Novel strategies to diagnose prosthetic or native bone and joint infections

INTRODUCTION

Bone and Joint Infections (BJI) are medically important, costly and occur in native and prosthetic joints. Arthroplasties will increase significantly in absolute numbers over time as well as the incidence of Prosthetic Joint Infections (PJI). Diagnosis of BJI and PJI is sub-optimal. The available diagnostic tests have variable effectiveness, are often below standard in sensitivity and/or specificity, and carry significant contamination risks during the collection of clinical samples. Improvement of diagnostics is urgently needed.

AREAS COVERED

We provide a narrative review on current and future diagnostic microbiology technologies. Pathogen identification, antibiotic resistance detection, and assessment of the epidemiology of infections via bacterial typing are considered useful for improved patient management. We confirm the continuing importance of culture methods and successful introduction of molecular, mass spectrometry-mediated and next-generation genome sequencing technologies. The diagnostic algorithms for BJI must be better defined, especially in the context of diversity of both disease phenotypes and clinical specimens rendered available.

EXPERT OPINION

Whether interventions in BJI or PJI are surgical or chemo-therapeutic (antibiotics and bacteriophages included), prior sensitive and specific pathogen detection remains a therapy-substantiating necessity. Innovative tests for earlier and more sensitive and specific detection of bacterial pathogens in BJI are urgently needed.

Assessment of VITEK® MS IVD database V3.0 for identification of Nocardia spp. using two culture media and comparing direct smear and protein extraction procedures

We assessed the performance of the VITEK® MS IVD V3.0 matrix-assisted laser desorption ionization - time of flight mass spectrometry (MALDI-ToF MS) V3.0 database for the identification of Nocardia spp. as compared with targeted DNA sequencing. A collection of 222 DNA sequence-defined Nocardia spp. strains encompassing 18 different species present or not in the database was tested. Bromocresol purple agar (BCP) and Columbia agar +5% sheep's blood (COS) culture media were used together with two different preparation steps: direct smear and a "3 attempts" procedure that covered (1) spotting of an extract, (2) new spotting of the same extract, and (3) spotting of a new extract. The direct smear protocol yielded low correct identification rates (≤ 15% for both media) whereas protein extraction yielded correct identification results (> 67% regardless of the media used.). The use of 2 additional attempts using repeat or new extracts increased correct identification rates to 87% and 91% for BCP and COS, respectively. When using the 3 attempts procedure, the best identification results, independent of media types, were obtained for N. farcinica and N. cyriacigeorgica (100%). Identification attempts 2 and 3 allowed to increase the number of correct identifications (BCP, +20%; COS, +13%). The enhancement in performance during attempts 2 and 3 was remarkable for N. abscessus (81% for both media) and low prevalence species (BCP, 70%; COS, 85%). Up to 3.4% and 2.4% of the strains belonging to species present in the database were misidentified with BCP and COS media, respectively. In 1.9% of the cases for BCP and 1.4% for COS, these misidentifications concerned a species belonging to the same phylogenetic complex. Concerning strains that are not claimed in the V3.0 database, N. puris and N. goodfellowi generated "No identification" results and 100% of the strains belonging to N. arthritidis, N.cerradoensis, and N. altamirensis yielded a misidentification within the same phylogenetic complex. Vitek® MS IVD V3.0 is an accurate and useful tool for identification of Nocardia spp.

2166. Performance Study on the New ETEST® Piperacillin/Tazobactam (P/T) MIC Strip

Background

Piperacillin/Tazobactam combination is a first-line antibiotic and carbapenem sparing option for severe infections due to Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. ETEST® strips allow to determine antimicrobial Minimum Inhibitory Concentration (MIC). ETEST® Piperacillin/Tazobactam (Ptc) was developped in 1995 against agar dilution reference method. Since then, resistance to Piperacillin/Tazobactam has been increasing and broth microdilution (BMD) substituted for agar dilution as the reference method. The new ETEST® P/T strip for determining MIC of Enterobacteriaceae, P. aeruginosa and A. baumannii was developed against BMD using a panel of recent strains well genotypically characterized. The aim of this study was to compare the performance of both strips on a panel of challenging strains harboring different-resistant mechanisms.

