322. Evaluation of the BioFire® Bone and Joint Infection (BJI) Panel for the Detection of Microorganisms and Antimicrobial Resistance Genes in Synovial Fluid Specimens

Background

Bone and Joint Infections (BJIs) present with non-specific symptoms that may include pain, swelling, and fever and are associated with high morbidity and significant risk of mortality. BJIs can be caused by a variety of bacteria and fungi, including anaerobes and microorganisms that can be challenging to culture or identify by traditional microbiological methods. Clinicians primarily rely on culture to identify the pathogen(s) responsible for infection. The BioFire^® Bone and Joint Infection (BJI) Panel (BioFire Diagnostics, Salt Lake City, UT) is designed to detect 15 gram-positive bacteria (including seven anaerobes), 14 gram-negative bacteria (including one anaerobe), two yeast, and eight antimicrobial resistance (AMR) genes from synovial fluid specimens in about an hour. The objective of this study was to evaluate the performance of an Investigational Use Only (IUO) version of the BioFire BJI Panel compared to various reference methods.

Methods

Remnant synovial fluid specimens, which were collected for routine clinical care at 13 study sites in the US and Europe, underwent testing using an IUO version of the BioFire BJI Panel. Performance of this test was determined by comparison to Standard of Care (SoC) consisting of bacterial culture performed at each study site according to their routine procedures.

Results

A total of 1544 synovial fluid specimens were collected and tested with the BioFire BJI Panel. The majority of specimens were from knee joints (77.9%) and arthrocentesis (79.4%) was the most common collection method. Compared to SoC culture, overall sensitivity was 90.2% and specificity was 99.8%. The BioFire BJI Panel yielded a total of 268 Detected results, whereas SoC yielded a total of 215 positive results for on-panel analytes.

Conclusion

The BioFire BJI Panel is a sensitive, specific, and robust test for rapid detection of a wide range of analytes in synovial fluid specimens. The number of microorganisms and resistance genes included in the BioFire BJI Panel, together with a reduced time-to-result and increased diagnostic yield compared to culture, is expected to aid in the timely diagnosis and appropriate management of BJIs.

Disclosures

Benjamin von Bredow, PhD, BioFire (Grant/Research Support) Jennifer Dien Bard, PhD, BioFire Diagnostic (Consultant, Scientific Research Study Investigator) Bart Kensinger, PhD, BioFire Diagnostics (Employee) Benedicte Pons, PhD, bioMerieux SA (Employee) Corinne Jay, PhD, bioMerieux SA (Employee)

Infections tropicales graves dans les départements français d’Amérique, Antilles françaises et Guyane

Les Antilles-Guyane (AG) sont les départements français du continent américain, situés en zone intertropicale. La diversité des écosystèmes ainsi que le climat tropical à très forte pluviosité exposent à un vaste panel de pathologies infectieuses. Ces territoires sont de plus l’objet de mouvements importants de populations, voyageurs ou migrants, ce qui joue un rôle significatif dans le développement d’épidémies et/ou de pathologies émergentes. Ces pathologies infectieuses dites « tropicales » peuvent nécessiter une prise en charge en réanimation. Nous rapportons ici les principales données récentes concernant ces pathologies (hors infection liée au VIH) ainsi que les stratégies diagnostiques et thérapeutiques, à l’usage des réanimateurs amenés à exercer en zone tropicale AG ou recevant en métropole des patients issus de cette région.

2290. Identification of Pathogens in Synovial Fluid Samples With an Automated Multiplexed Molecular Detection System

Background

Bone and Joint Infections (BJI) have high morbidity and are difficult to treat infections. Culture-based diagnosis is limited in its ability to recover fastidious bacteria and because several organisms can be involved; culture times of up to two weeks may be necessary for certain bacteria. The sensitivity of culture is also negatively impacted by antibiotics received before surgery. Alternatively, molecular methods offer a promising improvement for the diagnosis of BJI. The goal of this study was to evaluate a development version of Biofire^® Bone and Joint Infection (BJI) Panel (bioMerieux SA, BioFire Diagnostics, LLC) using synovial fluid samples.

Methods

121 synovial fluid specimens were collected from patients with suspected bone and joint infection in a pilot evaluation. All specimens were collected and tested in culture by the sites using their standard of care practices; in parallel, a leftover volume of 200 µL was tested on the BJI panel. BJI panel results were then compared with culture and discordant results were investigated using a comparator assay (PCR/sequencing).

