Papers by Pierre-Yves Donnio
Frontiers in Cellular and Infection Microbiology
Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their ... more Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their expression inside living colonized or infected organisms is essential for identifying sRNA functions, but few studies have looked at sRNA expression during host infection with bacterial pathogens. Insufficient in vivo studies monitoring sRNA expression attest to the difficulties in collecting such data, we therefore developed a non-mammalian infection model using larval Galleria mellonella to analyze the roles of Staphylococcus aureus sRNAs during larval infection and to quickly determine possible sRNA involvement in staphylococcal virulence before proceeding to more complicated animal testing. We began by using the model to test infected larvae for immunohistochemical evidence of infection as well as host inflammatory responses over time. To monitor sRNA expression during infection, total RNAs were extracted from the larvae and invading bacteria at different time points. The expression ...
International Journal of Antimicrobial Agents
A switch from aminoglycoside-containing 3-drug regimen to piperacillin-tazobactam as the first-li... more A switch from aminoglycoside-containing 3-drug regimen to piperacillin-tazobactam as the first-line treatment for complicated appendicitis in children allowed a dramatic reduction of protocols deviation, and antibacterial treatment duration No impact was observed on outcomes (post-operative complications, duration of hospital stay) Female gender and sepsis or septic shock on admission were the only variables independently associated with post-operative intra-abdominal abscess
Médecine et Maladies Infectieuses
ABSTRACT
European Journal of Clinical Microbiology & Infectious Diseases
Emerging infectious diseases, Sep 15, 2016
Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the trans... more Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD ...
Médecine et Maladies Infectieuses, 2004
L'examen direct permet de poser un diagnostic de prrsomption de peste.Simple 5. rdaliser 5. prior... more L'examen direct permet de poser un diagnostic de prrsomption de peste.Simple 5. rdaliser 5. priori,la microscopic pose de rdelles difficultrs de lecture. Pour rdsoudre ces difficuttrs, un test de diagnostic rapide (TDR) par immunochromatographie a 6t6 commercialisr. Notre allude va comparer les rrsultats obtenus par TDR (sur suc ganglionnaire) et par RT-PCR (sang total, srrums) chez des patients suspects de peste. M~thodes : 6tude rOrospective de 127 patients suivis de juin h septembre 2003 ayant prdsent6 de fa~on groupde des adrnopathies. Les donndes suivantes ont 6t6 6tudires : fige, sexe, origine grographiqne ; formule sanguine et VS ; TDR (antigbne F1 de Yersinia pestis) sur suc ganglionnaire de patients ; RT-PCR (Yersinia pestis et tularrmie) sur sang total et sdrums de patients ; 6tude cas-trmoin (20 tdmoins avec un TDR nrgatif). R~sultats : la recherche de t'antigrne F1 de Y. pestis darts le suc ganglionnaire a 6t6 positive chez 10 patients sur les 127 testds soit 07% des cas. L'rvolution a 6t6 favorable dans 127 cas (100% des cas). Sexe : masculin : 6 cas / fdminin : 4 cas. Age : 2 sont figrs de 0 5. 15 ans ; 3 cas de 16 5. 25 ans et les autres ont plus de 26 ans. Origine g~ographique : village Kehailia : 5 cas / autres rdgions : 5 cas. L'hypefleucocytose (GB> 10 000) retrouvde darts 30% des cas. La VS est < 30 dans 100% des cas. La RT-PCR (Yersinia pestis) sur sang total chez un patient avec un TDR positif et chez 4 patients avec un TDR nrgatif n'a pas retrouv6 d'ADN de Yersinia pestis. La RT-PCR (tulardmie) et l'agglutination sur lames ont 6t6 nrgatives dans les 5 cas. L'dtude cas-trmoin avec 20 patients avec un TDR ndgatif n'a pas mis en ~vidence de facteur de risque. Conclusion : l'rtude cas-trmoin n'a pas mis en 6vidence de diffdrence significative entre les cas avec TDR positif (10 cas) et ndgatif (20 cas). La RT-PCR n'a pas retrouv6 de I'ADN de Yersinia pestis tant chez la patiente avec un TDR positif et chez 4 patients avec un TDR nrgatif.
