Microbial community structure and metabolic profile of anthropized freshwater tributary channels from La Plata River, Argentina, to develop sustainable remediation strategies.

Microbial communities from freshwater sediments are involved in biogeochemical cycles and they can be modified by physical and chemical changes in the environment. Linking the microbial community structure (MCS) with physicochemistry of freshwater courses allows a better understanding of its ecology and can be useful to assess the ecological impact generated by human activity. The MCS of tributary channels from La Plata River affected by oil refinery (C, D, and E) and one also by urban discharges (C) was studied. For this purpose, 16S rRNA metabarcoding analysis, in silico metagenome functional prediction, and the hydrocarbon degradation potential (in silico predictions of hydrocarbon-degrading genes and their quantification by qPCR) of the MCS were studied. Principal coordinate analysis revealed that the MCS was different between sites, and it was not structured by the hydrocarbon content. Site C showed physicochemical characteristics, bacterial taxa, and an in silico functional prediction related to fermentative/heterotrophic metabolism. Site D, despite having higher concentration of hydrocarbon, presented autotrophic, syntrophic, and methanogenic pathways commonly involved in natural processes in anoxic sediments. Site E showed and intermediate autotrophic/heterotrophic behavior. The hydrocarbon degradation potential showed no positive correlation between the hydrocarbon-degrading genes quantified and predicted. The results suggest that the hydrocarbon concentration in the sites was not enough selection pressure to structure the bacterial community composition. Understanding which is the variable that structures the bacterial community composition is essential for monitoring and designing of sustainable management strategies for contaminated freshwater ecosystems.

Two-stage total hip arthroplasty for septic arthritis through the minimally invasive direct anterior approach.

The use of minimally invasive direct anterior approach to perform total hip arthroplasty is gaining increasing popularity for its short-term advantages, compared to other approaches. Nevertheless, its use in hip revision surgery has been criticized. We report here the first case of hip septic arthritis treated with two-stage THA through this tissue-sparing approach, with good implant positioning and functional results.

Bilateral osteochondritis dissecans of the patella in an adolescent skier with patellofemoral maltracking treated with pulsed electromagnetic field therapy.

Juvenile osteochondritis dissecans of the knee typically occurs in young athletes, and usually localizes on the medial femoral condyle. Bilateral localization is uncommon. Patellofemoral involvement is rare, mainly found in basketball and soccer players, and never related to patellofemoral congenital problems such as trochlear dysplasia. We report here the first case, to our knowledge, of bilateral juvenile osteochondritis dissecans with patellar localization in a young skier with patellofemoral maltracking and trochlear dysplasia.

Bilateral total hip arthroplasty through minimally invasive direct anterior approach after Legg-Calvé-Perthes disease.

Bilateral secondary osteoarthritis of the hip may affect also young patients following bilateral hip diseases such as slipped capital femoral epiphysis and developmental hip dysplasia. We report the case of an 18- year old male with a previous diagnosis of Legg-Calvé-Perthes disease who underwent a bilateral total hip arthroplasty through minimally invasive direct anterior approach, with optimal results at 1-year follow up.

Insights into the mechanisms of desiccation resistance of the Patagonian PAH-degrading strain Sphingobium sp. 22B.

AIM: To analyse the physiological response of Sphingobium sp. 22B to water stress. METHODS AND RESULTS: The strain was grown under excess of carbon source and then subjected to low (60RH) and high (18RH) water stress conditions for 96 h. Quantification of trehalose, glycogen, polyhydroxybutyrate (PHB) and transmission electron microscopy (TEM) was studied. Genes linked with desiccation were searched in Sphingobium sp. 22B and Sphingomonas 'sensu latu' genomes and their transcripts were quantified by real-time PCR. Results showed that, in the absence of water stress, strain 22B accumulated 4·76 ± 1·41% of glycogen, 0·84 ± 1·62% of trehalose and 44·9 ± 6·4% of PHB per cellular dry weight. Glycogen and trehalose were mobilized under water stressed conditions, this mobilization was significantly higher in 60RH in comparison to 18RH. Gene treY was upregulated sixfold in 60RH relative to control condition. TEM and quantification of PHB revealed that PHB was mobilized under 60RH condition accompanied by the downregulation of the phbB gene. TEM images showed an extracellular amorphous matrix in 18RH and 60RH. Major differences were found in the presence of aqpZ and trehalose genes between strain 22B and Sphingomonas genomes. CONCLUSION: Strain 22B showed a carbon conservative metabolism capable of accumulation of three types of endogenous carbon sources. The strain responds to water stress by changing the expression pattern of genes related to desiccation, formation of an extracellular amorphous matrix and mobilization of the carbon sources according to the degree of water stress. Trehalose, glycogen and PHB may have multiple functions in different degrees of desiccation. The robust endowment of molecular responses to desiccation shown in Sphingobium sp. 22B could explain its survival in semi-arid soil. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding the physiology implicated in the toleration of the PAH-degrading strain Sphingobium sp 22B to environmental desiccation may improve the bioaugmentation technologies in semi-arid hydrocarbon-contaminated soils.

