Clinical Characteristics and Risk Factors of Death among Patients with Vancomycin-Resistant Enterococci (VRE) during 8 Years (1994-2001) in a University Hospital

BACKGROUND: Vancomycin-resistant enterococci (VRE) infection is an emerging nosocomial problem. VRE usually multidrug-resistant, poses therapeutic dilemmas. The gene that encodes the resistance against vancomycin may spread the resistance to Staphylococcus aureus. However, there are no well-organized studies on the clinical manifestations and the factors that contribute to mortality in Korea. Herein, this study was focused on the clinical manifestations and mortality risks of patients with VRE infection during 8 years (1994-2001) in a university hospital. Understanding of the epidemiology and clinical manifestations of VRE would help develop control strategy of VRE outbreak in a hospital. METHOD: Sixty seven cases that had the VRE infection in Korea University Guro Hospital from January 1, 1994to December 12, 2001, were reviewed. We analyzed the risk factors of VRE infection and death by using univariable and multivariable statistic analyses. RESULTS: VRE infections have recently been increasing. Most of VRE infections were caused by Enterococcus faecium (85.1%) and Enterococcus faecalis (10.4%). Among 67 cases, 40 cases (59.7%) expressed VanA phenotype, 23 cases (34.3%) expressed VanB phenotype, and 3 cases expressed VanC phenotype (6%). The risk factors for death were renal dysfunction, central venous catheter insertion, and tracheostomy by using univariable analysis. The risk factor for death was renal dysfunction by using multivariable analysis. CONCLUSION: VRE has been increasing during the late 1990s in Korea. The VRE infection occurs especially in the patients who have renal dysfunction, long-term hospitalization, and ICU care. The implementation of careful isolation, infection control measures, prudent use of antibiotics, especially vancomycin, and periodic screening of patients populations are required to control VRE infection.

Evaluation of the Appropriateness of Approved Antibiotic Usage Guidlines in Korea: Comparison of Domestic Package Inserts with Physicians' Desk Reference

BACKGROUND: The appropriate usage of antibiotics needs informations such as its effectiveness for a given infection, administration route, the amount of effective dose, and the dose intervals. In this study, in order to find any significant discrepancy regarding to the details of explanation of the necessary information for appropriate antibiotic usages, we compares informations about 51 antibiotics, one from package inserts in Korea and the other from physician's desk reference (PDR) certified by FDA in the United States of America. MATERIALS AND METHODS: Package inserts about antibiotics, only oral or parenteral agent, were perused to collect three categories of data: the recommended dosage, dose interval, and adjustment of dose to indications or the severity of infection. These data available in Korea were compared with 61 antibiotics (32 oral and 29 parenteral agents) cited in PDR. RESULTS: Package inserts for 51 antibiotics were gathered, because the remaining 10 antibiotics in PDR are not domestically commercialized. Among data on antibiotics comparable with those in PDR, 59% (30 cases:15 oral and 15 parenteral agents) suggested the dose similar to that of PDR, 37% (19 cases:8 oral and 11 parenteral agents) recommend less dose, and 4% in only 2 oral agents showed more dose. About half of the drugs recommending lower dosage were imported from Japanese pharmaceutical company, and the recommended doses of these antimicrobial agents were similar to those in Japan. About 59% (30 cases: 15 oral and 15 parenteral agents) directed dose interval or duration similar to those of PDR and 17% (9 parenteral agents) suggested less administration or longer duration. Surprisingly, in contrast to only 6% (3 cases) of PDR, 24% (12 cases:10 oral and 2 parenteral agents) recommended more administration or shorter duration. About 39% (24 cases:13 oral and 7 parenteral agents) revealed no information for dose adjustment commens to indications or the severity of infection. CONCLUSION: This study revealed that many guidelines in Korea recommend lower doses and/or unreasonable dose intervals. In future studies, improved antibiotic usage guidelines should be established based on pharmacokinetic and pharmacodynamic researches, on the aspect of optimal dosage, dose interval, and dose adjustment commensurate to the indications and the severity of the infection.