Results

49 synovial fluid specimens (40%) were positive by culture vs. 72 with the BJI panel (59%). Of the 97 positive detections by the BJI panel, 58 were concordant with culture; the 39 additional organism detections were in majority confirmed by PCR/sequencing. Lastly, two false negative results corresponding to the same sample are under investigation.

Conclusion

The BJI Panel was able to identify most of the pathogens detected by culture. The majority of additional detections observed were confirmed by PCR/sequencing. While sites are currently enrolling more synovial fluids samples, these preliminary data suggest that a multiplexed molecular test may be more sensitive than culture to detect pathogens in synovial fluid specimens.

The data presented in this abstract have not been reviewed by FDA or other regulatory agencies for In Vitro Diagnostic use.

Disclosures

B. Pons, bioMerieux: Employee, Salary. C. Jay, bioMerieux: Employee, Salary. T. Martin, bioMerieux: Employee, Salary. I. Sothier, bioMerieux: Employee, Salary. H. Savelli, bioMerieux: Employee, Salary. B. Kensinger, bioFire a bioMerieux company: Employee, Salary. F. Laurent, BioFire (bioMerieux company): Investigator, Research support. L. Abad, BioFire (bioMerieux company): Investigator, Research support. C. Murphy, BioFire (bioMerieux company): Investigator, Research support. A. Craney, BioFire (bioMerieux company): Investigator, Research support. B. Schmitt, BioFire (bioMerieux company): Investigator, Research support. A. Waggoner, BioFire (bioMerieux company): Investigator, Research support. S. Butler-Wu, BioFire (bioMerieux): Investigator, Research support. C. Costales, BioFire (bioMerieux company): Investigator, Research support. J. Bien-Bard, BioFire (bioMerieux): Investigator, Research support. J. Mestas, BioFire (bioMerieux): Investigator, Research support. J. Esteban, BioFire (bioMerieux): Investigator, Research support. L. Salar-Vidal, BioFire (BioMerieux company)): Investigator, Research support. A. Harrington, BioFire (bioMerieux company): Investigator, Research support. S. Collier, BioFire (BioMerieux Company): Investigator, Research support. A. Leber, BioFire (bioMerieux company): Investigator, Research support. K. Everhart, BioFire (bioMerieux company): Investigator, Research support. J. M. Balada-Llasat, BioFire (bioMerieux company): Investigator, Research support. J. Horn, BioFire (bioMerieux company): Investigator, Research support. S. Magro, bioMerieux: Employee, Salary. K. Bourzac, BioFire a bioMerieux company: Employee, Salary.

[Acute respiratory distress syndrome complicating an acute chest syndrome: potential benefit of early combination of exchange transfusion and prone positioning]

We report the case of an 8-year-old sickle cell anemia child admitted for acute respiratory failure complicating acute chest syndrome. Because of threatening respiratory failure, tracheal intubation was performed immediately after ICU admission. The patient met the criteria for ARDS with a PaO2/FiO2 ratio of 94mmHg. An exchange transfusion was performed immediately after admission. HbS fraction failed from 69 % to 30 %. Fluid resuscitation with crystalloids and continuous norepinephrine infusion was needed because of arterial hypotension. Due to persistent severe hypoxemia with PaO2/FiO2 ratio below 100, the patient was placed in prone positioning 16hours after admission, for a total duration of 14hours. A second 12-hour session of prone positioning was performed 41h after admission and PaO2/FiO2 ratio reached 300mmHg after. Treatment also included transfusion of two red-cell pack on day 1 and 2 after admission in order to maintain hemoglobin level above 8g/dL, and a daily folic acid supplementation. The control of hyperthermia was achieved by a systematic parenteral administration of paracetamol. Cefotaxime and erythromycine were continued until day 7 despite the negative results of all bacteriological samples. The outcome was favorable from day 3 and the patient met the criteria for extubation on day 5. A first attempt of extubation was performed on day 5, but re-intubation was required because of laryngeal edema. Steroids were given for 48h and the patient was successfully extubated on day 7. She was discharged from the ICU on day 8, and from the hospital on day 12. We discuss the various treatments available for the management of acute chest syndrome and their actual relevance in acute respiratory distress syndrome in the absence of strong evidence-based guidelines in pediatric ARDS.

