Bilan infectieux à l'arrivée des enfants adoptés à l'étranger

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Epidémie d'entérobactéries à beta-lactamase à spectre étendu et de salmonella dans une pouponnière de Bamako (évaluation locale et suivi de cohorte)

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Caractères phénotypiques et moléculaires de souches de staphylococcus aureus de type communautaire isolées en Bretagne

RENNES1-BU Santé (352382103) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Comparaison du comportement in vitro de trois types de vis d'interférence utilisées dans les ligamentoplasties du pivot central vis-à-vis de l'adhérence de staphylococcus aureus

Les complications infectieuses après ligamentoplastie du pivot sont rares mais redoutables, car elles mettent en jeu le pronostic fonctionnel du patient. Leur prévention constitue donc une priorité, mais peu d'études se sont focalisées sur l'adhérence bactérienne et la formation de biofilm sur les principaux matériaux employés en chirurgie orthopédique. Ainsi, nous avons comparé in vitro l'adhérence de S.aureus sur trois types de vis d'interférence (en titane, acide polylactique ou PLA, et biocomposite PLA-hydroxyapatite), qui ont été incubées en présence de S.aureus, puis soniquées pour en décrocher le biofilm bactérien. Le sonicat a ensuite été ensemencé afin d'y dénombrer les bactéries. Les vis biocomposites se sont révélées plus sujettes à l'adhérence de S.aureus que les vis en titane ou en PLA. Ceci pourrait constituer un critère de choix supplémentaire pour le chirurgien, bien que des études complémentaires soient nécessaires pour confirmer ou non ces premiers résultats.The occurrence of an infection after anterior cruciate ligament reconstructions is a rare but serious event, which generates decreased functional results. As a result, prevention of infections is one of the highest priorities in this context. Nevertheless, only a few studies have focused on bacterial adhesion and biofilm formation on the main materials used in orthopaedic surgery. Therefore, we compared the in vitro behaviour of three types of interference screws (titane, polylactic acid, and biocomposite polylactic acid-hydroxyapatite) towards the adherence of S.aureus. The screws have been incubated with a bacterial suspension and subsequently sonicated to dislodge the biofilm. The sonicate was then inoculated on plates to quantify bacteria. A total of 45 screws were tested. Biocomposite screws showed a higher adherence than other screws, which could assist the surgeon in its choice, even though extensive studies are necessary to confirm these results or not.LYON1-BU Santé (693882101) / SudocRENNES1-BU Santé (352382103) / SudocSudocFranceF

Evaluation d'un automate d'identification bactérienne et d'antibiogramme, le vitek 2*, en utilisation de routine

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Caractérisation phénotypique et génotypique des Bactéries Multi Résistantes isolées au cours du suivi épidémiologique des enfants adoptés à l étranger

