Rapid and in-situ detection of fecal indicator bacteria in water using simple DNA extraction and portable loop-mediated isothermal amplification (LAMP) PCR methods.

Contamination of water by fecal matter and potential human enteric pathogens is a serious health concern. Microbiological water quality has been assessed by conventional culture-based methods of fecal indicator bacteria (FIB). Recently, molecular techniques for FIB have been introduced as alternative tools for rapid detection. However, such molecular techniques require a modern laboratory setting, expensive equipment, and skilled personnel. In this study, we developed a simple and rapid DNA extraction method based on a syringe filter without any specialized equipment. Furthermore, loop-mediated isothermal amplification (LAMP) PCR for fecal indicator bacteria (FIB) (i.e. E. coli and E. faecalis) was carried out using the DNA extracts from the syringe-filter based DNA extraction method. The efficiency of the extracted DNA from the syringe-filter based method was comparable to the results of the commercial kit method. We also tested fresh and marine-water collected directly from different locations in Singapore that were spiked with E. coli or E. faecalis. The LAMP assays combined with our DNA extraction method showed higher sensitivity and more tolerance to PCR inhibitors than that of conventional PCR methods. We further developed a portable LAMP device to conduct isothermal PCR reactions for rapid on-site measurement of FIB. As the color changes in the end point of the LAMP reaction can be observed with the naked eye, the portable LAMP device was easily operated and quick, obtaining results in 30 min. The simple, portable and user-friendly platform can be used as an initial screening for the rapid detection of the presence FIB in lower-resource settings. In conclusion, the portable LAMP device coupled with a syringe-filter based DNA extraction method enables us to detect the presence of FIB for assessing microbial water quality within 1 h without any sophisticated laboratory equipment or highly trained personnel.

Pseudomonas aeruginosa infection in cystic fibrosis: pathophysiological mechanisms and therapeutic approaches.

Pseudomonas aeruginosa is a remarkably versatile environmental bacterium with an extraordinary capacity to infect the cystic fibrosis (CF) lung. Infection with P. aeruginosa occurs early, and although eradication can be achieved following early detection, chronic infection occurs in over 60% of adults with CF. Chronic infection is associated with accelerated disease progression and increased mortality. Extensive research has revealed complex mechanisms by which P. aeruginosa adapts to and persists within the CF airway. Yet knowledge gaps remain, and prevention and treatment strategies are limited by the lack of sensitive detection methods and by a narrow armoury of antibiotics. Further developments in this field are urgently needed in order to improve morbidity and mortality in people with CF. Here, we summarize current knowledge of pathophysiological mechanisms underlying P. aeruginosa infection in CF. Established treatments are discussed, and an overview is offered of novel detection methods and therapeutic strategies in development.

Laparoscopic Adjustable Gastric Banding Revisions in Singapore: a 10-Year Experience.

BACKGROUND: Bariatric surgery is increasingly being carried out and revisional procedures have also risen in concert. A review of the complications and revisions might elucidate technical and patient factors that influence the outcomes of bariatric surgeries in Asian patients. The objective of this study is to review the safety and efficacy of revisional bariatric surgery in a single center in Singapore over a 10-year period. METHODS: The setting of this study is a single public hospital with a multidisciplinary bariatric service including a weight management center, specialized endocrinology services, and bariatric surgical team. Participants were selected for surgery based on body mass index (BMI) and comorbidities. All patients underwent primary laparoscopic adjustable gastric banding (LAGB). Patients were then analyzed according to the types of revisional surgeries. The primary outcome was the type of complications and revisional surgeries. Secondary outcomes include short-term excess weight loss and further complications. RESULTS: A total of 365 patients were analyzed. 9.6% had a secondary procedure. In particular, two groups of complications required revisional surgery: failure of sustained weight loss and complications related to the LAGB insertion and use. Revisional surgeries had equivalent major complication rates (5.7%) compared to primary bariatric surgeries (6.8%). Revisional surgeries such as revisional LAGB (4.9 ± 9.8 kg), laparoscopic sleeve gastrectomy (LSG; 6.9 ± 21.0 kg), Roux-en-Y gastric bypass (RYGB; 4.6 ± 13.0 kg), and bilio-pancreatic diversion (BPD; 3.5 ± 6.3 kg) had modest weight loss compared to primary weight loss (12.7 ± 9.5 kg). Primary LAGB had a greater percentage excess weight loss in the first and second years post-surgery compared to revisional surgeries. There was one mortality post-primary surgery and no post-revisional surgical mortalities. CONCLUSIONS: Revisional bariatric surgery for complications related to the primary surgery is safe but had reduced excess weight loss compared to the initial surgery.

