ABSTRACT
A narrow near-threshold proton-emitting resonance (E_{x}=11.4 MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4 keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the ß-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11 keV) emission channels.
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The microscopic structure of the low-energy electric dipole response, commonly denoted as pygmy dipole resonance (PDR), was studied for ^{120}Sn in a ^{119}Sn(d,pγ)^{120}Sn experiment. Unprecedented access to the single-particle structure of excited 1^{-} states below and around the neutron-separation threshold was obtained by comparing experimental data to predictions from a novel theoretical approach. The novel approach combines detailed structure input from energy-density functional plus quasiparticle-phonon model theory with reaction theory to obtain a consistent description of both the structure and reaction aspects of the process. The presented results show that the understanding of one-particle-one-hole structures of the 1^{-} states in the PDR region is crucial to reliably predict properties of the PDR and its contribution to nucleosynthesis processes.
ABSTRACT
New experimental data on the neutron single-particle character of the Pygmy Dipole Resonance (PDR) in ^{208}Pb are presented. They were obtained from (d,p) and resonant proton scattering experiments performed at the Q3D spectrograph of the Maier-Leibnitz Laboratory in Garching, Germany. The new data are compared to the large suite of complementary, experimental data available for ^{208}Pb and establish (d,p) as an additional, valuable, experimental probe to study the PDR and its collectivity. Besides the single-particle character of the states, different features of the strength distributions are discussed and compared to large-scale shell model (LSSM) and energy-density functional plus quasiparticle-phonon model theoretical approaches to elucidate the microscopic structure of the PDR in ^{208}Pb.
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This corrects the article DOI: 10.1103/PhysRevLett.123.082501.
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OBJECTIVE: Staphylococcusaureus is involved in around 20% of nosocomial pneumonia cases. Vancomycin used to be the reference antibiotic in this indication, but new molecules have been commercialized, such as linezolid. Previous studies comparing vancomycin and linezolid were based on models. Comparing their real costs from a hospital perspective was needed. METHODS: We performed a bicentric retrospective analysis with a cost-minimization analysis. The hospital antibiotic acquisition costs were used, as well as the laboratory test and administration costs from the health insurance cost scale. The cost of each hospital stay was evaluated using the national cost scale per diagnosis related group (DRG), and was then weighted by the stay duration. RESULTS: Fifty-eight patients were included. All bacteria identified in pulmonary samples were S. aureus. The cost of nursing care per stay with linezolid was 234.10 (SD=91.50) vs. 381.70 (SD=184.70) with vancomycin (P=0.0029). The cost of laboratory tests for linezolid was 172.30 (SD=128.90) per stay vs. 330.70 (SD=198.40) for vancomycin (P=0.0005). The acquisition cost of linezolid per stay was not different from vancomycin based on the price of the generic drug (54.92 [SD=20.54] vs. 40.30 [SD=22.70]). After weighting by the duration of stay observed, the mean cost per hospital stay was 47,411.50 for linezolid and 57,694.0 for vancomycin (NSD). CONCLUSION: These results, in favor of linezolid, support other former pharmacoeconomic study based on models. The mean cost per hospitalization stay was not statistically different between the two study groups, but a trend in favor of linezolid is emerging.
Subject(s)
Cross Infection/drug therapy , Linezolid/economics , Pneumonia, Staphylococcal/drug therapy , Vancomycin/economics , Aged , Costs and Cost Analysis , Cross Infection/economics , Cross Infection/nursing , Diagnosis-Related Groups , Drug Costs , Economics, Nursing , Female , France , Hospitalization/economics , Hospitals, Urban/economics , Humans , Infusions, Intravenous/economics , Length of Stay/economics , Linezolid/administration & dosage , Linezolid/therapeutic use , Male , Middle Aged , Pneumonia, Staphylococcal/economics , Pneumonia, Staphylococcal/nursing , Retrospective Studies , Staphylococcus aureus/drug effects , Vancomycin/administration & dosage , Vancomycin/therapeutic useABSTRACT
The elusive ß^{-}p^{+} decay was observed in ^{11}Be by directly measuring the emitted protons and their energy distribution for the first time with the prototype Active Target Time Projection Chamber in an experiment performed at ISAC-TRIUMF. The measured ß^{-}p^{+} branching ratio is orders of magnitude larger than any previous theoretical model predicted. This can be explained by the presence of a narrow resonance in ^{11}B above the proton separation energy.
