References of "Mainil, Jacques"
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See detailPathophysiological changes occurring during Escherichia coli endotoxin and Pasteurella multocida challenge in piglets: relationship with cough and temperature and predicitive value for intensity of lesions.
Halloy, David J; Bouhet, Sandrine; Oswald, Isabelle P et al

in Veterinary Research (2004), 35(3), 309-324

The aims of this study were (1) to correlate cough and body temperature (BT) with the severity of bronchopneumonia in pigs, (2) to determine whether these clinical signs can be used to early diagnose ... [more ▼]

The aims of this study were (1) to correlate cough and body temperature (BT) with the severity of bronchopneumonia in pigs, (2) to determine whether these clinical signs can be used to early diagnose bronchopneumonia and (3) to assess the predictive values of cough and BT regarding lung lesions. Bronchopneumonia was induced by administering E. coli endotoxin (LPS) combined with Pasteurella multocida type A (PmA) in the trachea of 13 piglets. Saline-instilled negative controls (n = 8), PmA inoculated (n = 6) and LPS instilled (n = 5) groups were also constituted. Cough and BT were recorded daily while the bronchopneumonia severity was assessed using bronchoalveolar lavage fluid (BALF) cytology, cytokines and measurement of lung lesion volume. Changes in expiratory breathing pattern were also measured (Penh). The combination of LPS and PmA induced a subacute bronchopneumonia characterised by macrophage, neutrophil, and lymphocyte infiltration, changes in Penh and an increase in the mRNA level of IFN-gamma while IL8, IL-18 and TNF-alpha mRNA levels remained unchanged. The daily body weight gain of infected animals was significantly reduced. Cough and BT changes were proportional to the intensity of the lung inflammatory process, functional respiratory changes and to the extent of macroscopic lesions. When comparing the individual values of cough and BT to thresholds defined for both parameters, an early diagnosis of pneumonia was possible. Considering the pooled data of each group, it was possible to define thresholds allowing an early segregation between the groups of diseased and healthy piglets. The daily values of cough and BT were predictive for the volume of lung lesions recorded at the end of the trial. In conclusion, cough and BT appear as potential indicators for the intensity and the evolution of the respiratory disease. They also seem to be good predictors for the magnitude of lung lesions and weight gain recorded at the study endpoint. [less ▲]

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See detailVirulence factors and specific properties of invasive Escherichia coli : IV) Necrotoxigenic strains
Mainil, Jacques ULg; Van Bost, S.

in Annales de Médecine Vétérinaire (2004), 148(3), 121-132

Escherichia coli bacterial species is subdivided into several pathogen strains in man and animals, on the basis of their specific properties and factors which are responsible for their virulence. The ... [more ▼]

Escherichia coli bacterial species is subdivided into several pathogen strains in man and animals, on the basis of their specific properties and factors which are responsible for their virulence. The pathogenic strains are classically subdivided into strains with intestinal tropism (enterotoxigenic, enteropathogenic, enterohaemmorrhagic, verotoxigenic and enteroinvasive) and with extraintestinal tropism (uropathogenic and invasive). Invasive strains cause septicaemia and/or bacteraemia with localisations in different internal organs (systemic infections). If specific virulence properties and factors of strains with intestinal tropism are quite well known and described, those of strains with extraintestinal tropism are much less characterised, especially in animals. The purpose of this series of review articles is to present the current knowledge on specific properties and factors of extraintestinal strains. The first three manuscripts reviewed the characteristics of adhesins and colonisation factors, transmucosal transfer, survival in blood and internal organs, and toxicity. After the presentation of the animal and human invasive E. coli, this fourth manuscript reviews the current knowledge on the necrotoxigenic strains and finishes with a discussion on the meaning of the bacterial virulence in general. [less ▲]

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See detailLes mycoplasmes respiratoires bovins: prévalence et propriétés de cyto-adhésion
Thomas, A.; Dizier, Isabelle ULg; Sachse, K. et al

Report (2004)

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See detailEnteropathogenic and enterohaemorrhagic Escherichia coli deliver a novel effector called Cif, which blocks cell cycle G(2)/M transition
Marches, O.; Ledger, T. N.; Boury, M. et al

in Molecular Microbiology (2003), 50(5), 1553-1567

Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. Both use a type III secretion system (TTSS) encoded by the 'locus of enterocyte effacement ... [more ▼]

Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. Both use a type III secretion system (TTSS) encoded by the 'locus of enterocyte effacement' (LEE) to subvert and attach to epithelial cells through the injection of a repertoire of effector molecules. Here, we report the identification of a new TTSS translocated effector molecule called Cif, which blocks cell cycle G(2)/M transition and induces the formation of stress fibres through the recruitment of focal adhesions. Cif is not encoded by the LEE but by a lambdoid prophage present in EPEC and EHEC. A cif mutant causes localized effacement of microvilli and intimately attaches to the host cell surface, but is defective in the ability to block mitosis. When expressed in TTSS competent LEE-positive pathogens, Cif is injected into the infected epithelial cells. These cells arrested at the G(2)/M phase displayed accumulation of inactive phosphorylated Cdk1. In conclusion, Cif is a new member of a growing family of bacterial cyclomodulins that subvert the host eukaryotic cell cycle. [less ▲]

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See detailPutative roles of the CNF2 and CDTIII toxins in experimental infections with necrotoxigenic Escherichia coli type 2 (NTEC2) strains in calves
Van Bost, S.; Roels, S.; Oswald, E. et al

in Microbes & Infection (2003), 5(13), 1189-1193

Newborn colostrum-restricted calves were orally inoculated with an Escherichia coli strain, identified originally as non-pathogenic, and into which the plasmid pVir was conjugally transferred. This ... [more ▼]

Newborn colostrum-restricted calves were orally inoculated with an Escherichia coli strain, identified originally as non-pathogenic, and into which the plasmid pVir was conjugally transferred. This resulted in diarrhea, intestinal lesions and extra-intestinal invasion, suggesting that factors affecting these pathogenic properties are located on pVir. In order to analyze the respective roles of the toxins CNF2 and CDTIII in the pathogenesis, colostrum-restricted calves were inoculated with isogenic mutants in the cnf2 and the cdt-III genes. The loss of cnf2 is associated with a reduction in the pathogenicity, since diarrhea does not occur in calves challenged, in spite of successful colonization of the intestine. Nevertheless, the mutant strain remains able to invade the bloodstream and to localize in the internal organs. Conversely, the calves inoculated with mutant in the cdt-III gene evolved in the same way as wild-type strain-inoculated calves with regard to clinical signs and macroscopic or microscopic lesions. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved. [less ▲]

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See detailAntibiotic susceptibilities of recent isolates of Mycoplasma bovis in Belgium
Thomas, Anne; Nicolas, C.; Dizier, Isabelle ULg et al

in Veterinary Record (2003), 153(14), 428-431

The susceptibilities of 40 recent Belgian field isolates of Mycoplasma bovis to 10 antimicrobial agents were assessed. Tiamulin was the most active antimicrobial agent against M bovis, with an initial ... [more ▼]

The susceptibilities of 40 recent Belgian field isolates of Mycoplasma bovis to 10 antimicrobial agents were assessed. Tiamulin was the most active antimicrobial agent against M bovis, with an initial inhibitory concentration (IIC50) of 0.06 microg/ml, but it is not licensed for the treatment of cattle. All three fluoroquinolones tested (danofloxacin, enrofloxacin and marbofloxacin) were effective against strains of M bovis, and had a minimum mycoplasmacidal concentration (MMC50) less than or equal to 1 microg/ml. Gentamicin was poorly effective, having an IIC50 of 8 microg/ml. Many strains of M bovis were resistant to tylosin, spectinomycin, lincomycin, tetracycline and oxytetracycline. [less ▲]

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See detailMultiplex PCRs for identification of necrotoxigenic Escherichia coli
Van Bost, S.; Jacquemin, E.; Oswald, E. et al

in Journal of Clinical Microbiology (2003), 41(9), 4480-4482

Two multiplex PCRs were developed for the detection of necrotoxigenic Escherichia coli virulence genes. M1 contained the primers for the toxins and the aerobactin, and M2 contained the primers for the ... [more ▼]

Two multiplex PCRs were developed for the detection of necrotoxigenic Escherichia coli virulence genes. M1 contained the primers for the toxins and the aerobactin, and M2 contained the primers for the adhesins. They were validated by single PCRs performed with reference E. coli strains and by multiplex PCRs with necrotoxigenic E. coli strains isolated from different animal species. [less ▲]

