scholarly journals Mathematical Model To Quantify the Effects of Risk Factors on Carbapenem-Resistant Acinetobacter baumannii

2014 ◽  
Vol 58 (9) ◽  
pp. 5239-5244 ◽  
Author(s):  
Michelle W. Tan ◽  
David C. Lye ◽  
Tat-Ming Ng ◽  
Michael Nikolaou ◽  
Vincent H. Tam
Keyword(s):  
Risk Factors ◽  
Linear Regression ◽  
Acinetobacter Baumannii ◽  
Antibiotic Consumption ◽  
Model Fit ◽  
Defined Daily Dose ◽  
Content Type ◽  
Carbapenem Resistant ◽  
The Impact ◽  
Over Time

ABSTRACTCarbapenem-resistantAcinetobacter baumannii(CRAB) infections are increasing, and they are associated with an increased risk of mortality in hospitalized patients. Linear regression is commonly used to identify concurrent trends, but it cannot quantify the relationship between risk factors and resistance. We developed a model to quantify the impact of antibiotic consumption on the prevalence of CRAB over time. Data were collected from January 2007 to June 2013 from our institution. Quarterly antibiotic consumption was expressed as defined daily dose/1,000 inpatient days. Six-month prevalence of CRAB was expressed as a percentage of all nonrepeatA. baumanniiisolates tested. Individual trends were identified using linear regression. Antibiotic consumption from 2007 to 2011 was input as a step function in a relationship with CRAB. Model fit was evaluated by visual inspection and the residual sum of squares. The final model was validated using the best-fit (95% confidence interval) parameter estimates and antibiotic consumption to predict CRAB prevalence from January 2012 to June 2013. Cefepime, ertapenem, and piperacillin-tazobactam consumption and CRAB prevalence increased significantly over time. CRAB prevalence was best correlated to ertapenem (use sensitive;r2= 0.76), and accounting for additional concurrent antibiotic use did not significantly improve model fit. Prospective validation with ertapenem consumption correlated well with CRAB observations, suggesting good predicting ability of the model. Our model provided the quantitative impact of antibiotic consumption on CRAB. We plan to further refine this model to account for multiple risk factors. Interventions should focus on controlling risk factors with the highest impact on resistance.

Adaptations of carbapenem resistant Acinetobacter baumannii (CRAB) in the hospital environment causing sustained outbreak

2021 ◽  
Vol 70 (3) ◽  
Author(s):  
Swati Sharma ◽  
Arghya Das ◽  
Tuhina Banerjee ◽  
Hiranmay Barman ◽  
Ghanshyam Yadav ◽  
...  
Keyword(s):  
Risk Factors ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Type Species ◽  
Hospital Environment ◽  
Genetic Profile ◽  
Content Type ◽  
Slow Growth Rate ◽  
Link Type ◽  
Carbapenem Resistant

Introduction. Carbapenem resistance in Acinetobacter baumannii ( A. baumannii ) is an emerging global threat. Gap statement. The adaptation strategies of A. baumannii for this emergence as a nosocomial pathogen has been less studied. Aim. This prospective study analysed a sustained outbreak of carbapenem resistant Acinetobacter baumannii (CRAB) in the intensive care unit (ICU) with reference to antimicrobial resistance and virulence in the colonizing and pathogenic isolates under carbapenem stress. Results. The CRAB isolates from initial and sustained outbreak were found harbouring multiple carbapenemase genes. These genes included bla OXA-23 ,bla IMP, bla VIM and bla NDM. From NICU environment three phenotypically carbapenem susceptible isolates were found carrying bla OXA-23, bla IMP, bla VIM genes. Prior imipenem therapy was one of the risk factors (P=0.0016). The outbreak was polyclonal. Under imipenem stress, outbreak isolates showed no loss of carbapenemase genes against stress free conditions (23.7±1.33 days). Biofilm formation increased with imipenem concentration, with outbreak isolates producing highest biomass. While the pathogens showed a slow growth rate on imipenem exposure, the colonisers grew rapidly (P <0.0001). Methods. Sustained outbreak of CRAB was identified in the ICU (July 2015 to December 2017). Risk factors for acquisition of CRAB was studied. A. baumannii isolates were also collected from the environments of ICU and neonatal ICU (NICU) and blood cultures of septic neonates. Isolates were characterized based on antimicrobial susceptibility, genetic profile, integrons carriage and clonality. Biofilm formation and growth kinetics were studied under varying carbapenem stress. Conclusion. Intense carbapenem exposure in the ICU facilitates persistence of CRAB by several adaptations causing sustained outbreaks.

scholarly journals The Impact of Intervention-Related Risk Factors on the Risk of Ventilator-Associated Pneumonia Is High in a Neurosurgical Intensive Care Unit

