Papers by Antoine Andremont
Antimicrobial Agents and Chemotherapy, 1989
To determine whether antibiotic treatment increases the risk of colonization by Pseudomonas aerug... more To determine whether antibiotic treatment increases the risk of colonization by Pseudomonas aeruginosa, we performed a case-control study comparing antibiotic exposure in cancer patients colonized by P. aeruginosa and in noncolonized controls. Of 88 patients, 76 had been exposed to at least one antibiotic, but colonization was not statistically associated with exposure to any specific antibiotic treatment, administered orally or parenterally, alone or in combination.
Communication présentée le 20 mai 2010) L'espèce Staphylococcus aureus a montré, au cours de ces ... more Communication présentée le 20 mai 2010) L'espèce Staphylococcus aureus a montré, au cours de ces dernières années, un fort pouvoir de colonisation naso-pharyngée, en particulier chez le porc. Le pourcentage de souches résistantes intrinsèques ou SAMR est variable mais le risque de colonisation est non négligeable pour les professionnels de la filière de production porcine, tels que les porchers, vétérinaires, employés d'abattoir. L'identification moléculaire par la technique de Multi Locus Sequence Typing (MLST) de souches initialement non typables (NT) par l'électrophorèse en champ pulsé indique la prédominance, aussi bien en Europe, en Amérique du Nord qu'en Asie, du type ST398 (ou CC398). Cette souche est encore peu résistante aux antibiotiques, à l'exception des tétracyclines, voire des macrolides et ne produit pas les facteurs de virulence rapportés habituellement chez le CA-MRSA, tels que la leucocidine de Panton-Valentine. Divers types d'infection sont maintenant rapportés chez l'homme dans plusieurs pays européens : infections cutanéo-muqueuses, pulmonaires, bactériémiques et endocardites. Des spécialistes évoquent, pour ces souches d'origine animale (LA pour Lifestock-Associated), l'éventualité « d'une nouvelle zoonose » malgré leur faible diffusion chez l'homme.
Journal of Antimicrobial Chemotherapy, 2012
‡D. G. and B. S. contributed equally to the present work. §Members of the ColoRea Study Group are... more ‡D. G. and B. S. contributed equally to the present work. §Members of the ColoRea Study Group are listed in the Acknowledgements section.
Clinical Infectious Diseases, 2009
The use of antimicrobials in food animals creates an important source of antimicrobial-resistant ... more The use of antimicrobials in food animals creates an important source of antimicrobial-resistant bacteria that can spread to humans through the food supply. Improved management of the use of antimicrobials in food animals, particularly reducing the usage of those that are "critically important" for human medicine, is an important step toward preserving the benefits of antimicrobials for people. The World Health Organization has developed and applied criteria to rank antimicrobials according to their relative importance in human medicine. Clinicians, regulatory agencies, policy makers, and other stakeholders can use this ranking when developing risk management strategies for the use of antimicrobials in food production animals. The ranking allows stakeholders to focus risk management efforts on drugs used in food animals that are the most important to human medicine and, thus, need to be addressed most urgently, such as fluoroquinolones, macrolides, and third-and fourth-generation cephalosporins. Antimicrobials decrease morbidity and mortality associated with serious and life-threatening infections. Antimicrobial resistance decreases the effectiveness of these drugs, increasing the risk of morbidity and mortality in serious diseases and, thus, compromising human health [1-6]. Antimicrobial resistance is an inevitable consequence of antimicrobial use. Poverty; suboptimal control of the sale, quality, and use of antimicrobials; and poor sewage and water systems are factors that contribute to the emergence and spread of
Clinical Microbiology Reviews, 2013
Infection control and hospital epidemiology, Jan 28, 2015
BACKGROUND The best strategy for controlling extended-spectrum β-lactamase-producing Enterobacter... more BACKGROUND The best strategy for controlling extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) transmission in intensive care units (ICUs) remains elusive. OBJECTIVE We developed a stochastic transmission model to quantify the effectiveness of interventions aimed at reducing the spread of ESBL-PE in an ICU. METHODS We modeled the evolution of an outbreak caused by the admission of a single carrier in a 10-bed ICU free of ESBL-PE. Using data obtained from recent muticenter studies, we studied 26 strategies combining different levels of the following 3 interventions: (1) increasing healthcare worker compliance with hand hygiene before and after contact with a patient; (2) cohorting; (3) reducing antibiotic prevalence at admission with or without reducing antibiotherapy duration. RESULTS Improving hand hygiene compliance from 55% before patient contact and 60% after patient contact to 80% before and 80% after patient contact reduced the nosocomial incidence rate of E...
