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Po-Ren Hsueh

Publications and source records attributed to Po-Ren Hsueh.

At least 55 records · Page 3Linked to original sources
PubMed2006

Rapid differentiation between members of the anginosus group and Streptococcus dysgalactiae subsp. equisimilis within beta-hemolytic group C and G streptococci by PCR.

Based on a pair of primers developed initially for differentiating the anginosus group from other viridans streptococci, the PCR reported here can also differentiate between members of the anginosus group and Streptococcus dysgalactiae subsp. equisimilis among beta-hemolytic group C and G streptococci. The resulting 742-bp PCR product was specific for members of the anginosus group, although a smaller, nonspecific product (361 bp) was generated from S. dysgalactiae subsp. equisimilis. Restriction digestion of the amplicon with XbaI and BsmI further differentiated Streptococcus anginosus from Streptococcus constellatus within the anginosus group.

Bacteriological Techniques↗
PubMed2006

Stenotrophomonas maltophilia bacteremia in pediatric patients-- a 10-year analysis.

BACKGROUND AND PURPOSE: Stenotrophomonas maltophilia bacteremia is an important cause of mortality among immunocompromised children. However, there has been little information concerning S. maltophilia bacteremia in the pediatric population. METHODS: We reviewed the drug susceptibility of bloodstream isolates of S. maltophilia and medical charts of S. maltophilia bacteremia patients less than 18 years old at the Department of Pediatrics, National Taiwan University Hospital from January 1993 to June 2003. The risk factors associated with mortality of the patients with S. maltophilia bacteremia were analyzed. RESULTS: In total, 32 episodes (31 patients) of S. maltophilia bacteremia were reviewed. The average rate of nosocomial bloodstream infection was 8.3 episodes per 100,000 patient-days, and an average of 6.4% of them were caused by S. maltophilia. Malignancy was the most common underlying disease (32%). Six episodes of S. maltophilia bacteremia had soft tissue involvement, and only 1 of them underwent surgical intervention and survived. These 32 isolates were most susceptible to trimethoprim-sulfamethoxazole (91%), and no obvious increase in multidrug resistance was noted in the previous 10 years. The crude mortality rate was 40.6%. Malignancy, failure to remove central venous catheter, and ineffective antibiotic treatment were significant risk factors for mortality. CONCLUSIONS: Early and effective antimicrobial therapy and removal of central venous catheter as soon as possible are vital for the successful management of S. maltophilia bacteremia.

Adolescent↗
PubMed2006

Survey of amphotericin B susceptibility of Candida clinical isolates determined by Etest.

BACKGROUND AND PURPOSE: The minimal inhibitory concentrations (MICs) of amphotericin B (AmB) determined by the National Committee for Clinical Laboratory Standards (NCCLS; NCCLS document M27-A) broth dilution method are in a relatively narrow ranges and this may lead to underestimation of the AmB-resistant rate in clinical isolates. We evaluated in vitro susceptibility of clinical isolates of Candida spp. to AmB using Etest and determined the distribution of AmB MICs in different species. METHODS: We used the Etest (AB Biodisk, Solna, Sweden) to evaluate the MICs of Candida isolates randomly collected during 2001-2003 in a teaching hospital. RESULTS: Of the 572 isolates evaluated, Candida albicans (50.7%) was the most common species, followed by Candida tropicalis (23.9%), Candida parapsilosis (13.1%), Candida glabrata (9.4%), Candida krusei (1.9%), and Candida guilliermondii (0.9%). The majority of isolates were from blood (85%). The minimal concentrations of AmB required to inhibit 50%/90% of the isolates (MIC(50)/MIC(90)) were 0.19/0.38 microg/mL for C. krusei, 0.125/0.38 microg/mL for C. glabrata, 0.094/0.25 microg/mL for C. tropicalis, 0.032/0.19 microg/mL for C. albicans, 0.016/0.125 microg/mL for C. parapsilosis, and 0.023/0.032 microg/mL for C. guilliermondii. Only 1 blood isolate of C. glabrata was resistant to AmB (MIC > or =1 microg/mL) [0.17%]. 18.2% of isolates were less susceptible to AmB (MIC > or =0.19 microg/mL) with the highest rates for C. krusei (63.6%), followed by C. glabrata (37.0%), C. tropicalis (29.9%), C. albicans (11.0%), C. parapsilosis (5.3%), and C. guilliermondii (0%). More isolates collected from patients with hematologic malignancy were less susceptible to AmB than those collected from those with other diseases (30.5% vs 15.4%, p<0.05). CONCLUSION: This study demonstrated that AmB resistance remains rare at this hospital in Candida clinical isolates despite increasing use of this agent during the past 4 decades.

