrutura
9.
Prev Vet Med ; 157: 70-77, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30086851

RESUMO

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae, has long been considered a goat-specific disease. Since 2007 there has been growing evidence that this disease can affect wild ungulates either kept in captivity or in the wild. In 2013, a large collection of sand gazelles (Gazella marica) held in the United Arab Emirates suffered heavy losses due to a CCPP epizootic confirmed by PCR and isolation. Animals displayed typical lesions, with unilateral pneumonia and profuse pleurisy. An initial antibiotic treatment consisting of tylosin administered in drinking water did not improve the animals' condition and vaccination failed to stop the spread to contiguous pens. A treatment with tetracycline mixed in feed pellets finally succeeded to stop the evolution of the disease. A subsequent vaccine trial, performed on naïve animals, showed that only a reference CCPP vaccine produced according to OIE standards induced a sero-conversion by CCPP competition ELISA, while the commercially available vaccines did not. A SEIRD compartment transmission model was developed to better understand the dynamics of the disease. The parameters were initially set as per expert opinion and then adjusted to fit the observed mortality data. The basic reproductive number R0 was estimated to be between 2.3-2.7, while the final mortality rate reached up to 70% in some pens. Transmission of infectious droplets from an external source, through a distance of at least the 50 m separating the pens from the perimeter fence, remains the most plausible explanation for the contamination of this stock of gazelles.


Assuntos
Antílopes , Pleuropneumonia Contagiosa/transmissão , Animais , Doenças das Cabras , Cabras , Mycoplasma capricolum , Pleuropneumonia Contagiosa/epidemiologia , Emirados Árabes Unidos/epidemiologia
10.
Vet Microbiol ; 195: 158-164, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27771062

RESUMO

The fastidious porcine respiratory pathogen Mycoplasma hyopneumoniae has proven difficult to culture since it was first isolated in 1965. A reliable solid medium has been particularly challenging. Moreover, clinical and pathological samples often contain the fast-growing M. hyorhinis which contaminates and overgrows M. hyopneumoniae in primary culture. The aim of this study was to optimise the culture medium for recovery of M. hyopneumoniae and to devise a medium for selection of M. hyopneumoniae from clinical samples also containing M. hyorhinis. The solid medium devised by Niels Friis was improved by use of Purified agar and incorporation of DEAE-dextran. Addition of glucose or neutralization of acidity in liquid medium with NaOH did not improve the final yield of viable organisms or alter the timing of peak viability. Analysis of the relative susceptibility of M. hyopneumoniae and M. hyorhinis strains to four antimicrobials showed that M. hyopneumoniae is less susceptible than M. hyorhinis to kanamycin. This was consistent in all UK and Danish strains tested. A concentration of 2µg/ml of kanamycin selectively inhibited the growth of all M. hyorhinis tested, while M. hyopneumoniae was able to grow. This forms the basis of an effective selective culture medium for M. hyopneumoniae.


Assuntos
Técnicas Bacteriológicas/métodos , Meios de Cultura/farmacologia , Mycoplasma hyopneumoniae/fisiologia , Antibacterianos/farmacologia , Meios de Cultura/química , Farmacorresistência Bacteriana , Mycoplasma hyorhinis/fisiologia , Especificidade da Espécie
11.
J Biotechnol ; 236: 35-44, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27497759

RESUMO

Fluorescence expression tools for stable and innocuous whole mycoplasma cell labelling have been developed. A Tn4001-derivative mini-transposon affording unmarked, stable mutagenesis in mycoplasmas was modified to allow the constitutive, high-level expression of mCherry, mKO2 and mNeonGreen. These tools were used to introduce the respective fluorescent proteins as chromosomal tags in the phylogenetically distant species Mycoplasma mycoides subsp. mycoides and Mycoplasma bovis. The production, selection and characterisation of fluorescent clones were straightforward and resulted in the unprecedented observation of red and green fluorescent mycoplasma colonies in the two species, with no apparent cytotoxicity. Equivalent fluorescence expression levels were quantified by flow cytometry in both species, suggesting that these tools can be broadly applied in mycoplasmas. A macrophage infection assay was performed to assess the usefulness of mNeonGreen-expressing strains for monitoring mycoplasma infections, and notably cell invasion. The presence of fluorescent mycoplasmas inside live phagocytic cells was detected and quantified by flow cytometry and corroborated by confocal microscopy, which allowed the identification of individual mycoplasmas in the cytoplasm of infected cells. The fluorescence expression tools developed in this study are suitable for host-pathogen interaction studies and offer innumerable perspectives for the functional analysis of mycoplasmas both in vitro and in vivo.