Methods

A total of 64 strains were tested using ETEST® P/T, ETEST® PTc and BMD: 48 Enterobacteriaceae including 25 resistant strains and 16 P. aeruginosa including 11 resistant strains. The results were analyzed for essential (EA) and category (CA) agreements, minor (mE), major (ME) and very major (VME) error rates using FDA/CLSI 2019 breakpoints (Enterobacteriaceae, P. aeruginosa: ≤ 16/4(S); ≥ 128/4(R) µg/mL).

Results

Although the panel of strains was challenging including different resistant mechanisms (acquired penicillinase, high-level cephalosporinase, acquired cephalosporinase, ESBL, carbapenemase), the new ETEST® P/T performance was significantly improved for Enterobacteriaceae with an EA at 92,2% without ME or VME. This improvement was also linked to the easiest reading (significant decrease of microcolonies in the ellipse zone). For P. aeruginosa, the performance was similar between the two strips but the new ETEST® P/T was better correlated with the BMD and showed an EA of 100%. The results are summarized in the table.

Conclusion

The new ETEST® P/T improved the MIC determination and resistance detection, as well as the reading of MIC end points for the routine use. This study emphasizes the need to check the performance of the antimicrobial susceptibility testing products by testing strains reflecting the current epidemiology.

Disclosures

All authors: No reported disclosures.

608. Emerging Methicillin Resistance Mechanism in mec Gene-Negative Staphylococci not Detected by Reference Methods

Background

B-lactam resistance in Staphylococci is mediated by mec genes usually diagnosed by disc diffusion Cefoxitin test (DDFOX) and PCR testing. Here, we report methicillin-resistant Staphylococcus lugdunensis and Staphylococcus aureus strains lacking mec gene misdiagnosed by reference methods. Since the strains are not B-lactamase hyperproducers we investigated the molecular basis of the methicillin resistance.

Methods

We tested 2 S. lugdunensis isolates (SL1, SL2) collected from distinct blood cultures of the same patient and 2 S. aureus isolates (SA1, SA2): (i) by DDFOX, (ii) for Oxacillin MIC by agar dilution (AD), (iii) by VITEK®2 (bioMérieux) for Oxacillin MIC (V2 OXA) and Cefoxitin Screen Test (V2 OXSF), (iv) for mecA, B, C genes by PCR and (v) by whole-genome sequencing (WGS).

Results

The 4 isolates were methicillin susceptible by DD FOX and mec negative. However, all the isolates displayed variable results for V2 OXA MIC (0.5 to ≥4 mg/L) and for V2 OXSF (POSITIVE, NEGATIVE). For SL1 and SL2 isolates, the V2 OXSF growth curve atypical pattern has led to investigating the OXSF wells. The plates inoculated with the broth extracted from the OXSF well showed 2 colony morphotypes (small “P” and regular “G”) for both isolates. The small colonies (SL1P, SL2P) were Oxacillin resistant (V2 OXA MIC≥4; AD MIC = 4) and V2 OXSF POSITIVE whereas the regular colonies (SL1G, SL2G) were Oxacillin susceptible (V2 OXA MIC = 2; AD MIC = 0.5) and V2 OXSF NEGATIVE. The 4 morphotypes were cefoxitin susceptible by DDFOX and mec negative. Interestingly, WGS revealed a GdpP truncation in the N-terminal domain only found in S. lugdunensis small colonies (SL1P, SL2P) phenotypically resistant to Oxacillin. GdpP is a cyclic diadenosine monophosphate phosphodiesterase enzyme which function is the hydrolysis of a signaling nucleotide.

Conclusion

We described mec negative S. lugdunensis and S. aureus strains expressing heterogeneous methicillin resistance detected by the VITEK2 OXSF test. S. lugdunensis subpopulation of small colonies resistant to oxacillin is associated with a truncation of GdpP protein previously described in S. aureus. Interestingly GdpP loss of function in Staphylococci is associated with a reduced growth and may arise as a result of the selective pressure of exposure to B Lactams.