Insights into the genome and proteome of Sphingomonas paucimobilis strain 20006FA involved in the regulation of polycyclic aromatic hydrocarbon degradation.

In order to study the mechanisms regulating the phenanthrene degradation pathway and the intermediate-metabolite accumulation in strain S. paucimobilis 20006FA, we sequenced the genome and compared the genome-based predictions to experimental proteomic analyses. Physiological studies indicated that the degradation involved the salicylate and protocatechuate pathways, reaching 56.3% after 15 days. Furthermore, the strain degraded other polycyclic aromatic hydrocarbons (PAH) such as anthracene (13.1%), dibenzothiophene (76.3%), and fluoranthene. The intermediate metabolite 1-hydroxy-2-naphthoic acid (HNA) accumulated during phenanthrene catabolism and inhibited both bacterial growth and phenanthrene degradation, but exogenous-HNA addition did not affect further degradation. Genomic analysis predicted 126 putative genes encoding enzymes for all the steps of phenanthrene degradation, which loci could also participate in the metabolism of other PAH. Proteomic analysis identified enzymes involved in 19 of the 23 steps needed for the transformation of phenanthrene to trichloroacetic-acid intermediates that were upregulated in phenanthrene cultures relative to the levels in glucose cultures. Moreover, the protein-induction pattern was temporal, varying between 24 and 96 h during phenanthrene degradation, with most catabolic proteins being overexpressed at 96 h-e. g., the biphenyl dioxygenase and a multispecies (2Fe-2S)-binding protein. These results provided the first clues about regulation of expression of phenanthrene degradative enzymes in strain 20006FA and enabled an elucidation of the metabolic pathway utilized by the bacterium. To our knowledge the present work represents the first investigation of genomic, proteomic, and physiological studies of a PAH-degrading Sphingomonas strain.

De novo metastatic head and neck squamous cell carcinoma: Why does locoregional control "always" matter?

De novo metastatic Head and Neck Squamous Cell Carcinoma (HNSCC) constitutes 10% of recurrent/metastatic (RM) cases. Radiotherapy (RT) has a crucial role in the treatment of locally advanced HNSCC, however its application on RM diseases is still limited. The advent of immune checkpoint inhibitors (ICIs) improves the survival of RM HNSCC, however median overall survival is still limited. Integration of locoregional RT with ICIs in de novo metastatic HNSCC represents a promising treatment option. This perspective aims to explore the role of the combination of locoregional and systemic treatment in improving outcomes for synchronous de novo metastatic HNSCC patients and highlights the principal crucial point in decision making.

Stereotactic Re-irradiation in Recurrent Prostate Cancer after Previous Postoperative or Definitive Radiotherapy: Long-term Results after a Median Follow-up of 4 Years.

