Bacterial adhesion inhibition by microalgal EPSs from Cylindrotheca closterium and Tetraselmis suecica biofilms.

In the food industry, successful bacterial pathogen colonization and persistence begin with their adhesion to a surface, followed by the spatial development of mature biofilm of public health concerns. Compromising bacterial settlement with natural inhibitors is a promising alternative to conventional anti-fouling treatments typically based on chemical biocides that contribute to the growing burden of antimicrobial resistance. In this study, three extracellular polymeric substance (EPS) fractions extracted from microalgae biofilms of Cylindrotheca closterium (fraction C) and Tetraselmis suecica (fraction Ta rich in insoluble scale structure and fraction Tb rich in soluble EPS) were screened for their anti-adhesive properties, against eight human food-borne pathogens belonging to Escherichia coli, Staphylococcus aureus, Salmonella enterica subsp. enterica, and Listeria monocytogenes species. The results showed that the fraction Ta was the most effective inducing statistically significant reduction for three strains of E. coli, S. aureus, and L. monocytogenes. Overall, EPSs coating on polystyrene surfaces of the different fractions increased the hydrophilic character of the support. Differences in bacterial adhesion on the different coated surfaces could be explained by several dissimilarities in the structural and physicochemical EPS compositions, according to HPLC and ATR-FTIR analysis. Interestingly, while fractions Ta and Tb were extracted from the same microalgal culture, distinct adhesion patterns were observed, highlighting the importance of the extraction process. Overall, the findings showed that EPS extracted from microalgal photosynthetic biofilms can exhibit anti-adhesive effects against food-borne pathogens and could help develop sustainable and non-toxic anti-adhesive surfaces for the food industry. KEY POINTS: •EPSs from a biofilm-based culture of C. closterium/T. suecica were characterized. •Microalgal EPS extracted from T. suecica biofilms showed bacterial anti-adhesive effects. •The anti-adhesive effect is strain-specific and affects both Gram - and Gram + bacteria.

Characteristics of spontaneous coagulase-negative staphylococcal spondylodiscitis: a retrospective comparative study versus Staphylococcus aureus spondylodiscitis.

BACKGROUND: Coagulase-negative staphylococci (CoNS) are increasingly implicated in recent patient series of spondylodiscitis, but there are no series of CoNS-spondylodiscitis available. The objective of this study was to compare the characteristics of patients with spontaneous CoNS-spondylodiscitis with those patients with Staphylococcus aureus (SA) spondylodiscitis. METHODS: This was a retrospective single center study involving 147 spontaneous infectious spondylodiscitis cases observed between 2000 and 2015. The 26 cases of CoNS-spondylodiscitis (15 confirmed) were compared with 30 cases of SA-spondylodiscitis. CoNS infection was considered confirmed if the same CoNS was isolated in at least two samples at two different times. RESULT: Patients with CoNS-spondylodiscitis were older (70 vs. 61 years of age; p = 0.01), had associated cancer more often (15% vs. 0%; p = 0.04) and had a longer diagnostic delay (>15 days in 88% vs. 60%; p = 0.01); experienced fever less often (19% vs. 50%; p = 0.01), and had lower white blood cell (7.6 vs. 9.9G/L; p = 0.01) and polymorphonuclear leucocyte counts (5.6 vs. 7.5G/L; p = 0.04). Patients with CoNS spondylodiscitis had less pronounced inflammatory syndrome (erythrocyte sedimentation rate [ESR]: 62 vs. 81 mm at 1 h; p = 0.03; CRP: 60 vs. 147 mg/L; p = 0.0003) and less common (ESR < 30 mm: 23% vs. 0%; p = 0.01; CRP < 10 mg/L: 23% vs. 0%; p = 0.005) in comparison with patients with SA infection. The infection entry site was most often an intravascular catheter (20% vs. 3%; p = 0.008). The level of positive percutaneous needle biopsies was comparable between CoNS and SA. Two patients who died both had SA infections. CONCLUSION: CoNS-spondylodiscitis involved at least 10% of spontaneous spondylodiscitis cases and was more common in elderly patients, afflicted by comorbidities, and its presentation was less virulent than that of those with SA-spondylodiscitis.

Ankle dorsiflexion after isolated medial versus complete proximal gastrocnemius recession: A cadaveric study.

