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1.
Haythem Gharsa Karim Ben Slama Elena Gómez-Sanz Carmen Lozano Naouel Klibi Ahlem Jouini Lilia Messadi Abdellatif Boudabous Carmen Torres 《Microbial ecology》2013,66(2):363-368
Nasal swabs of 100 healthy dogs were obtained in 2011 in Tunisia and tested for Staphylococcus pseudintermedius recovery. Antimicrobial resistance profile and virulence gene content were determined. Multilocus-sequence-typing (MLST) and SmaI-pulsed-field gel electrophoresis (PFGE) were investigated. S. pseudintermedius was recovered in 55 of the 100 tested samples (55 %), and one isolate per sample was further studied. All 55 S. pseudintermedius isolates were susceptible to methicillin (MSSP) but showed resistance to the following antimicrobials (% resistant isolates/resistance gene): penicillin (56.4/blaZ), tetracycline (40/tetM), trimethoprim-sulfamethoxazole (23.7), fusidic acid (9), kanamycin (3.7/aph(3´)-Ia), erythromycin-clindamycin (1.8/erm(B)), streptomycin (1.8/ant(6)-Ia), chloramphenicol (1.8) and ciprofloxacin (1.8). The following toxin genes were identified (% of isolates): lukS/F-I (98.2), expA (5.5), se-int (98.2), sec canine (1.8), siet (100), sea (5.5), seb (3.6), sec (10.9), sed (54.5), sei (5.5), sej (29.1), sek (3.6), ser (9.1), and hlg v (38.2). Ten different sequence-types were detected among 11 representative MSSP isolates: ST20, ST44, ST69, ST70, ST78, ST100, ST108, ST160, ST161, and ST162, the last three ones revealing novel alleles or allele combinations. Eleven different PFGE-patterns were identified in these isolates. The nares of healthy dogs could be a reservoir of antimicrobial resistant and virulent MSSP, highlighting the presence of the recently described exfoliating gene expA and several enterotoxin genes. 相似文献
2.
Klibi N Ben Slama K Sáenz Y Masmoudi A Zanetti S Sechi LA Boudabous A Torres C 《Canadian journal of microbiology》2007,53(3):372-379
Phenotypic and genotypic determination of virulence factors were carried out in 46 high-level gentamicin-resistant (HLGR) clinical Enterococcus faecalis (n=34) and Enterococcus faecium (n=12) isolates recovered from different patients in La Rabta Hospital in Tunis, Tunisia, between 2000 and 2003 (all these isolates harboured the aac(6')-aph(2") gene). The genes encoding virulence factors (agg, gelE, ace, cylLLS, esp, cpd, and fsrB) were analysed by PCR and sequencing. The production of gelatinase and hemolysin, the adherence to caco-2 and hep-2 cells, and the capacity for biofilm formation were investigated in all 46 HLGR enterococci. The percentages of E. faecalis isolates harbouring virulence genes were as follows: gelE, cpd, and ace (100%); fsrB (62%); agg (56%); cylLLS (41.2%); and esp (26.5%). The only virulence gene detected among the 12 HLGR E. faecium isolates was esp (58%). Gelatinase activity was detected in 22 of the 34 E. faecalis isolates (65%, most of them with the gelE+-fsrB+ genotype); the remaining 12 isolates were gelatinase-negative (with the gelE+-fsrB- genotype and the deletion of a 23.9 kb fragment of the fsr locus). Overall, 64% of the cylLLS-containing E. faecalis isolates showed beta-hemolysis. A high proportion of our HLGR E. faecalis isolates, in contrast to E. faecium, showed moderate or strong biofilm formation or adherence to caco-2 and hep-2 cells. 相似文献
3.
Potassium channel tetramerization domain containing proteins (KCTDs), which share a conserved BTB (Bric-a-brac, Tramtrack, Broad complex) domain at their N-terminus, are known to be involved in both developmental and neural processes. However, the developmental expression patterns and functional roles of most vertebrate KCTDs remain unknown. Using enhancer-trapping technology, we have identified a transgenic zebrafish line (ub49) where the vector insertion is in close proximity to kctd15a, and where transgenic marker (eGFP) expression closely reflects endogenous kctd15a expression. Both ub49 and kctd15a show strong maternal expression that suggests a functional role during epiboly and gastrulation. At later developmental stages, expression of eGFP in ub49 also shares the same spatiotemporal features as kctd15a in several neural tissues, including cranial placode precursors, retina, and different areas of the developing brain. In the retina, we observed eGFP labeling of the inner nuclear layer (INL), including a heterogenous population of amacrine cells, and both laminae of the inner plexiform layer (IPL). This expression pattern suggests that Kctd15a proteins have several context-dependent functional roles in both developmental and neural processes. The enhancer trap line, which is the first transgenic reporter of Kctd gene expression in vertebrates, also provides a novel tool to study kctd15a function in vivo. 相似文献
4.
