Response of biofilm bacterial communities to antibiotic pollutants in a Mediterranean river

Antibiotics are emerging contaminants, which wing to their bioactivity, may lead to short-term and long-term alterations of natural microbial communities in aquatic environment. We investigated the effects of antibiotics on biofilm bacterial communities in the Llobregat River (Northeast Spain). Three sampling sites were selected: two less polluted sites and one hotspot. River water was collected from each site and used both as inoculum and medium for growing biofilms in independent mesocosms. After 25d of biofilm colonization, we exposed the colonized biofilms to river waters from the downstream sites (progressively contaminated by antibiotics). A control from each site was maintained where the growing biofilm was always exposed to water from the same site. The bacterial community composition, bacterial live/dead ratio and extracellular enzyme activities of the biofilms were measured before and 9d after exposing the biofilms to increasing contaminated waters. Sixteen antibiotic compounds were detected in the water from the three sampling sites. At each site, the antibiotics present in the highest concentrations were sulfonamides, followed by quinolones and macrolides. Bacterial communities of biofilms grown with the three river waters differed markedly in their structure, but less so in terms of functional descriptors. After switching the medium water to increasing pollution, biofilms exhibited increased levels of actinobacteria (HGC), a trend that was associated to the higher antibiotic concentrations in the water. These biofilms also showed increased bacterial mortality, and decreased extracellular leucine-aminopeptidase and alkaline phosphatase. There was a significant correlation between antibiotic concentrations and biofilm responses. Our results indicate that the continuous entrance of antibiotics in running waters cause significant structural and functional changes in microbial attached communities.

Fasting plasma triglycerides predict the glycaemic response to treatment of type 2 diabetes by gastric electrical stimulation. A novel lipotoxicity paradigm

BACKGROUND

Non-stimulatory, meal-mediated electrical stimulation of the stomach (TANTALUS-DIAMOND) improves glycaemic control and causes modest weight loss in patients with Type 2 diabetes who are inadequately controlled on oral anti-diabetic medications. The magnitude of the glycaemic response in clinical studies has been variable. A preliminary analysis of data from patients who had completed 6 months of treatment indicated that the glycaemic response to the electrical stimulation was inversely related to the baseline fasting plasma triglyceride level.

METHOD

An analysis of 40 patients who had had detailed longitudinal studies for 12 months.

RESULTS

Twenty-two patients with fasting plasma triglycerides ≤ 1.7 mmol/l had mean decreases in HbA1c after 3, 6 and 12 months of gastric contraction modulation treatment of -15 ± 2.1 mmol/mol (-1.39 ± 0.20%), -16 ± 2.2 mmol/mol (-1.48 ± 0.20%) and -14 ± 3.0 mmol/mol (-1.31 ± 0.26%), respectively. In contrast, 18 patients with fasting plasma triglyceride > 1.7 mmol/l had mean decreases in HbA1c of -7 ± 1.7 mmol/mol (-0.66 ± 0.16%), -5 ± 1.6 mmol/mol (-0.44 ± 0.18%) and -5 ± 1.7 mmol/mol (-0.42 ± 0.16%), respectively. Pearson's correlation coefficient between fasting plasma triglyceride and decreases in HbA1c at 12 months of treatment was 0.34 (P < 0.05). Homeostasis model assessment of insulin resistance was unchanged during 12 months of treatment in patients with high baseline fasting triglycerides, while it progressively improved in patients with low fasting plasma triglycerides. Patients with low fasting plasma triglycerides had a tendency to lose more weight than those with high fasting plasma triglycerides, but this did not achieve statistical significance.

CONCLUSIONS

The data presented suggest the existence of a triglyceride lipotoxic mechanism that interferes with gastric/neural mediated pathways that can regulate glycaemic control in patients with type 2 diabetes. The data suggest the existence of a triglyceride lipotoxic pathway that interferes with gastric/neural mediated pathways that can regulate glycaemic control.

