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K T Luh

Publications and source records attributed to K T Luh.

At least 127 records · Page 7Linked to original sources
PubMed1998

Drug resistance patterns of tuberculosis in Taiwan.

To evaluate the patterns of drug resistance of Mycobacterium tuberculosis in Taiwan, a total of 1,091 isolates collected from patients from January 1996 through December 1996 were tested for drug susceptibility using the absolute concentration method at the Taiwan Provincial Chronic Disease Control Bureau. The overall drug rate of resistance to at least one drug was 35.5%. Among the 249 isolates from patients who had never been treated for tuberculosis, 16.1% were resistant to one or more drugs; 1.6% were resistant to at least isoniazid and rifampin. Of 200 patients with prior antituberculosis treatment, 67.0% had isolates resistant to one or more drugs and 46.0% had isolates resistant to at least isoniazid and rifampin. We conclude that drug-resistant M. tuberculosis is an important issue in tuberculosis treatment in Taiwan, especially when dealing with patients with a prior history of antituberculosis treatment. More aggressive interventions, such as directly observed therapy, short-course, are needed to improve the cure rate of pulmonary tuberculosis and to decrease resistance rates.

Adolescent↗
PubMed1998

Antimicrobial susceptibility testing for Klebsiella pneumoniae isolates resistant to extended-spectrum beta-lactam antibiotics.

Detection of Klebsiella pneumoniae strains with extended-spectrum beta-lactamase (ESBL)-related resistance phenotypes is becoming important in clinical microbiology laboratories. In this study, we investigated the usefulness of three screening methods, the Etest ESBL screen, the double-disk synergy test, and the ceftazidime disk test, for identifying ESBL-producing K. pneumoniae strains. The agar dilution method was used as the standard. We also determined the in vitro activity of several new antimicrobial agents against these organisms. Strains that exhibited an increase in the minimum inhibitory concentration (MIC) to the third-generation cephalosporins or aztreonam of 2 micrograms/mL or more, but were susceptible to the three cephamycins tested, were considered to have ESBL-related resistance phenotypes. The frequency of ESBL-producing K. pneumoniae isolates (according to the disk-diffusion method) has increased markedly in recent years, from 3.4% in 1993 to 10.3% in 1997. A total of 93 preserved isolates of K. pneumoniae collected from December 1995 through March 1997 were found to be resistant to at least one of the third-generation cephalosporins (cefotaxime and ceftazidime) or aztreonam using the routine disk diffusion method. Among these isolates, 35 were classified as having an ESBL phenotype using the agar dilution method. The remaining 58 isolates were classified as cephamycin resistant, which indicated resistance to both cephamycins and third-generation cephalosporins or aztreonam. The susceptibility rates of the ESBL-producing isolates were 11% for cefotaxime, 14% for ceftazidime, and 6% for aztreonam. The susceptibility rates of these 35 isolates to imipenem, ciprofloxacin, and ofloxacin were 100%, 80%, and 86%, respectively. Both the MIC50 and MIC90 of meropenem were 0.06 microgram/mL, while the MIC50 and MIC90 of BAY 12-8039 were 0.125 and 2 micrograms/mL, respectively. Thirty-two (91%) of the 35 isolates of K. pneumoniae with the ESBL-related resistance phenotype were detected by the Etest ESBL screen, while the ceftazidime disk screen test detected 77% of these isolates, and the double-disk synergy test detected 74%. The Etest ESBL screen appears to be an acceptable, convenient, and sensitive method for the detection of ESBL-producing isolates in the clinical microbiology laboratory.

Anti-Infective Agents↗
PubMed1998

Bacteremia and fungemia in patients with advanced human immunodeficiency virus (HIV) infection in Taiwan.