Amphotericin B↗
PubMed2006

Bacteremia caused by Salmonella enterica serotype Choleraesuis in Taiwan.

Since 1995, there has been a steady increase in the number of reported cases of Salmonella enterica serotype Choleraesuis (S. Choleraesuis) sepsis in Taiwan. Representative Taiwanese survey data from 1996 to 2004 revealed that these adult patients with S. Choleraesuis bacteremia presented with primary bacteremia (57%, especially immunocompromised hosts), mycotic aneurysm (16%), and fever (86%) predominantly. S. Choleraesuis septicemia demonstrated a higher invasion index (with secondary involved sites) than other Salmonella spp. In swine experiments, the inoculation dose of 10(3) colony forming units S. Choleraesuis was cleared without apparent sequelae. Transmission of specific strains (with mutations of GyrA and parC, subsequently resistance to fluoroquinolones) from swine, and the acquisition of genes (CMY-2, AmpC complex) encoding beta-lactamases (with resistance to extended-spectrum cephalosporins) have been implicated in the evolution of multiresistant phenotypes of S. Choleraesuis. The virulence plasmid of S. Choleraesuis (pSCV), and other genes mediating adhesion to the epithelial cell membrane of the gastrointestinal tract, were considered important pathogenic factors for S. Choleraesuis. Vaccines for domestic animals combined with effective controls on antibiotic use offer the greatest potential to control the increasing impact of S. Choleraesuis on humans.

Aneurysm, Infected↗
PubMed2005

Emergence of disseminated infections due to nontuberculous mycobacteria in non-HIV-infected patients, including immunocompetent and immunocompromised patients in a university hospital in Taiwan.

OBJECTIVES: Although disseminated nontuberculous mycobacteria (NTM) infection has been increasingly reported in patients with AIDS, this condition is still considered rare in non-HIV-infected patients. METHODS: We retrospectively reviewed the medical records of non-HIV-infected patients treated at National Taiwan University Hospital from January 1997 to December 2004 to search for epidemiological trends in disseminated NTM infection. Data analyzed included etiology, demographic characteristics, underlying disease, initial symptoms and signs, treatment, and outcomes. RESULTS: Disseminated NTM infections occurred in 15 non-HIV-infected patients during the study period. The mean age of these patients was 51 years (range 13-80). Among these patients, eight were males, and eight had various immunocompromised conditions. Fever was an initial presentation in 12 patients (80%). Diagnosis was made by positive blood (seven patients) or bone marrow culture (five patients) in the majority (73%) of patients. Infectious etiologies included Mycobacterium avium complex (MAC) in eight, rapidly growing mycobacteria (RGM) in four and Mycobacterium kansasii in three. The mean time from initial presentation to initiation of anti-NTM therapy was 130 days (ranged from 9 days to 17 months). Mortality was highest in patients with M. kansasii (100%), followed by RGM (25%) and MAC (12.5%). CONCLUSIONS: Although disseminated NTM infection is an emerging condition among patients without HIV infection, it is a condition which is associated with immune deficiency. A high level of clinical suspicion should be maintained for avoiding delayed diagnosis, especially in patients with underlying immunosuppression. Blood culture might play an important role in the early diagnosis of disseminated NTM disease. Early diagnosis can lead to appropriate diagnosis and reduce mortality.