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See detailIncreased nuclear Factor kappa B activity in milk cells of mastitis-affected cows
Boulanger, D.; Bureau, Fabrice ULg; Melotte, D. et al

in Journal of Dairy Science (2003), 86(4), 1259-1267

Bacterial mastitis is accompanied by a drastic increase in milk somatic cell count (SCC), with neutrophils being the predominant cell type found in the infected quarters. Accumulation and activation of ... [more ▼]

Bacterial mastitis is accompanied by a drastic increase in milk somatic cell count (SCC), with neutrophils being the predominant cell type found in the infected quarters. Accumulation and activation of neutrophils at the site of infection require local expression of many inflammatory genes encoding adhesion molecules, chemokines and cytokines. Most of the inflammatory genes contain binding sites for the nuclear factor kappaB (NF-kappaB) within their promoter and therefore partly depend on NF-kappaB for their expression. We thus hypothesized that an increase in NF-kappaB activity in the mammary gland could contribute to development of the neutrophilic inflammation that characterizes mastitis. In an attempt to verify this hypothesis, we first assessed milk cells from healthy and acute and chronic mastitis-affected cows for NF-kappaB activity using electrophoretic mobility shift assays. We next studied the relationships between the intensity of NF-kappaB activity in these cells and the degree of udder inflammation. Active NF-kappaB complexes were undetectable in milk cells from healthy cows, whereas high levels of NF-kappaB activity were always found in cells from cows with acute mastitis. In milk cells obtained from chronic mastitis-affected cows, NF-kappaB activity varied from low to high. Finally, the level of NF-kappaB activity measured in milk cells from chronic mastitis-affected cows was not correlated to SCC or to the proportion of neutrophils present in milk samples, but was highly correlated with the expression level of interleukin-8 and granulocyte/macrophage colony-stimulating factor, two NF-kappaB-dependent cytokines crucially involved in initiation and perpetuation of neutrophilic inflammation. These results suggest that NF-kappaB might play a role in mastitis pathogenesis. [less ▲]

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See detailAdherence of Mycoplasma bovis strains to bovine bronchial epithelial cells
Thomas, Anne; Sachse, K.; Farnir, Frédéric ULg et al

in Microbial Pathogenesis (2003), 34(3), 141-148

Mycoplasma bovis is responsible for considerable economic losses in cattle due to pneumonia, arthritis and mastitis. As the agent was shown to be capable of adhering to neutrophils and embryonic bovine ... [more ▼]

Mycoplasma bovis is responsible for considerable economic losses in cattle due to pneumonia, arthritis and mastitis. As the agent was shown to be capable of adhering to neutrophils and embryonic bovine lung (EBL) cells and invading the respiratory epithelium it is highly desirable to improve our understanding of cytadherence processes. Although several surface proteins likely to be directly involved in this initial stage of interaction between pathogen and host cells have been identified, these findings mainly referred to type strain PG45 adhering to the continuous EBL cell line. The present study provides new and complementary data about cytadherence of M. bovis based on adherence of various radiolabeled strains to a primary culture of bovine bronchial epithelial (BBE) cells using a standardized adherence assay. M. bovis was shown to adhere specifically to the primary culture of BBE cells. Inhibition of adherence was observed upon addition of monoclonal antibodies (MAbs), trypsin treatment of mycoplasmas, and competition with non-radiolabeled mycoplasma cells. Interestingly, three MAbs against proteins involved in adherence to EBL cells failed to inhibit significantly the adherence to BBE cells. On the other hand, significant reduction of adherence rates by MAbs 2A8 and 9F1 directed against epitopes of variable surface lipoproteins VspC and VspF, respectively, demonstrated the involvement of these proteins in adherence of M. bovis to primary culture of BBE cells. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailAdherence to various host cell lines of Mycoplasma bovis strains differing in pathogenic and cultural features
Thomas, Anne; Sachse, Konrad; Dizier, Isabelle ULg et al

in Veterinary Microbiology (2003), 91(2-3), 101-113

Mycoplasma bovis is known to be responsible for pneumonia and arthritis in calves, as well as mastitis in dairy cows. Despite clear evidence of its pathogenic potential, little is known about mechanisms ... [more ▼]

