1.Risk factors of bloodstream infections caused by vancomycin-resistant Enterococcus
Xuemei XU ; Siying WU ; Yi XIE ; Zhixing CHEN ; Ying MA ; Chao HE ; Mei KANG
Chinese Journal of Infection and Chemotherapy 2015;(5):447-451
Objective To analyze the bloodstream infections caused by vancomycin‐resistant Enterococcus (VRE)in West China Hospital and examine the risk factors of such infections for best control of VRE infections .Methods Case‐control method was used to compare the bloodstream infections due to VRE with those caused by vancomycin‐susceptible Enterococcus(VSE)from August 2010 to August 2014 in West China Hospital .The data were compared by T‐test ,Chi‐square test (univariate analysis) and logistic regression analysis (multivariate analysis) using SPSS 19 .0 software .Results A total of 31 VRE strains were isolated from bloodstream infections in the study period ,including 5 (16 .1 % ) strains of vancomycin‐resistant Enterococcus faecalis and 26 (83 .9 % )strains of vancomycin‐resistant Enterococcus faecium .In the past four years ,the prevalence of vancomycin‐resistant E . f aecalis in bloodstream infections was 1 .5% ,1 .6% ,1 .8% ,and 1 .2% ;while the prevalence of vancomycin‐resistant E . f aecium in bloodstream infections was 3 .8% ,4 .4% ,5 .8% ,and 7 .1% .Such VRE bloodstream infection was mainly found in Intensive Care Unit (ICU)(13 ,41 .9% )and Department of Neurosurgery (4 ,12 .9% ) .More than 90% of the isolates were resistant to ampicillin and erythromycin .But less than 20% of the strains were resistant to quinupristin‐dalfopristin and linezolid . Univariate analysis indicated that prolonged hospital stay , ICU admission , venous catheter ,prior carbapenem exposure , prior vancomycin/norvancomycin exposure were associated with VRE bloodstream infections .Logistic regression analysis confirmed that venous catheter was an independent risk factor of VRE bloodstream infections .Conclusions Venous catheter is an independent risk factor for VRE bloodstream infections . Infection control measures should be strengthened to prevent the outbreak of VRE‐related bloodstream infections .
2.Comparative study of VAC in the preoperative and postoperative treatment of bedsore united with skin flap
Chaoqi YIN ; Zhixing KANG ; Chengqun LUO ; Ping LI ; Jia CHEN ; Shaohua WANG ; Jianda ZHOU
Journal of Chinese Physician 2017;19(5):644-646,649
Objective To investigate the clinical efficacy and mechanism of vacuum-assisted closure (VAC) in the preoperative and postoperative treatment of bedsore united with skin flap.Methods Twenty two cases with bedsore were randomly divided into experimental and control groups.In the control group,the surgery of flap was performed after the treatment of continuous negative pressure about 7-10 days and the VAC was not applied after operation.While in the experimental group,VAC was not used before operation.It was applied on flaps as soon as sutured the border of flap and decubitus ulcers and removed after 7-10 days.By comparing the general appearance of two groups,microvessel count and the detection rate of bacterial culture and other indicators,the clinical effects of two treatments were investigated and the preliminary mechanism was analyzed.Results After preoperative VAC treatment,11 cases of control group showed a little granulation tissue growth,less subcutaneous hematoma and wound effusion,increased microvessel count and negative bacterial culture.However,there were 4 cases of death cavity residual,subcutaneous hematoma and wound effusion,positive bacterial culture and another 4 cases of delayed healing with skin flap repairing bedsore.The application of VAC in experimental group showed close contact of flap with the basement,less effusion,increased microvessel count and negative bacterial culture.One case of skin flap had a small area of separation,after the dressing of skin and the flap survived.The other wounds healed by first intention.Conclusions The use of VAC to repair bedsore can reduce the number of operation,and it is beneficial to the flap survival.
