Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy
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J. Infect. Chemother. · Jan 2015
Acinetobacter baumannii escape from neutrophil extracellular traps (NETs).
Acinetobacter baumannii and Pseudomonas aeruginosa are the same aerobic gram-negative bacillus and are usually harmless but cause infectious diseases in compromised hosts. Neutrophils play a critical role in infective protection against the extracellular growth of bacteria. Recently, a new biological defense mechanism called neutrophil extracellular traps (NETs) has been attracting attention. ⋯ In addition, we measured expression of myeloperoxidase (MPO), reactive oxygen species (ROS) and superoxide in neutrophils, and we found that these expression in P. aeruginosa-stimulated neutrophils was stronger than that in A. baumannii-stimulated neutrophils. Furthermore, A. baumannii was not killed by neutrophils, in contrast to P. aeruginosa. In this study, we show that the reactivity of neutrophils and their biological defense mechanism are different between A. baumannii and P. aeruginosa, which is important for understanding the pathogenicity of these bacteria.
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J. Infect. Chemother. · Oct 2014
Observational StudyRisk factors for ventilator-associated pneumonia in neonatal intensive care unit patients.
Ventilator-associated pneumonia (VAP) is a serious complication in neonatal patients on mechanical ventilation. The objective of this study was to examine the incidence and risk factors associated with VAP, particularly in every 7-day versus every 14-day ventilator circuit changes, in a neonatal intensive care unit (NICU). Seventy-one neonates hospitalized in the NICU were enrolled. ⋯ Second, to examine the effect of the frequency of changing ventilator circuits on the incidence of VAP, circuit changes were compared between the every 7-day group and the every 14-day group. The incidence of VAP per 1000 ventilator days was 9.66 for the every 7-day group and 8.08 for the every 14-day group, and there was no significant difference between the 2 groups. BW <626 g was a significant independent predictor of VAP, and decreasing the frequency of ventilator circuit changes from every 7 days to 14 days had no adverse effect on the VAP rate in the NICU.
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J. Infect. Chemother. · Oct 2014
Treatment outcomes of refractory MAC pulmonary disease treated with drugs with unclear efficacy.
We aimed to investigate the treatment outcomes of patients with refractory Mycobacterium avium complex (MAC) lung disease treated with regimens containing drugs with unclear efficacy. Of all patients diagnosed with MAC lung disease between April 2004 and September 2012 at a tertiary referral center in South Korea, the outcomes of 51 patients treated with regimens containing drugs with unclear efficacy (clofazimine, moxifloxacin, rifabutin, and linezolid) because of treatment failure after receiving standard treatment were retrospectively analyzed. The mean age (standard deviation) of the 51 patients was 59.0 (10.3) years and 29 (56.9%) were male. ⋯ Overall, 8 patients (15.7%) had a favorable response. Treatment outcomes did not differ by drug regimen or even by the combination of more than 2 drugs. The treatment outcomes of patients with refractory MAC lung disease were unsatisfactory with regimens containing possibly effective drugs such as clofazimine, moxifloxacin, rifabutin and linezolid.
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J. Infect. Chemother. · Oct 2014
The utility of biomarkers in differentiating bacterial from non-bacterial lower respiratory tract infection in hospitalized children: difference of the diagnostic performance between acute pneumonia and bronchitis.
The aim of this study is to investigate the utility of several biomarkers in differentiating bacterial community-acquired lower respiratory tract infection (CA-LRTI) from non-bacterial CA-LRTI in children and the difference of their diagnostic performance between pneumonia and bronchitis. A retrospective cohort study composed of 108 pediatric patients hospitalized for CA-LRTI was performed during 2010-2013. Based on the findings of chest X-ray and sputum samples, patients were divided into 4 categories, group of bacterial pneumonia or bronchitis, and non-bacterial (viral or etiology-unknown) pneumonia or bronchitis. ⋯ On the other hand, in the patients with bronchitis, neutrophil count was significantly decreased in non-bacterial bronchitis whereas no significant differences of WBC count, CRP level or PCT level were seen. In conclusion, PCT was the most useful marker to differentiate bacterial pneumonia whereas neutrophil count contributed most to the discrimination of bacterial bronchitis. The diagnostic performance of biomarkers may be different between pneumonia and bronchitis.
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J. Infect. Chemother. · Sep 2014
Case ReportsClinical characteristics of Raoultella ornithinolytica bacteremia: a case series and literature review.
Raoultella ornithinolytica is a rare pathogen in human infection and bacteremic cases had been scarcely reported. For further comprehension of the rare infection, we summarized clinical characteristics of 6 cases that were detected at our medical facility and 5 cases from previous literature. ⋯ The prognosis of the patients was quite satisfactory. Bacterial identification in this report was performed on the basis of biochemical tests alone, and further investigations by molecular analysis are required to confirm our findings.