Investigation on the status of healthcare-associated infections among 42 429 inpatients in Wuhan City / 公共卫生与预防医学

Objective To understand the current status of healthcare-associated infections (HAI) among inpatients in medical institutions of Wuhan, and to provide a scientific basis for improving the management of healthcare-associated infections. Methods A combined method of bedside investigation and case review of the patients’ medical records were used to investigate all hospitalized patients in 31 hospitals. Results A total of 42 429 inpatients were investigated, of whom 938 had HAI (2.21%), and 7 561 had community-associated infection (CAI, 17.82%). The top three departments with the highest prevalence rate of HAI were ICU (17.95%), hematology (8.49%), and neurosurgery (6.57%), while the top three departments with the highest prevalence rate of CAI were burns (75.00%), pediatric non-neonatal group (70.26%) and respiratory department (67.53%). Both healthcare-associated infections and community infections were mainly in the lower respiratory tract, which accounted for 47.33% and 53.00%, respectively. The main pathogens of both HAI and CAI were Gram-negative bacteria, which accounted for 65.03% and 57.73%, respectively. The use rate of antimicrobial drugs was 31.74%, and the detection rate of pathogenic bacteria before antimicrobial treatment was 55.77%. The three departments with the highest rates of the use of antibacterial drugs were the pediatric non-neonatal group (78.20%), the department of burns (75.00%) and the department of urology (73.24%). Conclusion ICU, hematology department, and neurosurgery department were high-risk departments for healthcare-associated infections. Pediatrics, burns, and urology departments were the departments with high use of antibacterial drugs. The pathogenic bacterial detection rate has declined, which needs to be strengthened.

Production of recombinant flagellin to develop ELISA-based detection of Salmonella Enteritidis

ABSTRACT Food-borne diseases, caused by the pathogenic bacteria, are highly prevalent in the world. Salmonella is one of the most important bacterial genera responsible for this. Salmonella Enteritidis (SE) is one of the non-typhoid Salmonellae that can be transmitted to human from poultry products, water, and contaminated food. In recent years, new and rapid detection methods such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) have been developed. In this study, recombinant FliC (rFliC) was produced to be used as an antigen. The immunization was conducted in mice with the purified recombinant FliC (rFliC). The mice were subcutaneously immunized with rFliC and elicited significant rFliC specific serum IgG antibodies. An indirect ELISA system was established for the detection of Salmonella Enteritidis. Our results confirmed that the recombinant flagellin can be one of the excellent indicators for the detection of Salmonella Enteritidis.

Significance of bacteria detection with filter paper method on diagnosis of diabetic foot wound infection / 中华烧伤杂志

