As the most common pathogen for healthcare -associated infection in European and American countries, Clostridium difficile has become increasingly popular in China and has posed a great threat to public health.Based on evidences retrieved from the PubMed and CNKI databases , this article reviews biological characters and dissemination patterns of C.difficile, epidemiology, burden and risk factors of C.difficile infection, and the surveillance, contact precaution, hand hygiene, antimicrobial stewardship, environment cleaning, use of probiotics and vaccine for the prevention of C.difficile infection.

Objective To understand the impact of methicillin-resistant Staphylococcus aureus (MRSA)blood-stream infection on the length of hospital stay,hospital mortality,and poor prognosis of patients.Methods 357 patients with Staphylococcus aureus (S .aureus)bacteremia in a hospital between January 1 ,2009 and December 31 , 2013 were surveyed and analyzed retrospectively.Results Of 357 patients,91 were infected with MRSA and 266 with methicillin-susceptible S .aureus (MSSA).The length of hospital stay was statistically different between MR-SA and MSSA group(29 d vs 23 d,P <0.01);before infection,length of hospital stay of MRSA group was longer than MSSA group(P <0.01 );after infection,length of hospital stay was not statistically different between two groups(17 d vs 16.5 d,P = 0.92 ).Mortality of MRSA group and MSSA group was not statistically different (13.19% vs 9.02%,χ2 =1 .28,P =0.26).The incidence of poor prognosis of MRSA group was higher than MSSA group(29.67% vs 16.92%,χ2 =6.85,P =0.01 ).Multivariate analysis results showed that MRSA infection was independent risk factor for poor prognosis (P <0.01).Conclusion MRSA infection doesn’t contribute to the pro-longation of hospital stay,but MRSA bloodstream infection is a risk factor for poor prognosis of patients.

Objective To explore the risk factors and prognosis of hospitalized patients with bloodstream infection due to carbapenem-resistant Acinetobacter baumannii (CRAB).Methods 163 patients with CRAB bloodstream in-fection from 2010 to 2013 were conducted retrospective case-control study,68 patients with bloodstream infection due to carbapenem-susceptible Acinetobacter baumannii (CSAB)during the same period were as control group. Results The independent risk factors for CRAB bloodstream infection were stay in intensive care unit(ICU)(OR, 1 .27[95%CI ,5.55-22.89])and emergency department(OR,3.57 [95%CI ,1 .67 -7.62])before infection.Pa-tients with CRAB bloodstream infection had lower 28-day survival rate than those with CSAB bloodstream infection (66.17% vs 96.95%,χ2 =15.71 ,P <0.001 ).The independent risk factors for influencing prognosis of Acineto-bacter baumannii bloodstream infection were infection of CRAB (HR 95% CI ,3.01 -67.28),blood disease(HR 95%CI ,3.77-25.97),cardiac insufficiency(HR 95%CI ,2.10-20.41),stay in ICU(HR 95%CI ,1 .01 -5.28), and age(HR 95%CI ,1 .01 -1 .04).Conclusion The independent risk factors for CRAB bloodstream infection are stay in ICU and emergency department before infection,CRAB bloodstream infection is risk factor for influencing prognosis of patients.

Objective To investigate the incidence of healthcare-associated infection (HAI)in patients in a respiratory in-tensive care unit (RICU)of a teaching hospital,and provide reference for HAI prevention and control.Methods All pa-tients admitted to this RICU from January to December 2014 were surveyed with prospective targeted monitoring method, surveyed data were analyzed statistically.Results A total of 561 patients were surveyed,43 patients developed 44 times HAI,HAI rate and HAI case rate were 7.66% and 7.84% respectively,incidence of HAI and adjusted incidence of HAI per 1 000 patient-days were 6.26‰ and 1.79‰ respectively.The main infection site was urinary tract (45.46%,n=20). Incidence of ventilator-associated pneumonia (VAP ),catheter-related bloodstream infection (CRBSI),and catheter-associat-ed urinary tract infection (CAUTI)per 1 000 catheter-days were 2.73‰(n=13),1.57‰(n=2),and 3.78‰(n=18)re-spectively.Incidence of HAI per 1 000 patient-days between the first and second half year of 2014 was significantly differ-ent(4.59‰ vs 7.89‰;u=-1.75,P =0.04).A total of 47 pathogenic strains were isolated,the main pathogens were gram-negative bacteria(n=26,55.32%).Conclusion The major HAI in RICU is device-associated infection,it is necessary to strengthen the management of invasive procedures;targeted monitoring can find the weak links of infection control prac-tice and helpful for taking effective prevention and control measures to reduce the incidence of HAI in ICU.