Nature Med, 2007
Sepsis, a leading cause of death worldwide, involves proinflammatory responses and inefficient ba... more Sepsis, a leading cause of death worldwide, involves proinflammatory responses and inefficient bacterial clearance 1,2 . Phagocytic cells play a crucial part in the prevention of sepsis by clearing bacteria through host innate receptors 3 . Here we show that the FcRc adaptor, an immunoreceptor tyrosine-based activation motif (ITAM)-bearing signal transduction subunit of the Fc receptor family, has a deleterious effect on sepsis. FcRc -/mice show increased survival during peritonitis, owing to markedly increased E. coli phagocytosis and killing and to lower production of the proinflammatory cytokine tumor necrosis factor (TNF)-a. The FcRc-associated receptor that inhibits E. coli phagocytosis is FccRIII (also called CD16), and its absence protects mice from sepsis. FccRIII binds E. coli, and this interaction induces FcRc phosphorylation, recruitment of the tyrosine phosphatase SHP-1 and phosphatidylinositide-3 kinase (PI3K) dephosphorylation. Decreased PI3K activity inhibits E. coli phagocytosis and increases TNF-a production through Toll-like receptor 4. We identified the phagocytic receptor negatively regulated by FcRc on macrophages as the class A scavenger receptor MARCO. E. coli-FccRIII interaction induces the recruitment of SHP-1 to MARCO, thereby inhibiting E. coli phagocytosis. Thus, by binding FccRIII, E. coli triggers an inhibitory FcRc pathway that both impairs MARCO-mediated bacterial clearance and activates TNF-a secretion.
J Pharm Sci, 2008
Pectin beads containing b-lactamases were designed for the hydrolysis of colonic residual antibio... more Pectin beads containing b-lactamases were designed for the hydrolysis of colonic residual antibiotics responsible for the emergence of resistance. Beads were prepared by ionotropic gelation in CaCl 2 and stabilized by coating with polyethylenimine (PEI) to resist disintegration in the upper GI tract. Particle characterization showed that dried beads had a diameter around 1 mm independently of the presence of PEI. Seven to ten percent (w/w) of PEI was located on bead surface forming a coating layer as observed by scanning electron microscopy. PEI improved considerably bead stability in simulated intestinal medium while affecting slightly the encapsulation efficiency of active blactamases. Coated beads were able to preserve b-lactamases from premature leakage in the upper GIT whereas, in simulated colonic medium, pectinases induced matrix degradation and reduction of b-lactamase content especially in beads coated in a 0.8% PEI solution. Finally, the pharmacokinetics of amoxicillin in rat after oral administration was not modified by the co-administration of beads containing b-lactamases. In conclusion, PEI-coated beads are stable in the upper GIT but remain sensitive to the action of pectinolytic enzymes allowing release of b-lactamases in a colonic medium without modification of the absorption of a b-lactam antibiotic when co-administered with loaded beads. ß
Data Revues 02488663 002900s1 08002944, Apr 6, 2008
International Journal of Pharmaceutics, 1987
... S. Henry-Michelland a , MJ Alonso a , A. Andremont b , P. Maincen c , J. Sauzières d , Corres... more ... S. Henry-Michelland a , MJ Alonso a , A. Andremont b , P. Maincen c , J. Sauzières d , Corresponding Author Contact Information and P ... rate, which was probably due to the external adsorption of the ampicillin onto the nanoparticles, after which liberation of ampi-cillin followed ...
Réanimation, 2006
The emergence of pathogenic bacteria resistant to antimicrobial agents is sometimes the result of... more The emergence of pathogenic bacteria resistant to antimicrobial agents is sometimes the result of a direct selection process within a well-defined infectious site. Most often, such emergence is the result of a two-steps mechanism which associate first the selection of resistant commensal bacteria and, second, the horizontal transfer of resistance between bacterial species, including pathogenic ones. Three practical examples of such emergence are described including: 1) the occurrence of a urinary tract infection resistant to fluoroquinolones; 2) a case of post-surgery peritonitis caused by a strain of Enterobacter sp. resistant to third generation cephalosporins; and 3) cases of infection due to Klebsiella sp. resistant to carbapenems, or to Staphylococcus aureus resistant to glycopeptides. The current and future means to prevent such events in clinical practice are listed.