Assuntos
Interações Hospedeiro-Patógeno/fisiologia , Imagem Molecular/métodos , Mycoplasma/química , Mycoplasma/citologia , Espectrometria de Fluorescência/métodos , Animais , Bovinos , Células Cultivadas , Citometria de Fluxo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Mycoplasma/metabolismo , Mycoplasma/patogenicidade , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/fisiopatologia , Fagócitos/citologia , Fagócitos/microbiologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reprodutibilidade dos Testes
12.
Vet Res ; 46: 122, 2015 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-26490663

RESUMO

In this study we explored the immunomodulatory properties of highly purified free galactan, the soluble exopolysaccharide secreted by Mycoplasma mycoides subsp. mycoides (Mmm). Galactan was shown to bind to TLR2 but not TLR4 using HEK293 reporter cells and to induce the production of the anti-inflammatory cytokine IL-10 in bovine macrophages, whereas low IL-12p40 and no TNF-α, both pro-inflammatory cytokines, were induced in these cells. In addition, pre-treatment of macrophages with galactan substantially reduced lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines TNF- and IL-12p40 while increasing LPS-induced secretion of immunosuppressive IL-10. Also, galactan did not activate naïve lymphocytes and induced only low production of the Th1 cytokine IFN-γ in Mmm-experienced lymphocytes. Finally, galactan triggered weak recall proliferation of CD4+ T lymphocytes from contagious bovine pleuropneumonia-infected animals despite having a positive effect on the expression of co-stimulatory molecules on macrophages. All together, these results suggest that galactan possesses anti-inflammatory properties and potentially provides Mmm with a mechanism to evade host innate and adaptive cell-mediated immune responses.


Assuntos
Imunidade Adaptativa , Doenças dos Bovinos/microbiologia , Galactanos/metabolismo , Imunidade Inata , Macrófagos/imunologia , Mycoplasma mycoides/fisiologia , Pleuropneumonia Contagiosa/microbiologia , Animais , Bovinos , Células HEK293 , Humanos , Interleucina-10/metabolismo , Polissacarídeos Bacterianos
13.
PLoS One ; 10(10): e0139678, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26431338

RESUMO

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm), is a severe respiratory disease of cattle responsible for major economic losses in sub-Saharan Africa. Disease control relies mainly on the use of empirically attenuated vaccines that provide limited protection. Thus, understanding the virulence mechanisms used by Mmm as well as the role of the host immune system in disease development, persistence, and control is a prerequisite for the development of new, rationally designed control strategies. The aim of this study was to assess the use of whole blood transcriptome analysis to study cattle-Mmm interactions, starting by the characterization of the bovine response to Mmm infection during the acute form of the disease. For that purpose, we compared the transcriptome profile of whole blood from six cattle, before challenge by contact with Mmm-infected animals and at the appearance of first clinical signs, using a bovine microarray. Functional analysis revealed that 680 annotated genes were differentially expressed, with an overwhelming majority of down-regulated genes characterizing an immunosuppression. The main bio-functions affected were "organismal survival", "cellular development, morphology and functions" and "cell-to cell signaling and interactions". These affected functions were consistent with the results of previous in vitro immunological studies. However, microarray and qPCR validation results did not highlight pro-inflammatory molecules (such as TNFα, TLR2, IL-12B and IL-6), whereas inflammation is one of the most characteristic traits of acute CBPP. This global gene expression pattern may be considered as the result, in blood, of the local pulmonary response and the systemic events occurring during acute CBPP. Nevertheless, to understand the immune events occurring during disease, detailed analyses on the different immune cell subpopulations, either in vivo, at the local site, or in vitro, will be required. Whole blood transcriptome analysis remains an interesting approach for the identification of bio-signatures correlating to recovery and protection, which should facilitate the evaluation and validation of novel vaccine formulations.


