Florence Tardy's research while affiliated with University of Lyon and other places

Publications (101)

Preprint
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Mycoplasma feriruminatoris is a fast-growing Mycoplasma species isolated from wild Caprinae and first described in 2013. M. feriruminatoris isolates have been associated with arthritis, keratoconjunctivitis, pneumonia and septicemia, but were also recovered from apparently healthy animals. To better understand what defines this species, we performe...
Article
Background: Bacteria belonging to the genus Mycoplasma are small-sized, have no cell walls and small genomes. They commonly cause respiratory disorders in their animal hosts. Three species have been found in the respiratory tract of horses worldwide, i.e. Mycoplasma (M.) equirhinis, M. pulmonis and M. felis, but their role in clinical cases remain...
Article
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Background Mycoplasma (M.) bovis is a major etiological agent of bovine respiratory disease, which is the most economically costly disease of cattle worldwide. Cattle disease surveillance on M. bovis is increasingly using gene-based techniques, such as multilocus sequence typing (MLST), or genome-based techniques such as core genome MLST that both...
Article
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Bovine respiratory disease (BRD) is common in calves in Algeria, but to date, Mycoplasma bovis has never been monitored as a potential etiological agent. Here, to assess the presence (direct detection) and circulation (indirect detection) of M. bovis, broncho-alveolar lavage fluids (BALF) and serum samples were collected from 60 veal calf farms in...
Article
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The bacterial secretome comprises polypeptides expressed at the cell surface or released into the extracellular environment as well as the corresponding secretion machineries. Despite their reduced coding capacities, Mycoplasma spp. are able to produce and release several components into their environment, including polypeptides, exopolysaccharides...
Article
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Bovine respiratory disease is the leading user of antibiotics (AB) in calf production. Mycoplasma (M.) bovis could lead to greater use of AB as it is a persistent and AB resistant causative agent for respiratory diseases. Two cross-sectional studies were set up to assess the effects of lot size and feeding system on M. bovis infection and the effec...
Article
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Mycoplasma infections are frequent in humans, as well as in a broad range of animals. However, antimicrobial treatment options are limited, partly due to the lack of a cell wall in these peculiar bacteria. Both veterinary and human medicines are facing increasing resistance prevalence for the most commonly used drugs, despite different usage practi...
Article
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Contagious agalactia is associated with mastitis, keratoconjunctivitis, arthritis, pneumonia, and septicemia in small ruminants in countries with large dairy industries worldwide. The causative agents belong to four (sub)species of the Mycoplasma genus that have remained essentially susceptible to antimicrobials, including to the widely-used tetrac...
Article
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Antimicrobial resistance (AMR) surveillance of mycoplasmas of veterinary importance has been held back for years due to lack of harmonized methods for antimicrobial susceptibility testing (AST) and interpretative criteria, resulting in a crucial shortage of data. To address AMR in ruminant mycoplasmas, we mobilized a long-established clinical surve...
Article
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Mycoplasma (M.) bovis is an important pathogen of cattle implicated in a broad range of clinical manifestations that adversely impacts livestock production worldwide. In the absence of a safe, effective, commercial vaccine in Europe, reduced susceptibility to reported antimicrobials for this organism has contributed to difficulties in controlling i...
Article
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Mycoplasma hyopneumoniae is the most costly pathogen for swine production. Although several studies have focused on the host-bacterium association, little is known about the changes in gene expression of swine cells upon infection. To improve our understanding of this interaction, we infected swine epithelial NPTr cells with M. hyopneumoniae strain...
Article
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Bovine respiratory diseases (BRD) are widespread in veal calf feedlots. Several pathogens are implicated, both viruses and bacteria, one of which, Mycoplasma bovis, is under-researched. This worldwide-distributed bacterium has been shown to be highly resistant in vitro to the main antimicrobials used to treat BRD. Our objective was to monitor the r...
Article
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Mycoplasma contamination threatens both the safety of biologics produced in cell substrates as well as the quality of scientific results based on cell-culture observations. Methods currently used to detect contamination of cells include culture, enzymatic activity, immunofluorescence and PCR but suffer from some limitations. High throughput sequenc...
Article
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Contagious agalactia (CA) is a disease caused equally by four Mycoplasma species, in single or mixed infections. Clinical signs are multiple, including mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia, non-specific, and expressed differently depending whether sheep or goats are affected, on causative mycoplasmas as well as type...
