Isolation Trend of Enterobacter, Citrobacter, and Serratia for the Recent Five Years and Antimicrobial Susceptibility of Derepressed AmpC beta-lactamase Producing Strains / 감염

BACKGROUND: Derepressed AmpC beta-lactamase producing Enterobacter cloacae, Citrobacter f reundii, and Serratia marcescens are important nosocomial pathogens and the infections are difficult to treat, because they are multi-drug resistant. The aim of this study was to determine the isolation rate and trend, and antimicrobial susceptibility of derepressed strains isolated from clinical specimens. METHODS: E. cloacae, S. marcescens, and C. f reundii isolated from 1996 through 2000 were enrolled in the study. Antimicrobial susceptibility was tested by NCCLS disk diffusion method. Derepressed strain was defined as strain non-susceptible to third generation cephalosporin. The isolation patterns of important gram-negative bacilli with the derepressed strains were analyzed with respect to years, patient's locations and specimens. RESULTS: Among the clinical isolates, the derepressed strains of E. cloacae, S. marcescens, and C. f reundii were 65%, 70%, and 56%. The proportion of the derepressed strains : E. cloacae increased from 68% in 1996 to 71% in 1998, however, decreased to 59% in 2000, S. marcescens increased from 68% in 1996 to 73% in 2000, C. f reundii decreased from 69% in 1996 to 41% in 2000. The proportion of the derepressed strains were high among the isolates from blood and respiratory specimens of inpatient and intensive care patient. The resistance rates of the depressed strains were 47~62% to third generation cephalosporin and aztreonam, 15~85% to aminoglycoside, 68% to cotrimoxazole, and 31% to levofloxacin. CONCLUSION: Among the clinical isolates of E. cloacae, S. marcescens, and C. f reundii, the derepressed strains were as high as 56~70%, and they were commonly isolated from blood and sputum specimens of inpatient and intensive care patient, and showed high resistance rates to the most antimicrobial agents.

Evaluation of Quantitative culture of Clostridium difficile From Fecal Specimens for the Diagnosis of C. difficile-associated Disease / 대한임상미생물학회지

BACKGROUND: C. difficile-associated diarrhea (CDAD), the most frequently identified cause of nosocomial diarrhea, results from the overgrowth of cytotoxin (toxin B)-producing strains. The aim of this study was to evaluate the quantitative culture of Clostridium difficile to improve the laboratory diagnosis of CDAD. METHODS: The quantitative culture and cytotoxin gene results were evaluated based on the findings of colonoscopy and/or histology of the biopsy specimens. RESULTS: Among the 402 specimens with cytotoxin-positive isolates, 301 (74.9%) contained > or =106 CFU/mL of C. difficile. Nine (60%) of the 15 pseudomembranous colitis patients yielded > or =106 CFU/mL of toxigenic isolate. The proportion of cytotoxin gene-positive isolates was higher in the specimens with > or =106 CFU/mL of C. difficile than in those with 102-<103 CFU/mL (86.5% vs. 66.7%). CONCLUSIONS: Quantitative culture may aid in the interpretation of toxigenic C. difficile culture results, and reduce false positivity, thus avoiding unnecessary treatment.

A Survey of Blood Component Use in Relation to International Statistical Classification of Diseases (ICD)-10 / 대한임상병리학회지

BACKGROUND: There are few recent studies on transfusion practice and blood use with regard to diagnoses of Korean recipients. We conducted a survey of blood component use in Yonsei University Medical Center in Seoul, Korea. METHODS: A survey was carried out on blood component transfusion from January 2000 to June 2000. Transfused components were listed by broad diagnostic categories formed from the principal diagnoses of the recipients according to the ICD-10. RESULTS: Of all investigated components (67,433 units), 18,623 units of RBCs (27.6%), 10,203 units of FFP (15.1%), 38,547 units of platelets (57.2%), and 60 units of whole blood (0.1%) were transfused. The transfusion rate in relation to sex was 1.7:1 and the majority of all blood units were transfused to patients aged <65 yrs (85.9%). The rate of blood component transfusion was the highest in the department of internal medicine (47,451 units, 70.4%). Of 18,623 RBCs units and 10,203 FFP units, 70.8% and 74.5% were transfused to patients in four diagnostic categories; neoplasms, digestive system diseases, circulatory system diseases, and leukemia or lymphoma. Of 38,547 platelets units, 87.8% were used in patients with neoplasms, leukemia or lymphoma, digestive system diseases and diseases of the blood and blood-forming organs. CONCLUSIONS: This survey provides information on the blood component usage in tertiary-care teaching hospital in Seoul, Korea. It demonstrates the concentration of today's blood utilization among a few diagnostic categories. This information is relevant for quality management of transfusion practice, cost analyses and for planning local and regional blood donation programs.