Prevalence and clinical prognosis of heteroresistant vancomycin-intermediate Staphylococcus aureus in a tertiary care center in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The emergence of heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) is increasingly challenging the methods for detection in diagnostic microbiology laboratories. However, the report of hVISA is rare in China. This study summarizes the prevalence and clinical features associated with hVISA infections at our institution and the local impact they have on clinical outcome.</p><p><b>METHODS</b>A total of 122 methicillin-resistant Staphylococcus aureus (MRSA) isolates which were of the causative pathogens were collected. One hundred and two patients for whom we had full information of MRSA pneumonia were included. Isolates of MRSA were collected using PCR to detect the mecA gene. Both Etest and macro Etest were performed to screen for hVISA. The Staphylococcal chromosome cassette mec (SCCmec) types were determined by multiplex PCR strategy. Logistic regression analysis was used to determine the risk factors.</p><p><b>RESULTS</b>Among the 122 MRSA isolates collected, 25 (20.5%) strains were identified as hVISA. There were 119 (97.5%) SCCmec III isolates, two (1.6%) SCCmec II isolates, and one (0.8%) SCCmec V isolate. The 30-day mortality of MRSA-hospital acquired pneumonia (HAP) was 37.3%, and 62.5% for hVISA-HAP. Vancomycin treatment was the independent risk factor of hVISA. Factors independently associated with 30-day mortality in all patients were acute physiology and Chronic Health Evaluation (APACHE) II score >20, multiple lobe lesions, and creatinine clearance rate (CCR) < 15 ml/min.</p><p><b>CONCLUSIONS</b>The prevalence of hVISA is 20.5% at our institution. hVISA-HAP patients had a poor clinical outcome. Vancomycin treatment was the independent predictors for hVISA infection. Factors independently associated with 30-day mortality in all patients were APACHE II score > 20, multiple lobe lesions and CCR < 15 ml/min.</p>

Nosocomial spread of hospital-adapted CC17 vancomycin-resistant Enterococcus faecium in a tertiary-care hospital of Beijing, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The incidence of vancomycin-resistant enterococci (VRE) appeared to be increasing in China, but very few nosocomial outbreaks have been reported. Our hospital had experienced an outbreak of VRE since March 2008 to March 2009. The objective of this study was to analyze the molecular features of the isolates and the control measures used to eradicate a VRE outbreak in a tertiary institution in China.</p><p><b>METHODS</b>We characterized VRE isolates from 21 infected and 11 colonized inpatients from a single hospital by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), the analysis of Tn1546-like elements and virulence genes detection. Infection control measures, including more environmental disinfection, screening for VRE colonization, contact precautions, education and strict antibiotic restriction, were implemented to control the outbreak.</p><p><b>RESULTS</b>During the outbreak, a total of 32 VRE strains were obtained. There were 21 strains found in Emergency Intensive Care Unit (EICU), 9 isolates from Geriatric Ward, and two from other units. All the isolates harbored the vanA gene, however, four of them exhibited the VanB phenotype. Meanwhile, MLST analysis revealed that all isolates belonged to clonal complex (CC) 17. With the infection-control measures, the epidemic was constrained in two units (EICU and Geriatric Ward). After March 2009, no further case infected with VRE was detected in the following one-year period.</p><p><b>CONCLUSION</b>The outbreak was controlled by continuous implementation of the infection control programme, and more rigorous infection control policy is needed.</p>

Hospital-acquired clostridium difficile-associated diarrhea / 中国医学科学院学报

Clostridium difficile-associated diarrhea (CDAD) is common among hospital-acquired bacterial diarrhea, its mortality and morbidity show an increasing trend in recent years. Improper antimicrobial drug use is one of the key reasons. Adequate hand hygiene of healthcare workers, thorough disinfection of hospital environment, and appropriate isolation of patients are effective measures to prevent the outbreak of hospital-aquired CDAD.

Changes of pathogens and susceptibility to antibiotics in hematology ward from years 2001 to 2005 / 中国实验血液学杂志

The purpose of this study was to determine the changes of pathogens in hematological ward and susceptibility of patients received chemotherapy to antibiotics. The pathogens were taken from blood, urine and sputum of patients who accepted chemotherapy from years 2001 to 2005, then were isolated and identified. The susceptibility test was performed by disk diffusion method. The results showed that the total of 418 strains were detected. Gram-negative bacteria were the most common of nosocomial infection. Pseudomonas aeruginosa, Enterobacter cloacae, E. coli account for the most of Gram negative- bacteria infection and most resistant to broad-spectrum penicillin, Acinetobacter baumannii showed a trend of increase. The ratios of gram positive bacteria and fungi were increased slowly, mainly as Enterococcus and Candida. Enterococcus is the most common cause of Gram-positive bacterial infection. Vancomycin resistance did not occur. It is concluded that Gram-negative bacteria are main cause of nosocomial infection in patients with hematological malignancies. Gram positive bacteria and fungi had been more frequent. Strains resistant to antimicrobial agents increase.