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 22, 2015
Multidrug-resistant Enterobacteriaceae (MRE) are widespread in the community, especially in trop... more Multidrug-resistant Enterobacteriaceae (MRE) are widespread in the community, especially in tropical regions. Travelers are at risk of acquiring MRE in these regions, but the precise extent of the problem is not known. From February 2012 to April 2013, travelers attending six international vaccination centers in the Paris area prior to traveling to tropical regions were asked to provide a feces sample before and after their trip. Those found to have acquired MRE were asked to send feces samples 1, 2, 3, 6 and 12 months after their return, or until MRE was no longer detected. The fecal relative abundance of MRE among all Enterobacteriaceae was determined in each carrier. Among 824 participating travelers, 574 provided feces samples before and after travel and were not MRE carriers before departure. Of these, 292 (50.9%) acquired an average of 1.8 MRE. Three travelers (0.5%) acquired carbapenemase-producing Enterobacteriaceae. The acquisition rate was higher in Asia (142/196, 72.4%...
Antimicrobial Resistance and Infection Control, 2013
Journal des Anti-infectieux, 2013
and sharing with colleagues.
Environmental microbiology reports, Jan 9, 2015
In this study we quantitatively evaluated the spread of resistance to β-lactams and of integrons ... more In this study we quantitatively evaluated the spread of resistance to β-lactams and of integrons in small rodents and marsupials living at various distances from a point of antibiotic's use. Rectal swabs from 114 animals were collected in Trois-Sauts, an isolated village in French Guiana, and along a 3 km transect heading through the nonanthropized primary forest. Prevalence of ticarcillin resistant enterobacteria was 36% (41/114). Klebsiella spp., naturally resistant to ticarcillin, were found in 31.1% (23/73) of animals from the village and in an equal ratio of 31.7% (13/41) of animals trapped along the transect. By contrast E. coli with acquired resistance to ticarcillin were found in 13.7% (10/73) of animals from the village and in only 2.4% (1/41) of those from the transect (600 m from the village). There was a huge diversity of E. coli and K. pneumoniae strains with very unique and infrequent sequence types. The overall prevalence of class 1 integrons carriage was 19.3% (2...
Médecine et maladies infectieuses, 2014
The increasing prevalence of extended spectrum beta-lactamase producing enterobacteriaceae (ESBLP... more The increasing prevalence of extended spectrum beta-lactamase producing enterobacteriaceae (ESBLPE) requires defining the use of carbapenems in first intention. We analyzed the associations between enterobacteriaceae bacteremia (EbBact) and ESBLPE carriage during 10 years in a 950-bed teaching hospital. We analyzed a 10-year (July 2001 to June 2011) prospective collection of bacteremia cases including 2 databases: (1) EbBact and (2) a computerized database of patients carrying EBLSE. Only one episode of EbBact was analyzed per patient and hospital stay. Factors associated with ESBLPE bacteremia were assessed by univariate and multivariate logistic regression analysis. Overall, 2355 cases of EbBact were identified, among which 135 (5.7%) were ESBLPE (2001-05: 1.4%, 2006-09: 7.6%, 2010-11: 14.2%). ESBLPE bacteremia was observed in 52 of the 88 (59%) patients carrying ESBLPE and in 83/2267 (3.7%) patients not known to be colonized with ESBLPE. Factors associated with ESBLPE bacteremia ...
Infection and immunity, 1997
Encapsulation of vaccines in biodegradable microspheres provides excellent mucosal immunogens wit... more Encapsulation of vaccines in biodegradable microspheres provides excellent mucosal immunogens with a high potential for immunization against bacterial infections. We tested the protective immunity elicited by intragastric vaccination with phosphorylcholine (PC) encapsulated in poly(DL-lactide-co-glycolide) (DL-PLG) microspheres against Salmonella typhimurium in a mouse model of invasive intestinal infection. We chose PC as the antigen because it was found to elicit an immune response after intestinal exposure of mice to PC-bearing S. typhimurium and because anti-PC immunity protects mice against Streptococcus pneumoniae, another PC-bearing microorganism. Mice were primed intragastrically on days 1, 2, and 3 and boosted on days 28, 29, and 30 with PC (280 microg) coupled to porcine thyroglobulin (PC-thyr) encapsulated in DL-PLG microspheres, free PC-thyr, or blank microspheres. A significant rise in anti-PC immunoglobulin A (IgA) titers, as measured by an enzyme-linked immunosorbent ...
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Papers by Antoine Andremont