AIMS: In 2018, we published early results from a cohort of patients treated with stereotactic body radiotherapy (SBRT) after previous radiotherapy with definitive or postoperative intent. We sought to provide extended follow-up of this cohort to confirm the safety and efficacy of this approach in a real-world scenario. MATERIALS AND METHODS: Fifty patients affected by local relapse after previous definitive or postoperative radiotherapy were treated with SBRT. Treatment provided a total dose of 30 Gy in five fractions. Data about biochemical relapse-free survival (BRFS) and metastasis-free survival (MFS), together with adverse events, were analysed. Toxicity was reported according to Common Terminology Criteria for Adverse Events (CTCAE) score v.4.03. RESULTS: After a median follow-up of 48.2 months, the median BRFS was 43 months. A Gleason score >7 and concomitant androgen deprivation therapy were shown to be predictors of the worst BRFS (hazard ratio 2.42, 95% confidence interval 1.09-5.41, P = 0.02; hazard ratio 2.83, 95% confidence interval 1.17-6.8, P = 0.02, respectively). The median MFS was not reached; concomitant androgen deprivation therapy was confirmed to be predictive of the worst MFS (hazard ratio 4.75, 95% confidence interval 1.52-14.8, P = 0.007). Late grade 1 and 2 rectal and bladder toxicity occurred in three (6%) and 13 (26%) patients, respectively. One patient experienced both grade 3 acute and chronic bladder toxicity. CONCLUSION: Salvage SBRT re-irradiation after previous postoperative or definitive radiotherapy for local prostate cancer recurrence confirmed promising results in terms of oncological outcomes and the safety of this approach.

Pattern of Recurrence After Stereotactic Radiotherapy in Prostate Cancer Patients With Nodal Pelvic Relapse. A Multi-Institutional Retrospective Analysis.

AIMS: Currently, when nodal pelvic oligorecurrent disease is detected, no standard treatment option is recommended. One possible salvage option is nodal stereotactic body radiotherapy (SBRT). Here we analysed recurrence patterns after nodal SBRT in patients affected by pelvic oligometastatic relapse after radical prostatectomy, and androgen deprivation therapy (ADT)-free survival in this population. MATERIALS AND METHODS: Data on 93 patients consecutively treated in five different institutions for pelvic oligorecurrent disease were reviewed. Inclusion criteria were biochemical recurrence after radical prostatectomy and imaging showing three or fewer metachronous lymphoadenopathies under aortic bifurcation. Patients underwent SBRT on all sites of disease. Concomitant ADT was allowed. RESULTS: After a median follow-up of 20 months (interquartile range 11-41), 57 patients had post-SBRT radiological evidence of relapse, for a median disease-free survival (DFS) of 15 months (95% confidence interval 9-24). Concomitant ADT was administered in 20 patients (21.5%). Overall, eight (8.6%), 21 (22.6%) and 28 (30.1%) patients had prostate bed only, pelvic nodal or distant relapse, respectively. The median ADT-free survival was not reached. Concomitant ADT, International Society for Urologic Pathology pattern at diagnosis < or ≥3, time to relapse ≤ or >12 months, prostate-specific antigen at recurrence < or ≥1.10 ng/ml and prostate-specific membrane antigen staging were not significantly associated with DFS. After relapse, 42 patients (45.2%) received a second SBRT course. CONCLUSION: Nodal SBRT yielded encouraging DFS and ADT-free survival in this population. Only a minority of patients developed prostate bed recurrence, suggesting that local treatment may be safely avoided. A consistent percentage of patients could be managed with a second SBRT course.

Application of the knowledge-based approach to strain selection for a bioaugmentation process of phenanthrene- and Cr(VI)-contaminated soil.

AIMS: The objective of this study was to apply the knowledge-based approach to the selection of an inoculum to be used in bioaugmentation processes to facilitate phenanthrene degradation in phenanthrene- and Cr(VI)-co-contaminated soils. METHODS AND RESULTS: The bacterial community composition of phenanthrene and phenanthrene- and Cr(VI)-co-contaminated microcosms, determined by denaturing gradient gel electrophoresis analysis, showed that members of the Sphingomonadaceae family were the predominant micro-organisms. However, the Cr(VI) contamination produced a selective change of predominant Sphingomonas species, and in co-contaminated soil microcosms, a population closely related to Sphingomonas paucimobilis was naturally selected. The bioaugmentation process was carried out using the phenanthrene-degrading strain S. paucimobilis 20006FA, isolated and characterized in our laboratory. Although the strain showed a low Cr(VI) resistance (0·250 mmol l⁻¹); in liquid culture, it was capable of reducing chromate and degrading phenanthrene simultaneously. CONCLUSION: The inoculation of this strain managed to moderate the effect of the presence of Cr(VI), increasing the biological activity and phenanthrene degradation rate in co-contaminated microcosm. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we have applied a novel approach to the selection of the adequate inoculum to enhance the phenanthrene degradation in phenanthrene- and Cr(VI)-co-contaminated soils.