Médecine et Maladies Infectieuses, 1989
Revue d Épidémiologie et de Santé Publique
ABSTRACT
La Revue du praticien
ABSTRACT
Pathologie Biologie
A total of 142 Acinetobacter baumanii strains isolated from hospital patients were biotyped accor... more A total of 142 Acinetobacter baumanii strains isolated from hospital patients were biotyped according to the scheme of Bouvet and Grimont. Most of the strains belonged to biotype 9 and were highly resistant to antibiotics including cephalosporins and amikacin. Imipenem and ticarcillin were the only drugs having a bactericidal activity against A. baumanii. The combination imipenem-netilmicin and ticarcillin-netilmicin were more rapidly bactericidal than imipenem or ticarcillin alone. No resistant strain to imipenem was isolated.
Pathologie Biologie
Fifty-four clinical isolates of Pasteurella are classified into different taxa. P. multocida subs... more Fifty-four clinical isolates of Pasteurella are classified into different taxa. P. multocida subsp.multocida is more frequently encountered than other subspecies of P. multocida. P. canis is only identified from wounds inflicted by animals. The frequency of isolation of different species and subspecies is comparable with that observed from animal isolates. The distribution of the strains in the capsular types is different according to the origin, human or animal, of the strains.
Pathologie Biologie
An IV vancomycin treatment induces a reduction of Gram positive cocci (Staphylococcus, Enterococc... more An IV vancomycin treatment induces a reduction of Gram positive cocci (Staphylococcus, Enterococcus) of the aerobic salivary and fecal flora. Some of these strains persisted during and after treatment, but remained susceptible to vancomycin. Others isolated Gram positive cocci were resistant to vancomycin before and after treatment. They were identified as Pediococcus sp., and Leuconostoc sp. There is a reduction of the number of Gram positive cocci, without increase of Gram negative rods, Lactobacillus, or Candida which are always resistant to vancomycin.
Pathologie Biologie
Most of Enterobacter cloacae strains produce chromosomally determined class I beta-lactamases whe... more Most of Enterobacter cloacae strains produce chromosomally determined class I beta-lactamases when they are exposed to beta-lactams. Imipenem is a strong inducer of these enzymes but is poorly affected by them. We compared the effect of imipenem on inducible, non-inducible and stably derepressed strains of E. cloacae using the killing curve system. With antibiotic concentrations of 0.5 mg/l or more, an intense dose-dependent bactericidal effect was observed within 4 to 6 hours. However the bactericidal activity was incomplete. With an inoculum as low as 10(5) bacteria/ml a regrowth was observed after 24 hours. Among the surviving bacteria imipenem had the same bactericidal kinetic than on the parental strain. Similar results were observed with inducible, non-inducible and stably derepressed strains.
Veterinary Research
― The presence of Pasteurella multocida in the oropharynx of 58 pig, cattle or rabbit bree... more ― The presence of Pasteurella multocida in the oropharynx of 58 pig, cattle or rabbit breeders whose livestock had suffered from pasteurellosis was investigated using a selective medium. Blood samples for serological studies were collected at the same moment. Nineteen breeders were found to host one P multocida subsp multocida strain. Oropharyngeal carriage of P multocida was found to be more frequent in pig breeders (42% of individuals) than in cattle (10%) or rabbit (0%) breeders. Genomic polymorphism among 10 D2 strains was found by restriction endonuclease analysis using pulsed-field gel electrophoresis (REA-PFGE). Antibodies to P multocida were found in the sera of 32 of these 58 breeders, whereas only 2 of the 70 controls had antibodies. These results, recorded from healthy individuals, show that P multocida, acting as an opportunistic bacterium, may be responsible for occupational diseases. Nevertheless, the strong prevalence of specific antibodies makes the presence of antibodies in the sera of these breeders an insufficient indication of a current patent infection. * Correspondence and reprints des 11 souches appartenant au type capsulaire D et au type somatique 2 a été obtenu par électrophorèse à champ pulsé, montrant leur polymorphisme génomique. Parmi les 58 éleveurs étudiés, 32 avaient dans leur sérum des anticorps dirigés contre P multocida. La positivité des anticorps sériques était indépendante de la présence ou non de la bactérie dans l'oropharynx. Dans un groupe témoin de 70 donneurs de sang vivant en milieu rural, seulement 2 d'entre eux avaient des anticorps. Ces résultats, observés chez des éleveurs en bonne santé, montrent que ceux-ci sont, avec une grande fréquence, exposés à une contamination par P multocida. Chez eux, la présence d'anticorps dirigés contre P multocida est la conséquence d'une immunisation itérative.