2020 ◽  
Vol 41 (S1) ◽  
pp. s407-s409
Author(s):  
Ksenia Ershova ◽  
Oleg Khomenko ◽  
Olga Ershova ◽  
Ivan Savin ◽  
Natalia Kurdumova ◽  
...  
Keyword(s):  
Risk Factors ◽  
Mechanical Ventilation ◽  
Negative Slope ◽  
Infection Prevention And Control ◽  
Ventilator Associated Pneumonia ◽  
Related Factors ◽  
Icu Patients ◽  
The Impact ◽  
Adf Test ◽  
Over Time

Background: Ventilator-associated pneumonia (VAP) represents the highest burden among all healthcare-associated infections (HAIs), with a particularly high rate in patients in neurosurgical ICUs. Numerous VAP risk factors have been identified to provide a basis for preventive measures. However, the impact of individual factors on the risk of VAP is unclear. The goal of this study was to evaluate the dynamics of various VAP risk factors given the continuously declining prevalence of VAP in our neurosurgical ICU. Methods: This prospective cohort unit-based study included neurosurgical patients who stayed in the ICU >48 consecutive hours in 2011 through 2018. The infection prevention and control (IPC) program was implemented in 2010 and underwent changes to adopt best practices over time. We used a 2008 CDC definition for VAP. The dynamics of VAP risk factors was considered a time series and was checked for stationarity using theAugmented Dickey-Fuller test (ADF) test. The data were censored when a risk factor was present during and after VAP episodes. Results: In total, 2,957 ICU patients were included in the study, 476 of whom had VAP. Average annual prevalence of VAP decreased from 15.8 per 100 ICU patients in 2011 to 9.5 per 100 ICU patients in 2018 (Welch t test P value = 7.7e-16). The fitted linear model showed negative slope (Fig. 1). During a study period we observed substantial changes in some risk factors and no changes in others. Namely, we detected a decrease in the use of anxiolytics and antibiotics, decreased days on mechanical ventilation, and a lower rate of intestinal dysfunction, all of which were nonstationary processes with a declining trend (ADF testP > .05) (Fig. 2). However, there were no changes over time in such factors as average age, comorbidity index, level of consciousness, gender, and proportion of patients with brain trauma (Fig. 2). Conclusions: Our evidence-based IPC program was effective in lowering the prevalence of VAP and demonstrated which individual measures contributed to this improvement. By following the dynamics of known VAP risk factors over time, we found that their association with declining VAP prevalence varies significantly. Intervention-related factors (ie, use of antibiotics, anxiolytics and mechanical ventilation, and a rate of intestinal dysfunction) demonstrated significant reduction, and patient-related factors (ie, age, sex, comorbidity, etc) remained unchanged. Thus, according to the discriminative model, the intervention-related factors contributed more to the overall risk of VAP than did patient-related factors, and their reduction was associated with a decrease in VAP prevalence in our neurosurgical ICU.Funding: NoneDisclosures: None

scholarly journals First Description of Two Sequence Type 2 Acinetobacter baumannii Isolates Carrying OXA-23 Carbapenemase in Pagellus acarne Fished from the Mediterranean Sea near Bejaia, Algeria

2016 ◽  
Vol 60 (4) ◽  
pp. 2513-2515 ◽  
Author(s):  
Soumia Brahmi ◽  
Abdelaziz Touati ◽  
Axelle Cadière ◽  
Nassima Djahmi ◽  
Alix Pantel ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Mediterranean Sea ◽  
Sequence Type ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Selective Agar ◽  
Agar Media ◽  
The Mediterranean ◽  
First Time

ABSTRACTTo determine the occurrence of carbapenem-resistantAcinetobacter baumanniiin fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producingA. baumanniistrains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [aac(6′)-Ib andaac(3′)-I genes].

scholarly journals Firm’s strategic choices and network knowledge dynamics: how do they affect innovation?

2018 ◽  
Vol 22 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Jose Antonio Belso-Martinez ◽  
Isabel Diez-Vial
Keyword(s):  
Absorptive Capacity ◽  
Knowledge Networks ◽  
Knowledge Network ◽  
Strategic Choices ◽  
Network Growth ◽  
Content Type ◽  
Endogenous Factors ◽  
The Impact ◽  
Innovative Capacity ◽  
Over Time

Purpose This paper aims to explain how the evolution of knowledge networks and firms’ strategic choices affect innovation. Endogenous factors associated with a path-dependent evolution of the knowledge network are jointly considered with a firm’s development of international relationships and increasing internal absorptive capacity over time. Design/methodology/approach In a biotech cluster, the authors gathered data on the firms’ characteristics and network relationships by asking about the technological knowledge they received in the cluster in 2007 and 2012 – “roster-recall” method. Estimation results were obtained using moderated regression analysis. Findings Firms that increase their involvement in knowledge networks over time also tend to increase their innovative capacity. However, efforts devoted to building international links or absorptive capacity negatively moderate the impact of network growth on innovation. Practical implications Practitioners have two alternative ways of increasing innovation inside knowledge networks: they can increase their centrality by developing their knowledge network interactions or invest in developing their internal absorptive capacity and new international sources of knowledge. Investing in both of these simultaneously does not seem to improve a firm’s innovative capacity. Originality/value Coupling firms’ strategic options with knowledge network dynamics provide a more complete way of explaining how firms can improve their innovative capacity.