Les bactéries productrices de b-lactamase à spectre étendu (BLSE) ont été rapportées dans de nombreux pays. Elles sont impliquées non seulement dans les infections nosocomiales mais également dans un nombre croissant d infections communautaires. Cependant, très peu de données sont disponibles sur la présence de ces bactéries multi-résistantes dans le cadre de l adoption internationale. Une étude a été menée dans le cadre d un Projet Hospitalier de Recherche Clinique présenté par les équipes de pédiatrie et de bactériologie du CHRU de Brest. Il avait pour but le suivi bactériologique du portage digestif d entérobactéries productrices de BLSE (EBLSE) chez tous les enfants adoptés à la pouponnière de Bamako (Mali) arrivant dans notre région et chez tous les membres de leurs familles adoptives. 422 souches d EBLSE ont été isolées entre 2002 et 2011 chez 58 enfants adoptés et chez 12 membres des familles adoptives (représentant 10 familles). Un enfant est toujours sous surveillance. L étude de la sensibilité in vitro de ces EBLSE vis-à-vis de 13 antibiotiques de la famille des b-lactamines par la méthode des disques a permis une première discrimination sur la base des différences observées entre les diamètres du céfotaxime et de la ceftazidime. 3 phénotypes se dégageaient avec: les souches dont le diamètre du céfotaxime était supérieur à celui de la ceftazidime, les souches présentant au contraire un diamètre plus grand autour de la ceftazidime et enfin celles dont les diamètres des 2 antibiotiques étaient sensiblement équivalents. Les extraits enzymatiques bruts des souches ont été obtenus par sonication et la détermination des points isoélectriques (pIs) par la technique d isoélectrofocalisation a montré que les souches produisaient entre une et trois enzymes de type BLSE dont les pis varient de 5,4 à 8,8. Les gènes de résistances vis-à-vis des -lactamines ont été étudiés par PCR suivi du séquençage des produits obtenus. L analyse des séquences a permis la mise en évidence d enzymes de type TEM-l, SHV-2a, SHV-1 1, 811V-12, CTX-M-14, CTX-M-15. Notre travail met en avant 2 éléments importants sur le plan épidémiologique : la durée du portage et la transmission intrafamiliale. Ce travail va se poursuivre puisque des enfants sont toujours en surveillance, qu ils présentent un portage anormalement long d entérobactéries productrices de BLSE. De plus, le suivi d une famille (enfant et membres de la famille) va faire l objet d un sujet de master.Extended Spectrum b-lactamase producing Enterobacteria (EESBL) have been reported in many countries both as nosocomial infections, but more recently also involved in many conununit-acquired infections. However, the presence of these multi-resistant bacteria (MRB) isn t well known in the context of international adoption. At Brest University Hospital, a study was conducted as part of a Hospital Clinical Research Project between the Pediatrics and Bacteriology units. It was followed by the goals of stools of children adopted within one month of their arrival and their families Between 2002 and 2011, 422 strains of ESB-producing Enterobacteriaceae were isolated in 58 adopted children and their adoptive families. 12 family member contract EESBL representating 10 adoptive families. One child is still in survey. The study of in vitro susceptibility of MRB to 13 b-lactam antibiotics by the disc method has noted a number of facts with 3 groups of strains: those with a larger diameter around CTX, those with a larger diameter at the level of CAZ, and finally those with comparable diameters between CTX and CAZ. The determination of isoelectric points (PIs) by the technique of isoelectric focusing showed that our strains produced one to three different ESBL with a range of PIs from 5.4 to 8.8. The analysis of extracted DNA (chromosomal and plasmid) subjected to PCR, using primers specific genes blaTEM, blaSHV, blaCTX-M showed the presence of different ESBL genes. ESBL-types such as TEM-l, SHV-2a, SHV-l1, SHV-12, CTX-M-14, CTX-M-15 were recover. This analysis of the strains also showed two important events: the duration of the carnage of ESBL and the household transmission. This monitoring also allowed highlighting a transmission within the family for five families; the genetic studies have proven the identity of bacteria isolated in children and in at least one family member.BREST-BU Médecine-Odontologie (290192102) / SudocSudocFranceF

Emergence of Ertapenem Resistance in an Escherichia coli Clinical Isolate Producing Extended-Spectrum β-Lactamase AmpC▿

Escherichia coli isolate MEV, responsible for a bloodstream infection, was resistant to penicillins, cephalosporins, and ertapenem. Molecular and biochemical characterization revealed the production of a novel, chromosome-borne, extended-spectrum AmpC (ESAC) β-lactamase with a Ser-282 duplication and increased carbapenemase activity. This study demonstrates for the first time that chromosome-borne ESAC β-lactamases can contribute to the emergence of ertapenem resistance in E. coli clinical isolates

OXA-427, a new plasmid-borne carbapenem-hydrolysing class D β-lactamase in Enterobacteriaceae.

OBJECTIVES: To describe a novel plasmid-borne class D carbapenemase (CHDL) named OXA-427 identified in several Enterobacteriaceae clinical isolates from nine patients in one Belgian hospital. METHODS: OXA-427-producing isolates were analysed by an electrochemical imipenem hydrolysis method (BYG Carba test), Carba NP test, conventional phenotypic assays and by molecular methods (PCR, whole sequencing of the OXA-427-encoding plasmid and cloning). The antimicrobial resistance profile of OXA-427 was analysed by expression of the cloned gene in Escherichia coli DH10B and J53. RESULTS: Eleven OXA-427-producing Enterobacteriaceae isolates of various species were identified from clinical specimens of nine patients between March 2012 and June 2014. OXA-427 shares only 22%-29% amino acid identity with OXA-48-like enzymes and other acquired CHDL (e.g. OXA-23, -24/40 and -58 of Acinetobacter spp.). Conversely, it appeared closely related to the chromosomal class D β-lactamase of Aeromonas media, Aeromonas hydrophila and Aeromonas sobria (99%, 89% and 77% of identity, respectively). When expressed in E. coli, OXA-427 hydrolysed imipenem and conferred resistance to extended-spectrum cephalosporins (mostly ceftazidime), penicillins including temocillin, and reduced susceptibility to carbapenems. The blaOXA-427 gene was located in a 45 kb resistance island on a 177 kb IncA/C plasmid. CONCLUSIONS: OXA-427 is a novel CHDL most closely related to chromosomal class D β-lactamase of A. media WS. It confers resistance to penicillins, ceftazidime and aztreonam and in some instances to carbapenems. OXA-427, which is not detectable by classical molecular tests, caused a protracted outbreak in one university hospital over a 2 year period

