The study of antibiotic resistance of extended-spectrum beta-lactamase-producing Klebsiella strains isolated from urinary tract infections in teaching Hospitals in Shahrekord

زمینه و هدف: سویه ‌های کلبسیلا به ویژه کلبسیلا پنومونیه، از جمله پاتوژن ‌های فرصت طلب در ایجاد عفونت ادراری به عنوان یکی از شایع ترین عفونت‌ ها در انسان محسوب می ‌شوند. این مطالعه به منظور بررسی مقاومت آنتی ‌بیوتیکی در سویه ‌های کلبسیلا مولد ESBL که از عفونت ادراری بیماران بستری و سرپایی مراجعه کننده به بیمارستان ‌های آموزشی شهرکرد جدا شدند، صورت پذیرفت. روش بررسی: مطالعه حاضر در سال ‌های 1393-1392 بر روی 150 ایزوله کلبسیلا جدا شده از عفونت ادراری بیماران بستری و سرپایی انجام گرفت. با انجام تست ‌های تشخیصی بیوشیمیایی و استفاده از محیط ‌های افتراقی، هویت ایزوله‌ های جدا شده تعیین گردید. شناسایی ارگانیسم ‌های مولد ESBL با انجام تست ‌های غربالگری و تست ‌های فنوتیپی تأییدی صورت پذیرفت. به منظور ارزیابی الگوی مقاومت آنتی ‌بیوتیکی، از روش دیسک دیفیوژن بهره گرفته شد. یافته ها: از مجموع 150 ایزوله جدا شده از عفونت ادراری، فراوانی سویه ‌های مولد ESBL، در بیماران بستری و سرپایی مراجعه کننده به بیمارستان ‌های آموزشی شهرکرد به ترتیب 64 و 48 گزارش شد. نتایج الگوی مقاومت آنتی‌ بیوتیکی در بیماران بستری و سرپایی به ترتیب برای آنتی ‌بیوتیک ‌های آمیکاسین 49 و 31، تری متوپریم سولفامتوکسازول 61 و 52، جنتامایسین 59 و 39، نیتروفورانتوئین 55 و 32، نورفلوکساسین 59 و 44، نالیدیکسیک اسید 72 و 53، سفپیم 45 و 33، ایمی ‌پنم 8 و 3، سفتریاکسون 41 و 35، سیپروفلوکساسین 60 و 48، سفتازیدیم 64 و 48 گزارش شد. نتیجه گیری: بر اساس مطالعه حاضر، سویه‌ های کلبسیلا جدا شده از عفونت ‌های ادراری بیماران بستری به میزان بالاتری ESBL تولید کردند که می‌تواند به علت مصرف بی رویه و مکرر سفالوسپورین‌ های نسل سوم و عدم تشخیص سویه‌ های کلبسیلا مولد ESBL در محیط ‌های درمانی باشد

Prevalence of extended-spectrum beta-lactamase-producing Klebsiella Pneumoniae isolates in nosocomial and community-acquired urinary tract infections

Background: Klebsiella pneumoniae is a family member of Enterobacteriaceae. Isolates of K. pneumoniae produce enzymes that cause decomposition of third generation cephalosporins. These enzymes are known as extended-spectrum beta-lactamase (ESBL). Resistance of K. pneumoniae to beta-lactamase antibiotics is commonly mediated by beta-lactamase genes. Objectives: The aim of this study was to identify the ESBL produced by K. pneumoniae isolates that cause community-acquired and nosocomial urinary tract infections within a one-year period (2013 to 2014) in Kashani and Hajar university hospitals of Shahrekord, Iran. Patients and Methods: From 2013 to 2014, 150 strains of K. pneumoniae isolate from two different populations with nosocomial and community-acquired infections were collected. The strains were then investigated by double disk synergism and multiplex polymerase chain reaction (PCR). Results: The study population of 150 patients with nosocomial and community-acquired infections were divided to two groups of 75 each. We found that 48 of the K. pneumoniae isolates in the patients with nosocomial infection and 39 isolates in those with community-acquired infections produced ESBL. The prevalence of TEM1, SHV1 and VEB1 in ESBL-producing isolates in nosocomial patients was 24%, 29.3% and 10.6%, and in community-acquired patients, 17.3%, 22.7% and 8%, respectively. Conclusions: Theprevalence of ESBL-producing K. pneumoniae isolate is of great concern; therefore, continuous investigationseems essential to monitor ESBL-producing bacteria in patients with nosocomial and community-acquired infections. © 2016, Ahvaz Jundishapur University of Medical Sciences