Disclosures

All authors: No reported disclosures.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

Weekly 20/56 mg/m² carfilzomib, lenalidomide, and dexamethasone until progression in early relapsed refractory multiple myeloma

8041

Background: Triplet-based Carfilzomib (K), Lenalidomide and Dexamethasone combination (KRd) has led to approval in early RRMM based on ASPIRE International phase 3 study. However, K was used on a twice a week basis at 27mg/m2 and limited to 18 months exposure. We have reported already that KRd on a weekly basis at 56 mg/m2 was active similar to ASPIRE KRd and safe. We report herein the long-term exposure data on KRd weekly given until progression. We aimed to evaluate the efficacy of KRd given on a prolong duration beyond 18months, and to validate the safety profile of continuous exposure to K. Methods: 28 patients were prospectively recruited. Carfilzomib 20/56mg/m2 was administered on days 1,8,15, Lenalidomide 25mg/day was given 21/28 days and Dexamethasone was administered weekly on 28 days cycles until progression. Results: With a median follow-up at start of KRd of 30 months, 50% of patients relapsed and 39% died. 24/28 patients received 1 prior line of treatment. 8/28 patients are still on treatment with duration > 24 month and 6/28 with duration > 30 months. The median number of cycles was 15. ORR and CBR was 85.7% and 89.3%, whom 46% ≥ CR ; with a median DOR of 13 months and 43% having more than 18 months. 6 patients had negative MRD at 10-6 and normalized PET CT. Median of OS is not reached, and the 30 month-expected OS from the start of KRd was 56%. The median PFS and EFS was at 29 months, and the 30 month-expected PFS and EFS was 45%. PFS and EFS being superimposable speaks to that there was no safety concern related to prolonged exposure to K. Only 4 patients stopped KRd for safety issues. Hematologic and non-hematologic adverse events ≥ grade 3 were reported in 16/28 and 10/28 patients. Adverse events ≥ grade 3 seen in ≥10% of patients were neutropenia, thrombocytopenia, vomiting and pyrexia. Of note, 5 patients (18%) were ≥ 65 years old and showed similar data compared to the cohort. Conclusions: KRd weekly is effective and safe to early in RRMM patients, provides improved safety profile to patients allowing treating patients until progression. Further studies are warranted to confirm this data on a larger early RRMM population and validate the concept of long duration of treatment using Carfilzomib combination.

1212. Whole Genome Sequencing for High-Resolution Methicillin-Resistant Staphylococcus aureus Outbreaks Tracing in Neonatal Intensive Care Units and In silico Resistance and Virulence Markers Detection

Background

The French National Reference Center for Staphylococci used whole genome sequencing (WGS) to investigate outbreaks due to a virulent MRSA clone containing the toxic shock syndrome toxin-1 (TSST-1+, sequence type 5, Geraldine clone) increasingly reported in neonatal intensive care units (ICUs).

Methods

We analyzed 48 isolates previously characterized by spa typing: 31 isolates from outbreak 1 (infected or colonized patients, healthcare workers carriage and environment), 12 isolates from four distinct outbreaks (2, 3, 4, and 5) that occurred in geographically independent neonatal ICUs, and five sporadic strains. We performed WGS using a de novo assembly approach to perform comparisons between isolates (EpiSeq®, bioMérieux). A phylogenetic analysis was constructed by comparing single nucleotide variations (SNVs) in 2020 core-genes using a cutoff of 40 SNVs for defining isolates belonging to the same transmission cluster. We detected in silico resistance and virulence markers using the same bioinformatic pipeline.

Results

For outbreak 1, 25/31 isolates with two distinct but related spa types t002 and t111 were highly related (<13 SNVs), suggesting the transmission of the same strain; 6/31 isolates were genetically distinct (>80 SNVs) from the previous cluster of 25 isolates suggesting their origin from separate sources. Interestingly the three isolates of outbreak 2 with a spa t111 differed by less than 22 SNVs from the main cluster of the 25 isolates of outbreak 1. This suggested origin from the same transmission cluster. The other three outbreaks showing respectively a spa t002 for outbreak 3 and outbreak 4 and a spa t045 for outbreak 5 were not affiliated to the main cluster of outbreak 1. The isolates carry numerous virulence factors (including TSST-1) and resistance markers confering a peculiar antibiotic resistance profile to the Geraldine clone.