PURPOSE: Gastrocnemius recession has been described in the treatment of gastrocnemius contracture. The aims of this study were: (1) to assess the change in ankle dorsiflexion after isolated medial gastrocnemius recession performed according to L.S. Barouk's technique; (2) to compare ankle dorsiflexion after isolated medial head with complete proximal gastrocnemius recession. METHODS: A cadaveric study was performed on 15 lower limb adult specimens. Isolated medial gastrocnemius head recession was initially performed, followed by an additional recession of the lateral gastrocnemius head. Ankle dorsiflexion torque was applied with 2 and 4 kg forces on second metatarsal head. Ankle dorsiflexion was measured with the knee both in extension and at 90° of flexion and values were recorded before surgery (T0), after medial head recession (T1) and after both heads recession (T2). Normality of data was assessed using the Shapiro-Wilk test, then measurements were compared in the three conditions with appropriate statistical tests. RESULTS: After isolated medial gastrocnemius recession (Δ = T1-T0), ankle dorsiflexion assessed with the knee in extension significantly increased by 5° ± 3 (range, -2 to 10) with a 2-kg torque (p = 0.02) and by 4.5° ± 3 (range, -4 to 10) with a 4-kg torque (p = 0.04). No significant difference was observed with the knee flexed at 90° (p > 0.05 for all measurements). After both gastrocnemius heads recession (Δ = T2-T1), although a further increase in dorsiflexion was noticed, statistical significance was not reached neither with the knee in extension nor at 90° of flexion (p > 0.05 for all measurements). CONCLUSION: In this study, isolated medial gastrocnemius head recession performed according to LS Barouk's technique was effective in improving ankle dorsiflexion, whereas the additional release of the lateral head did not produce any significant change. LEVEL OF EVIDENCE: Level V, cadaveric study.

Disrupting quorum sensing alters social interactions in Chromobacterium violaceum.

Quorum sensing (QS) is a communication system used by bacteria to coordinate a wide panel of biological functions in a cell density-dependent manner. The Gram-negative Chromobacterium violaceum has previously been shown to use an acyl-homoserine lactone (AHL)-based QS to regulate various behaviors, including the production of proteases, hydrogen cyanide, or antimicrobial compounds such as violacein. By using combined metabolomic and proteomic approaches, we demonstrated that QS modulates the production of antimicrobial and toxic compounds in C. violaceum ATCC 12472. We provided the first evidence of anisomycin antibiotic production by this strain as well as evidence of its regulation by QS and identified new AHLs produced by C. violaceum ATCC 12472. Furthermore, we demonstrated that targeting AHLs with lactonase leads to major QS disruption yielding significant molecular and phenotypic changes. These modifications resulted in drastic changes in social interactions between C. violaceum and a Gram-positive bacterium (Bacillus cereus), a yeast (Saccharomyces cerevisiae), immune cells (murine macrophages), and an animal model (planarian Schmidtea mediterranea). These results underscored that AHL-based QS plays a key role in the capacity of C. violaceum to interact with micro- and macroorganisms and that quorum quenching can affect microbial population dynamics beyond AHL-producing bacteria and Gram-negative bacteria.

euHCVdb: the European hepatitis C virus database.

The hepatitis C virus (HCV) genome shows remarkable sequence variability, leading to the classification of at least six major genotypes, numerous subtypes and a myriad of quasispecies within a given host. A database allowing researchers to investigate the genetic and structural variability of all available HCV sequences is an essential tool for studies on the molecular virology and pathogenesis of hepatitis C as well as drug design and vaccine development. We describe here the European Hepatitis C Virus Database (euHCVdb, http://euhcvdb.ibcp.fr), a collection of computer-annotated sequences based on reference genomes. The annotations include genome mapping of sequences, use of recommended nomenclature, subtyping as well as three-dimensional (3D) molecular models of proteins. A WWW interface has been developed to facilitate database searches and the export of data for sequence and structure analyses. As part of an international collaborative effort with the US and Japanese databases, the European HCV Database (euHCVdb) is mainly dedicated to HCV protein sequences, 3D structures and functional analyses.

Correction: EGFR C797S, EGFR T790M and EGFR sensitizing mutations in non-small cell lung cancer revealed by six-color crystal digital PCR.

[This corrects the article DOI: 10.18632/oncotarget.26446.].

Primary infectious spondylodiscitis in 51 patients over 75 years old: A comparative study. / Espondilodiscitis infecciosa primaria en 51 pacientes mayores de 75 años: estudio comparativo.