ABSTRACT
The neutron-capture reaction plays a critical role in the synthesis of the elements in stars and is important for societal applications including nuclear power generation and stockpile-stewardship science. However, it is difficult-if not impossible-to directly measure neutron capture cross sections for the exotic, short-lived nuclei that participate in these processes. In this Letter we demonstrate a new technique which can be used to indirectly determine neutron-capture cross sections for exotic systems. This technique makes use of the (d,p) transfer reaction, which has long been used as a tool to study the structure of nuclei. Recent advances in reaction theory, together with data collected using this reaction, enable the determination of neutron-capture cross sections for short-lived nuclei. A benchmark study of the ^{95}Mo(d,p) reaction is presented, which illustrates the approach and provides guidance for future applications of the method with short-lived isotopes produced at rare isotope accelerators.
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We study the sequential breakup of E/A=24.0 MeV ^{7}Li projectiles excited through inelastic interactions with C, Be, and Al target nuclei. For peripheral events that do not excite the target, we find very large spin alignment of the excited ^{7}Li projectiles longitudinal to the beam axis. This spin alignment is independent of the target used, and we propose a simple alignment mechanism that arises from an angular-momentum-excitation-energy mismatch. This mechanism is independent of the potential used for scattering and should be present in many scattering experiments.
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The exotic nucleus ^{11}Be has been extensively studied and much experimental information is available on the structure of this system. We treat, within the framework of renormalized nuclear field theory in both configuration and 3D space, the mixing of bound and continuum single-particle states through the coupling to collective vibrations of the ^{10}Be core. We also take care of the Pauli principle acting not only between the single valence particle explicitly considered and those participating in the collective states, but also between fermions involved in two-phonon virtual states dressing the single-particle motion. In this way, it is possible to simultaneously and quantitatively account for the energies of the 1/2^{+}, 1/2^{-} low-lying states, the centroid and line shape of the 5/2^{+} resonance and the one-nucleon stripping and pickup absolute differential cross sections involving ^{11}Be as either target or residual nucleus. Also for the dipole transition connecting the 1/2^{+} and 1/2^{-} parity inverted levels as well as the isotopic shift of the charge radius. Theory provides a unified and exhaustive nuclear structure and reaction characterization of the many-body effects which are at the basis of this paradigmatic one-neutron halo system.
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The aim of this study was to evaluate whether recent systemic anti-inflammatory agents (AIAs) exposure in patients with sore throat managed with or without antibiotic therapy influenced the risk of peritonsillar abscess (PTA). We conducted a multicenter case-control study in 13 French university hospitals in 2009-2012 comparing patients admitted with PTA to matched controls: patients with sore throat but without PTA who were followed up for 10 days after visiting their primary-care physician. In the multivariate stepwise logistic regression model comparing 120 cases with PTA to 143 controls, factors significantly associated with PTA were male gender (odds ratio [OR], 2.0; p = 0.03), smoking (OR, 2.0; p = 0.03), and prior self-medication with systemic AIAs (OR, 3.5; p = 0.01). Topical treatment was associated with significant protection against PTA (OR, 0.3; p < 0.001). In conclusion, self-medication with systemic AIAs appears to be an independent factor associated with the occurrence of PTA. This is an important message as non-steroidal AIAs access is favored by their over-counter availability in pharmacies. This finding must be interpreted with caution due to the study design and a prospective, randomized study is needed to substantiate these possible causal risk factors.