Shamin Li Claudine Joseph Chantal Becourt Jihene Klibi Sandrine Luce Daniele Dubois-Laforgue Etienne Larger Christian Boitard Kamel Benlagha 《PloS one》2014,9(4)
We explored in this study the status and potential role of IL-17-producing iNKT cells (iNKT17) in type 1 diabetes (T1D) by analyzing these cells in patients with T1D, and in NOD mice, a mouse model for T1D. Our analysis in mice showed an increase of iNKT17 cells in NOD vs control C57BL/6 mice, partly due to a better survival of these cells in the periphery. We also found a higher frequency of these cells in autoimmune-targeted organs with the occurrence of diabetes, suggesting their implication in the disease development. In humans, though absent in fresh PMBCs, iNKT17 cells are detected in vitro with a higher frequency in T1D patients compared to control subjects in the presence of the proinflammatory cytokine IL-1β, known to contribute to diabetes occurrence. These IL-1β-stimulated iNKT cells from T1D patients keep their potential to produce IFN-γ, a cytokine that drives islet β-cell destruction, but not IL-4, with a reverse picture observed in healthy volunteers. On the whole, our results argue in favour of a potential role of IL-17-producing iNKT cells in T1D and suggest that inflammation in T1D patients could induce a Th1/Th17 cytokine secretion profile in iNKT cells promoting disease development. 相似文献
5.
Activity of Six Essential Oils Extracted from Tunisian Plants against Legionella pneumophila
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Naouel Chaftar Marion Girardot Nathalie Quellard Jérôme Labanowski Tawfik Ghrairi Khaled Hani Jacques Frère Christine Imbert 《化学与生物多样性》2015,12(10):1565-1574
The aim of this study was to investigate the composition of six essential oils extracted from Tunisian plants, i.e., Artemisia herba‐alba Asso , Citrus sinensis (L.) Osbeck , Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L., and Thymus vulgaris L., and to evaluate their activity against Legionella pneumophila (microdilution assays). Eight Legionella pneumophila strains were studied, including the two well‐known serogroup 1 Lens and Paris strains as controls and six environmental strains isolated from Tunisian spas belonging to serogroups 1, 4, 5, 6, and 8. The essential oils were generally active against L. pneumophila. The activities of the A. herba‐alba, C. sinensis, and R. officinalis essential oils were strain‐dependent, whereas those of the J. phoenicea and T. vulgaris oils, showing the highest anti‐Legionella activities, with minimum inhibitory concentrations (MICs) lower than 0.03 and lower than or equal to 0.07 mg/ml, respectively, were independent of the strains' serogroup. Moreover, the microorganisms treated with T. vulgaris essential oil were shorter, swollen, and less electron‐dense compared to the untreated controls. Isoborneol (20.91%), (1S)‐α‐pinene (18.30%) β‐phellandrene (8.08%), α‐campholenal (7.91%), and α‐phellandrene (7.58%) were the major components isolated from the J. phoenicea oil, while carvacrol (88.50%) was the main compound of the T. vulgaris oil, followed by p‐cymene (7.86%). This study highlighted the potential interest of some essential oils extracted from Tunisian plants as biocides to prevent the Legionella risk. 相似文献
6.
Julien Bertrand Naouel Tennoune Rachel Marion‐Letellier Alexis Goichon Philippe Chan Khaly Mbodji David Vaudry Pierre Déchelotte Moïse Coëffier 《Proteomics》2013,13(22):3284-3292
The ubiquitin proteasome system (UPS) is the major pathway of intracellular protein degradation and may be involved in the pathophysiology of inflammatory bowel diseases or irritable bowel syndrome. UPS specifically degrades proteins tagged with an ubiquitin chain. We aimed to identify polyubiquitinated proteins during inflammatory response in intestinal epithelial HCT‐8 cells by a proteomic approach. HCT‐8 cells were incubated with interleukin 1β, tumor necrosis factor‐α, and interferon‐γ for 2 h. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using antiubiquitin antibody. Differential ubiquitinated proteins were then identified by LC‐ESI MS/MS. Seven proteins were differentially ubiquitinated between control and inflammatory conditions. Three of them were chaperones: Grp75 and Hsc70 were more ubiquitinated (p < 0.05) and Grp78 was less ubiquitinated (p < 0.05) under inflammatory conditions. The results for Grp75 and Grp78 were then confirmed in HCT‐8 cells and in 2‐4‐6‐trinitrobenzen sulfonic acid induced colitis in rats mimicking inflammatory bowel disease by immunoprecipitation. No difference was observed in irritable bowel syndrome like model. In conclusion, we showed that a proteomic approach is suitable to identify ubiquitinated proteins and that UPS‐regulated expression of Grp75 and Grp78 may be involved in inflammatory response. Further studies should lead to the identification of ubiquitin ligases responsible for Grp75 and Grp78 ubiquitination. 相似文献
7.
