Monto Ho

Susceptibilities of Candida species to amphotericin B and fluconazole: The emergence of fluconazole resistance in Candida tropicalis

OBJECTIVE To determine the susceptibilities of Candida species isolated from Taiwan to amphotericin B and fluconazole. DESIGN Prospective surveillance study. METHODS Each hospital was asked to submit up to 10 C. albicans and 40 non-albicans Candida species during the collection period, from April 15 to June 15, 1999. One isolate was accepted from each episode of infection. The broth microdilution method was used to determine susceptibilities to amphotericin B and fluconazole. RESULTS Only 3 of 632 isolates, one each of C. famata, C. krusei, and C. tropicalis, were resistant to amphotericin B. A total of 53 (8.4%) of 632 clinical yeast isolates, consisting of 4% C. albicans, 8% C. glabrata, 15% C. tropicalis, and 70% C. krusei, were resistant to fluconazole. In contrast, no C. parapsilosis isolate was resistant to fluconazole. Isolates from tertiary-care medical centers had higher rates of resistance to fluconazole than did those from regional and local hospitals (11.4% vs 6.6%). Isolates from different sources showed different levels of susceptibility to fluconazole. All of the isolates with the exception of C. tropicalis and C. krusei isolated from blood were susceptible to fluconazole. A pattern of co-resistance to both amphotericin B and fluconazole was observed. CONCLUSIONS Non-albicans Candida species had higher rates of resistance to fluconazole than did C. albicans (44 of 395 [11.2%] vs 9 of 237 [3.8%]; P = .002). The increasing rate of fluconazole resistance in C. tropicalis (15%) is important because C. tropicalis is one of the most commonly isolated non-albicans Candida species.

Risk factors for fatal candidemia caused by Candida albicans and non-albicans Candida species.

BackgroundInvasive fungal infections, such as candidemia, caused by Candida species have been increasing. Candidemia is not only associated with a high mortality (30% to 40%) but also extends the length of hospital stay and increases the costs of medical care. Sepsis caused by Candida species is clinically indistinguishable from bacterial infections. Although, the clinical presentations of the patients with candidemia caused by Candida albicans and non-albicans Candida species (NAC) are indistinguishable, the susceptibilities to antifungal agents of these species are different. In this study, we attempted to identify the risk factors for candidemia caused by C. albicans and NAC in the hope that this may guide initial empiric therapy.MethodsA retrospective chart review was conducted during 1996 to 1999 at the Veterans General Hospital-Taipei.ResultsThere were 130 fatal cases of candidemia, including 68 patients with C. albicans and 62 with NAC. Candidemia was the most likely cause of death in 55 of the 130 patients (42.3 %). There was no significant difference in the distribution of Candida species between those died of candidemia and those died of underlying conditions. Patients who had one of the following conditions were more likely to have C. albicans, age ≧ 65 years, immunosuppression accounted to prior use of steroids, leukocytosis, in the intensive care unit (ICU), and intravascular and urinary catheters. Patients who had undergone cancer chemotherapy often appeared less critically ill and were more likely to have NAC.ConclusionClinical and epidemiological differences in the risk factors between candidemia caused by C. albicans and NAC may provide helpful clues to initiate empiric therapy for patients infected with C. albicans versus NAC.

Community-Acquired Acinetobacter baumannii Bacteremia in Adult Patients in Taiwan

ABSTRACT We determined the clinical and microbiologic characteristics of community-acquired Acinetobacter baumannii bacteremia in 19 adult patients. We found that malignancy was the most frequent underlying disease. The overall mortality rate was 58%. All 14 available isolates were identified as genomic species 2 (A. baumannii) by 16S ribosomal DNA sequencing and were found to be genetically distinct by pulsed-field gel electrophoresis.

The roles of mutations in gyrA, parC, and ompK35 in fluoroquinolone resistance in Klebsiella pneumoniae