Assuntos
Doenças dos Bovinos/genética , Terapia de Imunossupressão , Inflamação/veterinária , Mycoplasma mycoides/genética , Transcriptoma , Animais , Bovinos , Doenças dos Bovinos/imunologia , Perfilação da Expressão Gênica , Inflamação/genética , Inflamação/imunologia
14.
Vet Res ; 46: 74, 2015 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-26149260

RESUMO

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp), is a devastating disease of domestic goats and of some wild ungulate species. The disease is currently spreading in Africa and Asia and poses a serious threat to disease-free areas. A comprehensive view of the evolutionary history and dynamics of Mccp is essential to understand the epidemiology of CCPP. Yet, analysing the diversity of genetically monomorphic pathogens, such as Mccp, is complicated due to their low variability. In this study, the molecular epidemiology and evolution of CCPP was investigated using a large-scale genomic approach based on next-generation sequencing technologies, applied to a sample of strains representing the global distribution of this disease. A highly discriminatory multigene typing system was developed, allowing the differentiation of 24 haplotypes among 25 Mccp strains distributed in six genotyping groups, which showed some correlation with geographic origin. A Bayesian approach was used to infer the first robust phylogeny of the species and to date the principal events of its evolutionary history. The emergence of Mccp was estimated only at about 270 years ago, which explains the low genetic diversity of this species despite its high mutation rate, evaluated at 1.3 × 10(-6) substitutions per site per year. Finally, plausible scenarios were proposed to elucidate the evolution and dynamics of CCPP in Asia and Africa, though limited by the paucity of Mccp strains, particularly in Asia. This study shows how combining large-scale genomic data with spatial and temporal data makes it possible to obtain a comprehensive view of the epidemiology of CCPP, a precondition for the development of improved disease surveillance and control measures.


Assuntos
Variação Genética , Genoma Bacteriano , Técnicas de Genotipagem/métodos , Doenças das Cabras/epidemiologia , Mycoplasma capricolum/genética , Pleuropneumonia Contagiosa/epidemiologia , África/epidemiologia , Animais , Ásia/epidemiologia , Teorema de Bayes , Evolução Molecular , Doenças das Cabras/microbiologia , Cabras , Pleuropneumonia Contagiosa/microbiologia , Turquia/epidemiologia
15.
Appl Environ Microbiol ; 81(2): 676-87, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25398856

RESUMO

Mycoplasmas of the Mycoplasma mycoides cluster are all ruminant pathogens. Mycoplasma mycoides subsp. mycoides is responsible for contagious bovine pleuropneumonia and is known to produce capsular polysaccharide (CPS) and exopolysaccharide (EPS). Previous studies have strongly suggested a role for Mycoplasma mycoides subsp. mycoides polysaccharides in pathogenicity. Mycoplasma mycoides subsp. mycoides-secreted EPS was recently characterized as a ß(1→6)-galactofuranose homopolymer (galactan) identical to the capsular product. Here, we extended the characterization of secreted polysaccharides to all other members of the M. mycoides cluster: M. capricolum subsp. capripneumoniae, M. capricolum subsp. capricolum, M. leachii, and M. mycoides subsp. capri (including the LC and Capri serovars). Extracted EPS was characterized by nuclear magnetic resonance, resulting in the identification of a homopolymer of ß(1→2)-glucopyranose (glucan) in M. capricolum subsp. capripneumoniae and M. leachii. Monoclonal antibodies specific for this glucan and for the Mycoplasma mycoides subsp. mycoides-secreted galactan were used to detect the two polysaccharides. While M. mycoides subsp. capri strains of serovar LC produced only capsular galactan, no polysaccharide could be detected in strains of serovar Capri. All strains of M. capricolum subsp. capripneumoniae and M. leachii produced glucan CPS and EPS, whereas glucan production and localization varied among M. capricolum subsp. capricolum strains. Genes associated with polysaccharide synthesis and forming a biosynthetic pathway were predicted in all cluster members. These genes were organized in clusters within two loci representing genetic variability hot spots. Phylogenetic analysis showed that some of these genes, notably galE and glf, were acquired via horizontal gene transfer. These findings call for a reassessment of the specificity of the serological tests based on mycoplasma polysaccharides.


Assuntos
Loci Gênicos , Mycoplasma mycoides/genética , Mycoplasma mycoides/metabolismo , Polissacarídeos Bacterianos/biossíntese , Animais , Bovinos , Análise por Conglomerados , Transferência Genética Horizontal , Genes Bacterianos , Genoma Bacteriano , Espectroscopia de Ressonância Magnética , Mycoplasma mycoides/isolamento & purificação , Filogenia , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Homologia de Sequência
16.
BMC Vet Res ; 10: 48, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24565080