Adolescent↗
PubMed2005

High frequency of linezolid-associated thrombocytopenia and anemia among patients with end-stage renal disease.

BACKGROUND: Data about the efficacy and tolerability of linezolid for the treatment of gram-positive bacterial infections in patients with end-stage renal disease (ESRD) are lacking. METHODS: This retrospective case-control study compared the tolerability and efficacy of linezolid therapy for patients with ESRD and patients with non-end-stage renal disease (NESRD), all of whom had gram-positive bacterial infections. RESULTS: There were 58 men and 33 women enrolled in the study, with a mean age of 61.5 years (range, 45.4-81.2 years). Among these patients, 28 (30.8%) were receiving hemodialysis at the start of linezolid treatment. The ESRD group had a higher percentage of patients with diabetes mellitus (57.1% vs. 33.3%; P = .029) and an older mean age (+/-SD) (72.1 +/- 10.8 years vs. 56.8 +/- 20.4 years; P < .001), compared with the NESRD group. Severe thrombocytopenia (platelet count, < 100 x 10(9) platelets/L) and anemia were significantly more frequent in the ESRD group, compared with the NESRD group (78.6% vs. 42.9% [P = .003] and 71.4% vs. 36.5% [P = .003], respectively). The independent risk factors for thrombocytopenia identified by logistic regression analysis were pretreatment disease severity score (odds ratio [OR], 1.34; 95%, confidence interval [CI], 1.13-1.60; P = .001), central catheter-related infection (OR, 4.96; 95% CI, 1.08-22.73; P = .046), and ESRD (OR, 6.14; 95% CI, 1.63-23.26; P = .007). ESRD was the only independent risk factor for anemia (OR, 4; 95% CI, 1.50-10.64; P = .006). Survival analysis for the development of thrombocytopenia or death showed significant differences between patients with ESRD and patients with NESRD (P < .001). CONCLUSIONS: The lower tolerability of linezolid in patients with ESRD, compared with those with NESRD, is evidenced by the higher rates of thrombocytopenia and anemia in the former group. The severity of these conditions necessitates treatment discontinuation for patients with ESRD more often than for patients with NESRD.

Acetamides↗
PubMed2005

Relationships between antimicrobial use and antimicrobial resistance in Gram-negative bacteria causing nosocomial infections from 1991-2003 at a university hospital in Taiwan.

This study was conducted to evaluate the relationship between antimicrobial resistance and antimicrobial use in a university hospital in Taiwan. Disk susceptibility data of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia and other non-fermentative Gram-negative bacilli causing nosocomial infections were evaluated. Data on annual patient-days and annual consumption (defined daily dose (DDD) per 1000 patient-days) of extended-spectrum cephalosporins (cefotaxime, ceftriaxone, ceftazidime, flumoxef, cefepime and cefpirome), beta-lactam-beta-lactamase inhibitor combinations (ticarcillin/clavulanic acid and piperacillin/tazobactam), carbapenems (imipenem and meropenem), aminoglycosides (amikacin, gentamicin and tobramycin), fluoroquinolones (ciprofloxacin (oral and injectable) and oral levofloxacin and moxifloxacin) from 1991 to 2003 were analysed. Increasing trends of incidences of several of these bacteria causing all nosocomial infections or nosocomial bloodstream infections were noted from 1991 to 2003. The annual patient-days of the hospital significantly increased, from 360210 in 1991 to 672676 in 2002 (linear regression analysis, P < 0.05), but slightly decreased in 2003 (629168) owing to the severe acute respiratory syndrome epidemic in Taiwan. The rise in cefotaxime-resistant or ciprofloxacin-resistant E. coli and meropenem-resistant P. aeruginosa was significantly correlated with increased consumption of extended-spectrum cephalosporins, beta-lactam-beta-lactamase inhibitor combinations, carbapenems, fluoroquinolones and aminoglycosides (for ciprofloxacin-resistant E. coli and meropenem-resistant P. aeruginosa only) in the hospital (Pearson's correlation coefficient, r > 0.72 (or < -0.72) and P-value < 0.05). Increased ciprofloxacin-resistant K. pneumoniae and meropenem-resistant Acinetobacter spp. was significantly associated with the increased usage of extended-spectrum cephalosporins but not with the other four classes of antibiotics. This 13-year study in a hospital demonstrated significant changes in antimicrobial use, which may have affected antimicrobial resistance in certain Gram-negative bacteria at the hospital.