The dynamics of regional and global expansion

2015 ◽  
Vol 23 (4) ◽  
pp. 306-327 ◽  
Author(s):  
Christian Geisler Asmussen ◽  
Bo Bernhard Nielsen ◽  
Tom Osegowitsch ◽  
Andre Sammartino
Keyword(s):  
Design Methodology ◽  
Global Market ◽  
Market Penetration ◽  
Content Type ◽  
Global Expansion ◽  
Rates Of Change ◽  
Global Space ◽  
The Impact ◽  
The Relationship ◽  
Over Time

Purpose – The purpose of this paper is to model and test the dynamics of home-regional and global penetration by multi-national enterprises (MNEs). Design/methodology/approach – Drawing on international business (IB) theory, the authors model MNEs adjusting their home-regional and global market presence over time. The authors test the resulting hypotheses using sales data from a sample of 220 of the world’s largest MNEs over the period 1995-2005. The authors focus specifically on the relationship between levels of market penetration inside and outside the home region and rates of change in each domain. Findings – The authors demonstrate that MNEs do penetrate both home-regional and global markets, often simultaneously, and that penetration levels often oscillate within an MNE over time. The authors show firms’ rates of regional and global expansion to be affected by their existing regional and global penetration, as well as their interplay. Finally, the authors identify differences in the steady states at which firms stabilize their penetration levels in the home-regional and the global space. The findings broadly confirm the MNE as an interdependent portfolio with important regional demarcations. Originality/value – The authors identify complex interdependencies between home-regional and global penetration and growth, paving the way for further studies of the impact of regions on MNE expansion.

scholarly journals Impact of Extended-Spectrum β-Lactamase Production on Treatment Outcomes of Acute Pyelonephritis Caused by Escherichia coli in Patients without Health Care-Associated Risk Factors

2015 ◽  
Vol 59 (4) ◽  
pp. 1962-1968 ◽  
Author(s):  
Sun Hee Park ◽  
Su-Mi Choi ◽  
Dong-Gun Lee ◽  
Sung-Yeon Cho ◽  
Hyo-Jin Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Health Care ◽  
Treatment Outcomes ◽  
Acute Pyelonephritis ◽  
Esbl Production ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
The Impact

ABSTRACTExtended-spectrum β-lactamase-producingEscherichia coli(ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused byE. coliat a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3;P= 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38;P= 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65;P= 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused byE. colishowed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30;P= 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12;P= 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associatedE. coliAPN.

Three stages of entrepreneurial orientation: the founder’s role

2019 ◽  
Vol 26 (2) ◽  
pp. 285-306 ◽  
Author(s):  
Torbjörn Ljungkvist ◽  
Börje Boers ◽  
Joachim Samuelsson
Keyword(s):  
Entrepreneurial Orientation ◽  
Single Case ◽  
Annual Reports ◽  
Structured Interviews ◽  
Theoretical Understanding ◽  
Content Type ◽  
Five Dimensions ◽  
The Impact ◽  
Over Time

Purpose The purpose of this paper is to understand the development of the five dimensions of entrepreneurial orientation (EO) over time by taking a founder’s perspective. Design/methodology/approach The paper draws on an in-depth single-case study. It combines semi-structured interviews in the company with archival data, such as annual reports, press clips and interviews in business magazines. Findings The results indicate that the EO dimensions change from being personalized and directly solution-oriented to being intangible value-creation-oriented. Originality/value By suggesting ownership-based EO configurations, this study contributes insights into how different ownership forms propel EO. These configurations – that is, personal, administrative based and intangible focused – show the impact of the EO dimensions and provide a systematic and theoretical understanding of EO change over time.

scholarly journals Semimechanistic Pharmacokinetic/Pharmacodynamic Modeling of Fosfomycin and Sulbactam Combination against Carbapenem-Resistant Acinetobacter baumannii

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Sazlyna Mohd Sazlly Lim ◽  
Aaron J. Heffernan ◽  
Jason A. Roberts ◽  
Fekade B. Sime
Keyword(s):  
Acinetobacter Baumannii ◽  
Treatment Options ◽  
Pharmacodynamic Modeling ◽  
Synergistic Activity ◽  
Bacterial Burden ◽  
Target Attainment ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Time Kill

