This study is concerned with the mathematical modelling of the vibration response characteristic of a special dissimilar composite beam based on experimental modal analysis. Here, experimental modal ...analyses of three different dissimilar polyamide 6 composite beams, which are connected to each other by hot plate welding are performed. The measured natural frequencies are compared with finite element predictions for verification purposes. Modal information obtained by experiments is used to construct a mathematical model representing vibration response characteristic of beams by applying multi degree of freedom curve fitting method. The model showing modal characteristics of dissimilar beams is now ready to be used in different kinds of excitations to predict the frequency response of vibration.
The purpose of this investigation was to compare the efficacy of colistin-based therapies in extremely drug-resistant
Acinetobacter
spp. bloodstream infections (XDR-ABSI). A retrospective study was ...conducted in 27 tertiary-care centers from January 2009 to August 2012. The primary end-point was 14-day survival, and the secondary end-points were clinical and microbiological outcomes. Thirty-six and 214 patients 102 (47.7 %): colistin–carbapenem (CC), 69 (32.2 %): colistin–sulbactam (CS), and 43 (20.1 %: tigecycline): colistin with other agent (CO) received colistin monotherapy and colistin-based combinations, respectively. Rates of complete response/cure and 14-day survival were relatively higher, and microbiological eradication was significantly higher in the combination group. Also, the in-hospital mortality rate was significantly lower in the combination group. No significant difference was found in the clinical (
p
= 0.97) and microbiological (
p
= 0.92) outcomes and 14-day survival rates (
p
= 0.79) between the three combination groups. Neither the timing of initial effective treatment nor the presence of any concomitant infection was significant between the three groups (
p
> 0.05) and also for 14-day survival (
p
> 0.05). Higher Pitt bacteremia score (PBS), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Charlson comorbidity index (CCI), and prolonged hospital and intensive care unit (ICU) stay before XDR-ABSI were significant risk factors for 14-day mortality (
p
= 0.02,
p
= 0.0001,
p
= 0.0001,
p
= 0.02, and
p
= 0.01, respectively). In the multivariable analysis, PBS, age, and duration of ICU stay were independent risk factors for 14-day mortality (
p
< 0.0001,
p
< 0.0001, and
p
= 0.001, respectively). Colistin-based combination therapy resulted in significantly higher microbiological eradication rates, relatively higher cure and 14-day survival rates, and lower in-hospital mortality compared to colistin monotherapy. CC, CS, and CO combinations for XDR-ABSI did not reveal significant differences with respect to 14-day survival and clinical or microbiological outcome before and after propensity score matching (PSM). PBS, age, and length of ICU stay were independent risk factors for 14-day mortality.
The aim of this study was to determine the independent risk factors, morbidity, and mortality of central nervous system (CNS) infections caused by
Listeria monocytogenes
. We retrospectively ...evaluated 100 episodes of neuroinvasive listeriosis in a multinational study in 21 tertiary care hospitals of Turkey, France, and Italy from 1990 to 2014. The mean age of the patients was 57 years (range, 19–92 years), and 64% were males. The all-cause immunosuppression rate was 54 % (54/100). Forty-nine (49 %) patients were referred to a hospital because of the classical triad of symptoms (fever, nuchal rigidity, and altered level of consciousness). Rhombencephalitis was detected radiologically in 9 (9 %) cases. Twenty-seven (64 %) of the patients who had cranial magnetic resonance imaging (MRI) performed had findings of meningeal and parenchymal involvement. The mean delay in the initiation of specific treatment was 6.8 ± 7 days. Empiric treatment was appropriate in 52 (52 %) patients. The mortality rate was 25 %, while neurologic sequelae occurred in 13 % of the patients. In the multivariate analysis, delay in treatment odds ratio (OR), 1.07 95 % confidence interval (CI), 1.01–1.16 and seizures (OR, 3.41 95 % CI, 1.05–11.09) were significantly associated with mortality. Independent risk factors for neurologic sequelae were delay in treatment (OR, 1.07 95 % CI, 1.006–1.367) and presence of bacteremia (OR, 45.2 95 % CI, 2.73–748.1). Delay in the initiation of treatment of neuroinvasive listeriosis was a poor risk factor for unfavorable outcomes. Bacteremia was one of the independent risk factors for morbidity, while the presence of seizures predicted worse prognosis. Moreover, the addition of aminoglycosides to ampicillin monotherapy did not improve patients’ prognosis.
