Photocatalytic inactivation of dual- and mono-species biofilms by immobilized TiO2.

Biofilms formed by different bacterial species are likely to play key roles in photocatalytic resistance. This study aims to evaluate the efficacy of a photocatalytic immobilized nanotube system (TiO2-NT) (IS) and suspended nanoparticles (TiO2-NP) (SS) against mono- and dual-species biofilms developed by Gram-negative and Gram-positive strains. Two main factors were corroborated to significantly affect the biofilm resistance during photocatalytic inactivation, i.e., the biofilm-growth conditions and biofilm-forming surfaces. Gram-positive bacteria showed great photosensitivity when forming dual-species biofilms in comparison with the Gram-positive bacteria in single communities. When grown onto TiO2-NT (IS) surfaces for immobilized photocatalytic systems, mono- and dual-species biofilms did not exhibit differences in photocatalytic inactivation according to kinetic constant values (p > 0.05) but led to a reduction of ca. 3-4 log10. However, TiO2-NT (IS) surfaces did affect biofilm colonization as the growth of mono-species biofilms of Gram-negative and Gram-positive bacteria is significantly (p ≤ 0.05) favored compared to co-culturing; although, the photocatalytic inactivation rate did not show initial bacterial concentration dependence. The biofilm growth surface (which depends on the photocatalytic configuration) also favored resistance of mono-species biofilms of Gram-positive bacteria compared to that of Gram-negative in immobilized photocatalytic systems, but opposite behavior was confirmed with suspended TiO2 (p ≤ 0.05). Successful efficacy of immobilized TiO2 for inactivation of mono- and dual-species biofilms was accomplished, making it feasible to transfer this technology into real scenarios in water treatment and food processing.

Long-term follow-up of a multicentre cohort study on laparoscopic peritoneal lavage for perforated diverticulitis.

AIM: Laparoscopic peritoneal lavage has increasingly been investigated as a promising alternative to sigmoidectomy for perforated diverticulitis with purulent peritonitis. Most studies only reported outcomes up to 12 months. Therefore, the objective of this study was to evaluate long-term outcomes of patients treated with laparoscopic lavage. METHODS: Between 2008 and 2010, 38 patients treated with laparoscopic lavage for perforated diverticulitis in 10 Dutch teaching hospitals were included. Long-term follow-up data on patient outcomes, e.g. diverticulitis recurrence, reoperations and readmissions, were collected retrospectively. The characteristics of patients with recurrent diverticulitis or complications requiring surgery or leading to death, categorized as 'overall complicated outcome', were compared with patients who developed no complications or complications not requiring surgery. RESULTS: The median follow-up was 46 months (interquartile range 7-77), during which 17 episodes of recurrent diverticulitis (seven complicated) in 12 patients (32%) occurred. Twelve patients (32%) required additional surgery with a total of 29 procedures. Fifteen patients (39%) had a total of 50 readmissions. Of initially successfully treated patients (n = 31), 12 (31%) had recurrent diverticulitis or other complications. At 90 days, 32 (84%) patients were alive without undergoing a sigmoidectomy. However, seven (22%) of these patients eventually had a sigmoidectomy after 90 days. Diverticulitis-related events occurred up to 6 years after the index procedure. CONCLUSION: Long-term diverticulitis recurrence, re-intervention and readmission rates after laparoscopic lavage were high. A complicated outcome was also seen in patients who had initially been treated successfully with laparoscopic lavage with relevant events occurring up to 6 years after initial surgery.

Influence of incubation conditions on the formation of model biofilms by Listeria monocytogenes and Salmonella Typhimurium on abiotic surfaces.

AIMS: This research aims to develop strongly adherent and mature model biofilms (on a 20 cm² polystyrene surface) for two pathogenic species, i.e. Listeria monocytogenes and Salmonella Typhimurium. These model biofilms can be used as standards to study biofilms or to study/compare the influence of different inactivation technologies. METHODS AND RESULTS: Three influencing factors on the formation of biofilms are investigated, i.e. growth medium, incubation temperature and incubation time, which are three easily controllable environmental factors. Optical density measurement and plate counts were used to evaluate the adherence and the maturity of the biofilms, respectively. Confocal laser scanning microscopy was used to verify most important findings obtained with previously mentioned assays. Results indicated that mature and strongly adherent L. monocytogenes biofilms are obtained following 13 h of incubation at 30°C with BHI as growth medium. For S. Typhimurium, an incubation period of 19 h at 25°C was required with 20-fold diluted TSB as growth medium. CONCLUSIONS: Based on previously mentioned assays, a protocol for the formation of reproducible model biofilms was obtained. SIGNIFICANCE AND IMPACT OF THE STUDY: The developed model biofilms can be applied as a standard to study biofilms (in different research fields) and their subsequent inactivation by different methods. In addition, the results of this study could be used to control biofilm formation (e.g. by setting a maximum allowed surface temperature).

[A woman with acute abdominal pain after a gastric bypass]. / Een vrouw met acute buikpijn na een gastric bypass.

A 35-year-old woman with a history of gastric bypass presented with acute abdominal pain, nausea and an urge to move. She showed normal vital signs. We found abdominal guarding and elevated ASAT, ALAT and LDH. A CT scan showed the whirl sign, caused by a mesenteric herniation through the Roux-en-Y gastric bypass.

Fracture of the pancreas in two patients after a go-kart accident.

BACKGROUND: After blunt abdominal trauma, an isolated injury to the pancreatic duct is uncommon. Physical signs and laboratory parameters are often inaccurate, and missing this diagnosis can cause serious clinical problems. CASE OUTLINES: Two young women (aged 18 and 20 years) are reported who sustained isolated trauma to the pancreatic duct in go-kart accidents. Each patient sustained a fracture of the pancreas.This injury was diagnosed only after a period of clinical observation with repeated laboratory parameters, ultrasound and CT scan. Pancreatic tissue was conserved by performing a pancreaticojejunostomy. DISCUSSION: After any episode of blunt abdominal trauma, isolated injury to the pancreatic duct should be considered. Serum analysis, ultrasonography and CT scanning can be helpful in early diagnosis. Preservation of pancreatic tissue can be achieved with a good clinical outcome.