[Effect of the inoculant strain Sphingomonas paucimobilis 20006FA on the bacterial composition of a phenanthrene-degrading consortium]. / Efecto de la inoculación de la cepa Sphingomonas paucimobilis 20006FA sobre la composición de un consorcio bacteriano degradador de fenantreno.

The effect of the inoculant strain Sphingomonas paucimobilis 20006FA on the bacterial composition of a phenanthrene-degrading consortium obtained from a pristine soil in sequencing batch cultures was studied. Inoculated (F200+1) and non-inoculated (F200) phenanthrene-degrading consortia, were obtained. Bacterial diversity of consortia was studied at cultivable (phenotype and genotype characterization) and non-cultivable (PCR-DGGE) levels. During the successive cultures, a loss in the phenanthrene-degrading capacity and a decrease in the bacterial diversity were observed in both consortia. Although inoculation did not produce any significant changes in the consortia phenanthrene-degrading capacity (29.9% F200 and 27.6% F200+1), it did produce changes in the bacterial composition, showing a differential structural dynamics in the DGGE profiles of the inoculated consortium. In both consortia, a dominant band placed at the same position as that of the DNA of the inoculant strain in the DGGE gel could be observed. However, isolated cultures from the consortia which had an identical band position to that of S. paucimobilis 20006FA in the PCR-DGGE profile showed low similarity with respect to the inoculant strain (RAPD).

Antibacterial coating of implants: are we missing something?

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user's cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma. Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199-206. DOI: 10.1302/2046-3758.85.BJR-2018-0316.

Aldosterone receptor antagonism and heart failure: insights from an outpatient clinic.

OBJECTIVE: In randomized clinical trials, aldosterone antagonists have been shown to reduce mortality and morbidity in heart failure (HF). The aim of the present study was to examine the risk-benefit profile of aldosterone antagonists in routine clinical practice. METHODS: A retrospective analysis, extending over a 1-year period, of the clinical, instrumental and laboratory data of 264 HF outpatients was performed. All patients were on a beta-blocker and an ACE-inhibitor (or angiotensin-II receptor-blocker) and 151 were taking an aldosterone antagonist. RESULTS: At baseline, subjects treated with aldosterone antagonists had a higher NYHA class, a larger left-ventricular end-diastolic volume, a worse ejection fraction and a higher systolic pulmonary arterial pressure (sPAP). During follow-up, a greater reduction in sPAP and a tendency towards improved systolic and diastolic function were observed in subjects treated with aldosterone antagonists. Moreover, clinical and laboratory parameters did not deteriorate in patients taking aldosterone antagonists. Mortality rates were similar in the two groups (8.6% vs. 8.8%, P = NS). CONCLUSIONS: The use of aldosterone antagonists in HF is associated with an improvement in cardiac function and is well tolerated. In the present study, patients administered these agents had a comparable clinical outcome to that of the control group, despite important differences in baseline risk.

Hyaluronic Acid and Its Composites as a Local Antimicrobial/Antiadhesive Barrier.

Living in biofilms is probably the most common condition for bacteria and fungi and biofilm-related infections account for the majority of bacterial infectious diseases worldwide. Among others biofilm-related infections, those associated with implanted biomaterials have an enormous and still largely underestimated impact in orthopaedics and trauma, cardio-surgery and several other surgical disciplines. Given the limited efficacy of existing antibiotics in the prevention and treatment of bacterial biofilms, new strategies are needed to protect implants and host tissues, overcoming the striking ability of the microorganisms to adhere on different surfaces and to immediately protect themselves by forming the biofilm matrix. Adhesion is a necessary first step in microbial colonization and pathogenesis and provides a potential target for new preventive and treatment approach. Among various polymers, tested as antibacterial coatings, hyaluronic acid and some of its composites do offer a well-established long-term safety profile and a proven ability to reduce bacterial adhesion and biofilm formation. Aim of the present review is to summarize the available evidence concerning the antiadhesion/antibiofilm activity of hyaluronic acid and some of its derivatives to reduce/prevent bacterial adhesion and biofilm formation in various experimental and clinical settings.