Annales de biologie clinique
Out of 900 dialysates analysed over 15 months at the Rennes Regional Hospital, 116 cloudy specime... more Out of 900 dialysates analysed over 15 months at the Rennes Regional Hospital, 116 cloudy specimens with a leucocyte count of more than 100/mm3 were studied. Three methods of laboratory diagnosis based on physical or chemical disruption of leucocytes were evaluated: saponin incorporated in the agar medium, sonication, and the Isolator lysis centrifugation system. Sensitivity was improved (52%) for the three methods combined compared with the standard method (37%). The Isolator system (51%, P &lt; 0.05) gave the best results. Direct microscopic examination nevertheless remains essential for its indicative value (sensitivity 33% of positive dialysates). The leucocyte count was correlated with the percentage of culture positivity (43% from 100-200/mm3 compared with 62% from 500-1000/mm3); 80% of organisms were Gram-positive bacteria and most were coagulase-negative staphylococci. Opportunistic pathogens such as Corynebacterium jeikeium were frequently isolated.
La Presse Médicale
ABSTRACT
La Presse Médicale
Bactericidal activities of ciprofloxacin and sparfloxacin were compared to other antibiotics acti... more Bactericidal activities of ciprofloxacin and sparfloxacin were compared to other antibiotics active against human isolates of Pasteurella multocida. Three human isolates of Pasteurella multocida were used for killing-curve studies with ciprofloxacin and sparfloxacin comparatively to others antibiotics. At 2x the MIC, ciprofloxacin and sparfloxacin exhibited a killing of more than 99.9% of the initial viable cells that was achieved within 6 h of incubation. These activities were faster than those of amoxycillin and cefpodoxime. No regrowth was observed after 24 h of incubation. Doxycycline and clarithromycin used at MICx2 had no bactericidal activities. It was concluded that fluoroquinolones, namely ciprofloxacin and sparfloxacin, can be considered having good bactericidal activity against P. multocida.
Pathologie Biologie
To determine the prevalence of quinolone resistance in Salmonella typhimurium strains from humans... more To determine the prevalence of quinolone resistance in Salmonella typhimurium strains from humans or animals (cattle, poultry, swine), the S. typhimurium strains isolated at a teaching hospital and at the central veterinary laboratory of the same district between January 1, 1995, and December 31, 1996 were studied. Susceptibility to nalidixic acid was determined using the disk diffusion method. Strains with decreased susceptibility to nalidixic acid were subjected to minimal inhibitory concentration (MIC) determination for pefloxacin, ofloxacin, ciprofloxacin, norfloxacin, levofloxacin, and grepafloxacin. Decreased susceptibility to nalidixic acid was demonstrated for 41 of the 309 strains studied and increased from 8.5% in 1995 to 18.6% in 1996. MIC90 values of fluoroquinolones for strains with decreased susceptibility to nalidixic acid were lower than 1 mg/L, which is the cutoff above which a strain is classified as susceptible, but were higher than for strains that were susceptib...
European Respiratory Journal
We report the case of a nonimmunocompromised female patient, who developed exogenous lipoid pneum... more We report the case of a nonimmunocompromised female patient, who developed exogenous lipoid pneumonia with Mycobacterium fortuitum infection at diagnosis, later followed by Aspergillus fumigatus infection. The association of exogenous lipoid pneumonia with atypical mycobacterial infection is uncommon but well-recognized, but, to our knowledge, association with A. fumigatus infection has not previously been reported.
Transfusion Clinique et Biologique
This work presents the procedure applied by our hospital to assess the quality and security of in... more This work presents the procedure applied by our hospital to assess the quality and security of intra operative autotransfusion. The suitability of the three following variables has to be constantly assessed: performance of the machines to concentrate and wash collected blood, bacterial contamination of processed blood and rate of adverse events. We note that the procedure is applied with participation of medical and nursing staff. Since its setting-up, we note an amelioration of suitable variables.
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Papers by Pierre-Yves Donnio