Aminoglycosides↗
PubMed2005

Mycobacterium tuberculosis in Taiwan.

OBJECTIVE: The resurgence of tuberculosis (TB) and the emergence of drug resistance of Mycobacterium tuberculosis (MTB) isolates are of great impact on public health. METHODS: Taiwanese data on disease burden of TB and anti-microbial resistance of MTB identified from Annual Reports of Centre for Disease Control, Department of Health, Taiwan and from peer-reviewed publications from MEDLINE (1995-2004). RESULTS: In Taiwan in 2002, the incidence (per 100,000 population) of tuberculosis was 74.6 and it was higher in aborigines (289.8) and in people living in mountainous regions (256.0). The mortality rate of tuberculosis in Taiwan in 2002 was 5.68 per 100,000 population. Susceptibility data summarized from 1990 to 2002 reports showed primary resistance ranged from 4.7 to 12% for isoniazid, 0.7 to 5.9% for rifampin, 1 to 6% for ethambutol, and 4 to 11% for streptomycin. The overall rates of multidrug-resistant tuberculosis (MDRTB) among new cases and previously treated cases were 1 to 3% and 15 to 46%, respectively. The increasing burden of patients with MDRTB infection, the persistent high rate of mortality, the lack of nationwide surveillance system using the standard methodology to determine the trends and current status of resistance, and the inadequate current TB control infrastructure and training to accomplish the tasks required to implement the directly observed treatment short-course (DOTS) strategy are having a great impact on public health in Taiwan. CONCLUSIONS: High disease burden of TB and high resistance rates in MTB as well as inappropriateness of the current control infrastructure for TB services illustrate increasingly serious health problems from TB in Taiwan.

Adolescent↗
PubMed2005

Characteristics of community-acquired and health care-associated Staphylococcus aureus bacteremia in patients treated at the emergency department of a teaching hospital.

The changing epidemiology of Staphylococcus aureus bacteremia has been noted worldwide. This enhanced awareness appears to be closely associated with the evolution of health care systems. To further delineate this change and to clarify the prevalence of true community-acquired methicillin-resistant S. aureus (MRSA), reclassification for community-onset bacteremia was proposed. Exposure to health care system, such as nursing home residence, regular outpatient invasive interventions, and prior hospitalization within 1 year, was identified among the community-onset S. aureus bacteremia patients. During the 1-year study period, 102 episodes of S. aureus bacteremia from the emergency department patients of a teaching hospital were prospectively enrolled. Nine of the episodes were hospital-acquired, 56 episodes were associated with health care system exposure, and the remaining 37 episodes were classified as true community-acquired bacteremia. The characteristics of patients, primary site of infection, antimicrobial susceptibilities of S. aureus isolates, adequacy of initial antimicrobial therapy, and percentage of metastatic infections differed significantly between health care-associated and true community-acquired S. aureus bacteremias. Prevalence of MRSA infection in true community-acquired bacteremia was low in contrast to bacteremia with health care-associated exposure (2.7% versus 42.9%, P < 0.01). In conclusion, clinical characteristics and risk of contracting methicillin-resistant S. aureus bacteremia among community patients with and without exposure to health care system are distinct. Precise classification of patients is mandatory for the surveillance of antimicrobial resistance and selection of rationale empirical antibiotics.

Adult↗
PubMed2005

An esophageal mass with coexistent Mycobacterium chelonae and Candida albicans infections in an immunocompetent adult.