Conclusion

WGS provides the resolution power to reveal unsuspected transmission events not indicated by conventional methods (different spa type). Based on its high resolution WGS is an all in one tool for epidemiology, virulence and resistance analysis. It really transforms outbreak management and infection control practice for an early response and should replace conventional methods for detection of MRSA transmission.

Disclosures

G. Durand, bioMérieux: Employee, Salary. F. Javerliat, bioMérieux: Employee, Salary.

Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS

Background:

Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses.

Objective:

To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy.

Methods:

We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992–1995 and 2005–2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis.

Results:

A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78).

Conclusion:

Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

Routine Whole-Genome Sequencing for Outbreak Investigations of Staphylococcus aureus in a National Reference Center

The French National Reference Center for Staphylococci currently uses DNA arrays and spa typing for the initial epidemiological characterization of Staphylococcus aureus strains. We here describe the use of whole-genome sequencing (WGS) to investigate retrospectively four distinct and virulent S. aureus lineages [clonal complexes (CCs): CC1, CC5, CC8, CC30] involved in hospital and community outbreaks or sporadic infections in France. We used a WGS bioinformatics pipeline based on de novo assembly (reference-free approach), single nucleotide polymorphism analysis, and on the inclusion of epidemiological markers. We examined the phylogeographic diversity of the French dominant hospital-acquired CC8-MRSA (methicillin-resistant S. aureus) Lyon clone through WGS analysis which did not demonstrate evidence of large-scale geographic clustering. We analyzed sporadic cases along with two outbreaks of a CC1-MSSA (methicillin-susceptible S. aureus) clone containing the Panton–Valentine leukocidin (PVL) and results showed that two sporadic cases were closely related. We investigated an outbreak of PVL-positive CC30-MSSA in a school environment and were able to reconstruct the transmission history between eight families. We explored different outbreaks among newborns due to the CC5-MRSA Geraldine clone and we found evidence of an unsuspected link between two otherwise distinct outbreaks. Here, WGS provides the resolving power to disprove transmission events indicated by conventional methods (same sequence type, spa type, toxin profile, and antibiotic resistance profile) and, most importantly, WGS can reveal unsuspected transmission events. Therefore, WGS allows to better describe and understand outbreaks and (inter-)national dissemination of S. aureus lineages. Our findings underscore the importance of adding WGS for (inter-)national surveillance of infections caused by virulent clones of S. aureus but also substantiate the fact that technological optimization at the bioinformatics level is still urgently needed for routine use. However, the greatest limitation of WGS analysis is the completeness and the correctness of the reference database being used and the conversion of floods of data into actionable results. The WGS bioinformatics pipeline (EpiSeq^TM) we used here can easily generate a uniform database and associated metadata for epidemiological applications.

Emergence of Clostridium difficile tcdC variant 078 in Marseille, France

The purpose of this investigation was to evaluate the epidemiology of hypervirulent Clostridium difficile ribotypes from January 2013 to February 2017 in the Marseille area of southern France. By using the Xpert Clostridium difficile Epi polymerase chain reaction (PCR) assay and sequencing the tcdC gene, we characterised C. difficile isolates from symptomatic patients diagnosed with C. difficile infection (CDI) in Marseille university hospitals. We first tested retrospectively 278 C. difficile samples isolated from January 2013 to December 2014 and observed a high prevalence of isolates with tcdC mutations and deletions previously described in both hypervirulent ribotypes RT027 and RT078 (16.4% and 10.7%, respectively). We highlighted the co-circulation of these two hypervirulent C. difficile tcdC variants (tV) with distinct epidemiological characteristics. While an RT027 outbreak occurred mainly as healthcare-associated infection in the elderly, CDI caused by tV078 occurred mainly in a younger population as community-associated infection. From January 2016, a systematic survey of these two hypervirulent C. difficile ribotypes revealed the emergence of CDI caused by tV078, currently being more prevalent than RT027 in the Marseille area. The present study is the first report of the emergence of CDI caused by tV078 in southern France. We showed the simultaneous circulation and sequential spread of hypervirulent ribotypes, such as RT027 and tV078. This emphasises the need for an efficient surveillance system for CDI with ribotyping and an optimised management of CDI caused by hypervirulent strains.