In vitro Antimicrobial Activity of Linezolid (Zyvox(R)) against Multidrug Resistant Gram-Positive Organism

BACKGROUND: The emergence of multi-drug resistant Gram-positive cocci, such as MRSA, VRE, and VRSA, necessitated to develop new antibiotics, which could replace the glycopeptide. As a result, a new antibiotics named linezolid was developed. Linezolid is different line of oxazolidinones with a good oral bioavailability, compared to other antibiotics. Since appropriate oral antibiotics are not presently available for MRSA, which is a major cause of nosocomial and community acquired infections, the introduction of linezolid will have favorable effect on treatment of infections such as pneumonia or skin infections. In this study, we investigated the antibiotic effect of linezolid on MRSA and VRE isolated from patients who were treated in Korea University Guro Hospital. MATERIAL AND METHODS: By using broth microdilution and agar dilution method we measured minimum inhibitory concentration (MIC) with sixty S. aureus, forty three Enterococcus spp., and twenty five S. pneumoniae isolates from patients who were diagnosed as skin, soft tissue, respiratory, and urinary infections in Korea University Guro Hospital from January, 1998 to December, 2002. RESULTS: All of S. aureus used in this study were MRSA, and MIC90 of linezolid was below 2 microgram/ml (MIC ranged between 1-2 microgram/ml). All of Enterococcus spp. were VRE, and had MIC90 of 2 microgram/ml (MIC ranged between 1 to 4 microgram/ml). One of the VRE showed intermediate susceptibility with MIC of 4 microgram/ml. However, none was resistant with MIC breakpoint above 8 microgram/ml. All of S. pneumoniae were resistant to penicillin, but they were susceptible to linezolid with MIC90 of 1 microgram/ml(MIC range 0.5-1 microgram/ml). CONCLUSION: In conclusions, linezolid has an excellent in vitro antibiotic effect on multi-drug resistant Gram-positive cocci, such as MRSA, PRSP, and VRE.

Antimicrobial Susceptibility of Causative Microorganisms in Adults with Acute Pyelonephritis at One University-Affiliated Hospital in Southwestern Seoul

BACKGROUND: The purpose of this study is to recommend the initial therapeutic regimen for adult patients with acute pyelonephritis (APN) according to the changes of antimicrobial susceptibility patterns of causative microorganisms isolated from patients with APN. METHODS: We reviewed medical charts of 229 APN patients, who had been treated at Korea University Guro Hospital from 1st of January, 1999 to 31st of December, 2001. We investigated the demographic data, clinical findings, durations of hospital treatment, antimicrobial susceptibility patterns of the causative microorganisms and initial antibiotic regimens in patients with APN. RESULTS: In this study, 229 adult patients with APN were classified into simple APN patients (118 patients, 51.5%) and complicated APN patients (111 patients, 48.4%). Mean age of patients with simple APN was 38.2+/-14.1 years old and that of patients with complicated APN was 56.1+/-14.9 years old. Mean age of patients with complicated APN was significantly higher than that of simple APN patients (P<0.0001). Escherichia coli was the most common microorganism both in simple APN (96.7%) group and in complicated APN (90.6%) group. Antimicrobial susceptibility of E. coli was at the low level of ampicillin (31%/20%) and trimethoprim-sulfamethoxazole (42.6%/34.2%) in each group. In contrast, ciprofloxacin (11.5%/22.7%), gentamicin (16.4%/22%) and cefotaxime (0%/8.2%) resistance remained at relatively lower level. In comparison of simple APN with complicated APN, ciprofloxacin and gentamicin resistances were higher in complicted APN group. Average duration of hospitalization (5.9+/-2.3 days/8.2+/-4.6 days) and duration of antibiotic use (12.1+/-3.9 days/15.3+/-10.0 days) were significantly longer in complicated APN. CONCLUSIONS: The results of this study suggests that 3rd cephalosporin, aminoglycoside or quinolone antibiotic would considered as one of the initial therapeutic regimen for patients with simple APN in southwestern Seoul.

A Case of Relapsed Subarachnoid Racemose Cysticercosis Successfully Treated with Albendazole

The so-called racemose cysticercosis, a rare variety of neurocysticercosis occurring in ventricles or basal cisterns, is characterized by abnormal growth of cystic membranes with degeneration of Taenia solium heads (scolex). Although lesions of this type are known to follow a progressive course even after ventricular shunting, there are limitations of case series treated with antiparasitic drugs, and the optimal duration of the treatment is not yet known. We report a case of relapsed racemose cysticercosis in the Sylvian fissure, who has been successfully treated with albendazole and adjunct corticosteroid for 4 weeks. The patient had been previously treated with praziquantel and ventriculoperitoneal shunt, and maintained on the anticonvulsant drug for one year, but returned to the hospital due to seizure recurrence. The patient has been well in seizure-free state for the follow-up 2 years after albendazole therapy. The subarachnoid racemose cysticercosis seems to respond well to treatment of corticosteroid along with prolonged albendazole.