New light shed on charge transfer in fundamental H+ + H2 collisions

There is no consensus on the magnitude and shape of the charge transfer cross section in low-energy H+ + H2 collisions, in spite of the fundamental importance of these collisions. Experiments have thus been carried out in the energy range 15≤E≤5000  eV. The measurements invalidate previous recommended data for E≤200  eV and confirm the existence of a local maximum around 45 eV, which was predicted theoretically. Additionally, vibrationally resolved cross sections allow us to investigate the evolution of the underlying charge transfer mechanism as a function of E.

High-resolution probe of coherence in low-energy charge exchange collisions with oriented targets

The trapping lasers of a magneto-optical trap have been used to bring Rb atoms into well defined oriented states. Coupled to recoil-ion-momentum spectroscopy, this provided a unique MOTRIMS setup which was able to probe scattering dynamics, including the coherence features, with unprecedented resolution. The technique was applied to the low-energy charge exchange reactions Na+ + Rb(5p±1)→Na(3p,4s)+Rb+. The measurements revealed detailed features of the collisional interaction which were employed to improve the theoretical description. As such, it was possible to ascertain the validity of the intuitive models used to predict the most likely capture transitions.

[Multiple organ failure complicating a severe acute necrotising pancreatitis secondary of a severe hypertriglyceridemia: a case report]

We report the case of a 42-year-old man admitted for a multi-organ failure with a coma, a hemodynamic instability, a respiratory distress syndrome, an acute renal failure and a thrombocytopenia. The blood samples highlighted a milky serum and allowed to diagnose an acute pancreatitis associated with a major dyslipidemia: hypertriglyceridemia 11,800 mg/dL and hypercholesterolemia 1195 mg/dL. The CT-scans do not reveal any cerebral abnormalities but highlighted pancreatic lesions without biliary obstruction. A multi-organ failure complicating a severe acute pancreatitis secondary of a major hypertriglyceridemia was mentioned. Despite the absence of clear guidelines, a session of plasma exchange was started in emergency. Symptomatic treatment with protective ventilation, vasopressors, continuous heparin and insulin was continued. The clinical and biological course was good in parallel of the normalization of lipid abnormalities. The patient was discharged at day 17 with a lipid-lowering therapy. We discuss the various treatments available for the management of acute pancreatitis complicating a severe hypertriglyceridemia and their actual relevance in the absence of clear recommendations.

Role of the ionic potential in high harmonic generation

Recollision processes provide direct insight into the structure and dynamics of electronic wave functions. However, the strength of the process sets its basic limitations--the interaction couples numerous degrees of freedom. In this Letter we decouple the basic steps of the process and resolve the role of the ionic potential which is at the heart of a broad range of strong field phenomena. Specifically, we measure high harmonic generation from argon atoms. By manipulating the polarization of the laser field we resolve the vectorial properties of the interaction. Our study shows that the ionic core plays a significant role in all steps of the interaction. In particular, Coulomb focusing induces an angular deflection of the electrons before recombination. A complete spatiospectral analysis reveals the influence of the potential on the spatiotemporal properties of the emitted light.

Influence of nuclear exchange on nonadiabatic electron processes in H(+)+H2 collisions

H(+)+H(2) collisions are studied by means of a semiclassical approach that explicitly accounts for nuclear rearrangement channels in nonadiabatic electron processes. A set of classical trajectories is used to describe the nuclear motion, while the electronic degrees of freedom are treated quantum mechanically in terms of a three-state expansion of the collision wavefunction. We describe electron capture and vibrational excitation, which can also involve nuclear exchange and dissociation, in the E = 2-1000 eV impact energy range. We compare dynamical results obtained with two parametrizations of the potential energy surface of H(3)(+) ground electronic state. Total cross sections for E > 10 eV agree with previous results using a vibronic close-coupling expansion, and with experimental data for E < 10 eV. Additionally, some prototypical features of both nuclear and electron dynamics at low E are discussed.