Subject(s)
Anti-Inflammatory Agents/adverse effects , Anti-Inflammatory Agents/therapeutic use , Peritonsillar Abscess/epidemiology , Adolescent , Adult , Aged , Case-Control Studies , Child , Child, Preschool , Female , France/epidemiology , Humans , Infant , Male , Middle Aged , Prospective Studies , Risk Assessment , Young AdultABSTRACT
The aim of this study was to describe the epidemiology of hospitalized patients with peritonsillar abscess (PTA). We conducted a multicenter survey in 13 French university hospitals in 2009-2012 describing 412 patients. Median age was 29 year (range, 2-84) and current smoking habit was reported by 177 (43 %) patients. Most of the patients (92 %) had consulted a physician for sore throat within 10 days before admission for PTA diagnosis. Additional symptoms such as visible tonsil abnormalities (83 %), tender cervical adenopathy (57 %) and fever ≥ 38.5 °C (53 %) were also reported. A total of 65 % patients (269/412) reported recent systemic anti-inflammatory agents (AIAs) exposure by medical prescription (70 %), self-medication (22 %), or both (8 %); 61 % and 27 % reported recent exposure to antibiotic and topical treatments for sore throat, respectively. Non-steroidal AIAs were used most often (45 %), particularly arylpropionic derivatives. A rapid diagnosis antigen test (RDT) for Streptococcus pyogenes was performed in 70 (17 %) patients and was positive in 17 (24 %), of whom 9 (53 %) were exposed to AIAs and 14 (82 %) to antibiotics. To treat PTA, antibiotic therapy was given to 392 (95 %) patients. Of 333 antibiotic prescriptions, amoxicillin-clavulanic acid and metronidazole were the most prescribed antibiotics (42 and 17 %, respectively). Surgical drainage of the abscess was performed in 119 (29 %) cases and tonsillectomy in 75 (18 %) cases. The clinical outcome was favorable during the hospital stay in 404 (98 %) patients. In conclusion, patients with sore throat are often exposed to AIAs before PTA diagnosis, and antibiotic prescription was not often based on the RDT positivity.
Subject(s)
Peritonsillar Abscess/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Child , Child, Preschool , Comorbidity , Female , France/epidemiology , Hospitalization , Hospitals, University , Humans , Male , Middle Aged , Peritonsillar Abscess/diagnosis , Peritonsillar Abscess/drug therapy , Peritonsillar Abscess/microbiology , Risk Factors , Surveys and Questionnaires , Treatment Outcome , Young AdultABSTRACT
OBJECTIVE: Prosthetic vascular graft infection (PVGI) is an emerging disease, mostly caused by staphylococci, with limited data regarding efficacy of current antistaphylococcal agents. We aimed to assess the efficacy of different antibiotic regimens. METHODS: Six different strains of MSSA and MRSA were used. We compared results of minimal biofilm inhibitory and eradicating concentrations (MBICs and MBECs) obtained with a Calgary Biofilm Pin Lid Device (CBPD) with those yielded by an original Dacron(®)-related minimal inhibitory and eradicating concentration measure model. We then used a murine model of Staphylococcus aureus vascular prosthetic material infection to evaluate efficacy of different antibiotic regimens: vancomycin and daptomycin combined or not with rifampicin for MRSA and the same groups with cloxacillin and cloxacillin combined with rifampicin for MSSA. RESULTS: We demonstrated that classical measures of MBICs and MBECs obtained with a CPBD could overestimate the decrease in antibiotic susceptibility in material-related infections and that the nature of the support used might influence the measure of biofilm susceptibility, since results yielded by our Dacron(®)-related minimal eradicating assay were lower than those found with a plastic device. In our in vivo model, we showed that daptomycin was significantly more bactericidal than comparators for some strains of MRSA or MSSA but not for all. For the majority of strains, it was as efficient as comparators. The addition of rifampicin to daptomycin did not enhance daptomycin efficacy. CONCLUSIONS: Despite the heterogeneity of results according to bacterial strains, these innovative models represent an option to better evaluate the in vitro efficacy of antibiotics on Dacron(®)-related biofilm S. aureus infections, and to screen different antibiotic regimens in a mouse model of PVGIs.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Prosthesis-Related Infections/drug therapy , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Animals , Biofilms/drug effects , Daptomycin/administration & dosage , Disease Models, Animal , Drug Therapy, Combination/methods , Female , Mice , Microbial Sensitivity Tests , Models, Biological , Prosthesis-Related Infections/microbiology , Rifampin/administration & dosage , Staphylococcal Infections/microbiology , Staphylococcus aureus/physiology , Treatment Outcome , Vancomycin/administration & dosageABSTRACT
BACKGROUND: Chemotherapy is commonly used as myeloablative conditioning treatment to prepare patients for haematopoietic stem cell transplantation (HSCT). Chemotherapy leads to several side effects, with gastrointestinal (GI) mucositis being one of the most frequent. Current models of GI mucositis pathophysiology are generally silent on the role of the intestinal microbiome. AIM: To identify functional mechanisms by which the intestinal microbiome may play a key role in the pathophysiology of GI mucositis, we applied high-throughput DNA-sequencing analysis to identify microbes and microbial functions that are modulated following chemotherapy. METHODS: We amplified and sequenced 16S rRNA genes from faecal samples before and after chemotherapy in 28 patients with non-Hodgkin's lymphoma who received the same myeloablative conditioning regimen and no other concomitant therapy such as antibiotics. RESULTS: We found that faecal samples collected after chemotherapy exhibited significant decreases in abundances of Firmicutes (P = 0.0002) and Actinobacteria (P = 0.002) and significant increases in abundances of Proteobacteria (P = 0.0002) compared to samples collected before chemotherapy. Following chemotherapy, patients had reduced capacity for nucleotide metabolism (P = 0.0001), energy metabolism (P = 0.001), metabolism of cofactors and vitamins (P = 0.006), and increased capacity for glycan metabolism (P = 0.0002), signal transduction (P = 0.0002) and xenobiotics biodegradation (P = 0.002). CONCLUSIONS: Our study identifies a severe compositional and functional imbalance in the gut microbial community associated with chemotherapy-induced GI mucositis. The functional pathways implicated in our analysis suggest potential directions for the development of intestinal microbiome-targeted interventions in cancer patients.