Clinical Characteristics and Risk Factors of Death among Patients with Vancomycin-Resistant Enterococci (VRE) during 8 Years (1994-2001) in a University Hospital

BACKGROUND: Vancomycin-resistant enterococci (VRE) infection is an emerging nosocomial problem. VRE usually multidrug-resistant, poses therapeutic dilemmas. The gene that encodes the resistance against vancomycin may spread the resistance to Staphylococcus aureus. However, there are no well-organized studies on the clinical manifestations and the factors that contribute to mortality in Korea. Herein, this study was focused on the clinical manifestations and mortality risks of patients with VRE infection during 8 years (1994-2001) in a university hospital. Understanding of the epidemiology and clinical manifestations of VRE would help develop control strategy of VRE outbreak in a hospital. METHOD: Sixty seven cases that had the VRE infection in Korea University Guro Hospital from January 1, 1994to December 12, 2001, were reviewed. We analyzed the risk factors of VRE infection and death by using univariable and multivariable statistic analyses. RESULTS: VRE infections have recently been increasing. Most of VRE infections were caused by Enterococcus faecium (85.1%) and Enterococcus faecalis (10.4%). Among 67 cases, 40 cases (59.7%) expressed VanA phenotype, 23 cases (34.3%) expressed VanB phenotype, and 3 cases expressed VanC phenotype (6%). The risk factors for death were renal dysfunction, central venous catheter insertion, and tracheostomy by using univariable analysis. The risk factor for death was renal dysfunction by using multivariable analysis. CONCLUSION: VRE has been increasing during the late 1990s in Korea. The VRE infection occurs especially in the patients who have renal dysfunction, long-term hospitalization, and ICU care. The implementation of careful isolation, infection control measures, prudent use of antibiotics, especially vancomycin, and periodic screening of patients populations are required to control VRE infection.

Evaluation of the Appropriateness of Approved Antibiotic Usage Guidlines in Korea: Comparison of Domestic Package Inserts with Physicians' Desk Reference

BACKGROUND: The appropriate usage of antibiotics needs informations such as its effectiveness for a given infection, administration route, the amount of effective dose, and the dose intervals. In this study, in order to find any significant discrepancy regarding to the details of explanation of the necessary information for appropriate antibiotic usages, we compares informations about 51 antibiotics, one from package inserts in Korea and the other from physician's desk reference (PDR) certified by FDA in the United States of America. MATERIALS AND METHODS: Package inserts about antibiotics, only oral or parenteral agent, were perused to collect three categories of data: the recommended dosage, dose interval, and adjustment of dose to indications or the severity of infection. These data available in Korea were compared with 61 antibiotics (32 oral and 29 parenteral agents) cited in PDR. RESULTS: Package inserts for 51 antibiotics were gathered, because the remaining 10 antibiotics in PDR are not domestically commercialized. Among data on antibiotics comparable with those in PDR, 59% (30 cases:15 oral and 15 parenteral agents) suggested the dose similar to that of PDR, 37% (19 cases:8 oral and 11 parenteral agents) recommend less dose, and 4% in only 2 oral agents showed more dose. About half of the drugs recommending lower dosage were imported from Japanese pharmaceutical company, and the recommended doses of these antimicrobial agents were similar to those in Japan. About 59% (30 cases: 15 oral and 15 parenteral agents) directed dose interval or duration similar to those of PDR and 17% (9 parenteral agents) suggested less administration or longer duration. Surprisingly, in contrast to only 6% (3 cases) of PDR, 24% (12 cases:10 oral and 2 parenteral agents) recommended more administration or shorter duration. About 39% (24 cases:13 oral and 7 parenteral agents) revealed no information for dose adjustment commens to indications or the severity of infection. CONCLUSION: This study revealed that many guidelines in Korea recommend lower doses and/or unreasonable dose intervals. In future studies, improved antibiotic usage guidelines should be established based on pharmacokinetic and pharmacodynamic researches, on the aspect of optimal dosage, dose interval, and dose adjustment commensurate to the indications and the severity of the infection.