BACKGROUND AND OBJETIVE: The incidence of infectious spondylodiscitis has been shown to rise with age; however, they had not been extensively investigated in the very elderly. MATERIAL AND METHODS: This retrospective, monocentric study included patients hospitalized in our department of rheumatology for primary infectious spondylodiscitis between 2000 and 2015, and compared over 75-year-olds with younger patients. RESULTS: Of the 152 patients, 51 (33.6%) were≥75 years old, 59 were 61-74, and 42 were≤60. Patients≥75 years old were more often institutionalized (7.8 vs. 0; P=.02), were less often subject to infection risk factors (27.5 vs. 54.5%; P=.02), but did not differ from the others as regards the frequency of diabetes and cancer. Time to diagnosis was shorter for the under 60-year-olds (23 vs. 30 vs. 30 day for each age group, respectively; P<.05). There were no differences among the age groups in terms of spondylodiscitis localization, frequency of neurological symptoms and fever, frequency or intensity of inflammatory syndrome, imaging use, frequency of microorganism identification, blood culture positivity, or use and efficacy of disco-vertebral biopsy. Microorganism distribution was comparable among the groups, except for Gram-negative bacilli, with Escherichia coli more common in over 75-year-olds (7/8 vs. 4/14; P=.02). Duration of antibiotherapy and hospitalization was comparable across the age groups. Five patients died, all over 75 years old (5/51 vs. 0/101; P=.001). CONCLUSION: Age is a risk factor for primary spondylodiscitis, associated with significant mortality in over 75-year-olds (10%). For these elderly patients, spondylodiscitis does not bear any other distinguishing features.

EGFR C797S, EGFR T790M and EGFR sensitizing mutations in non-small cell lung cancer revealed by six-color crystal digital PCR.

Background: Detection of EGFR sensitizing and p.T790M and p.C797S resistance mutations is particularly important for non-small cell lung cancer (NSCLC) patient therapy management. Non-invasive blood-based monitoring of these mutations may pave the way to a fine-tuned personalized treatment. Digital PCR has emerged as an extremely sensitive method to detect rare mutations, however its major limitation is the number of hotspots that can be simultaneously differentiated. Methods: We developed a 6-color digital PCR assay for the detection and quantification of 19 most prevalent EGFR sensitizing and resistance mutations and evaluated this assay on 82 tumor and plasma samples from NSLC patients. Results: Limits of detection (LOD) for the 6-color digital PCR assay were assessed on serial dilutions of DNA standards. We found that the 6-color assay enabled detection of mutant fractions as low as 1 mutant in 1025 wild-type molecules, depending on the mutation targeted, when assayed in a background of 10 000 wild-type DNA copies. EGFR mutant allelic fraction was also measured on tumor and plasma samples by 6-color digital PCR, and displayed a highly significant correlation with next generation sequencing and 3-color digital PCR. Lastly, the 6-color digital PCR assay was performed on several longitudinal plasma samples from four patients and revealed levels of sensitizing and resistance EGFR mutations that reflected well the course of the disease. Conclusion: This 6-color Crystal digital PCR assay could represent a robust solution using digital PCR for the monitoring of EGFR mutations.

Three-decade trends in the distribution of organisms causing septic arthritis in native joints: single-center study of 374 cases.

OBJECTIVE: A rise in the incidence of septic arthritis due to methicillin-resistant Staphylococcus aureus (MRSA) has been reported in several parts of the world. Here, our objective was to look for changes over the last 30years in the distribution and antibiotic susceptibility profiles of organisms responsible for septic arthritis. METHODS: We conducted a single-center retrospective study of all cases of septic arthritis documented by joint specimens and/or blood cultures between 1979 and 2008. Prosthetic joint infections were excluded. RESULTS: We enrolled 374 patients, of whom 127, 136, and 111 were included during each decade, respectively. We detected no significant time trends in the proportions of staphylococci (67%, 65%, and 64%), streptococci (14%, 21%, and 17%), or Gram-negative rods (7%, 10%, and 14%). Tuberculosis was more common during the earliest decade (1979-1988, n=10, 4, 2%; P<0.05). No significant changes occurred in the proportions of methicillin-resistant staphylococci or MRSA (13%, 11%, 15%). Age and prevalence of risk factors for infection increased over time. CONCLUSION: The distribution and susceptibility of organisms causing septic arthritis has changed little over time. Our findings do not support the use of broader-spectrum antibiotics when empirical treatment is deemed necessary at our center.