Guirat-Dhouib N Baccar Y Mustapha IB Ouederni M Chouaibi S El Fekih N Barbouche MR Fezaa B Kouki R Hmida S Mellouli F Bejaoui M 《Clinical and molecular allergy : CMA》2012,10(1):6-4
Background
Major histocompatibility complex class II deficiency, also referred to as bare lymphocyte syndrome is a rare primary Immunodeficiency disorder characterized by a profondly deficient human leukocyte antigen class II expression and a lack of cellular and humoral immune responses to foreign antigens. Clinical manifestations include extreme susceptibility to viral, bacterial, and fungal infections. The infections begin in the first year of life and involve usually the respiratory system and the gastrointestinal tract. Severe malabsorption with failure to thrive ensues, often leading to death in early childhood. Bone marrow transplantation is the curative treatment.Case reports
Here we report two cases with a late outcome MHC class II deficiency. They had a long term history of recurrent bronchopulmonary and gastrointestinal infections. Bone marrow transplantation could not be performed because no compatible donor had been identified. At the age of 12 years, they developed oral papillomatous lesions related to HPV (human papillomavirus). The diagnosis of HPV infection was done by histological examination. HPV typing performed on the tissue obtained at biopsy showed HPV type 6. The lesions were partially removed after two months of laser treatment.Conclusions
Viral infections are common in patients with MHC class II and remain the main cause of death. Besides warts caused by HPV infection do not exhibit a propensity for malignant transformation; they can cause great psychosocial morbidity. 相似文献8.
North‐African house martins endure greater haemosporidian infection than their European counterparts
Juan van Rooyen Tania Jenkins Naouel Lahlah Philippe Christe 《Journal of avian biology》2014,45(5):450-456
Afro‐Palearctic migrant species are exposed to parasites at both breeding and over‐wintering grounds. The house martin Delichon urbicum is one such migratory species facing high instances of blood parasite infection. In an attempt to determine whether breeding European house martins harbour similar blood parasite communities to populations breeding in North Africa, birds were sampled at their breeding grounds in Switzerland and Algeria. Moreover, haemosporidian prevalence and parasite communities were compared to published data sets on Spanish and Dutch breeding populations. This study furthermore wanted to establish whether co‐infection with multiple genera or lineages of parasites had negative e?ects on host body condition. Breeding house martins caught in Algeria showed a higher prevalence of avian haemosporidian parasites than did European populations. Swiss house martins showed a prevalence comparable to that of Spanish and Dutch populations. There were slight differences in the haemosporidian community between European and North‐African populations in terms of composition and abundance of each lineage. Similar to the Dutch house martins, but in contrast to the Spanish population, infection status and number of genera of parasites infecting single hosts did not in?uence Swiss house martin body condition. 相似文献
9.
Ben Khalifa N Tyteca D Marinangeli C Depuydt M Collet JF Courtoy PJ Renauld JC Constantinescu S Octave JN Kienlen-Campard P 《FASEB journal》2012,26(2):855-867
The two major isoforms of human APP, APP695 and APP751, differ by the presence of a Kunitz-type protease inhibitor (KPI) domain in the extracellular region. APP processing and function is thought to be regulated by homodimerization. We used bimolecular fluorescence complementation (BiFC) to study dimerization of different APP isoforms and mutants. APP751 was found to form significantly more homodimers than APP695. Mutation of dimerization motifs in the TM domain did not affect fluorescence complementation, but native folding of KPI is critical for APP751 homodimerization. APP751 and APP695 dimers were mostly localized at steady state in the Golgi region, suggesting that most of the APP751 and 695 dimers are in the secretory pathway. Mutation of the KPI led to the retention of the APP homodimers in the endoplasmic reticulum. We finally showed that APP751 is more efficiently processed through the nonamyloidogenic pathway than APP695. These findings provide new insight on the particular role of KPI domain in APP dimerization. The correlation observed between dimerization, subcellular localization, and processing suggests that dimerization acts as an efficient regulator of APP trafficking in the secretory compartments that has major consequences on its processing. 相似文献
10.
A novel simple and rapid PCR-based site-directed mutagenesis method 总被引:11,自引:0,他引:11
Rabhi I Guedel N Chouk I Zerria K Barbouche MR Dellagi K Fathallah DM 《Molecular biotechnology》2004,26(1):27-34
Site-directed mutagenesis (SDM) is a powerful tool for exploring protein structure and function, and several procedures adjusted
to specific purposes are still being developed. Herein we describe a straightforward and efficient method with versatile applications
for introducing site-specific alterations in any deoxyribonucleic acid (DNA) sequence cloned in a plasmidic expression vector.
In this polymerase chain reaction (PCR)-based SDM method, forward and reverse primers are used to amplify the plasmid containing
the sequence of interest. The primers are designed so that the desired modifications are introduced at the 5′ end of one of
the primers, whereas the other primer starts with the nucleotide at position (−1) of the one to be modified. The PCR is carried
out using Pfu DNA polymerase. The blunt-ended PCR-generated DNA fragment is self-ligated and used to transform Escherichia coli. Mutant clones are screened by colony hybridization using the mutagenic primer as probe and the presence of the mutation
is confirmed by direct DNA sequencing. This procedure was used efficiently to introduce substitutions, deletions, and insertions
in the DNA sequences coding for a recombinant form (scFv) of antibody 107 specific of the human CR3 molecule, the rat α integrin
CD11b A-domain and the human CD8β cloned in pPICZαB, pGEX-2T, and CDM8 expression vectors, respectively. 相似文献