Cryptococcal meningitis (CM) is mostly seen in immunocompromised patients, particularly human immunodeficiency virus (HIV)-positive patients, but CM may also occur in apparently immunocompetent ...individuals. Outcome analyses have been performed in such patients but, due to the high prevalence of HIV infection worldwide, CM patients today may be admitted to hospitals with unknown HIV status, particularly in underdeveloped countries. The objective of this multicenter study was to analyze all types of CM cases in an aggregate cohort to disclose unfavorable outcomes. We retrospectively reviewed the hospitalized CM patients from 2000 to 2015 in 26 medical centers from 11 countries. Demographics, clinical, microbiological, radiological, therapeutic data, and outcomes were included. Death, neurological sequelae, or relapse were unfavorable outcomes. Seventy (43.8%) out of 160 study cases were identified as unfavorable and 104 (65%) were HIV infected. On multivariate analysis, the higher Glasgow Coma Scale (GCS) scores (
p
= 0.021), cerebrospinal fluid (CSF) leukocyte counts > 20 (
p
= 0.038), and higher CSF glucose levels (
p
= 0.048) were associated with favorable outcomes. On the other hand, malignancy (
p
= 0.026) was associated with poor outcomes. Although all CM patients require prompt and rational fungal management, those with significant risks for poor outcomes need to be closely monitored.
In low- and middle-income countries (LMICs), the burden of healthcare-associated infections (HCAIs) is not known due to a lack of national surveillance systems, standardized infection definitions, ...and paucity of infection prevention and control (IPC) organizations and legal infrastructure.
To determine the status of IPC bundle practice and the most frequent interventional variables in LMICs.
A questionnaire was emailed to Infectious Diseases International Research Initiative (ID-IRI) Group Members and dedicated IPC doctors working in LMICs to examine self-reported practices/policies regarding IPC bundles. Responding country incomes were classified by World Bank definitions into low, middle, and high. Comparison of LMIC results was then made to a control group of high-income countries (HICs).
This survey reports practices from one low-income country (LIC), 16 middle-income countries (MICs) (13 European), compared to eight high-income countries (HICs). Eighteen (95%) MICs had an IPC committee in their hospital, 12 (63.2%) had an annual agreed programme and produced an HCAI report. Annual agreed programmes (87.5% vs 63.2%, respectively) and an annual HCAI report (75.0% vs 63.2%, respectively) were more common in HICs than MICs. All HICs had at least one invasive device-related surveillance programme. Seven (37%) MICs had no invasive device-related surveillance programme, six (32%) had no ventilator-associated pneumonia prevention bundles, seven (37%) had no catheter-associated urinary tract infection prevention bundles, and five (27%) had no central line-associated bloodstream infection prevention bundles.
LMICs need to develop their own bundles with low-cost and high-level-of-evidence variables adapted to the limited resources, with further validation in reducing infection rates.
Methicillin-resistant
Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide, and MRSA infections are frequent in intensive ...care units (ICUs).
A prospective study was implemented to investigate the risk factors for ICU-acquired MRSA infections.
This study was conducted in surgical and neurologic ICUs from May to November 2003. The patients staying in ICUs more than 48 hours were included in the study. All of the patients were visited daily, and data were recorded on individual forms for each patient until discharge or death. Nasal swab cultures were done within 48 hours of ICU admission and repeated every week until the patients colonized with MRSA or were discharged from ICUs. ICU-acquired MRSA infection was diagnosed when MRSA was isolated from the infected site.