Urban wastewater treatment plants as hotspots for the release of antibiotics in the environment: a review

Urban wastewater treatment plants (UWTPs) are among the main sources of antibiotics' release into various compartments of the environment worldwide. The aim of the present paper is to critically review the fate and removal of various antibiotics in wastewater treatment, focusing on different processes (i.e. biological processes, advanced treatment technologies and disinfection) in view of the current concerns related to the induction of toxic effects in aquatic and terrestrial organisms, and the occurrence of antibiotics that may promote the selection of antibiotic resistance genes and bacteria, as reported in the literature. Where available, estimations of the removal of antibiotics are provided along with the main treatment steps. The removal efficiency during wastewater treatment processes varies and is mainly dependent on a combination of antibiotics' physicochemical properties and the operating conditions of the treatment systems. As a result, the application of alternative techniques including membrane processes, activated carbon adsorption, advanced oxidation processes (AOPs), and combinations of them, which may lead to higher removals, may be necessary before the final disposal of the effluents or their reuse for irrigation or groundwater recharge.

Urban wastewater treatment plants as hotspots for antibiotic resistant bacteria and genes spread into the environment: a review

Urban wastewater treatment plants (UWTPs) are among the main sources of antibiotics' release into the environment. The occurrence of antibiotics may promote the selection of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB), which shade health risks to humans and animals. In this paper the fate of ARB and ARGs in UWTPs, focusing on different processes/technologies (i.e., biological processes, advanced treatment technologies and disinfection), was critically reviewed. The mechanisms by which biological processes influence the development/selection of ARB and ARGs transfer are still poorly understood. Advanced treatment technologies and disinfection process are regarded as a major tool to control the spread of ARB into the environment. In spite of intense efforts made over the last years to bring solutions to control antibiotic resistance spread in the environment, there are still important gaps to fill in. In particular, it is important to: (i) improve risk assessment studies in order to allow accurate estimates about the maximal abundance of ARB in UWTPs effluents that would not pose risks for human and environmental health; (ii) understand the factors and mechanisms that drive antibiotic resistance maintenance and selection in wastewater habitats. The final objective is to implement wastewater treatment technologies capable of assuring the production of UWTPs effluents with an acceptable level of ARB.

Reversible switching of ultrastrong light-molecule coupling

We demonstrate that photochromic molecules enable switching from the weak- to ultrastrong-coupling regime reversibly, by using all-optical control. This switch is achieved by photochemically inducing conformational changes in the molecule. Remarkably, a Rabi splitting of 700 meV is measured at room temperature, corresponding to 32% of the molecular transition energy. A similar coupling strength is demonstrated in a plasmonic structure. Such systems present a unique combination of coupling strength and functional capacities.

Laser-assisted lead extraction: the European experience

AIMS

The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented.

METHOD AND RESULTS

The Excimer is a cool cutting laser (50 degrees C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13-96) were extracted at 14 European centres. Mean implantation time was 74 months (3-358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1-300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred.

CONCLUSION

Pacing and implantable cardioverter-defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

Abschätzung des Knochenalters mit einer neuen Ultraschallmethode

PURPOSE

Determination of skeletal development in children is important. The most used evaluation method is to study left hand X-ray based on the standards depicted by Greulich and Pyle. The aim of our study was to compare the accuracy of a new sonographically based method with the standard method.

MATERIAL AND METHODS

160 consecutive evaluated children and adolescents (77 male, 83 female) who received a X-ray of the left hand were evaluated. Ultrasound examination of the same hand was performed on the same day using the BonAge system (Sunlight Medical Ltd., Israel). This system evaluates the relationship between the velocity of the wave (speed of sound) passing thorough the distal radial and ulna epiphysis and growth, using gender- and ethnicity-based algorithms. Three experienced investigators (U1-U3) analysed the X-ray and assigned bone age scores based on the Greulich and Pyle atlas (G and P). The investigators were blinded to the calendary age (CA) of the patient and also for the BonAge result. Correlation between BonAge system results and G and P was performed using SPSS 12.0.1.

RESULTS

In 152 patients BonAge measurement could be performed successfully. The correlation between the three investigators using the G and P method was between 0.977 and 0.980; correlation between the BonAge system and the investigators (U1-U3) was 0.902 and 0.920. The paired t-test showed no significant differences between the BonAge system and the three investigators and also for the comparison between U1 and U2. There were significant differences between U1 vs. U3 and U2 vs. U3 (p < 0.05).

DISCUSSION

The BonAge device demonstrates the ability to produce an sufficient assessment of bone age using an ultrasound method. The results are correlated with conventional skeletal age evaluation using the G and P method. Advantages of the ultrasound device are objectivity, lack of ionizing radiation, and easy accessibility. In the case of first investigation X-ray is necessary to look for dissociated skeletal age, dysplasia, and mineralisation.