3.The analysis of pathogenic bacteria for inpatients with systemic lupus erythematosus or lupus nephritis
Hui WANG ; Lijuan WU ; Dan ZHAO ; Minxue LIU ; Zhixing CHEN ; Mei KANG ; Yi XIE
Chongqing Medicine 2016;45(36):5072-5074,5077
Objective To retrospectively analyse pathogenic bacteria isolated from inpatients with lupus erythematosus (SLE) and lupus nephritis (SLE‐LN ) ,and provide references for diagnosis and treatment for these patients with infection . Methods A total of 380 inpatients diagnosed with SLE/SLE‐LN in our hospital from 2010 to 2014 were enrolled in this study ,in‐cluding 96 cases of patients with SLE‐LN .Bacterial inoculation ,culture ,isolation ,identification and drug sensitivity test were carried out .Statistical analysis and susceptibility analysis was performed by using the SPSS 19 .0 and WHONET5 .6 software .Results For patients with SLE and SLE‐LN ,urinary tract infection accounted for 25 .0% and 27 .1% ,hematogenous infection accounted for 8 .1% and 10 .4% ,skin tissue infection accounted for 12 .0% and 8 .3% ,respectively .The most common gram negative bacteria was Escherichia coli ,which accounted for 25 .53% and 30 .21% in patients with SLE and patients with SLE‐LN ,respectively .Followed by Bauman Acinetobacter ,which accounted for 13 .42% and 14 .54% in patients with SLE and patients with SLE‐LN ,respectively . The most common gram positive bacteria was Staphylococcus aureus ,which accounted for 11 .58% and 11 .46% in patients with SLE and patients with SLE‐LN ,respectively .Strains of Escherichia coli were isolated from urine specimens of 69 .79% of patients with SLE and 66 .67% patients with SLE‐LN ,the percentages were significantly higher than that of the conventional urine culture (45% ,P< 0 .01) .The resistance rate of Escherichia coli strains isolated from patients with SLE to quinolones was higher than 66 .00% ,the resistance rate to ampicillin was 89 .69% ,and the resistance rate to piperacillin/tazobactam was low (3 .09% ) .The iso‐lation rates of ESBLs‐producing Escherichia coli strains and ESBLs‐producing Klebsiella pneumoniae strains in patients with SLE‐LN were higher than those in patients with SLE .Conclusion The patients with SLE have a higher risk for infection .The beta‐lac‐tams could be used for the treatment of Escherichia coli urinary tract infection in patients with SLE .
4.Analysis of the carbapenemase-producing mechanism of Enterobacteriaceae with decreased susceptibility to carbapenems.
Tingting WANG ; Dongdong LI ; Chuanmin TAO ; Yi XIE ; Mei KANG ; Zhixing CHEN
Journal of Southern Medical University 2013;33(11):1600-1604
OBJECTIVETo analyze the distribution of Enterobacteriaceae isolated from West China Hospital, investigate the antibiotic resistance profile of Enterobacteriaceae with decreased susceptibility to carbapenems and explore the molecular mechanism.
METHODSForty-five Enterobacteriaceae strains resistant or with reduced susceptibility to carbapenems were isolated from patients in West China Hospital. The antimicrobial susceptibility and carbapenemase-producing phenotypes of the bacteria were examined and specific PCR were performed to determine the molecular mechanism.
RESULTSOf the 45 isolates, 17, 21 and 36 were resistant or intermediate strains to imipenem, meropenem and ertapenem, respectively. The majority of these isolates showed resistance to cephalosporins. The modified Hodge test resulted in the highest positivity rate (77.8%), followed by EDTA disc test (57.8%) and PBA disc test (22.2%). BlaTEM, blaSHV and blaCTX-M were detected in 60.0%, 53.3% and 15.6% of these strains with reduced susceptibility. The rate of strains carrying 2 or more genes was 44.4%, and the detection rate of blaIMP was 48.9%. BlaKPC was identified in 4 (8.9%) high-level resistant strains and confirmed to locate on the plasmid.
CONCLUSIONProduction of carbapenemase contributes to reduced susceptibility of carbapenems in Enterobacteriaceae. The presence of blaKPC, MBL and ESBL, and their possible combinations can be the main factor contributing to carbapenem resistance or reduced susceptibility in Enterobacteriaceae. The KPC-2 carbapenemase gene located on the plasmids we found in this study can cause potential horizontal transmission across strains.
Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; metabolism ; Carbapenems ; pharmacology ; Cephalosporins ; pharmacology ; Enterobacteriaceae ; drug effects ; enzymology ; genetics ; Gene Amplification ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Thienamycins ; pharmacology ; beta-Lactam Resistance ; beta-Lactamases ; genetics ; metabolism ; beta-Lactams ; pharmacology