A colorimetric nanosensor based on a selective target-responsive aptamer kissing complex

Herein, we report a novel approach for the design of a colorimetric aptasensor based on functionalized gold nanoparticle probes. This approach relies on the conjugation of nanoparticles by two functional DNA and RNA hairpins that engage specific kissing (loop-loop) interactions in response to the addition of a small analyte ligand, leading to particle aggregation and then red-to-purple colour change of the colloidal solution.

"Intestinimonas massiliensis" sp. nov, a new bacterium isolated from human gut

Here we report the main features of the proposed new bacterial species “Intestinimonas massiliensis” sp. nov. The type strain GD2^T (CSUR = P1930) was isolated from the gut microbiota of a healthy patient using a culturomics approach combined with taxonogenomics.

Normal postoperative appearances of lung cancer

The major lung resections are the pneumonectomies and lobectomies. The sublobar resections are segmentectomies and wedge resections. These are performed either through open surgery through a thoracotomy or by video-assisted mini-invasive surgery for lobectomies and sublobar resections. Understanding the procedures involved allows the normal postoperative appearances to be interpreted and these normal anatomical changes to be distinguished from potential postoperative complications. Surgery results in a more or less extensive physiological adaptation of the chest cavity depending on the lung volume, which has been resected. This adaptation evolves during the initial months postoperatively. Chest radiography and computed tomography can show narrowing of the intercostal spaces, a rise of the diaphragm and shift of the mediastinum on the side concerned following major resections.

Description of Clostridium phoceensis sp. nov., a new species within the genus Clostridium

Clostridium phoceensis sp. nov., strain GD3^T (= CSUR P1929 = DSM 100334) is the type strain of C. phoceensis sp. nov., a new species within the genus Clostridium. This strain was isolated from the gut microbiota of a 28-year-old healthy French man. C. phoceensis is a Gram-negative, spore-forming, nonmotile, strictly anaerobic bacterium. We describe its complete genome sequence and annotation, together with its phenotypic characteristics.

TLR9 re-expression in cancer cells extends the S-phase and stabilizes p16(INK4a) protein expression

Toll-like receptor 9 (TLR9) recognizes bacterial, viral or cell damage-associated DNA, which initiates innate immune responses. We have previously shown that TLR9 expression is downregulated in several viral induced cancers including HPV16-induced cervical neoplasia. Findings supported that downregulation of TLR9 expression is involved in loss of anti-viral innate immunity allowing an efficient viral replication. Here we investigated the role of TLR9 in altering the growth of transformed epithelial cells. Re-introducing TLR9 under the control of an exogenous promoter in cervical or head and neck cancer patient-derived cells reduced cell proliferation, colony formation and prevented independent growth of cells under soft agar. Neither TLR3, 7, nor the TLR adapter protein MyD88 expression had any effect on cell proliferation, indicating that TLR9 has a unique role in controlling cell growth. The reduction of cell growth was not due to apoptosis or necrosis, yet we observed that cells expressing TLR9 were slower in entering the S-phase of the cell cycle. Microarray-based gene expression profiling analysis highlighted a strong interferon (IFN) signature in TLR9-expressing head and neck cancer cells, with an increase in IFN-type I and IL-29 expression (IFN-type III), yet neither IFN-type I nor IL-29 production was responsible for the block in cell growth. We observed that the protein half-life of p16(INK4a) was increased in TLR9-expressing cells. Taken together, these data show for the first time that TLR9 affects the cell cycle by regulating p16(INK4a) post-translational modifications and highlights the role of TLR9 in the events that lead to carcinogenesis.

Multigene testing of moderate-risk genes: be mindful of the missense

BACKGROUND

Moderate-risk genes have not been extensively studied, and missense substitutions in them are generally returned to patients as variants of uncertain significance lacking clearly defined risk estimates. The fraction of early-onset breast cancer cases carrying moderate-risk genotypes and quantitative methods for flagging variants for further analysis have not been established.