Objective To monitor ventilator-associated event (VAE) for the first time in an intensive care unit (ICU) in China,understand the applicability,incidence,and clinical significance of VAE in China.Methods Targeted monitoring on VAE was performed among patients ≥18 years and with mechanical ventilation (MV)＞2 days in the ICU of a hospital between January 2014 and September 2015,incidence of VAE was calculated,and patients were grouped according to whether or not they had VAE,prognostic factors were analyzed statistically.Results A total of 1 004 patients were monitored,the total hospital stay was 13 795 days in patients who used ventilator,307 (30.58％) cases of VAE occurred,incidence of VAE per 1 000 ventilator-days was 22.25.Univariate analysis showed that patients with VAE had longer length of ICU stay and MV,and higher mortality rate than patients without VAE when they moved out of ICU (all P＜0.05).Multivariate logistic regression analysis showed that VAE was independent risk factor for length of ICU stay,duration of MV,as well as mortality when patients moved out of ICU(all P＜0.05).Conclusion Judgment of VAE is based on MV parameters,it is more objective and accurate.There is a high incidence of VAE among ICU patients,it may lead to poor clinical outcomes,and has good values for the targeted monitoring on ICU patients in large comprehensive hospitals of China.

Objective To explore strategies and measures to improve hand hygiene (HH)compliance and correctness of health care workers (HCWs)in a large hospital.Methods The WHO multimodal hand hygiene improvement strategy was adopted by healthcare-associated infection(HAI)management department of a hospital,measures consisted of five key com-ponents,including:system change,education and training,evaluation and feedback,reminders in the workplace,and insti-tutional safety climate.HH compliance and correctness of HCWs were observed by infection control practitioners,HH compliance and correctness in January-June of 2012 (pre-intervention)and January-June of 2014 (post-intervention)were compared,effectiveness of intervention strategies were evaluated.Results HH compliance rate and correctness rate of post-intervention were both higher than pre-intervention (75.92% [8 369/11 023]vs 53.67% [5 127/9 553],P <0.001;94.11%[7 782/8 269]vs 83.88%[3 642/4 342],P <0.001).Of different occupations,HH compliance rates of doctors and nurses were significantly different before and after intervention (both P <0.001),while workers and staff of other oc-cupations before and after intervention were not significantly different(both P >0.05).Except ‘after body fluid exposure’, HH compliance rates of the other four indications for HH before and after intervention were significantly different(all P <0.001).Conclusion HH compliance and correctness of HCWs can be improved after adopting WHO multimodal hand hy-giene improvement strategy.

Objective To study the effects of efflux pump inhibitors(CCCP and PAβN)on carbapenems in Pseudomonas aernginosa(P.aeruginosa)clinical isolates and investigate the association between the resistance to imipenem or meropenem and expression levels of efflux pumps of P.aeruginosa.Methods MICs of imipenem or meropenem combined with efflux pump inhibitors including carbonyl cyanide m-chlorophenylhydrazone(CCCP,107 strains)and Phe-Arg-β-naphthylamide(PAβN,71 strains)against imipenem-resistant strains were determined by agar dilution method,and changes of MICs were observed.For 32 strains with different resistant phenotypes to imipenem and meropenem,the mRNA expression levels of three efflux pump genes(mexA,mexD and mexF)were quantified by real time fluorescent quantitative PCR.Results The resistance rate of imipenem and meropenem didn't prove any significant difference in the presence of efflux pump inhibitors.The X2 value of imipenem combined with CCCP and PAβN were 0.338 and 0.086,respectively(P＞0.05),while that of meropenem combined with CCCP and PAβN were 1.065 and 1.458(P＞0.05).No significant in MICs of carbapenems were seen in over half of P. aeruginesa isolates. MICs of carbapenems was significantly downregulated for 4-fold or above in eight isolates. Overexpression of efflux pumps genes were present in 24 of 27 carbapenem-resistant isolates(88. 9% ). Efflux pumps genes including MexAB-OprM, MexCD-OprJ and MexEF-OprN were all overexpressed in 13 isolates,constituting 54. 2% of all carbapenem-resistant isolates. There were 3 isolates in which beth MexAB-OprM and MexCD-OprJ showed overexpression,constituting 12. 5%. Also,MexAB-OprM and MexEF-OprN overexpressed in 3 isolates. There were 2 isolates (8.3%) showing MexEF-OprN overexpression and MexAB-OprM alone. MexCD-OprJ didn't showed overexpression alone. Furthermore,the expression levels of efflux pumps genes mexA,mexD and mexF in isolates susceptible to both in imipenem and meropenem were 0. 48±0. 48,0. 48±0. 53 and 0. 30±0. 41,respectively,which were much lower than that in carbapenem-resistant ones (P＜0. 05 ). MexA gene was expressed at a higher level in meropenemresistant isolates than meropenem-susceptible ones (P＜0. 05 ). Conclusions When the concentration of CCCP and PAβN were 5 μg/ml and 20 μg/ml respectively,the efforts on the carhapenems resistance of P.aeruginosa were small Overexpression of MexAB-OprM might play an important role in meropenemresistance in P. aerugines. Overexpression of MexCD-OprJ and MexEF-OprN was associated with imipenemresistance. However,the relationship between them and meropenem-resistance need to be explored in the future.