Multicentre prospective evaluation of histological and molecular criterion for diagnosis of prosthetic-joint infection

International audienceObjectives:This multicenter prospective study was performed to assess the contribution of broad range PCR diagnosis in prosthetic-joint infection (PJI).Methods:Adult patients treated for PJI at 7 centers were included between December 2010 and March 2012. Six per-operative samples were obtained for each patient, 5 for conventional cultures and 16S rRNA gene real-time PCR followed by sequencing, and 1 for histopathological classification according to Morawietz. Cultures and PCR were performed in a highly standardized manner, with 3 quality controls of PCR analyses. An infection was considered as proved (3 criteria: per-operative, bacteriological and histological), probable (clinical or bacteriological criterium), or excluded (no criterium). Molecular criterium for predicting PJI was determined using the bacteriological one as reference (&gt;=1 positive sample for virulent organism, and &gt;=3 positive samples for coagulase-negative staphylococci (CoNS) and P. acnes).Results:299 patients were included, 264 with suspicion of sepsis (S) and 35 as controls (C). The 264 S presented with acute (19%), or chronic suspicion of PJI (81%). Infection was proved or probable in 212/264 S (80%), with the bacteriological criterium in 189/212 S (89%). Out of these, 156 (83%) had monomicrobial and 33 (17%) polymicrobial infections. The isolated pathogens were S. aureus (40%), CoNS (25%), streptococci (14%), Gram-Negative rods (10%), and anaerobes 8%.Histology results were not available for 55 patients, leaving 244 patients available for analysis. Histological findings of infection (Morawietz types II or III) were present in 128/169 (76%) proved or probable infections, in 3 patients without any other criterium, and were absent in excluded infections (n=42) and controls (n=29). PCR results were not analysable for 32 patients (S=28, C=4), leaving 267 patients (S=236, C=31) available for analysis. Molecular criterium of infection was present in 63/68 (93%) proved infections, 83/124 (67%) probable infections, 3/42 excluded infections, 0/2 histological criterium alone and 2/31 controls. Molecular criterium of infection was absent in 34/189 (18%) culture-positive S, and present in 8/23 culture-negative S (8 patients treated with antibiotics).Conclusions:According to this multicenter prospective study, 16S rRNA gene real-time PCR is less susceptible than culture for diagnosis of PJI. Molecular analysis could be recommended in culture-negative patients who were receiving antibiotics.</p

Multicentre external quality control evaluating universal 16S polymerase chain reaction (PCR) in the diagnosis of bone and joint infections

International audienceObjectives:During a multicentrer French Study performed to assess the contribution of 16S PCR in the diagnosis of prosthesis osteoarticular infections, 300 patients were included from December 2009 to April 2012. An external quality control (QC) was considered essential due to the diversity of molecular equipment for each laboratory. Three sets were held, for each including 4 bacterial DNA extracts (E) and 4 crushed osteoarticular deep samples.Methods:Extraction: 0,2 ml of pretreated S (PK, 37 °C, 3h) with elution in 0.1 ml. Four laboratories used Qiagen manual extraction and 3 others used automated extraction 1 MagnaPur Roche, 1 Easy Mag, BioMérieux and 1 iPrep, Invitrogen. Real time 16S PCR with SybrGreen was performed with degenerate primers amplifying 658pb followed by sequencing. In the 7 centers, PCR thermocyclers used were 2 MX 3000p Agilent, 1 Roche Light Cycler, 1 Abi 7900 and 1 Applied Step one plus, 1 Smartcycler Cepheid,1 Biorad Chrono 4 and for PCR premix, Takara premix exTaq, Applied, Promega and Biorad were used.Results: 168 QC were sent and 160 responses were analyzed (1 laboratory did not participate in the first QC series). Expected results were obtained in 97.5% for Extracts and 95% for Samples. Sensitivity and Specificity were 100 and 90% for E and 93.3 and 100% for S. Ct standard deviations (SD) for E were from 1 to 9 while SD was 2 to 7 for S. For centers using the same premix, the results were closer, SD 0.5 to 1.5 (3 Ct gap max). For S, no influence of extraction system was observed.Conclusion:If extraction system had no influence, premix seems to be the most important factor influencing the value of threshold. This QC demonstrates the possibility to obtain good and homogeneous results by using the same 16S PCR in laboratories with different equipments for molecular bone and joint infection diagnosis