In vitro Antimicrobial Activity of Linezolid (Zyvox(R)) against Multidrug Resistant Gram-Positive Organism

BACKGROUND: The emergence of multi-drug resistant Gram-positive cocci, such as MRSA, VRE, and VRSA, necessitated to develop new antibiotics, which could replace the glycopeptide. As a result, a new antibiotics named linezolid was developed. Linezolid is different line of oxazolidinones with a good oral bioavailability, compared to other antibiotics. Since appropriate oral antibiotics are not presently available for MRSA, which is a major cause of nosocomial and community acquired infections, the introduction of linezolid will have favorable effect on treatment of infections such as pneumonia or skin infections. In this study, we investigated the antibiotic effect of linezolid on MRSA and VRE isolated from patients who were treated in Korea University Guro Hospital. MATERIAL AND METHODS: By using broth microdilution and agar dilution method we measured minimum inhibitory concentration (MIC) with sixty S. aureus, forty three Enterococcus spp., and twenty five S. pneumoniae isolates from patients who were diagnosed as skin, soft tissue, respiratory, and urinary infections in Korea University Guro Hospital from January, 1998 to December, 2002. RESULTS: All of S. aureus used in this study were MRSA, and MIC90 of linezolid was below 2 microgram/ml (MIC ranged between 1-2 microgram/ml). All of Enterococcus spp. were VRE, and had MIC90 of 2 microgram/ml (MIC ranged between 1 to 4 microgram/ml). One of the VRE showed intermediate susceptibility with MIC of 4 microgram/ml. However, none was resistant with MIC breakpoint above 8 microgram/ml. All of S. pneumoniae were resistant to penicillin, but they were susceptible to linezolid with MIC90 of 1 microgram/ml(MIC range 0.5-1 microgram/ml). CONCLUSION: In conclusions, linezolid has an excellent in vitro antibiotic effect on multi-drug resistant Gram-positive cocci, such as MRSA, PRSP, and VRE.

Antimicrobial Susceptibility of Causative Microorganisms in Adults with Acute Pyelonephritis at One University-Affiliated Hospital in Southwestern Seoul

BACKGROUND: The purpose of this study is to recommend the initial therapeutic regimen for adult patients with acute pyelonephritis (APN) according to the changes of antimicrobial susceptibility patterns of causative microorganisms isolated from patients with APN. METHODS: We reviewed medical charts of 229 APN patients, who had been treated at Korea University Guro Hospital from 1st of January, 1999 to 31st of December, 2001. We investigated the demographic data, clinical findings, durations of hospital treatment, antimicrobial susceptibility patterns of the causative microorganisms and initial antibiotic regimens in patients with APN. RESULTS: In this study, 229 adult patients with APN were classified into simple APN patients (118 patients, 51.5%) and complicated APN patients (111 patients, 48.4%). Mean age of patients with simple APN was 38.2+/-14.1 years old and that of patients with complicated APN was 56.1+/-14.9 years old. Mean age of patients with complicated APN was significantly higher than that of simple APN patients (P<0.0001). Escherichia coli was the most common microorganism both in simple APN (96.7%) group and in complicated APN (90.6%) group. Antimicrobial susceptibility of E. coli was at the low level of ampicillin (31%/20%) and trimethoprim-sulfamethoxazole (42.6%/34.2%) in each group. In contrast, ciprofloxacin (11.5%/22.7%), gentamicin (16.4%/22%) and cefotaxime (0%/8.2%) resistance remained at relatively lower level. In comparison of simple APN with complicated APN, ciprofloxacin and gentamicin resistances were higher in complicted APN group. Average duration of hospitalization (5.9+/-2.3 days/8.2+/-4.6 days) and duration of antibiotic use (12.1+/-3.9 days/15.3+/-10.0 days) were significantly longer in complicated APN. CONCLUSIONS: The results of this study suggests that 3rd cephalosporin, aminoglycoside or quinolone antibiotic would considered as one of the initial therapeutic regimen for patients with simple APN in southwestern Seoul.

A Case of Relapsed Subarachnoid Racemose Cysticercosis Successfully Treated with Albendazole

The so-called racemose cysticercosis, a rare variety of neurocysticercosis occurring in ventricles or basal cisterns, is characterized by abnormal growth of cystic membranes with degeneration of Taenia solium heads (scolex). Although lesions of this type are known to follow a progressive course even after ventricular shunting, there are limitations of case series treated with antiparasitic drugs, and the optimal duration of the treatment is not yet known. We report a case of relapsed racemose cysticercosis in the Sylvian fissure, who has been successfully treated with albendazole and adjunct corticosteroid for 4 weeks. The patient had been previously treated with praziquantel and ventriculoperitoneal shunt, and maintained on the anticonvulsant drug for one year, but returned to the hospital due to seizure recurrence. The patient has been well in seizure-free state for the follow-up 2 years after albendazole therapy. The subarachnoid racemose cysticercosis seems to respond well to treatment of corticosteroid along with prolonged albendazole.