Subject(s)
Antineoplastic Agents/adverse effects , Lymphoma, Non-Hodgkin/drug therapy , Mucositis/chemically induced , Mucositis/metabolism , RNA, Ribosomal, 16S/drug effects , Actinobacteria/drug effects , Adult , Antineoplastic Agents/therapeutic use , Dysbiosis/chemically induced , Dysbiosis/metabolism , Dysbiosis/microbiology , Feces/microbiology , Female , Firmicutes/drug effects , Gastrointestinal Microbiome/drug effects , Hematopoietic Stem Cell Transplantation/methods , High-Throughput Nucleotide Sequencing , Humans , Lymphoma, Non-Hodgkin/therapy , Male , Middle Aged , Mucositis/microbiology , Proteobacteria/drug effects , RNA, Ribosomal, 16S/metabolismABSTRACT
BACKGROUND: Gastrointestinal mucositis is defined as inflammation and/or ulcers of the gastrointestinal tract occurring as a complication of chemotherapy and radiation therapy, and affects about 50% of all cancer patients. AIM: To assess the role of gut microbiota in the pathogenesis of gastrointestinal mucositis and the potential for manipulations of the microbiota to prevent and to treat mucositis. METHODS: Search of the literature published in English using Medline, Scopus and the Cochrane Library, with main search terms 'intestinal microbiota', 'bacteremia', 'mucositis', 'chemotherapy-induced diarrhoea', 'chemotherapy-induced mucositis', 'radiotherapy-induced mucositis'. RESULTS: The gut microbiota plays a major role in the maintenance of intestinal homoeostasis and integrity. Patients receiving cytotoxic and radiation therapy exhibit marked changes in intestinal microbiota, with most frequently, decrease in Bifidobacterium, Clostridium cluster XIVa, Faecalibacterium prausnitzii, and increase in Enterobacteriaceae and Bacteroides. These modifications may contribute to the development of mucositis, particularly diarrhoea and bacteraemia. The prevention of cancer therapy-induced mucositis by probiotics has been investigated in randomised clinical trials with some promising results. Three of six trials reported a significantly decreased incidence of diarrhoea. One trial reported a decrease in infectious complications. CONCLUSIONS: The gut microbiota may play a major role in the pathogenesis of mucositis through the modification of intestinal barrier function, innate immunity and intestinal repair mechanisms. Better knowledge of these effects may lead to new therapeutic approaches and to the identification of predictive markers of mucositis.