Article
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Background: Mycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide. Infection can result in a variety of clinical signs, such as arthritis, pneumonia, mastitis and keratoconjunctivitis, none of which are M. bovis-specific. Laboratory diagnosis is therefore important. S...
Article
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The capacity of Mycoplasmas to engage in horizontal gene transfers has recently been highlighted. Despite their small genome, some of these wall-less bacteria are able to exchange multiple, large portions of their chromosome via a conjugative mechanism that does not conform to canonical Hfr/oriT models. To understand the exact features underlying m...
Article
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...
Article
Surveillance and control of Mycoplasma spp. responsible for contagious agalactia (CA) in caprine herds are important challenges in countries with a large small-ruminant dairy industry. In the absence of any clinical signs, being able to determine the potential circulation of mycoplasmas within a herd could help to prevent biosecurity issues during...
Article
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Background Several species-specific PCR assays, based on a variety of target genes are currently used in the diagnosis of Mycoplasma bovis infections in cattle herds with respiratory diseases and/or mastitis. With this diversity of methods, and the development of new methods and formats, regular performance comparisons are required to ascertain dia...
Article
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Horizontal Gene Transfer was long thought to be marginal in Mycoplasma a large group of wall-less bacteria often portrayed as minimal cells because of their reduced genomes (ca. 0.5 to 2.0 Mb) and their limited metabolic pathways. This view was recently challenged by the discovery of conjugative exchanges of large chromosomal fragments that equally...
Data
A. Validation of 3f3 dot blotting for EV semi-quantification. EV were extracted from 6h, 48h and 96h cultures of M. mycoides subsp. mycoides strain Afadé in m-PPLO medium. Three production batches were done for each time point. EV are indicated by black arrowheads on electron micrographs. Their density was estimated by counting the number of EV per...
Data
Comparison of size distribution of EV (n = 322, three production batches) purified from M. mycoides subsp. mycoides Afadé (black bars) and cells (n = 124) from a stationary phase culture of M. mycoides subsp. mycoides Afadé (white bars). EV and cells were observed by TEM after negative staining and diameter was estimated using ImageJ. (TIF)
Data
Proteins identified from the Triton X-114 fractions of EV. Proteins are classified according to their PAI. (DOCX)
Article
Link to full text: https://authors.elsevier.com/c/1X1jZ1L~HfyNBz . Contagious agalactia is a mycoplasmosis that affects small ruminants, is associated with loss of milk production and high morbidity rates, and is highly deleterious to dairy industries. The etiological agents are four mycoplasma (sub)species, of which the relative importance depends...
Article
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The genus Mycoplasma, a group of free-living, wall-less prokaryotes includes more than 100 species of which dozens are primary pathogens of humans and domesticated animals. Mycoplasma species isolated from wildlife are rarely investigated but could provide a fuller picture of the evolutionary history and diversity of this genus. In 2013 several iso...
Data
Specificity of the m16S_qPCR (a) and GFP_qPCR (b) when tested on the p_GFP DNA loading probe and p_m16S(0.9kb) reference. (PDF)
Article
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Mycoplasmas (a generic name for Mollicutes) are a predominant bacterial contaminant of cell culture and cell derived products including viruses. This prokaryote class is characterized by very small size and lack of a cell wall. Consequently, mycoplasmas escape ultrafiltration and visualization under routine microscopic examination, hence the ease w...
Data
Alignments of U1 and U8 primers on plant chloroplast genomic DNAs that were blindly identified after qPCR of phytoplasma free and contaminated plant samples and sequencing of obtained amplicons. (PDF)
Data
Optimisation of elongation temperature during m16S qPCR of p_m16S(0.9kb), A. laidlawii and M. pulmonis DNA. Tm peak of 16S rDNA amplicon is indicated by the dotted line on each graph. (PDF)
Data
m16S qPCR detects a subset of bacteria in addition to Mollicutes with p_m16S(0.9kb) and water (a), detected (b-d) and non-detected (e) bacteria with amplicons sizes from panels a-d (f). Tm peak of 16S rDNA amplicon is indicated by the dotted line on each graph. (PDF)
Data
List of Ternericutes and Bacteria targeted by U1 and U8 primers after a search without mismatches or with up to 5 mismatches located upstream of the last 5 nt at primer 3’ end. (XLSX)
Data
List of Mollicutes targeted by U1 and U8 primers after BLAST search in GenBank and alignments of targeted sequences. (XLSX)
Article
Mycoplasma bovis is considered an emerging threat to bovine production in industrialized countries. Its control depends on good husbandry and efficient chemotherapy practices. In France, clinical isolates collected after 2009 showed a drastic loss of susceptibility to most antimicrobials when compared with isolates collected in 1978-1979. The aim o...