In a survey of 541 Klebsiella pneumoniae isolates from 44 hospitals in Taiwan, three distinct populations were identified by the disk diffusion method according to the disribution of zone diameters of ciprofloxacin. Isolates with resistant, reduced-susceptible, and susceptible to fluoroquinolone were defined as CIP zone diameters of < or = 15 mm, 16-26 mm, and > or = 27 mm, respectively. Thus, in addition to 38 (7%) resistant isolates, there were 30 (5.5%) reduced-susceptible isolates and 473 (87.5%) susceptible isolates. A total of 34 isolates consisting of nine resistant, 13 reduced-susceptible, and 12 susceptible isolates were assessed for point mutations in gyrA and parC and the outer membrane profiles. The susceptibility to fluoroquinolone of 13 reduced-susceptible isolates was not altered in the presence of carbonyl cyanide m-chlorophenylhydrazone, an efflux inhibitor, showing that efflux is not a major contributor to reduced susceptibility. In addition to single mutation in gyrA, OmpK35 porin loss can also be the first step for developing fluoroquinolone resistance. No strain possesses a parC mutation without the simultaneous presence of a gyrA mutation, suggesting that mutations in parC play a complementary role for higher-level of fluoroquinolone resistance and fluoroquinolone resistance is a multistep process.

Correlates of antibiotic use in Taiwan hospitals

OBJECTIVE To determine factors that correlate with increased antibiotic use among adult inpatients in Taiwan. DESIGN Retrospective survey of medical records. SETTING 14 acute-care hospitals (8 regional hospitals, 6 medical centers) in Taiwan. PARTICIPANTS A systematic probability sample from each hospital, totaling 663 adult inpatients who were discharged or had died in early 1999. MEASUREMENTS Infectious disease physicians at the 14 hospitals collected data from medical records regarding patient demographics, hospitalization, discharge diagnosis, and antibiotics received. RESULTS A total of 447 (67%) patients received antibiotics for an overall rate of 813 antibiotic-days (number of days patients received each antibiotic)/1,000 patient-days. Both the proportion of beds in intensive care units ([ICUs] Pearson correlation coefficient [r], 0.67; 95% confidence interval [CI 95], 0.36-0.89; P<.01) and the proportion of patients admitted to surgical services (r, 0.66; CI 95, 0.20-0.88; P=.01) correlated with the mean patient rate of antibiotic-days/hospital-day (MPAUD). In contrast, we found no correlation between the proportion of patients who received antibiotics and the MPAUD. Using multiple linear regression, medical center status was the only independent predictor for increased MPAUD (regression coefficient [b], 0.15; CI 95, 0.05-0.24; P<.01). There was no correlation between pooled rates of antibiotic-days/hospital-day and any hospital demographic factors. First-generation cephalosporin (39%) and aminoglycoside (24%) use accounted for the majority of antibiotic-days. CONCLUSIONS Antibiotic use is greater in medical centers than in regional hospitals and appears to be independent of surgical case mix or the proportion of ICU beds. Determination of multiple, independent measures of antibiotic use may be necessary to understand the relation between antibiotic use and resistance in hospital.

Antimicrobial usage in ambulatory patients with respiratory infections in Taiwan, 2001.

BACKGROUND AND PURPOSE Excess use of antimicrobials by ambulatory patients is a determinant of antimicrobial resistance. This study investigated the types of illnesses for which antimicrobials were prescribed and the amounts prescribed with special emphasis on respiratory infections for the year in which the Bureau of National Health Insurance (BNHI) enforced a policy to restrict antimicrobials for upper respiratory infections. The number of ambulatory patients seen and the types of ambulatory facilities in Taiwan were also described. METHODS Raw data were obtained from the BNHI database on every 500 th visit in 2001. Medical diagnoses were categorized according to the ICD-9-CM system. Antimicrobial consumption was expressed in defined daily doses per 1000 population per day (DDD/1000/day). RESULTS Among the population of 22.3 million in Taiwan, there were 285.8 million ambulatory patient visits (12.8 per person), including 108.9 million visits (4.9 per person) for respiratory infections, of which 62.7 million (2.8 per person) were for upper respiratory infections (URI). Antimicrobial consumption was 19.83 DDD/1000/day [standard error (SE), 0.00055], of which 9.97 DDD/1000/day (SE, 0.00047) were for respiratory infections and 4.03 DDD/1000/day (0.00055) were for URI. 23.6% of visits for URI entailed a prescription for antimicrobials. About two-thirds (66.5%) of ambulatory patients were seen in clinics, mostly private ones, and 67.6% of all antimicrobials were received there. Aminopenicillins and cephalosporins constituted 35.2% and 19.5%, respectively, of antimicrobials prescribed. CONCLUSIONS Despite the new BNHI rule restricting antimicrobial usage for URI, Taiwan still has an excessive number of ambulatory patient visits, especially for respiratory infections and URI. The majority of antimicrobials used were for URI. They were mostly prescribed in private clinics rather than hospital outpatient departments.