Mycobacteria chelonae was originally included in group IV of Runyon's classification of atypical mycobacteria. This rapidly growing environmental organism often caused infections in immunocompromised hosts. Candida albicans is a ubiquitous micro-organism and frequently isolated from the gastrointestinal tract. These two micro-organisms seldom cause esophageal diseases in healthy humans. We report a case of a fruit farmer with a submucosa tumor of distal esophagus caused by coexistence of M. chelonae and C. albicans infections, which was successfully treated by surgical resection and following antimicrobial regimens postoperatively.

Adult↗
PubMed2005

In vitro susceptibilities of aerobic and facultative Gram-negative bacilli isolated from patients with intra-abdominal infections worldwide: the 2003 Study for Monitoring Antimicrobial Resistance Trends (SMART).

OBJECTIVES: The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance programme was begun in 2002 to monitor antimicrobial resistance trends among aerobic and facultative Gram-negative bacilli (GNB) isolated from intra-abdominal infections worldwide. METHODS: In 2003, 74 medical centres from 23 countries collected isolates for testing. Antimicrobial susceptibility testing was performed using broth microdilution according to the NCCLS guidelines for MIC testing. RESULTS: A total of 5658 aerobic and facultative GNB were isolated from intra-abdominal infections. Enterobacteriaceae composed 84% of the total isolates. Among the agents tested, the carbapenems were the most consistently active against the Enterobacteriaceae. E. coli was the most common isolate (46%), and the susceptibility rate to the quinolone (70-90% susceptible), cephalosporin (80-97% susceptible), aminoglycoside (77-100% susceptible) and carbapenem (99-100% susceptible) agents tested varied among geographic regions, with isolates from the Asia/Pacific region generally being the most resistant. Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically in 9% of E. coli, 14% of Klebsiella spp., and 14% of Enterobacter spp. worldwide. ESBL producers generally had a more antibiotic-resistant profile than non-ESBL producers. CONCLUSIONS: Antimicrobial resistance among GNB isolated from intra-abdominal infections is a problem worldwide, especially in the Asia/Pacific region. The carbapenems ertapenem, meropenem and imipenem are highly active in vitro against Enterobacteriaceae isolated from intra-abdominal sites, including organisms that produce ESBLs.

Abdomen↗
PubMed2005

Changing bacteriology of adult community-acquired lung abscess in Taiwan: Klebsiella pneumoniae versus anaerobes.

BACKGROUND: Most literature regarding lung abscess focuses on anaerobic bacterial lung abscess, and aerobic gram-negative bacillary infection is less frequently discussed. This study was conducted to investigate the bacteriology of community-acquired lung abscess and to improve the empirical therapeutic strategy for adults with community-acquired lung abscess. METHODS: We reviewed and analyzed data on 90 consecutive adult cases of bacteriologically confirmed community-acquired lung abscess treated during 1995-2003 at a tertiary university hospital in Taiwan. RESULTS: We found that a high proportion (21%) of cases of lung abscess were due to Klebsiella pneumoniae infection, which differs from the findings of previous studies. Lung abscess due to K. pneumoniae was associated with underlying diabetes mellitus (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.0-18.4; P = .039) and negatively correlated with a time from onset of symptoms to diagnosis of >30 days (OR, 0.2; 95% CI, 0.1-0.7; P = .008). A higher percentage of patients with K. pneumoniae lung abscess had concomitant bacteremia (OR, 9.4; 95% CI, 1.1-81.9; P = .032), delayed defervesence (OR, 9.2; 95% CI, 1.8-47.8; P = .004), and multiple cavities noted on radiographs (OR, 11.0; 95% CI, 1.3-94.9; P = .015), compared with patients with anaerobic bacterial lung abscess. The rate of nonsusceptibility to clindamycin and penicillin among anaerobes and Streptococcus milleri group isolates increased. CONCLUSION: K. pneumoniae has become a more common cause of lung abscess than before, and a high proportion of anaerobes and S. milleri strains have become resistant to penicillin and clindamycin. A beta-lactam/beta-lactamase inhibitor or second- or third-generation cephalosporin with clindamycin or metronidazole is suggested as empirical antibiotic therapy for community-acquired lung abscess.

Adult↗