Draft Whole-Genome Sequence of Sphingobium sp. 22B, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from Semiarid Patagonia, Argentina.

Sphingobium sp. 22B is a polycyclic aromatic hydrocarbon-degrading strain isolated from Patagonia, Argentina, with capabilities to withstand the environmental factors of that semiarid region. The draft genome shows the presence of genes related with responses to carbon starvation and drying environmental conditions.

Calcium-Based, Antibiotic-Loaded Bone Substitute as an Implant Coating: A Pilot Clinical Study.

Background: Implant-related infections remain a major complication after orthopaedic surgery. Antibacterial coating of implants may prevent bacterial adhesion and biofilm formation. However, in spite of extensive preclinical research in the field, antibacterial coatings to protect orthopaedic implants in the clinical setting remain particularly few. The aim of the present study is to evaluate the safety of a calcium-based, antibiotic-loaded bone substitute as an antibacterial coating of cementless joint prosthesis. Methods: From March 2013 to August 2015, 20 consecutive patients scheduled for cementless or hybrid two-stage revision surgery for peri-prosthetic joint infection were included in this prospective, observational, pilot study. Cerament G or Cerament V, a gentamicin or vancomycin-loaded calcium-based resorbable bone substitute (60% calcium sulphate, 40% hydroxyapatite), was applied at surgery on the stem surface of hip (n=7) or knee (n=13) revision prosthesis. After surgery, all patients underwent clinical (HHS or KSS and SF-12 score), laboratory and radiographic evaluation at 3, 6 and 12 months and yearly thereafter. Results: At a minimum of 12 months follow-up, 19/20 (95%) patients showed no recurrence of infection and no signs of radiographic loosening of the stem. No adverse events were associated with the use of Cerament G or V. Conclusions: This is the first pilot clinical study on the short-term safety of using a calcium-based, gentamicin or vancomycin-loaded bone substitute as a surface coating on cementless prosthetic implants. If confirmed by larger studies and at longer follow-ups, these findings may open a new prospective to protect intra-operatively orthopedic implants from bacterial adhesion, through the use of resorbable, osteoconductive, antibiotic carriers.

Two flavonoids and other compounds from the aerial parts of Centaurea bracteata from Italy.

The flowering aerial parts of Centaurea bracteata Scop. (Asteraceae) have been studied for the first time. Nineteen compounds were isolated and identified, namely a sterol glucoside, two phenolic acids, three quinic acid derivatives, and 13 flavonoids, two of which, are new natural products. Structural elucidation was performed mainly by mean of FABMS, 1D and 2D NMR spectroscopy.

A flavonoid sulphate and other compounds from the roots of Centaurea bracteata.

The roots of Centaurea bracteata Scop. (Asteraceae) have been studied for the first time. Twenty-three compounds were isolated and identified, namely a sterol glucoside, two quinic acid derivatives, one sugar, and 19 flavonoids (five sulphates), one of which, centaradixin, resulted in a new natural product. Structural elucidation was performed mainly by means of FABMS, 1D and 2D NMR spectroscopy. NMR data of some sulphate flavonoids are reported for the first time.

Flavonoids and a saponin from Spartium junceum.

Two new flavonoids, 5,8-dihydroxy-4'-methoxy-6,7-methylenedioxyisoflavone and carthamidin-7-O-alpha-L-rhamnopyranoside and a new triterpenoid saponin, 3 beta,16 beta,22 beta,24-tetrahydroxy-olean-12- ene-3-beta-yl-]beta-D-glucopyranosyl (1-->2)]-alpha-L-rhamnopyranoside (junceoside), were isolated from Spartium junceum. Their structures were elucidated by means of IR, UV, MS, 1H, 13C NMR, 13C NMR DEPT and 2D NMR experiments. Apigenin-7-O-beta-D-glucopyranoside and genistein-8-C-beta-D-glucopyranoside, never previously found in this plant, were also isolated.