Mycoplasma bovis is known to be responsible for pneumonia and arthritis in calves, as well as mastitis in dairy cows. Despite clear evidence of its pathogenic potential, little is known about mechanisms of cytadherence and the molecular factors involved. The purpose of this work was to compare adherence rates of M. bovis field strains to different host cell lines and study the effects of cloning and sub-culturing M. bovis strains on their adherence properties. Eighteen metabolically labeled M. bovis strains isolated from different pathological backgrounds were examined in adherence trials using four different host cell lines, i.e. embryonic bovine lung (EBL), embryonic bovine trachea (EBTr), Madin Darby bovine kidney (MDBK) and rabbit kidney (RK) cells. Although large interstrain variations in adherence rates (3.4-19.1%) were measured they could not be correlated to the pathological background (pneumonia, arthritis or mastitis). Adherence rates to the fibroblast cell line (EBTr) were significantly lower than those to the three epithelial cell lines (EBL, MDBK and RK). The only non-pathogenic strain (221/89) exhibited lower adherence rates than three isolates from clinical mastitis. Interestingly, adherence rates were significantly reduced after in vitro passaging. In contrast, no effect of single cloning of strains on adherence was observed. There was no general correlation between expression of variable surface proteins (Vsps) as monitored by immunoblotting and adherence rates, although alterations in Vsp expression profiles were seen as a consequence of passaging. As there is probably a large number of adhesins, variable and non-variable, on the surface of M. bovis cells the issue is very complex, and the most active components have yet to be identified. [less ▲]

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See detailMycoplasma bovis : summary of current knowledge
Thomas, Anne; Mainil, Jacques ULg; Linden, Annick ULg

in Annales de Médecine Vétérinaire (2003), 147(1, FEB-MAR), 23-39

Mycoplasmas frequently infect cattle. Amongst them, M. Bovis is the most pathogenic species in countries free from contagious bovine pleuropneumonia because it is responsible for bronchopneumonia ... [more ▼]

Mycoplasmas frequently infect cattle. Amongst them, M. Bovis is the most pathogenic species in countries free from contagious bovine pleuropneumonia because it is responsible for bronchopneumonia, arthritis and mastitis, and is thus associated with strong economic losses. Several studies have shown the frequency of M. bovis in Europe and the spread of antibiotic-resistant strains. Considering the absence of vaccine in Europe, it is essential to understand this bacteria in order to control the infection in cattle. In this context, this paper aims at summarizing the current knowledge about M. bovis. [less ▲]

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See detailMycoplasma bovis dans le complexe respiratoire bovin et propriétés de cyto-adhésion in vitro
Thomas, Anne; Dizier, Isabelle ULg; Sachse, K. et al

in Annales de Médecine Vétérinaire (2003), 147(4, AUG-SEP), 267-272

Mycoplasmas frequently infect cattle, causing especially respiratory diseases. Mycoplasma bovis is the most important pathogenic species in countries free of bovine contagious pleuropneumonia. This ... [more ▼]

Mycoplasmas frequently infect cattle, causing especially respiratory diseases. Mycoplasma bovis is the most important pathogenic species in countries free of bovine contagious pleuropneumonia. This species was frequently isolated in Belgium from cattle with respiratory disease. Furthermore, associations were often observed with pasteurellas and bovine respiratory syncytial virus. Of these M. bovis isolates, many were resistant to several antimicrobial agents which are used in cattle practice, except to fluoroquinolones. Inasmuch the high frequency of M. bovis isolation and antibiotic resistances, it is very important to understand the pathogenicity of this bacteria in order to optimize prophylactic tools. Therefore, the study of the cytadherence of M. bovis is essential since it represents the first step of the bacterial infection. According to our experimental results, PG45 is not representative of field isolates because of its low adherence rates to various cell lines. This could be explained by the high number of subcultures of this pathogenic strain underwent since its first isolation, which sharply contrasts with other isolates. M. bovis adheres specifically to bovine bronchial epithelial cells in primary culture. Proteins such as variable surface proteins C and F are involved in this step as observed by decreased adherence rates after trypsinization of mycoplasma cells or addition of monoclonal antibodies. [less ▲]