Direct inhibition of excision/synthesis DNA repair activities by cadmium: analysis on dedicated biochips

The well established toxicity of cadmium and cadmium compounds results from their additive effects on several key cellular processes, including DNA repair. Mammalian cells have evolved several biochemical pathways to repair DNA lesions and maintain genomic integrity. By interfering with the homeostasis of redox metals and antioxidant systems, cadmium promotes the development of an intracellular environment that results in oxidative DNA damage which can be mutagenic if unrepaired. Small base lesions are recognised by specialized glycosylases and excised from the DNA molecule. The resulting abasic sites are incised, and the correct sequences restored by DNA polymerases using the opposite strands as template. Bulky lesions are recognised by a different set of proteins and excised from DNA as part of an oligonucleotide. As in base repair, the resulting gaps are filled by DNA polymerases using the opposite strands as template. Thus, these two repair pathways consist in excision of the lesion followed by DNA synthesis. In this study, we analysed in vitro the direct effects of cadmium exposure on the functionality of base and nucleotide DNA repair pathways. To this end, we used recently described dedicated microarrays that allow the parallel monitoring in cell extracts of the repair activities directed against several model base and/or nucleotide lesions. Both base and nucleotide excision/repair pathways are inhibited by CdCl₂, with different sensitivities. The inhibitory effects of cadmium affect mainly the recognition and excision stages of these processes. Furthermore, our data indicate that the repair activities directed against different damaged bases also exhibit distinct sensitivities, and the direct comparison of cadmium effects on the excision of uracile in different sequences even allows us to propose a hierarchy of cadmium sensibility within the glycosylases removing U from DNA. These results indicate that, in our experimental conditions, cadmium is a very potent DNA repair poison.

Near-threshold high-order harmonic spectroscopy with aligned molecules

We study high-order harmonic generation in aligned molecules close to the ionization threshold. Two distinct contributions to the harmonic signal are observed, which show very different responses to molecular alignment and ellipticity of the driving field. We perform a classical electron trajectory analysis, taking into account the significant influence of the Coulomb potential on the strong-field-driven electron dynamics. The two contributions are related to primary ionization and excitation processes, offering a deeper understanding of the origin of high harmonics near the ionization threshold. This Letter shows that high-harmonic spectroscopy can be extended to the near-threshold spectral range, which is in general spectroscopically rich.

Determination of polynuclear aromatic hydrocarbons (PAHs) in sewage sludge by micellar electrokinetic capillary chromatography and HPLC-fluorescence detection: a comparative study

Two different methods, based on micellar electrokinetic capillary chromatography (MECC-DA) and high performance liquid chromatography (HPLC)-fluorescence detection, were studied to separate and determine 12 polynuclear aromatic hydrocarbons (PAHs) of 16 PAHs recommended by the Environmental Protection Agency (EPA) in sewage sludge. beta-cyclodextrin was used as a micelle precursor in a sodium borate buffer solution which included the surfactant sodium dodecyl sulphate (SDS) and the acetonitrile dissolvent. The following parameters: temperature, voltage, pH, concentrations of buffer solution and injection time, were optimized by an experimental design (Nemrodw programme). Furthermore, HPLC-fluorescence detection and separation conditions are reported. The mobile phase was acetonitrile-water in different percentages. Precision, accuracy, linearity and detection and quantification limits were determined. This method was applied in the analysis of sewage sludge from a wastewater depuration station in Crispijana (Alava, Spain). In this case, it is necessary to carry out a solid phase extraction step for its determination. The method was validated by the analysis of a certificated sample of LGC 6182, and finally samples of sewage sludge were analysed weekly for two years, obtaining in all cases results under the legal limits for the use of sewage sludge in agriculture.

[Nodular thrombophlebitis and granulomatous systemic disease]

INTRODUCTION

Nodular thrombophlebitis is septal hypodermitis characterised by vasculitis with vein thrombosis. It may indicate serious underlying disorders.

EXEGESIS

We present two cases of nodular superficial phlebitis, which revealed tuberculosis and sarcoidosis.

CONCLUSION

Nodular thrombophlebitis are classic during evolution of Behçet disease or Buerger vasculitis. In sarcoidosis, erythema nodosum and granulomatous involvement are the most common cutaneous manifestation. Nodular thrombophlebitis has never been described. Panniculitis are classical in tuberculosis. But most cases are erythema nodosum and cases of erythema induratum of Bazin. Nodular thrombophlebitis could reveal thrombophilic abnormalities, and even more neoplasms especially when they are recurrent and migratory.