Prevalence of class D carbapenemases among extended-spectrum β-lactamases producing Escherichia coli isolates from educational hospitals in Shahrekord

Introduction: Extended-spectrum β-lactamases (ESBLs) are a set of plasmid-borne, various and quickly evolving enzymes that are a main therapeutic issue now-a-days for inpatient and outpatient treatment. Aim: The aim of this study was to determine multi-drug resistance (MDR) and ESBLs producing E. coli strains, prevalence of class D Carbapenemases among ESBLs producing Escherichia coli isolates from educational hospitals in Shahrekord, India. Materials and Methods: Uropathogenic Escherichia coli strains were isolated from patients with Urinary Tract Infections (UTIs). The agar disc diffusion test was used to characterize the antimicrobial sensitivity of the E. coli isolates. The ESBL positive strains were identified by phenotypic double-disk synergy test, by third-generation cephalosporin in combination with or without clavulanic acid. Multiplex PCR was carried out for detection of the three families of OXA-type carbapenamases including OXA-23, OXA-24, and OXA-48 in E. coli strains. Results: All bacterial isolates were susceptible to meropenem. Ninety isolates produced ESBL, 55 E. coli isolates from inpatients, and 35 isolates from outpatients, with a significant association (p< 0.05). The prevalence of OXA-23, OXA-24, and OXA-48 in the ESBLs producing isolates was respectively 21%, 18%, and 11% for inpatients, and 10%, 8%, and 6% for outpatients. Conclusion: ESBL-producing E. coli isolates are also a major threat in the clinical setting. The findings of this study indicated the high occurrence of ESBLs and multiple antibiotic resistance in E. coli isolates

Demixing in binary mixtures with differential diffusivity at high density

Spontaneous phase separation, or demixing, is important in biological phenomena such as cell sorting. In particle-based models, an open question is whether differences in diffusivity can drive such demixing. While differential-diffusivity-induced phase separation occurs in mixtures with a packing fraction up to $0.7$ [Weber et al. Phys Rev Lett 2016], here we investigate whether demixing persists at even higher densities relevant for cells. For particle packing fractions between $0.7$ and $1.0$ the system demixes, but at packing fractions above unity the system remains mixed, exposing re-entrant behavior in the phase diagram. We also find that a confluent Voronoi model for tissues does not phase separate, consistent with the highest-density particle-based simulations.Comment: 4 pages, plus 4 page supplemental material

Interpreting comprehensive two-dimensional gas chromatography using peak topography maps with application to petroleum forensics