OBJECTIVE:To establish HPLC fingerprints of taproot and rhizome of Paenoia lactiflora,and to compare the similarity and difference of them.METHODS:The determination was performed on Phenomenex C18 column with mobile phase consisted of acetonitrile-0.1％ phosphoric acid (gradient elution) at the flow rate of 1.0 mL/min.The detection wavelength was set at 230 nm,and column temperature was 30 ℃.The sample size was 10 tL.Using paeoniflorin as reference,HPLC chromatograms of the taproot and rhizome of P lactiflora were established.Common peak identification and similarity evaluation were performed by using TCM Chromatogram Fingerprint Similarity Evaluation System (2012 edition).RESULTS:There were 9 common peaks in HPLC chromatograms of taproot and rhizome of P lactiflora.The similarity of taproot with rhizome of P lactiflora was higher than 0.9.CONCLUSIONS:Established fingerprints can provide reference for identification and quality evaluation of P lactiflora.The effective constituent of taproot and rhizome of P lactiflora are uniform but have small difference.

Objective To improve hand hygiene (HH)compliance of health care workers (HCWs)in neonatal in-tensive care units(NICUs)in China through a series of intervention measures.Methods A multicenter study was conducted,17 tertiary first class hospitals in 9 provinces and cities were selected,HH compliance of HCWs in these hospitals were investigated every month according to HH investigation method of World Health Organization.From October 1 ,2013 to March 31 ,2014 was pre-intervention stage;from April 1 ,2014 to September 30,2014 was post-intervention stage,timely feedback and intensified training were conducted at post-intervention stage.Results HH compliance rates of HCWs before and after intervention were 80.29% and 80.85% respectively,there was no sig-nificant difference (P >0.05).HH compliance rates of HCWs in different sizes of ICUs were significantly different before and after intervention (all P <0.05),in NICUs with<20 beds and 20-30 beds after the intervention were both significantly higher than before intervention (both P <0.05 ),while >30 beds were significantly lower than before intervention(P <0.001 );HH compliance rate of cleaners increased from 58.82% before intervention to 68.09% after intervention (P <0.05 );Of different hand hygiene indications,except before clean/aseptic task, compliance to the other HH indications were significantly different between before and after intervention(all P <0.05).Conclusion HH compliance is high among HCWs in NICUs in China,intervention measures,such as inten-sified training and timely feedback have certain influence in compliance to HH among HCWs at different sizes of ICUs,of different occupations,and at different HH indications.

Objective To evaluate the effect of comprehensive intervention measures on improving hand hygiene (HH)compliance of health care workers(HCWs)in intensive care units (ICUs)by multicenter study.Methods A total of 47 hospitals in 12 provinces and cities were enrolled in the study,from October 2013 to September 2014, HH compliance among HCWs in ICUs was investigated according to World Health Organization HH investigation method,HH compliance rates before and after intervention were compared.Results HH compliance rate of HCWs in ICUs increased from 73.70%(11 155/15 135)before intervention to 78.70%(18 206/23 132)after intervention (χ2 =128.16,P <0.01);except northeast region ,HH compliance of HCWs in the other provinces increased signif-icantly after intervention(all P <0.05);among all departments,HH compliance of HCWs in general ICUs,respira-tory ICUs,emergency ICUs,and surgical ICUs increased significantly(all P <0.05);HH compliance of HCWs of all kinds of occupations increased significantly(all P <0.05);HH compliance rates before touching a patient,before clean/aseptic procedure,after touching a patient,and after touching patient surroundings increased significantly after intervention(all P <0.01 ).Conclusion Comprehensive interventions are helpful for improving HH compliance of HCWs in ICUs. Objective To evaluate the effect of comprehensive intervention measures on improving hand hygiene (HH)compliance of health care workers(HCWs)in intensive care units (ICUs)by multicenter study.Methods A total of 47 hospitals in 12 provinces and cities were enrolled in the study,from October 2013 to September 2014, HH compliance among HCWs in ICUs was investigated according to World Health Organization HH investigation method,HH compliance rates before and after intervention were compared.Results HH compliance rate of HCWs in ICUs increased from 73.70%(11 155/15 135)before intervention to 78.70%(18 206/23 132)after intervention (χ2 =128.16,P <0.01);except northeast region ,HH compliance of HCWs in the other provinces increased signif-icantly after intervention(all P <0.05);among all departments,HH compliance of HCWs in general ICUs,respira-tory ICUs,emergency ICUs,and surgical ICUs increased significantly(all P <0.05);HH compliance of HCWs of all kinds of occupations increased significantly(all P <0.05);HH compliance rates before touching a patient,before clean/aseptic procedure,after touching a patient,and after touching patient surroundings increased significantly after intervention(all P <0.01 ).Conclusion Comprehensive interventions are helpful for improving HH compliance of HCWs in ICUs.