Investigation of laser-irradiated Ar cluster dynamics from K-shell x-ray emission measurements

Intense (up to a few 10(17) W/ cm2) femtosecond (down to 40 fs) laser pulses are focused onto a partially clusterized argon gas jet. The target was previously characterized and optimized in order to get a homogeneous and dense jet of clusters with a well controlled size. The interaction leads to x-ray emission that is absolutely calibrated and spectrally resolved using a high resolution time-integrated spectrometer in the K-shell range (from 2.9 to 4.3 keV). X-ray spectra are investigated as a function of different laser temporal parameters such as the nanosecond prepulse contrast, the laser pulse duration, and the femtosecond delay between two different laser pulses. The cluster size ranges from 180 to 350 angstroms and irradiation by laser pulses with both linear and circular polarization is investigated. The experimental results are discussed in terms of the laser-cluster interaction dynamics. They are compared with the predictions of collision-dominated nanoplasma models. However, further interaction processes are required in order to explain the observed characteristic lines demonstrating highly charged ions up to Ar16+.

[Gastroparesis on a gastric ulcer]

INTRODUCTION

Gastroparesis is the failure of the stomach to empty because of decreased gastric motility. It's a fairly frequent medical problem. Diabetes is the most common known cause.

OBSERVATION

The first case report is that of an 82 year-old woman, in whom acute gastric distension occurred, evoking a gastric volvulus on the scan. Upper endoscopy revealed gastric ulcers. All symptoms disappeared with medical treatment. The second case report concerns a 37 year-old man who was admitted with signs of occlusion. CT scans revealed acute gastric distension. Emergency surgery revealed no gastric volvulus. Upper endoscopy revealed gastritis and numerous ulcers. The signs regressed with medical treatment.

DISCUSSION

Our observations are original in their -pseudo-surgical discovery. Acute gastric distension is rare, but must be recognised because of the risk of perforation and rupture of the stomach walls. These case reports are also original in their aetiology. Gastric ulcers are rarely described in this situation. CONCLUSION; Gastroparesis is a frequent situation but potentially severe. A review of the principle signs, aetiology and treatment is made.

Monocentric close-coupling expansion to provide ejected electron distributions for ionization In atomic collisions

A new monocentric close-coupling expansion, in terms of spherical Bessel functions confined in a finite box, is presented and implemented for &pmacr;+H(1s) collisions. Besides total ionization cross sections, this method also provides reliable ejected electron distributions, which are beyond the scope of usual close-coupling expansions and basically confirm the recent classical description of Illescas and Riera [Phys. Rev. Lett. 80, 3029 (1998)].

Effects of smoking on local delivery of controlled-release doxycycline as compared to scaling and root planing

This paper examines the effects of smoking on the treatment outcomes of two nonsurgical therapies: (1) scaling and root planing alone (SRP) or (2) controlled-release of subgingivally delivered doxycycline hyclate in a polylactic acid based polymer gel. Subjects from 2 9-month multicenter studies were classified as nonsmokers (never smoked: 100 subjects), former smokers (137 subjects), and current smokers (> or = 10 cigarettes/day: 121 subjects). Clinical parameters were analyzed for treated sites with baseline probing depths > or = 5 mm and for a subset of treated sites with baseline probing depths of > or = 7 mm. Clinical parameters (plaque levels, clinical attachment levels, pocket depths, and bleeding on probing) were analyzed at baseline, 4, 6, and 9 months. In the doxycycline treated group in general, there were neither marked significant differences in clinical attachment gain nor differences in probing depth reduction among the 3 smoking groups. On the other hand, in the scaling and root planing treated group in general, there were significant differences in clinical attachment gain and pocket depth reduction, with non-smokers responding better than former smokers and current smokers at 6 and 9 months. These differences in clinical response between scaling and root planing alone versus controlled-release of locally-delivered doxycycline hyclate among these 3 smoking groups are discussed in relation to treatment implications for smokers.

Speciation of ionic alkyllead compounds in human urine by gas chromatography-mass spectrometry after butylation through a Grignard reaction

One analytical procedure for the determination of ionic alkyllead in human urine has been studied. The system consists of the extraction of Me3Pb+, Et3Pb+ and Pb2+ at pH 9.0 with diethyldithiocarbamate to an organic phase. Then, the ionic compounds are butylated with BuMgCl and the final organic solution is analyzed by GC-MS-SIM. The elimination of both foam and gels in the extraction step and the general procedure for the urine are discussed. The recovery of compounds ranges from 105.1% for Me3Pb+ to 97.2% for Et3Pb+ using hexane as extracting agent and detection limits are 18.4 pg/ml of Me3Pb+ and 19.2 pg/ml of Et3Pb+ in urine. The speciation of ionic alkylleads in the urine of a petrol station worker showed a value of 27.9 pg/ml of Me3Pb+ in urine and Et3Pb+ was below the detection limit.