RESUMO

BACKGROUND: Few serological tests are available for detecting antibodies against Mycoplasma capricolum subsp. capripneumoniae, the causal agent of contagious caprine pleuropneumonia (CCPP). The complement fixation test, the test prescribed for international trade purposes, uses a crude antigen that cross-reacts with all the other mycoplasma species of the "mycoides cluster" frequently infecting goat herds. The lack of a more specific test has been a real obstacle to the evaluation of the prevalence and economic impact of CCPP worldwide. A new competitive ELISA kit for CCPP, based on a previous blocking ELISA, was formatted at CIRAD and used to evaluate the prevalence of CCPP in some regions of Kenya, Ethiopia, Mauritius, Tajikistan and Pakistan in an international collaborative study. RESULTS: The strict specificity of the test was confirmed in CCPP-free goat herds exposed to other mycoplasma species of the "mycoides cluster". Prevalence studies were performed across the enzootic range of the disease in Africa and Asia. Seroprevalence was estimated at 14.6% in the Afar region of Ethiopia, whereas all the herds presented for CCPP vaccination in Kenya tested positive (individual seroprevalence varied from 6 to 90% within each herd). In Mauritius, where CCPP emerged in 2009, nine of 62 herds tested positive. In Central Asia, where the disease was confirmed only recently, no positive animals were detected in the Wakhan District of Afghanistan or across the border in neighboring areas of Tajikistan, whereas seroprevalence varied between 2.7% and 44.2% in the other districts investigated and in northern Pakistan. The test was also used to monitor seroconversion in vaccinated animals. CONCLUSIONS: This newly formatted CCPP cELISA kit has retained the high specificity of the original kit. It can therefore be used to evaluate the prevalence of CCPP in countries or regions without vaccination programs. It could also be used to monitor the efficacy of vaccination campaigns as high-quality vaccines induce high rates of seroconversion.


Assuntos
Ensaio de Imunoadsorção Enzimática/veterinária , Doenças das Cabras/epidemiologia , Mycoplasma capricolum , Pleuropneumonia Contagiosa/microbiologia , Pleuropneumonia/veterinária , Animais , Anticorpos Monoclonais , Vacinas Bacterianas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Saúde Global , Doenças das Cabras/microbiologia , Cabras , Internacionalidade , Pleuropneumonia/epidemiologia , Pleuropneumonia Contagiosa/epidemiologia , Pleuropneumonia Contagiosa/prevenção & controle , Estudos Soroepidemiológicos
17.
PLoS One ; 8(7): e68373, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23869216

RESUMO

Contagious bovine pleuropneumonia is a severe respiratory disease of cattle that is caused by a bacterium of the Mycoplasma genus, namely Mycoplasma mycoides subsp. mycoides (Mmm). In the absence of classical virulence determinants, the pathogenicity of Mmm is thought to rely on intrinsic metabolic functions and specific components of the outer cell surface. One of these latter, the capsular polysaccharide galactan has been notably demonstrated to play a role in Mmm persistence and dissemination. The free exopolysaccharides (EPS), also produced by Mmm and shown to circulate in the blood stream of infected cattle, have received little attention so far. Indeed, their characterization has been hindered by the presence of polysaccharide contaminants in the complex mycoplasma culture medium. In this study, we developed a method to produce large quantities of EPS by transfer of mycoplasma cells from their complex broth to a chemically defined medium and subsequent purification. NMR analyses revealed that the purified, free EPS had an identical ß(1->6)-galactofuranosyl structure to that of capsular galactan. We then analyzed intraclonal Mmm variants that produce opaque/translucent colonies on agar. First, we demonstrated that colony opacity was related to the production of a capsule, as observed by electron microscopy. We then compared the EPS extracts and showed that the non-capsulated, translucent colony variants produced higher amounts of free EPS than the capsulated, opaque colony variants. This phenotypic variation was associated with an antigenic variation of a specific glucose phosphotransferase permease. Finally, we conducted in silico analyses of candidate polysaccharide biosynthetic pathways in order to decipher the potential link between glucose phosphotransferase permease activity and attachment/release of galactan. The co-existence of variants producing alternative forms of galactan (capsular versus free extracellular galactan) and associated with an antigenic switch constitutes a finely tuned mechanism that may be involved in virulence.


Assuntos
Mycoplasma mycoides/metabolismo , Polissacarídeos Bacterianos/metabolismo , Variação Antigênica , Vias Biossintéticas , Biologia Computacional , Galactanos , Mycoplasma mycoides/ultraestrutura , Ressonância Magnética Nuclear Biomolecular , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação
19.
Genome Announc ; 1(3)2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-23766408

RESUMO

We report here the draft genome sequences of Mycoplasma alkalescens, Mycoplasma arginini, and Mycoplasma bovigenitalium. These three species are regularly isolated from bovine clinical specimens, although their role in disease is unclear.

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