Article
Parmi les nombreuses espèces de mycoplasmes isolées chez les bovins, Mycoplasma bovis est l’espèce pathogène la plus fréquemment retrouvée en France. Ceci a été démontré grâce aux données du réseau d’épidémiosurveillance de l’Anses, Vigimyc, qui analyse les isolats qui proviennent de nombreux laboratoires. En France, M. bovis participe essentiellem...
Article
Mycoplasma bovis induit de nombreuses infections. Les symptômes respiratoires sont peu spécifiques.
Article
Pour mettre en évidence la présence de M. bovis en élevage lors d’un épisode aigu, un diagnostic direct est nécessaire. Au contraire, pour connaître le statut d’un troupeau vis-à-vis de l’infection par M. bovis, le diagnostic indirect avec des tests sérologiques est plutôt conseillé.
Article
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The respiratory tract of swine is colonized by several bacteria among which are three Mycoplasma species: Mycoplasma flocculare, Mycoplasma hyopneumoniae and Mycoplasma hyorhinis. While colonization by M. flocculare is virtually asymptomatic, M. hyopneumoniae is the causative agent of enzootic pneumonia and M. hyorhinis is present in cases of pneum...
Article
Full-text available
Background: The respiratory tract of swine is colonized by several bacteria among which are three Mycoplasma species: Mycoplasma flocculare, Mycoplasma hyopneumoniae and Mycoplasma hyorhinis. While colonization by M. flocculare is virtually asymptomatic, M. hyopneumoniae is the causative agent of enzootic pneumonia and M. hyorhinis is present in c...
Article
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Importance: Many if not all bacteria are able to secrete polysaccharides, either attached to the cell-surface or exported unbound into the extracellular environment. Both types of polysaccharides can play a role in the bacterial-hosts interactions. Mycoplasmas are no exception despite their poor overall metabolic capacity. We showed here thatM. ag...
Article
Aims: Mycoplasma agalactiae is responsible for Contagious Agalactia, a severe syndrome affecting small ruminants worldwide and resulting in significant economic losses in countries with an important dairy industry. The aim of this study was to examine the antimicrobial susceptibility patterns of M. agalactiae isolates in France, their evolution ov...
Article
Mycoplasma bovis is considered a major contributor to respiratory diseases in young cattle. Resistant M. bovis isolates have been increasingly reported worldwide due to extensive use of antimicrobials to treat bovine pneumonia. The frequency of isolates resistant to fluoroquinolones varies considerably from one country to another. The MICs of isola...
Article
Mycoplasma (M.) bovis has recently emerged as a major, worldwide etiological agent of bovine respiratory diseases leading to huge economic losses mainly due to high morbidity and mortality as well as poor growth rates. The spread of M. bovis infections between different animals, herds, regions or countries has been often reported to be connected to...
Article
Full-text available
Comparative genomics have revealed massive Horizontal Gene Transfer (HGT) in between Mycoplasma species sharing common ruminant hosts. Further results pointed towards an integrative conjugative element (ICE) as an important contributor of HGT in the small ruminant pathogen Mycoplasma agalactiae. To estimate the prevalence of ICEs in ruminant mycopl...
Article
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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...
Article
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Unlabelled: Horizontal gene transfer (HGT) is a main driving force of bacterial evolution and innovation. This phenomenon was long thought to be marginal in mycoplasmas, a large group of self-replicating bacteria characterized by minute genomes as a result of successive gene losses during evolution. Recent comparative genomic analyses challenged t...
Article
Mycoplasma mycoides subsp. mycoides (Mmm) strain Afadé had previously been shown to undergo spontaneous phase variations between an opaque capsulated variant and a translucent variant devoid of a capsule but able to secrete cell-free exopolysaccharides. This phase variation is associated with an ON/OFF genetic switch in a glucose permease gene. In...
Article
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Mollicutes is a class of parasitic bacteria that have evolved from a common Firmicutes ancestor mostly by massive genome reduction. With genomes under 1 Mbp in size, most Mollicutes species retain the capacity to replicate and grow autonomously. The major goal of this work was to identify the minimal set of proteins that can sustain ribosome biogen...