Subject(s)
Antineoplastic Agents/adverse effects , Intestinal Diseases/microbiology , Intestines/microbiology , Mucositis/microbiology , Radiation Injuries/microbiology , Animals , Diarrhea/drug therapy , Diarrhea/etiology , Diarrhea/microbiology , Humans , Intestinal Diseases/drug therapy , Intestinal Diseases/etiology , Microbiota , Mucositis/drug therapy , Mucositis/etiology , Neoplasms/drug therapy , Neoplasms/microbiology , Neoplasms/radiotherapy , Probiotics/therapeutic use , Radiation Injuries/drug therapyABSTRACT
AIMS: This survey was made to study the epidemiology of multiresistant bacteria (MRB) in the French community, among elderly patients 65 years of age or more, carrying third-generation cephalosporin-resistant (3GC-resistant) Enterobacteriaceae, and the co-resistance of prescribed antibiotics. METHODS: The data was collected in 2009 in the West of France by MedQual, a network of 174 private laboratories. RESULTS: Two thousand one hundred and sixty strains of the 88,255 identified Enterobacteria strains were 3GC-resistant (2.4%) and 945 of these strains (41.8%) were isolated from elderly patients 65 years of age or more. Escherichia coli was the predominant 3GC-resistant strain (72.7%). 51.4% of the 945 patients in whom a 3GC-resistant strain was isolated produced an extended-spectrum ß-lactamase (ESBL). The main risk factors for infection with the 3GC-resistant strain were hospitalization and antibiotic treatment in the previous year (58.2 and 86.9%, respectively). Hospitalization during the previous year was more frequent among elderly patients who lived at home compared with those who lived in nursing homes (P<0.05). The production of ESBL, among the 945 patients who carried the 3GC-resistant strains, was similar among patients who lived at home compared with those who lived in nursing homes (51.4% versus 49.7%). CONCLUSION: Microbiologists should warn family physicians about MRB isolates with a specific antimicrobial resistance pattern (3GC-resistant, fluoroquinolone-resistant, etc.) to prescribe more effective medications.
Subject(s)
Cephalosporin Resistance , Enterobacteriaceae Infections/drug therapy , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/drug effects , Aged , Aged, 80 and over , Drug Resistance, Multiple , Enterobacteriaceae/isolation & purification , Female , France , Humans , Male , Prospective StudiesABSTRACT
OBJECTIVES: The aim of this study was to consider the implementation of a network of infectious diseases (ID) experts to optimize the antibiotic prescriptions of community and hospital practitioners. METHODS: An observational prospective study was conducted among ID experts in the Pays-de-la-Loire Region to evaluate the number of calls and to determine the practitioner's reasons for soliciting ID expertise. For each phone consultation, four criteria were recorded during 5 days: origin of the call (internal/external), kind of question (diagnostic/therapeutic) time spent for the advice provided, type of advice. RESULTS: A total of 386 phone consultations for 20 infectious disease specialists were recorded during the study period (5 days); 81% were internal to the hospital, 7.7% from another hospital, and 11.3% from private practice, 56.3% of the questions concerned a therapeutic strategy, 21% a diagnostic advice, and 22.6% concerned both diagnosis and therapy. Two third of the questions were answered within 10minutes. In 68.7% of cases, the ID specialist answered immediately, 19.8% of calls required following-up the patient, 6% led to refer the patient to an ID consultation, and 5.5% to hospitalization. CONCLUSION: The survey results stress the important need for such ID expertise, both in hospitals and in ambulatory medicine. Collaboration of ID specialists in a regional network would allow an easy and permanent access to antibiotic therapy advice for prescribers. This network would improve the quality and safety of care.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Computer Communication Networks/organization & administration , Expert Testimony/statistics & numerical data , Infectious Disease Medicine/organization & administration , Referral and Consultation/statistics & numerical data , Telephone/statistics & numerical data , Ambulatory Care Facilities , Bacterial Infections/diagnosis , Bacterial Infections/drug therapy , Computer Communication Networks/statistics & numerical data , Drug Utilization , Expert Testimony/methods , Family Practice , France , Health Care Surveys , Hospitalization/statistics & numerical data , Hospitals, Private , Hospitals, Public , Humans , Interprofessional Relations , Medicine , Professional Practice , Prospective Studies , Quality Improvement , Time FactorsABSTRACT
The second-order distorted wave Born approximation implementation of two-particle transfer direct reactions which includes simultaneous and successive transfer, properly corrected by non-orthogonality effects, is tested with the help of controlled nuclear structure and reaction inputs against data spanning the whole mass table, and showed to constitute a quantitative probe of nuclear pairing correlations.
