Transcriptome of the quorum-sensing signal-degrading Rhodococcus erythropolis responds differentially to virulent and avirulent Pectobacterium atrosepticum.

Social bacteria use chemical communication to coordinate and synchronize gene expression via the quorum-sensing (QS) regulatory pathway. In Pectobacterium, a causative agent of the blackleg and soft-rot diseases on potato plants and tubers, expression of the virulence factors is collectively controlled by the QS-signals N-acylhomoserine lactones (NAHLs). Several soil bacteria, such as the actinobacterium Rhodococcus erythropolis, are able to degrade NAHLs, hence quench the chemical communication and virulence of Pectobacterium. Here, next-generation sequencing was used to investigate structural and functional genomics of the NAHL-degrading R. erythropolis strain R138. The R. erythropolis R138 genome (6.7 Mbp) contained a single circular chromosome, one linear (250 kbp) and one circular (84 kbp) plasmid. Growth of R. erythropolis and P. atrosepticum was not altered in mixed-cultures as compared with monocultures on potato tuber slices. HiSeq-transcriptomics revealed that no R. erythropolis genes were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the avirulent P. atrosepticum mutant expI, which is defective for QS-signal synthesis. By contrast 50 genes (<1% of the R. erythropolis genome) were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the NAHL-producing virulent P. atrosepticum. Among them, quantitative real-time reverse-transcriptase-PCR confirmed that the expression of some alkyl-sulfatase genes decreased in the presence of a virulent P. atrosepticum, as well as deprivation of organic sulfur such as methionine, which is a key precursor in the synthesis of NAHL by P. atrosepticum.

Membrane disruption and anti-quorum sensing effects of synergistic interaction between Lavandula angustifolia (lavender oil) in combination with antibiotic against plasmid-conferred multi-drug-resistant Escherichia coli.

AIM: The aim of this study was to investigate the mode of action of the lavender essential oil (LV) on antimicrobial activity against multi-drug-resistant Escherichia coli J53 R1 when used singly and in combination with piperacillin. METHOD AND RESULTS: In the time-kill analysis, a complete killing of bacteria was observed based on colony counts within 4 h when LV was combined with piperacillin during exposure at determined FIC concentrations. Analysis of the membrane permeabilizing effects of LV on treated cultures through their stability against sodium dodecyl sulphate revealed that the LV played a role in disrupting the bacterial cell membrane. The finding is further supported by scanning electron microscopy analysis and zeta potential measurement. In addition, reduction in light production expression of E. coli [pSB1075] by the LV showed the presence of potential quorum sensing (QS) inhibitors. CONCLUSIONS: These results indicated that the LV has the potential to reverse bacterial resistance to piperacillin in E. coli J53 R1. It may operate via two mechanisms: alteration of outer membrane permeability and inhibition of bacterial QS. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings offer a novel approach to develop a new option of phytopharmaceuticals against multi-drug-resistant E. coli.

Robotic-assisted laparoscopic radical cystoprostatectomy and extracorporeal continent urinary diversion: highlight of surgical techniques and outcomes.

BACKGROUND: We report our technique for robotic-assisted laparoscopic radical cystoprostatectomy (RARCP) and extracorporeal urinary diversion and present their clinical outcomes. METHODS: Between October 2003 and December 2008 we performed 58 RARCPs with extracorporeal continent urinary diversion. Preoperative, operative and postoperative data was evaluated. RESULTS: Mean patient age was 68 (range 46-89) years, with an average American Society of Anesthesiologists classification of 2.9. Mean operative time was 8 (range 5-11) h. Median blood loss was 450 ml. Thirteen patients received intra-operative blood transfusions and 22 patients received peri-operative blood transfusions. Continent urinary diversions were performed by means of the Studer technique (n = 42) or Indiana pouch (n = 16). Mean number of lymph nodes examined on lymphadenectomy was 27 (range 0-52). CONCLUSIONS: Our RARCP and continent diversion technique is a safe and feasible option for primary urothelial carcinoma of the bladder. Oncological and surgical outcomes are comparable to open cystectomy series.

Hip subluxation and dislocation in Duchenne muscular dystrophy.

Although hip subluxation and dislocation occur commonly in neuromuscular diseases such as cerebral palsy, spinal muscular atrophy and myelomeningocele, they are not known to commonly affect patients with Duchenne Muscular Dystrophy. In this study, 15 out of 54 patients whose hip radiographs were reviewed showed unilateral subluxation, one had bilateral subluxation and three had unilateral dislocation. Having established that hip subluxation and dislocation develop frequently in patients with Duchenne Muscular Dystrophy, serial hip radiographs should be taken as has been advocated for cerebral palsy. The possible relationship between subluxation and pelvic tilt also calls for better control of sitting posture to prevent pelvic tilt. Spinal stabilization should be carried out at an early age when any scoliosis and pelvic tilt are still mild, so that progressive subluxation of the hip may be delayed or prevented, in addition to maintaining sitting balance and comfort.