METHODS

We evaluated rare missense substitutions identified from a mutation screen of ATM, CHEK2, MRE11A, RAD50, NBN, RAD51, RINT1, XRCC2 and BARD1 in 1297 cases of early-onset breast cancer and 1121 controls via scores from Align-Grantham Variation Grantham Deviation (GVGD), combined annotation dependent depletion (CADD), multivariate analysis of protein polymorphism (MAPP) and PolyPhen-2. We also evaluated subjects by polygenotype from 18 breast cancer risk SNPs. From these analyses, we estimated the fraction of cases and controls that reach a breast cancer OR≥2.5 threshold.

RESULTS

Analysis of mutation screening data from the nine genes revealed that 7.5% of cases and 2.4% of controls were carriers of at least one rare variant with an average OR≥2.5. 2.1% of cases and 1.2% of controls had a polygenotype with an average OR≥2.5.

CONCLUSIONS

Among early-onset breast cancer cases, 9.6% had a genotype associated with an increased risk sufficient to affect clinical management recommendations. Over two-thirds of variants conferring this level of risk were rare missense substitutions in moderate-risk genes. Placement in the estimated OR≥2.5 group by at least two of these missense analysis programs should be used to prioritise variants for further study. Panel testing often creates more heat than light; quantitative approaches to variant prioritisation and classification may facilitate more efficient clinical classification of variants.

Multicolumn spinal cord stimulation for significant low back pain in failed back surgery syndrome: design of a national, multicentre, randomized, controlled health economics trial (ESTIMET Study)

BACKGROUND

Many studies have demonstrated the efficacy of spinal cord stimulation (SCS) for chronic neuropathic radicular pain over recent decades, but despite global favourable outcomes in failed back surgery syndrome (FBSS) with leg pain, the back pain component remains poorly controlled by neurostimulation. Technological and scientific progress has led to the development of new SCS leads, comprising a multicolumn design and a greater number of contacts. The efficacy of multicolumn SCS lead configurations for the treatment of the back pain component of FBSS has recently been suggested by pilot studies. However, a randomized controlled trial must be conducted to confirm the efficacy of new generation multicolumn SCS. Évaluation médico-économique de la STImulation MEdullaire mulTi-colonnes (ESTIMET) is a multicentre, randomized study designed to compare the clinical efficacy and health economics aspects of mono- vs. multicolumn SCS lead programming in FBSS patients with radicular pain and significant back pain.

MATERIALS AND METHODS

FBSS patients with a radicular pain VAS score≥50mm, associated with a significant back pain component were recruited in 14 centres in France and implanted with multicolumn SCS. Before the lead implantation procedure, they were 1:1 randomized to monocolumn SCS (group 1) or multicolumn SCS (group 2). Programming was performed using only one column for group 1 and full use of the 3 columns for group 2. Outcome assessment was performed at baseline (pre-implantation), and 1, 3, 6 and 12months post-implantation. The primary outcome measure was a reduction of the severity of low back pain (bVAS reduction≥50%) at the 6-month visit. Additional outcome measures were changes in global pain, leg pain, paraesthesia coverage mapping, functional capacities, quality of life, neuropsychological aspects, patient satisfaction and healthcare resource consumption.

TRIAL STATUS

Trial recruitment started in May 2012. As of September 2013, all 14 study centres have been initiated and 112/115 patients have been enrolled. Preliminary results are expected to be published in 2015.

TRIAL REGISTRATION

Clinical trial registration information-URL: www.clinicaltrials.gov. Unique identifier NCT01628237.

Modeling and evaluation of compliance to water quality regulations in bathing areas on the Daoulas catchment and estuary (France)

The microbiological quality of waters in estuaries determines their acceptability for recreational uses. Microbiological contamination often results from urban wastewater discharges or non-point source pollution (manure spreading), and can cause bathing zones to be closed. European regulations (EC/7/2006) have proposed standards (500 E. coli/100 ml) for the acceptability areas for bathing. In this study, two models were associated to simulate contamination: SWAT on a catchment and MARS 2D in the downstream estuary. After river flow calibration and validation, two scenarios were simulated in SWAT, and E. coli fluxes obtained at the main outlet of the catchment were then introduced into MARS 2D to follow E. coli concentrations in the estuary. An annual evaluation of compliance to bathing area water quality standards was then calculated, linked with daily rainfall classes. Water quality in the estuary was below the standard on 13 days, including 5 days with rainfall superior to 10 mm, due to faecal contamination from soil leaching by rain, and 5 days with rainfall ranging from 0.1 to 5 mm/day, due to the high frequency of this level of rainfall. To conclude, this study allowed us to demonstrate the efficiency of models to gain a better understanding on water quality degradation factors.

