With beta-lactam drugs and immunosuppressants widely used, the infection caused by Acinetobacter baumannfi （Ab） has become more and more serious with multidrug resistant Acinetobacter baumannfi （MDRAb） emerging an...With beta-lactam drugs and immunosuppressants widely used, the infection caused by Acinetobacter baumannfi （Ab） has become more and more serious with multidrug resistant Acinetobacter baumannfi （MDRAb） emerging and worsening rapidly. Compared with other patients, the incidence and multidrug resistance of MDRAb are higher in children in pediatric intensive care unit （PICU） because of immune deficiency, severe basic diseases, prolonged hospitalization and invasive operations. Hence it is significant to study the epidemiology and changes of antibacterial susceptibility in order to reduce the incidence of MDRAb in children. A total 115 patients with MDRAb pneumonia and 45 patients with negative MDRAb （NMDRAb） pneumonia who had been treated from January 2009 to August 2011 were studied retrospectively at the PICU of Wuhan Children＇s Hospital. Clinical data were analyzed with univariate and multivariate Logistic regression. In 176 clinical strains of Acinetobacter baumannfi isolated, there were 128 strains of MDRAb, accounting for 72.73%. Drug susceptibility tests showed that the resistance rates of 13-1actam antibiotics were more than 70% except for cefoperazone sulbactam. The rates to carbapenems were higher than 90%. They were significantly higher than those of NMDRAb. Amikacin, levofloxacin, ciprofloxacin and minocycline had the lowest drug-resistance rates （〈20%）. Multivariate Logistic regression revealed that ICU stay, the time of mechanical ventilation, anemia, hypoproteinemia and the use of carbapenems were independent risk factors for MDRAb pneumonia. MDRAb is an important opportunistic pathogen to pneumonia in PICU, and its drug-resistance is severe. It increases significantly the mortality of patients. It is important to take the effective prevention measures for controlling it.展开更多
Objective:To determine the risk factors and outcomes of imipenem-resistant Acinetobacter baumannii(IRAB) bloodstream infection(BSI) cases,since there is very little publication on Aeinetobacter baumannii infections fr...Objective:To determine the risk factors and outcomes of imipenem-resistant Acinetobacter baumannii(IRAB) bloodstream infection(BSI) cases,since there is very little publication on Aeinetobacter baumannii infections from Malaysia.Methods:A cross sectional study of 41 cases(73.2%) of imipenem-sensitive Acinetobacter baumanii(ISAB) and 15 cases(26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia.Results:There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days[OR 1.23(95%CI 1.01,1.50)].Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group,statistically they were not significant.There was no significant difference in term of outcomes between the two groups.Conclusions:Although statistically not significant,this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects.展开更多
Background Multidrug-resistant Acinetobacter baumannii （MDRAB） is an important and emerging hospital-acquired pathogen worldwide. This study was conducted to identify the sources of MDRAB and its role in respiratory...Background Multidrug-resistant Acinetobacter baumannii （MDRAB） is an important and emerging hospital-acquired pathogen worldwide. This study was conducted to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit （ICU） patients. Methods We conducted a prospective active surveillance study of MDRAB in three ICUs at a Chinese Hospital from April to August 2011, to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia. Results One hundred and fourteen （13.0%） MDRAB isolates were detected from 876 specimens, with a sensitivity of 11.6% （55/474） in screening of the pharyngeal and tracheal swabs, and 14.7% （59/402） of the sputum/endotracheal aspirates. MDRAB colonization/infection was found in 34 （26.8%） of 127 patients, including 16 （12.6%） cases of pure colonization and 18 （14.2%） cases of pneumonia （two pre-ICU-acquired cases of pneumonia and 16 ICU-acquired cases of pneumonia）. Previous respiratory tract MDRAB colonization was found in 22 （17.3%） patients： eight （6.3%） were pre-ICU-acquired colonization and 14 （11.0%）ICU-acquired colonization. Of eight pre-ICU-colonized patients, five were transferred from other wards or hospitals with hospitalization 〉72 hours, and three came from the community with no previous hospitalization. Overall, 6/22 colonized patients presented with secondary pneumonia; only two （9.1%） colonized MDRAB strains were associated with secondary infections. Respiratory tract MDRAB colonization had no significant relationship with nosocomial pneumonia （P=0.725）. In addition, acute respiratory failure, mechanical ventilation, renal failure, and prior carbapenem use were risk factors for MDRAB colonization/infection. Conclusions A high proportion of cases of MDRAB colonization/infection in ICU patients were detected through screening cultures. About one-third were acquired from general wards and the community before ICU admission. The low incidence of MDRAB colonization-related pneumonia questions the appropriateness of targeted antibiotic therapy.展开更多
Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B ...Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.展开更多
文摘With beta-lactam drugs and immunosuppressants widely used, the infection caused by Acinetobacter baumannfi （Ab） has become more and more serious with multidrug resistant Acinetobacter baumannfi （MDRAb） emerging and worsening rapidly. Compared with other patients, the incidence and multidrug resistance of MDRAb are higher in children in pediatric intensive care unit （PICU） because of immune deficiency, severe basic diseases, prolonged hospitalization and invasive operations. Hence it is significant to study the epidemiology and changes of antibacterial susceptibility in order to reduce the incidence of MDRAb in children. A total 115 patients with MDRAb pneumonia and 45 patients with negative MDRAb （NMDRAb） pneumonia who had been treated from January 2009 to August 2011 were studied retrospectively at the PICU of Wuhan Children＇s Hospital. Clinical data were analyzed with univariate and multivariate Logistic regression. In 176 clinical strains of Acinetobacter baumannfi isolated, there were 128 strains of MDRAb, accounting for 72.73%. Drug susceptibility tests showed that the resistance rates of 13-1actam antibiotics were more than 70% except for cefoperazone sulbactam. The rates to carbapenems were higher than 90%. They were significantly higher than those of NMDRAb. Amikacin, levofloxacin, ciprofloxacin and minocycline had the lowest drug-resistance rates （〈20%）. Multivariate Logistic regression revealed that ICU stay, the time of mechanical ventilation, anemia, hypoproteinemia and the use of carbapenems were independent risk factors for MDRAb pneumonia. MDRAb is an important opportunistic pathogen to pneumonia in PICU, and its drug-resistance is severe. It increases significantly the mortality of patients. It is important to take the effective prevention measures for controlling it.
基金Supported by Universiti Sains Malaysia(No:304/PPSP/6131378)
文摘Objective:To determine the risk factors and outcomes of imipenem-resistant Acinetobacter baumannii(IRAB) bloodstream infection(BSI) cases,since there is very little publication on Aeinetobacter baumannii infections from Malaysia.Methods:A cross sectional study of 41 cases(73.2%) of imipenem-sensitive Acinetobacter baumanii(ISAB) and 15 cases(26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia.Results:There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days[OR 1.23(95%CI 1.01,1.50)].Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group,statistically they were not significant.There was no significant difference in term of outcomes between the two groups.Conclusions:Although statistically not significant,this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects.
文摘Background Multidrug-resistant Acinetobacter baumannii （MDRAB） is an important and emerging hospital-acquired pathogen worldwide. This study was conducted to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit （ICU） patients. Methods We conducted a prospective active surveillance study of MDRAB in three ICUs at a Chinese Hospital from April to August 2011, to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia. Results One hundred and fourteen （13.0%） MDRAB isolates were detected from 876 specimens, with a sensitivity of 11.6% （55/474） in screening of the pharyngeal and tracheal swabs, and 14.7% （59/402） of the sputum/endotracheal aspirates. MDRAB colonization/infection was found in 34 （26.8%） of 127 patients, including 16 （12.6%） cases of pure colonization and 18 （14.2%） cases of pneumonia （two pre-ICU-acquired cases of pneumonia and 16 ICU-acquired cases of pneumonia）. Previous respiratory tract MDRAB colonization was found in 22 （17.3%） patients： eight （6.3%） were pre-ICU-acquired colonization and 14 （11.0%）ICU-acquired colonization. Of eight pre-ICU-colonized patients, five were transferred from other wards or hospitals with hospitalization 〉72 hours, and three came from the community with no previous hospitalization. Overall, 6/22 colonized patients presented with secondary pneumonia; only two （9.1%） colonized MDRAB strains were associated with secondary infections. Respiratory tract MDRAB colonization had no significant relationship with nosocomial pneumonia （P=0.725）. In addition, acute respiratory failure, mechanical ventilation, renal failure, and prior carbapenem use were risk factors for MDRAB colonization/infection. Conclusions A high proportion of cases of MDRAB colonization/infection in ICU patients were detected through screening cultures. About one-third were acquired from general wards and the community before ICU admission. The low incidence of MDRAB colonization-related pneumonia questions the appropriateness of targeted antibiotic therapy.
基金supported by the National Key Research and Development Program of China (2017YFC1600100 and2017YFC1200203)the National Natural Science Foundation of China (81702040)the National Science Foundation of Zhejiang Province,China (LY20H190002)
文摘Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.