To understand the etiology and clinical outcome of bacterial and fungal sepsis in patients with advanced human immunodeficiency virus (HIV) infection in Taiwan, we conducted a prospective study of nonmycobacterial bacteremia and fungemia in HIV-infected patients with fever who were admitted to a university hospital in Taiwan during a 42-month period. Of 210 patients, 41 (19.5%) had a total of 52 episodes of sepsis due to nonmycobacterial bacteria or fungi, or both (15.5% of 336 episodes of fever). All but one patient had acquired immunodeficiency syndrome (AIDS), and the mean CD4 lymphocyte count was 29/microL (range, 0-321/microL). A total of 57 pathogens (39 bacteria and 18 fungi) were isolated from blood; polymicrobial sepsis due to both bacteria and fungi occurred in four episodes. Nontyphoid Salmonella (NTS) was the most common cause of community-acquired bacteremia (24/30, 80%). Staphylococcus aureus bacteremia was diagnosed in three episodes while Streptococcus pneumoniae bacteremia was found in only one. Cryptococcus neoformans was the most common cause of fungemia and was responsible for 12 episodes, while fungemia due to Penicillium marneffei and Histoplasma capsulatum, two emerging fungi in Taiwan, were diagnosed in four cases and one case, respectively. Nine episodes, eight of bacteremia and one of candidemia, were nosocomial. The overall in-hospital mortality was 29%, and nosocomial sepsis was associated with a higher mortality rate (56%, p = 0.02). The mean duration of survival after recovery from initial sepsis was 426 days. We conclude that NTS bacteremia was the most common cause of sepsis in patients with advanced HIV infection in Taiwan and clinicians caring for such patients should watch for emerging fungal infections. Nosocomial sepsis was associated with a high mortality rate. The mean survival duration after recovery from sepsis of our patients was short.

AIDS-Related Opportunistic Infections↗
PubMed1998

Heterogeneity of resistance elements in clinical isolates of enterococci with high-level gentamicin resistance.

High-level resistance (minimum inhibitory concentration, MIC > 1,000 micrograms/ml) to gentamicin (HLGR) in enterococci is common in Taiwan. In this study, we investigated the distribution of gentamicin resistance elements in enterococci isolated at National Taiwan University Hospital in a 1-year period, and also examined the transfer and the genetic variability of the resistance elements of different isolates. Among 109 isolates tested, 43 (39%) HLGR isolates were identified. HLGR was most common in Enterococcus faecium isolates (7/15, 47%), followed by Enterococcus faecalis (34/80, 43%), Enterococcus avium (1/5, 20%), and Enterococcus casseliflavus (1/9, 11%). To understand the mechanism of resistance transfer, four isolates of E. faecalis and five isolates of E. faecium showing HLGR were studied. Transfer of resistance markers to a plasmid-free recipient strain of E. faecalis JH2-7 was observed, with transfer frequencies ranging from 10(-2) to 10(-8). All of the transconjugants contained plasmids, with sizes ranging from 45 kb to larger than 70 kb. At least three plasmid patterns were observed on digestion with HaeIII. Hybridization with a probe specific for the aac6'aph2" gentamicin resistance gene confirmed that all of these HLGR isolates carried a Gm(r) determinant, though the hybridization patterns of the plasmids from E. faecalis and E. faecium were different. Although many similarities exist among enterococcal Gm(r) determinants, the results suggest heterogeneity may occur in the flanking regions of resistance elements.

DNA Transposable Elements↗
PubMed1997

Increasing incidence of nosocomial Chryseobacterium indologenes infections in Taiwan.

To understand the clinical features, antimicrobial therapy, and epidemiology of Chryseobacterium indologenes infections, the medical records of 36 patients with nosocomial Chryseobacterium indologenes infections seen over a three-year period at National Taiwan University Hospital were reviewed. The 36 isolates recovered from these patients were studied by molecular typing and determination of antimicrobial susceptibility patterns. Nine patients had underlying neoplastic diseases, seven had diabetes mellitus, five had burn wounds, and four had uremia. The clinical syndrome included ten patients with intraabdominal infections, nine with wound sepsis, six with intravascular catheter-related bacteremia, and four with ventilator-associated pneumonia. Thirteen patients had monomicrobial bacteremia, and four had polymicrobial bacteremia. Nineteen patients (53%) developed infections associated with various indwelling devices. The deaths of five patients (14%) were directly attributable to infection with Chryseobacterium indologenes. All isolates recovered showed a wide range of resistance to commonly used antimicrobial agents. The random amplified polymorphic DNA (RAPD) patterns of the isolates differed from each other, indicating the absence of epidemiological relatedness among these isolates. Nosocomial infection caused by multiresistant Chryseobacterium indologenes appears to be an emerging problem in Taiwan and should be studied further.