ABSTRACT Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are now considered potential treatments for CR-AB. This study aimed to explore the utility of fosfomycin-sulbactam combination (FOS/SUL) therapy against CR-AB isolates. Synergism of FOS/SUL against 50 clinical CR-AB isolates was screened using the checkerboard method. Thereafter, time-kill studies against two CR-AB isolates were performed. The time-kill data were described using a semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Monte Carlo simulations were then performed to estimate the probability of stasis, 1-log kill, and 2-log kill after 24 h of combination therapy. The FOS/SUL combination demonstrated a synergistic effect against 74% of isolates. No antagonism was observed. The MIC50 and MIC90 of FOS/SUL were decreased 4- to 8-fold, compared to the monotherapy MIC50 and MIC90. In the time-kill studies, the combination displayed bactericidal activity against both isolates and synergistic activity against one isolate at the highest clinically achievable concentrations. Our PK/PD model was able to describe the interaction between fosfomycin and sulbactam in vitro. Bacterial kill was mainly driven by sulbactam, with fosfomycin augmentation. FOS/SUL regimens that included sulbactam at 4 g every 8 h demonstrated a probability of target attainment of 1-log10 kill at 24 h of ∼69 to 76%, compared to ∼15 to 30% with monotherapy regimens at the highest doses. The reduction in the MIC values and the achievement of a moderate PTA of a 2-log10 reduction in bacterial burden demonstrated that FOS/SUL may potentially be effective against some CR-AB infections.

Brand awareness: revisiting an old metric for a new world

2017 ◽  
Vol 26 (5) ◽  
pp. 469-476 ◽  
Author(s):  
Jenni Romaniuk ◽  
Samuel Wight ◽  
Margaret Faulkner
Keyword(s):  
Market Share ◽  
Brand Management ◽  
Brand Awareness ◽  
Underlying Structure ◽  
Cross Sectional ◽  
Content Type ◽  
Country Level ◽  
Global Brand ◽  
The Impact ◽  
Over Time

Purpose Brand awareness is a pivotal, but often neglected, aspect of consumer-based brand equity. This paper revisits brand awareness measures in the context of global brand management. Design/methodology/approach Drawing on the method of Laurent et al. (1995), this cross-sectional longitudinal study examines changes in brand awareness over time, with sample sizes of approximately 300 whisky consumers per wave in three countries: United Kingdom, Taiwan and Greece. Findings There is consistency in the underlying structure of awareness scores across countries, and over time, extending the work of Laurent et al. (1995). Results show that a relevant operationalisation of brand awareness needs to account for the history of the brand. Furthermore, the nature of the variation of brand awareness over time interacts with a brand’s market share. Research limitations/implications When modelling the impact of brand awareness researchers need to consider two factors – the brand’s market share and whether a more stable or volatile measure is sought. This avoids mis-specifying the country-level contribution of brand awareness. Practical implications Global brand managers should be wary of adopting a “one size fits all” approach. The choice of brand awareness measure depends on the brand’s market share, and the desire for higher sensitivity or stability. Originality/value The paper provides one of the few multi-country investigations into brand awareness that can help inform global brand management.

Rebuilding Nepal: traditional and modern approaches, building or diminishing resilience?

2018 ◽  
Vol 9 (3) ◽  
pp. 218-229 ◽  
Author(s):  
Catherine Forbes
Keyword(s):  
Building Materials ◽  
Local Community ◽  
Vernacular Architecture ◽  
Research Approach ◽  
Content Type ◽  
Knowledge And Skills ◽  
Masonry Construction ◽  
Action Research Approach ◽  
The Impact ◽  
Over Time

Purpose The purpose of this paper is to highlight the importance of vernacular architecture and traditional knowledge to building resilience in Nepal and the impact of modernisation on that resilience and architectural diversity. Design/methodology/approach Using an action research approach, including field observations and discussions with local community members, artisans, architects, engineers and other international experts, the study examines the resilience of traditional building typologies to natural hazards in Nepal, including earthquake; the changes that have occurred over time leading to the failure and/or rejection of traditional construction; and a review of post-earthquake reconstruction options, both traditional and modern. Findings Although traditional approaches have been cyclically tested over time, this study found that changes in building materials, technologies, knowledge and skills, access to resources, maintenance practices, urban environments and societal aspirations have all contributed to the popular rejection of vernacular architecture following the earthquakes. Research limitations/implications The research is limited to traditional timber and masonry construction in the Kathmandu Valley and surrounding mountain areas. Practical implications To improve resilience the study identifies the need for capacity building in both traditional and modern construction technologies; adoption of approaches that use local materials, knowledge and skills, whilst addressing local timber shortages and access issues; a transparent construction certification system; good drainage; and regular maintenance. Originality/value The study critically evaluates the impact of technological, environmental, social and economic changes over time on the resilience of vernacular housing in Nepal.

Sign in / Sign up

Export Citation Format

Share Document