Incidence and predictors of side-branch compromise in primary percutaneous coronary intervention for acute myocardial infarction.

OBJECTIVE: We aimed to determine the incidence and predictors of side-branch compromise (SBC) in patients who underwent primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: Little data exist on SBC in AMI patients, especially in the drug-eluting stent era. METHODS: We recruited 174 patients who underwent primary PCI over a 12-month period. After reviewing their coronary angiograms, we included for analysis 102 patients with a side branch >2 mm arising from the culprit lesion and that was spanned by a coronary stent. SBC was defined as post-stent implantation TIMI flow of <3 in the side branch. RESULTS: Among the 102 patients analyzed, drug-eluting stents (n = 77), bare-metal stents (n = 17), and bioresorbable vascular scaffolds (n = 8) were used to treat the culprit lesions. Final TIMI flow of the main vessel was 2 or 3 in 101 patients (99%). SBC occurred in 23 patients (final side branch TIMI flow 0, n = 6; TIMI 1, n = 4; TIMI 2, n = 13), giving an incidence of 22.5%. Multivariate analysis showed non-left anterior descending (LAD) culprit vessel (odds ratio [OR], 3.66; 95% confidence interval [CI], 1.22-10.95; P=.02), higher peak creatine kinase level (OR, 1.03 for every 100-unit increase; 95% CI, 1.01-1.05; P=.01), and Rentrop score of 2/3 (OR, 3.57; 95% CI, 0.98-13.04; P=.055) to be independent predictors of SBC. CONCLUSIONS: The incidence of SBC was 22.5%. The independent predictors of SBC were non-LAD culprit vessel, larger infarct size, and good collateral vessel formation.

Determination of the severity of underlying lesions in acute myocardial infarction on the basis of collateral vessel development.

BACKGROUND: We aimed to address the conflict over whether the underlying lesion that leads to acute myocardial infarction (AMI) is representative of low-grade or high-grade stenosis. Because the development of collateral vessels is an indication of ischemia, their presence was used as a surrogate marker for the existence of a high-grade lesion. METHODS: Coronary angiography was used to assess 159 patients, divided into two groups, with (Rentrop 1-3) and without (Rentrop 0) collateral vessels, who had AMI with ST-segment elevation for which they underwent a percutaneous coronary intervention with the implantation of a coronary stent and had baseline thrombolysis in myocardial infarction 0/1 flow. RESULTS: Of the 159 patients recruited, the presence of collateral vessels was detected in 95 (collateral group; 60%), indicating that the causal lesion was representative of a high-grade stenosis. Among these 95 patients, the Rentrop scores were 1, 2, and 3 in 57 (60%), 33 (34.7%), and six (5.3%) patients, respectively. Logistic regression analysis showed that a baseline thrombolysis in myocardial infarction 0 flow (hazard ratio, 4.6; 95% confidence interval, 1.4-14.6; P=0.01) and a culprit right coronary artery (hazard ratio, 3.0; 95% confidence interval, 1.4-6.2; P=0.007) were independent predictors of the development of collateral vessels. CONCLUSION: The majority of AMI cases can be attributed to a severe stenosis, as demonstrated by the presence of collateral vessels in 60% of the patients in this study.