Objective@#To evaluate the significance of bacteria detection with filter paper method on diagnosis of diabetic foot wound infection.@*Methods@#Eighteen patients with diabetic foot ulcer conforming to the study criteria were hospitalized in Liyuan Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from July 2014 to July 2015. Diabetic foot ulcer wounds were classified according to the University of Texas diabetic foot classification (hereinafter referred to as Texas grade) system, and general condition of patients with wounds in different Texas grade was compared. Exudate and tissue of wounds were obtained, and filter paper method and biopsy method were adopted to detect the bacteria of wounds of patients respectively. Filter paper method was regarded as the evaluation method, and biopsy method was regarded as the control method. The relevance, difference, and consistency of the detection results of two methods were tested. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of filter paper method in bacteria detection were calculated. Receiver operating characteristic (ROC) curve was drawn based on the specificity and sensitivity of filter paper method in bacteria detection of 18 patients to predict the detection effect of the method. Data were processed with one-way analysis of variance and Fisher's exact test. In patients tested positive for bacteria by biopsy method, the correlation between bacteria number detected by biopsy method and that by filter paper method was analyzed with Pearson correlation analysis.@*Results@#(1) There were no statistically significant differences among patients with wounds in Texas grade 1, 2, and 3 in age, duration of diabetes, duration of wound, wound area, ankle brachial index, glycosylated hemoglobin, fasting blood sugar, blood platelet count, erythrocyte sedimentation rate, C-reactive protein, aspartate aminotransferase, serum creatinine, and urea nitrogen (with F values from 0.029 to 2.916, P values above 0.05), while there were statistically significant differences among patients with wounds in Texas grade 1, 2, and 3 in white blood cell count and alanine aminotransferase (with F values 4.688 and 6.833 respectively, P<0.05 or P<0.01). (2) According to the results of biopsy method, 6 patients were tested negative for bacteria, and 12 patients were tested positive for bacteria, among which 10 patients were with bacterial number above 1×105/g, and 2 patients with bacterial number below 1×105/g. According to the results of filter paper method, 8 patients were tested negative for bacteria, and 10 patients were tested positive for bacteria, among which 7 patients were with bacterial number above 1×105/g, and 3 patients with bacterial number below 1×105/g. There were 7 patients tested positive for bacteria both by biopsy method and filter paper method, 8 patients tested negative for bacteria both by biopsy method and filter paper method, and 3 patients tested positive for bacteria by biopsy method but negative by filter paper method. Patients tested negative for bacteria by biopsy method did not tested positive for bacteria by filter paper method. There was directional association between the detection results of two methods (P=0.004), i. e. if result of biopsy method was positive, result of filter paper method could also be positive. There was no obvious difference in the detection results of two methods (P=0.250). The consistency between the detection results of two methods was ordinary (Kappa=0.68, P=0.002). (3) The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of filter paper method in bacteria detection were 70%, 100%, 1.00, 0.73, and 83.3%, respectively. Total area under ROC curve of bacteria detection by filter paper method in 18 patients was 0.919 (with 95% confidence interval 0-1.000, P=0.030). (4) There were 13 strains of bacteria detected by biopsy method, with 5 strains of Acinetobacter baumannii, 5 strains of Staphylococcus aureus, 1 strain of Pseudomonas aeruginosa, 1 strain of Streptococcus bovis, and 1 strain of bird Enterococcus. There were 11 strains of bacteria detected by filter paper method, with 5 strains of Acinetobacter baumannii, 3 strains of Staphylococcus aureus, 1 strain of Pseudomonas aeruginosa, 1 strain of Streptococcus bovis, and 1 strain of bird Enterococcus. Except for Staphylococcus aureus, the sensitivity and specificity of filter paper method in the detection of the other 4 bacteria were all 100%. The consistency between filter paper method and biopsy method in detecting Acinetobacter baumannii was good (Kappa=1.00, P<0.01), while that in detecting Staphylococcus aureus was ordinary (Kappa=0.68, P<0.05). (5) There was no obvious correlation between the bacteria number of wounds detected by filter paper method and that by biopsy method (r=0.257, P=0.419). There was obvious correlation between the bacteria numbers detected by two methods in wounds with Texas grade 1 and 2 (with r values as 0.999, P values as 0.001). There was no obvious correlation between the bacteria numbers detected by two methods in wounds with Texas grade 3 (r=-0.053, P=0.947).@*Conclusions@#The detection result of filter paper method is in accordance with that of biopsy method in the determination of bacterial infection, and it is of great importance in the diagnosis of local infection of diabetic foot wound.

Design improvement and application of transfer trolley for collection and distribution in central sterile supply department / 医疗卫生装备

Objective To modify the existed transfer trolley for collection and distribution so as to enhance cleaning and disinfection.Methods The existed transfer trolley was added with an intake pipe,a spray nozzle,a drilled divider,a drainage pipe and etc for perfusion rinse,and equipped with auxiliary mechanisms such as a protective support and preserver.Omnidirectional cleaning and disinfection of the trolley were executed by the intake pipe,nozzle and high-pressure irrigation machine.Results The trolley prevented the disinfection solution from spitting,ensured the safety of the staff and environment,and had the qualified rate of disinfection being 100％.Conclusion The modified transfer trolley gains advantages in environmental protection,energy saving and practicability,and thus is worthy promoting clinically.

Evaluation of the value of anaerobic culture in bacterial contamination forapheresis platelets / 中国输血杂志

Objective To determine the potential deficiency due to lack of anaerobic culture and evaluate the effect to reduce adverse reaction associated to transfusion-translated bacterial infection.Methods The result of 9 758 units of apheresis platelet concentrates (PCs)detected with automated microbial detection system were reviewed and the medical records of the patients that received the contaminated PCs were followed.Results The confirmed positive rates by aerobic and anaerobic cultures were 0.06％ (6/9 758)and 0.16％ (16/9 758),respectively.In 10 of 16 yield cases,only the anaerobic culture was positive.The most of the bacterial detected by anaerobic culture only were Propionibacterium acnes.Their mean detection time from inoculation was 96.8±18.21 hours.Conclusion Addition of anaerobic culture would enhance the detection of bacterial contamination in PCs.However,since only slow-growing bacteria were detected,and because their clinical significance was debatable,blood service should select feasible and costeffective projects using only aerobic bottle for bacterial screening,like the majority of licensed blood centers in North America and Hong Kong,China.