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chemistry Central Journal 10 (2016): 75, doi:10.1186/s13065-016-0211-y.Comprehensive two-dimensional gas chromatography (GC×GC) provides high-resolution separations across hundreds of compounds in a complex mixture, thus unlocking unprecedented information for intricate quantitative interpretation. We exploit this compound diversity across the (GC×GC) topography to provide quantitative compound-cognizant interpretation beyond target compound analysis with petroleum forensics as a practical application. We focus on the (GC×GC) topography of biomarker hydrocarbons, hopanes and steranes, as they are generally recalcitrant to weathering. We introduce peak topography maps (PTM) and topography partitioning techniques that consider a notably broader and more diverse range of target and non-target biomarker compounds compared to traditional approaches that consider approximately 20 biomarker ratios. Specifically, we consider a range of 33–154 target and non-target biomarkers with highest-to-lowest peak ratio within an injection ranging from 4.86 to 19.6 (precise numbers depend on biomarker diversity of individual injections). We also provide a robust quantitative measure for directly determining “match” between samples, without necessitating training data sets. We validate our methods across 34 (GC×GC) injections from a diverse portfolio of petroleum sources, and provide quantitative comparison of performance against established statistical methods such as principal components analysis (PCA). Our data set includes a wide range of samples collected following the 2010 Deepwater Horizon disaster that released approximately 160 million gallons of crude oil from the Macondo well (MW). Samples that were clearly collected following this disaster exhibit statistically significant match (99.23±1.66)% using PTM-based interpretation against other closely related sources. PTM-based interpretation also provides higher differentiation between closely correlated but distinct sources than obtained using PCA-based statistical comparisons. In addition to results based on this experimental field data, we also provide extentive perturbation analysis of the PTM method over numerical simulations that introduce random variability of peak locations over the (GC×GC) biomarker ROI image of the MW pre-spill sample (sample #1 in Additional file 4: Table S1). We compare the robustness of the cross-PTM score against peak location variability in both dimensions and compare the results against PCA analysis over the same set of simulated images. Detailed description of the simulation experiment and discussion of results are provided in Additional file 1: Section S8. We provide a peak-cognizant informational framework for quantitative interpretation of (GC×GC) topography. Proposed topographic analysis enables (GC×GC) forensic interpretation across target petroleum biomarkers, while including the nuances of lesser-known non-target biomarkers clustered around the target peaks. This allows potential discovery of hitherto unknown connections between target and non-target biomarkers.This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI-015), and the DEEP-C consortium, and in part by NSF Grants OCE-0969841 and RAPID OCE-1043976 as well as a WHOI interdisciplinary study award

Presenting a Model Regarding the Effect of Ethical Sensitivity and Its Associated Components on the Quality of Research among Academic Personnel

Background and Objective: Ethical sensitivity is one of the criteria regarding the professional competence of researchers, which affects the ethical performance of the researcher. Since compliance with the principles and rules of ethics is an effective factor in providing high quality research results, the present study was conducted to investigate the ethical sensitivity and its associated components on the quality of research among academic personnel of universities of medical sciences in metropolitan area No. 1 in Iran. Methods: This cross-sectional study was conducted on 320 academic personnel of universities of medical sciences in metropolitan area No. 1 (Guilan, Mazandaran, Golestan, Babol, Shahrud, and Semnan) who were selected by stratified random sampling. Data were collected using ethical sensitivity and research quality questionnaires. The ethical sensitivity questionnaire includes 50 questions and two dimensions of "functional and individual", each of which includes 4 fields. The researcher-made questionnaire of research quality includes 31 questions and 4 fields. The questionnaires were rated from 1 to 5 according to Likert scale. Ethical sensitivity was compared between researchers based on work experience, academic degree and gender. Then, the effect of each component of ethical sensitivity on the quality of the research was evaluated. Findings: Out of 320 studied samples, 223 were male (69.7%) and 97 were female (30.3%). In people with experience of less than 10 years, the mean score of honesty was 15.74±3.21, ethical behavior was 30.50±5.74, accountability was 33.81±5.64, decision-making was 23.62±4.28, and interpersonal communication was 18.66±3.56, indicating higher values compared to people with an experience of more than 10 years (p<0.01). Among the dimensions of ethical sensitivity, the dimensions of honesty and discipline showed positive and significant effects on the quality of research. However, the effect of respect for the client, ethical behavior, professional knowledge, accountability, decision-making and interpersonal communication was not statistically significant despite the effect on the quality of the research. Discipline had the greatest effect on research quality (β=0.293). The R2 value (0.489) shows that about 49% of the variance of the research quality score is explained by the dimensions of ethical sensitivity. Ethical sensitivity with a standard coefficient of 7.758 had an effect on the quality of research. Conclusion: The results of the present study showed that ethical sensitivity, especially the dimensions of honesty and discipline, has an effect on the quality of research