Overall, 249 patients were followed during the study. MRSA infection was detected in 21 (8.4%) of these patients. The most frequent infection was primary bloodstream infection (10/21, 47%). It was followed by pneumonia (8/21, 38%) and surgical site infection (3/21, 14%). Nasal MRSA colonization was detected in 59 (23.7%) patients, and 12 of them (20.3%) developed MRSA infection. In univariate analysis, hospitalization period in an ICU, intraabdominal and orthopedic pathologies, mechanical ventilation, central venous catheter insertion, total parenteral nutrition, previous antibiotic use, surgical ICU stay, nasal MRSA colonization, and presence of more than 2 patients having nasal colonization in the same ICU at the same time were found significant for MRSA infections. In multivariate analysis; hospitalization period in an ICU (OR, 1.090; 95% CI: 1.038-1.144,
P = .001), central venous catheter insertion (OR, 1.822; 95% CI: 1.095-3.033,
P = .021), previous antibiotic use (OR, 2.337; 95% CI: 1.326-4.119,
P = .003) and presence of more than 2 patients having nasal colonization in the same ICU at the same time (OR, 1.398; 95% CI: 1.020-1.917,
P = .037) were independently associated with MRSA infections.
According to the our results, hospitalization period in an ICU, presence of patients colonized with MRSA in the same ICU at the same time, previous antibiotic use, and central venous catheter insertion are independent risk factors for ICU-acquired MRSA infections. Detection of these factors helps to decrease the rate of MRSA infections in the ICUs.
This study was performed to compare the mortality associated with carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem sensitive A. baumannii (CSAB) infections, to identify potential ...risk factors for CRAB infections, and to investigate the effects of potential risk factors on mortality in CRAB and CSAB patients. This retrospective case-control study was conducted in a university hospital between January 1, 2005 and December 30, 2006. One hundred and ten patients with CRAB and 55 patients with CSAB infection were identified during the study period. The mortality rate was 61.8% and 52.7% in CRAB and CSAB cases, respectively (P = 0.341). In CRAB cases, the risk factors for mortality were identified as intubation (odds ratio OR, 3.3; 95% confidence interval CI, 1.0–10.1; P = 0.042) and high APACHE II score (OR, 1.2; 95% CI, 1.1–1.3; P = 0.000), by multivariate analysis. Previous use of carbapenem (OR, 6.1; 95% CI, 2.2–17.1; P = 0.001) or aminopenicillin (OR, 2.5; 95% CI, 1.2–5.1; P = 0.013) were independently associated with carbapenem resistance. Although the mortality rate was higher among patients with CRAB infections, this difference was not found to be statistically significant. Previous use of carbapenem and aminopenicillin were found to be independent risk factors for infections with CRAB.
Objective Empirical beta-lactam monotherapy has become the standard therapy in febrile neutropenia. The aim of this study was to compare the efficacy and safety of piperacillin–tazobactam versus ...carbapenem therapy with or without amikacin in adult patients with febrile neutropenia. Methods In this prospective, open, single-center study, 127 episodes were randomized to receive either piperacillin–tazobactam (4 × 4.5 g IV/day) or carbapenem meropenem (3 × 1 g IV/day) or imipenem (4 × 500 mg IV/day) with or without amikacin (1 g IV/day). Doses were adjusted according to renal function. Clinical response was determined during and at completion of therapy. Results One hundred and twenty episodes were assessable for efficacy (59 piperacillin–tazobactam, 61 carbapenem). Mean duration of treatment was 14.8 ± 9.6 days in the piperacillin–tazobactam group and 14.7 ± 8.8 days in the carbapenem group (P > 0.05). Mean days of fever resolution were 5.97 and 4.48 days for piperacillin–tazobactam and carbapenem groups, respectively (P > 0.05). Similar rates of success without modification were found in the piperacillin–tazobactam (87.9%) and in the carbapenem groups (75.4%; P > 0.05). Fungal infection occurrence rates were 30.5 and 18% in piperacillin–tazobactam and carbapenem groups, respectively (P = 0.05). Antibiotic modification rates were 30.5 and 13.1% (P = 0.02) and the addition of glycopeptides to empirical antibiotic regimens rates were 15.3 and 44.3% for piperacillin–tazobactam and carbapenem groups, respectively (P = 0.001). The rude mortality rates were 14% (6/43) and 29.3% (12/41) in piperacillin–tazobactam and carbapenem groups, respectively (P = 0.08). Conclusions The effect of empirical regimen of piperacillin–tazobactam regimen is equivalent to carbapenem in adult febrile neutropenic patients.
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