Article
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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 "myc...
Article
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Motivation Among challenges that hamper reaping the benefits of genome assembly are both unfinished assemblies and the ensuing experimental costs. First, numerous software solutions for genome de novo assembly are available, each having its advantages and drawbacks, without clear guidelines as to how to choose among them. Second, these solutions pr...
Article
Full-text available
Horizontal gene transfer (HGT) is a major force of microbial evolution but was long thought to be marginal in mycoplasmas. In silico detection of exchanged regions and of loci encoding putative Integrative Conjugative Elements (ICE) in several mycoplasma genomes challenged this view, raising the prospect of these simple bacteria being able to conju...
Article
Full-text available
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a new technology for the identification of bacteria. In this study, we aimed to evaluate its applicability to human and ruminant mycoplasma identification, which can be demanding and time-consuming using phenotypic or molecular method...
Data
Schematic representation of the predicted membrane topology of Mmm EpsG (MSC_0108) glycosyltransferase. Numbers indicate the localization of transmembrane helices. DxD (red) and RxxQW (blue) motifs are showed. (TIF)
Article
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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 cel...
Data
Northern blot hybridization of total RNA of the opaque (OP) and translucent (TR) colony variants of Mmm strain Afadé with a cps (MSC_0109) or rDNA 16S probe. Total RNA extraction and northern blot hybridization was performed as previously described [1]. The rDNA 16S probe was obtained by PCR [2]. Transcription of the rDNA 16S was used to normalize...
Article
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We report here the draft genome sequences of Mycoplasma auris and Mycoplasma yeatsii, two species commonly isolated from the external ear canal of Caprinae.
Article
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Mycoplasma putrefaciens is one of the etiologic agents of contagious agalactia in goats. We report herein the complete genome sequence of Mycoplasma putrefaciens strain 9231.
Article
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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.
Conference Paper
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The rtPCR assay proved to efficiently detect DNA from all Contagious Agalactia causative agents, with a satisfying limit of detection. When challenged with milk samples from farms, the rtPCR assay gave results comparable (94%) to that obtained by classical culture step. The rare discrepancies tend to prove that the DNA extraction step is critical e...
Data
Table S2. History of mycoplasma strains and plasmid screening.
Data
Figure S2. Detection of pMyBK1 ssDNA intermediates by Southern blot hybridization. Total DNA from Mycoplasma yeatsii type strain GIH TS (lane 1-2) was analyzed on a 0.8% agarose gel (A) with (+) or without (-) prior S1 nuclease treatment. Southern blot (B) was performed with digoxigenin-labeled pMyBK1 probe under non-denaturing conditions. M, DNA l...
Data
Figure S1. Nucleotide sequences of the predicted ctRNA coding strands. The counter-transcripts were first identified by analogy with those of pMV158 or its derivative pLS1. These ctRNA overlap the rep gene start and have a length of only a few tens of nucleotides. Using the consensus sequence TTGACA – (N17) –TG-N-TATAAT for the promoter, putative p...
Data
Table S3. Pairwise nucleic sequence identities between mycoplasma plasmids. Global alignments of the full-length nucleic sequence of mycoplasma plasmids were accomplished using a Needleman–Wunsch algorithm implemented in the Needleall program (Needleman & Wunsch, 1970). Identity percents are indicated. Rep group refers to Rep phylogeny (see Figure...
Data
Figure S3. Expression of spiralin in Mcc using pMyBK1 derivatives. Whole cell dot immunoblot of 12 Mcc transformants harboring the spiralin expression vector pCM-K3-spi (a) or the empty vector pCM-K3 (b). Mycoplasma cells were applied to a nitrocellulose membrane and probed with rabbit anti-spiralin antibodies and anti-rabbit IgG peroxidase conjuga...
Article
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The evolution of mycoplasmas from a common ancestor with Firmicutes has been characterized not only by genome down-sizing but also by horizontal gene transfer between mycoplasma species sharing a common host. The mechanisms of these gene transfers remain unclear because our knowledge of the mycoplasma mobile genetic elements is limited. In particul...
Article
Full-text available
Background The genetic diversity of Mycoplasma agalactiae (MA) isolates collected in Spain from goats in an area with contagious agalactia (CA) was assessed using a set of validated and new molecular typing methods. Validated methods included pulsed field gel electrophoresis (PFGE), variable number o