The application of polymerized lipid vesicles as colorimetric biosensors for real-time detection of pathogens in drinking water

The inadequate treatments given to the served waste water which are disposal to the rivers and sea coast are the major sources of faecal Microorganisms and enteric bacterial pathogens. They are among the most serious effects of water pollution bringing risks on public health. None of the current methods for detection of pathogens offer real-time on site solutions, are capable of delivering a simple visual detection signal, or can be easily instrumented as an indicator of the presence of a pathogen in water. The use of lipid vesicles incorporating Polydiacetylenes (PDAs) for the development of biosensors for “real-time” detection of pathogens has become an alternative, due to its potential for simple colorimetric response against harmful environmental effectors. However, its actual application in the field has been complicated because lipid vesicles are unable to respond specifically to environmental changes. In this paper, we report several experimental trials leading to improved response in the detection of flagellated pathogens in drinking water. Chromatic biomimetic membranes of TRCDA/DMPC and TRCDA/DMPC/Tryptophan were used in agar and liquid media, which were challenged with different amounts of Escherichia coli and Salmonella typhimurium. In addition, the effect of some divalent cations on the interaction with vesicles TRCDA/DMPC was investigated. The results indicated an improvement in the response times, both visually and quantitatively, through the use of TRIS-EDTA and proper growing conditions for E. coli and Salmonella. With the application of both conditions, it was possible by incubation at 35ºC to promote bacterial growth, therefore avoiding a dramatic effect on the colour change over control samples which may invalidate the test. Our experiments indicated that the minimum bacterial concentration necessary to produce the transition from blue to red on the vesicles as biosensor approaches 10(8) CFU/ml within 4 hrs...

Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection / 药物分析学报

A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET28a expression vector and the recombinant protein was produced in Escherichia coli BL21. The recombinant luciferase, equipped with a polyhistidine affinity tag, was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient purification of a recombinant luciferase with final yield 1.995mg/L of cell culture. Experiments on the recombinant luciferase also showed that the relative light units (RUL) of the enzyme were 5.8×108, and the specific activity was 2.9×1010 RLU/mg. By applying adenosine triphosphate (ATP) bioluminescence to detection of the coin bacteria using the recombinant protein, the ATP content of bacteria was 9.48×10-16mol/mL, and was identical to the bacteria counts (4500CFU/mL) in order of magnitude. Taken together, our results provided a simple and efficacious method of the preparation of recombinant luciferase, which could be applied in the determination of bacteria via ATP bioluminescence.

Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection / 西安交通大学学报·英文版

A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET28a expression vector and the recombinant protein was produced in Escherichia coli BL21. The recombinant luciferase, equipped with a polyhistidine affinity tag, was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient purification of a recombinant luciferase with final yield 1.995 mg/L of cell culture. Experiments on the recombinant luciferase also showed that the relative light units (RUL) of the enzyme were 5.8×108, and the specific activity was 2.9×1010 RLU/mg. By applying adenosine triphosphate (ATP) bioluminescence to detection of the coin bacteria using the recombinant protein, the ATP content of bacteria was 9.48×10-16mol/mL, and was identical to the bacteria counts (4 500 CFU/mL) in order of magnitude. Taken together, our results provided a simple and efficacious method of the preparation of recombinant luciferase, which could be applied in the determination of bacteria via ATP bioluminescence.

Effects of Intermittent Catheterization Methods on Detecting Urine Bacteria in Patients with Spinal Cord Injury / 中华医院感染学杂志

OBJECTIVE To investigate the influence of intermittent catheterization methods and indwelling catheterization methods on the urinary tract infection in patients with spinal cord injury.METHODS After eighty cases of spinal cord injury,the urine retention patients caused by bladder dysfunction were respectively used intermittent catheterization and indwelling catheterization.The urinary tract infection rates of regucally urine culture were compared.By use of intermittent catheterization,the bladder function was trained.Bacteria culture and identification of the urine from the patients were conducted after 15 or 30 days of intermittent catheterization and indwelling catheterization respectively.RESULTS The rates of urinary tract infection(colony count≥1?10 CFU/ml) after 15 or 30 days of intermittent catheterization were 32.6% and 31.5%,respectively.Which were significantly lower than those of indwelling catheterization(100%)(P

Management for Visitors in Newborn Nursery / 中华医院感染学杂志

OBJECTIVE To strengthen the management for visitors in the newborn nursery,in order to reduce the newborn hospital infection rate and enhance the hospital infection management quality in the newborn nursery.METHODS Taken the air and the object surface sampling in the newborn nursery,and the sampling derived from the hands of staff and visitors to undertake the contrast examination.RESULTS Before and after visits,the air pollution rate was over norm by increase of 58.3%,and after disinfection it declined 75.0%,after visiting,the object surface contamination rate was over norm by 56.3%,after disinfection it fell by 77.1%.Before washing-hands,the bacterial contamination rate of visitors and staff was over norm by respectively 100.0% and 68.3%,after washing,the passing rate of visitors was 92.0%,and no medical staff were over norm.CONCLUSIONS To adopt the effective management for visitors in the newborn nursery is very important to reduce the hospital infection rate in newborn nursery.