Subject(s)
Electron Transport , Electrons , Models, Chemical , Quantum Theory , Computer SimulationABSTRACT
BACKGROUND: The difficulty to diagnose community-acquired pneumonia (CAP) and the lack of scientific data regarding the optimal duration of antibiotic therapy are responsible for overprescribing antibiotics. OBJECTIVE: The authors had for objective to perform a systematic review of the international medical literature on strategies aimed at reducing antibiotic consumption for CAP. METHODS: We performed a Pubmed search using the keywords CAP, antibiotic use, duration of antibiotic therapy, procalcitonin, short-course treatment, and biomarkers. We then made a critical review of the selected articles. RESULTS: Our review identified two strategies used to reduce antibiotic consumption for CAP. The first one was based on procalcitonin (PCT) use. This strategy, even though reducing the duration of antibiotic therapy, does not seem optimal since it is associated with longer antibiotic treatment than recommended by the Infectious Diseases Society of America. Moreover, this strategy is associated with an increased cost in biochemical tests. The other strategy is based on a 2-step clinical reassessment: 1) during the first 24 hours of hospitalization, to confirm the diagnosis of CAP and 2) during hospitalization, to shorten the duration of antibiotic therapy according to the patient's clinical status. CONCLUSION: Clinical reassessment, currently little studied compared to PCT guidance algorithm, seems to be promising to reduce antibiotic consumption for CAP. Especially since it was never compared to PCT guidance strategy in a randomized clinical trial.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Community-Acquired Infections/drug therapy , Inappropriate Prescribing/prevention & control , Pneumonia/drug therapy , Anti-Bacterial Agents/administration & dosage , Biomarkers , Calcitonin/blood , Calcitonin Gene-Related Peptide , Clinical Trials as Topic , Community-Acquired Infections/blood , Community-Acquired Infections/diagnosis , Diagnosis, Differential , Drug Administration Schedule , Drug Utilization , Hospitalization , Humans , Pneumonia/blood , Pneumonia/diagnosis , Practice Guidelines as Topic , Protein Precursors/blood , Pulmonary Edema/diagnosisABSTRACT
Bacteremia remains a major cause of life-threatening complication in patients with cancer. Significant changes in the spectrum of microorganisms isolated from blood culture have been reported in cancer patients over the past years. The aim of our systematic review was to inventory the recent trends in epidemiology and antibiotic resistance of microorganisms causing bacteremia in cancer patients. Data for this review was identified by searches of Medline, Scopus and Cochrane Library for indexed articles and abstracts published in English since 2008. The principal search terms were: "antimicrobial resistance", "bacteremia", "bacterial epidemiology", "bloodstream infection", "cancer patients", "carbapenem resistance", "Escherichia coli resistance", "extended-spectrum ß-lactamase producing E. coli", "febrile neutropenia", "fluoroquinolone resistance", "neutropenic cancer patient", "vancomycin-resistant Enterococcus", and "multidrug resistance". Boolean operators (NOT, AND, OR) were also used in succession to narrow and widen the search. Altogether, 27 articles were selected to be analyzed in the review. We found that Gram-negative bacteria were the most frequent pathogen isolated, particularly in studies with minimal use of antibiotic prophylaxis. Another important trend is the extensive emergence of antimicrobial-resistant strains associated with increased risk of morbidity, mortality and cost. This increasing incidence of antibiotic resistance has been reported in Gram-negative bacteria as well as in Gram-positive bacteria. This exhaustive review, reporting the recent findings in epidemiology and antibiotic resistance of bacteremia in cancer patients, highlights the necessity of local continuous surveillance of bacteremia and stringent enforcement of antibiotic stewardship programs in cancer patients.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteremia/epidemiology , Bacteria/drug effects , Drug Resistance, Bacterial , Neoplasms/complications , Bacteria/classification , Bacteria/isolation & purification , Humans , IncidenceABSTRACT
Staphylococcus aureus, a major responsible microorganism of osteomyelitis, represents a challenge to treat because of the poor penetration of antibiotics in bone and increasing minimum inhibitory concentrations (MICs) to glycopeptides. The calcium-deficient apatites (CDA), closer to the biological components found in bone and other calcified tissues, have osteoconductive properties. So, to process severe osseous infections, CDA can be used to deliver in the infectious site antibiotics like linezolid. The acute experimental osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA) was induced in rabbit's femurs and surgery mimicking human procedures was performed at day three after inoculation. Animals were randomly assigned to treatment groups: L((IV)) [4-day linezolid IV infusion, human-equivalent dose of 10 mg/kg/12 h], L((CDA50%)) (100 mg CDA with linezolid 500 µg/mg) and L((CDA50%)) + L((IV)). Surviving bacteria were counted in bone marrow (BM) and bone (Bo) at day 3 (before treatment), day 7 (4-day treatment) or day 17 (14-day treatment). L(iv) was effective after a 4-day treatment with a log(10)CFU/g decrease of -2.63 ± 1.92 and -2.17 ± 1.58 in bone marrow and bone, respectively. CDA loaded with linezolid enhance the efficacy of the IV linezolid regimen by more than one log(10)CFU/g.