Staphylococcal chromosome cassette evolution in Staphylococcus aureus inferred from ccr gene complex sequence typing analysis

Staphylococcal chromosome cassette mec (SCCmec) elements within major lineages of healthcare- and community-associated methicillin-resistant Staphylococcus aureus (MRSA) clones were characterised using intra-SCCmec multilocus sequencing. A strong correlation was observed between sequence- and PCR-based typing methods (p <0.001). However, phylogenetic analysis of the SCCmec locus using concatenated sequences evidenced few recombination events. Sequence type (ST)-SCCmec1 was found in SCCmec elements types I and IV, suggesting the evolution of an SCCmecI element into an SCCmecIV element. This coincided with the spread of the clone harbouring this SCCmec element into the community. No correlation was observed between ST-SCCmec lineage and MRSA lineage, confirming multiple acquisitions of SCCmec by S. aureus. This was exemplified by the SCCmecIV ST-SCCmec10 element, which was detected in all of the clonal complexes examined, including healthcare- and community-associated MRSA. The acquisition of this SCCmec element was five- to ten-fold more common than that of others. Models of MRSA clone evolution suggest that this SCCmec was first found in the paediatric clone.

The contribution of large genomic deletions at the CDKN2A locus to the burden of familial melanoma

Mutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the CDKN2A locus at 9p21, which encodes two unrelated proteins, p16^INK4a and p14^ARF. Rare mutations in CDK4 have also been linked to the disease. Although the CDKN2A gene has been shown to be the major melanoma predisposing gene, there remains a significant proportion of melanoma kindreds linked to 9p21 in which germline mutations of CDKN2A have not been identified through direct exon sequencing. The purpose of this study was to assess the contribution of large rearrangements in CDKN2A to the disease in melanoma-prone families using multiplex ligation-dependent probe amplification. We examined 214 patients from independent pedigrees with at least two CMM cases. All had been tested for CDKN2A and CDK4 point mutation, and 47 were found positive. Among the remaining 167 negative patients, one carried a novel genomic deletion of CDKN2A exon 2. Overall, genomic deletions represented 2.1% of total mutations in this series (1 of 48), confirming that they explain a very small proportion of CMM susceptibility. In addition, we excluded a new gene on 9p21, KLHL9, as being a major CMM gene.

Colonoscopy results of a French regional FOBT-based colorectal cancer screening program with high compliance

BACKGROUND AND STUDY AIMS

Mass screening for colorectal cancer in France was initiated in pilot regions on the basis of the fecal occult blood test (FOBT) followed by colonoscopy in positive cases. We report the colonoscopy results in one of the first areas to be screened (Ille et Vilaine).

PATIENTS AND METHODS

Of the total regional population of 908,449, 187,342 of the 213,635 potential screening candidates who were aged 50 - 74 years were invited for FOBT. Of the 51.3% compliant individuals, 2.6% were positive, and of these 90.7% agreed to undergo colonoscopy (n = 2246). The colonoscopy procedure details, findings, and complications were recorded. Subjects were classified according to the most advanced lesion. Positive predictive values of FOBT were calculated according to sex and age.

RESULTS

Colonoscopy was complete in 96.3% of cases. Only 23 adverse events were encountered (1.02%). Colorectal cancer was diagnosed in 237 cases (10.6%, 78.4% of which were clinical stages I - II). The rates of overall adenomas and advanced adenomas were 33.1 % and 21.6 %, respectively. The risk of cancer and advanced adenoma increased significantly in men and in older people.

CONCLUSION

The results of mass screening with FOBT followed by colonoscopy in this population-based study are very encouraging in terms of compliance, early findings, and complications. Extension of this program to the whole of France is justified.