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See detailLeçon publique : "Quorum-sensing chez les bactéries ou quand les bactéries dialoguent"
Mainil, Jacques ULg

Thèse d’agrégation de l’enseignement supérieur (2003)

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See detailVirulence factors and specific properties of invasive Escherichia coli: III. Toxin production
Van Bost, S.; Mainil, Jacques ULg

in Annales de Médecine Vétérinaire (2003), 147(5, OCT-NOV), 327-342

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their ... [more ▼]

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their pathogenic characters. The pathogenic strains are classically subdivided into strains with intestinal tropism (enterotoxigenic, enteropathogenic, enterohaemmorrhagic, verotoxigenic and enteroinvasive) and with extraintestinal tropism (uropathogenic and invasive). Invasive strains cause septicaemia and/or bacteraemia with localisations in different internal organs (systemic infections). If specific virulence properties and factors of strains with intestinal tropism are quite well known and described, those of strains with extraintestinal tropism are much less characterised, especially in animals. The purpose of this serie of review articles is to present the current knowledge on specific properties and factors of extraintestinal strains: adhesins and colonisation factors, transmucosal transfer and survival in blood and internal organs, toxicity. The fourth manuscript will deal with the invasive strains themselves, focusing on the necrotoxigenic strains. This third manuscript presents the current knowledge on toxins produced by invasive strains of E. coli: endotoxins, cytotoxic necrotising factors, cytolethal distending toxins and haemolytic toxins. [less ▲]

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See detailVirulence factors and specific properties of invasive Escherichia coli: II. Mucosal transfer and invasive properties
Mainil, Jacques ULg

in Annales de Médecine Vétérinaire (2003), 147(3, JUN-JUL), 159-171

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their ... [more ▼]

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their pathogenic characters. The pathogenic strains are classically subdivided into strains with intestinal tropism (enterotoxigenic, enteropathogenic, entero-haemorrhagic, verotoxigenic and enteroinvasive) and with extraintestinal tropism (uropathogenic and invasive). Invasive strains cause septicaemia and/or bacteraemia with localisations in different internal organs (systemic infections). If specific virulence properties and factors of strains with intestinal tropism are quite well known and described, those of strains with extraintestinal tropism are much less characterised, especially in animals. The purpose of this serie of review articles is to present the current knowledge on specific properties and factors of extraintestinal strains : adhesins and colonisation factors, transmucosal transfer and survival in blood and internal organs, toxicity. The fourth manuscript will deal with the invasive strains themselves, focusing on the necrotoxigenic strains. This second manuscript presents the current knowledge on the transmucosal transfer, resistance to the bactericidal activity of the complement, resistance to phagocytosis and production of colicins, that were, for several years, considered as an important specific property of invasive strains of E coli. [less ▲]

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See detailVirulence factors and specific properties of invasive Escherichia coli: I. Adhesins and colonisation factors
Mainil, Jacques ULg

in Annales de Médecine Vétérinaire (2003), 147(2, APR-MAY), 105

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their ... [more ▼]

Escherichia coli bacterial species is subdivided into several strains that are pathogenic for man and animals, on the basis of their specific properties and factors which are responsible for their pathogenic characters. The pathogenic strains are classically subdivided into strains with intestinal tropism (enterotoxigenic, enteropathogenic, enterohaemmorrhagic, verotoxigenic and enteroinvasive) and with extraintestinal tropism (uropathogenic and invasive). Invasive strains cause septicaemia and/or bacteraemia with localisations in different internal organs (systemic infections): If specific virulence properties and factors of strains with intestinal tropism are quite well known and described, those of strains with extraintestinal tropism are much less characterised, especially in animals. The purpose of this serie of review articles is to present the current knowledge on specific properties and factors of extraintestinal strains: adhesins and colonisation factors, transmucosal transfer and survival in blood and internal organs, toxicity. The fourth manuscript will deal with the invasive strains themselves, focusing on the necrotoxigenic strains. This first manuscript presents the current knowledge on the receptors, roles in pathogenesis, structures, genetic determinism and identification methods of fimbrial adhesins of P (Pap, Prs), S (Sfa, F1C, Sfr) and F17 (Vir, Att25, FY, 20K, G, Att111) families and of afimbrial adhesins of Afa family (Afa, Nfa, F1845, Bma, Dr...). [less ▲]

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