Adolescent↗
PubMed1997

Haemophilus aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess in a patient with liver cirrhosis.

Haemophilus aphrophilus is rarely implicated as an aetiology of spinal epidural abscess. A 73-year-old woman with liver cirrhosis who developed H. aphrophilus bacteraemia complicated with vertebral osteomyelitis and spinal epidural abscess is presented. Without surgical decompression, she was successfully treated with cefotaxime for 3 weeks, followed by maintenance with ciprofloxacin for another 10 weeks. The clinical features of eight previously reported cases of vertebral osteomyelitis without epidural abscess due to H. aphrophilus are reviewed.

Abscess↗
PubMed1997

Outbreak of scarlet fever at a hospital day care centre: analysis of strain relatedness with phenotypic and genotypic characteristics.

An outbreak of scarlet fever involving 12 children occurred at a hospital day care centre from February to March 1996. Twenty-five throat isolates of Streptococcus pyogenes (GAS, group A streptococcus) available from 24 children, including 10 children with scarlet fever and 14 asymptomatic carriers, and one asymptomatic staff member were studied for the presence of genes encoding streptococcal pyrogenic exotoxin types A (speA), B (speB), and C (speC) and for protease activity. Antimicrobial susceptibilities using the E-test, cluster analysis by cellular fatty acid composition and random amplified polymorphic DNA (RAPD) patterns by means of arbitrarily-primed polymerase chain reaction (APPCR) of the isolates were performed to investigate the outbreak. Only one isolate from an asymptomatic child possessed the speA gene. All isolates possessed the speB gene and 24 (96%) isolates were positive for the speC gene. There was no difference in protease activity between isolates from children with scarlet fever and from asymptomatic carriers. Thirteen isolates (10 recovered from children with scarlet fever, two from asymptomatic children, and one from the staff member) were considered to be the same strain according to the identical antimicrobial susceptibility profile and RAPD patterns and were also considered to be similar by cluster analysis of fatty acid composition. These findings suggest that the outbreak was caused by a unique clone of GAS. We conclude that RAPD typing and cluster analysis by cellular fatty acids composition both provide a powerful tool for epidemiological investigation of GAS infections.

Child Day Care Centers↗
PubMed1997

In vitro activities of antimicrobial agents, alone and in combinations, against Burkholderia cepacia isolated from blood.

Burkholderia cepacia is a widespread, environmental gram-negative bacillus that is associated with nosocomial infections. This bacterium is considered to be an important pathogen in immunocompromised patients and is inherently resistant to multiple antimicrobial agents. To compare the activity of different antimicrobial agents and the potential of combinations against invasive strains of B. cepacia, we collected 36 isolates of B. cepacia from blood cultures and checked their susceptibilities to 13 antimicrobials by broth microdilution method. Most strains tested were susceptible to minocycline (94.4%), ceftazidime (86.1%), ciprofloxacin (83.3%), and trimethoprim-sulfamethoxazole (83.3%). All strains were resistant to aminoglycosides, and only some strains were susceptible to imipenem (16.7%), aztreonam (19.4%), moxalactam (25.0%), piperacillin (25.0%), and carbenicillin (47.2%). The effects of combinations of ceftazidime with amikacin, ceftazidime with ciprofloxacin, and ciprofloxacin with amikacin were assayed by checkerboard titration method. Synergistic effect was found in 28 out of 36 tested strains (77.8%), when ceftazidime was combined with amikacin, in 25 out of 36 strains (69.4%) when ceftazidime was combined with ciprofloxacin, and in only 8 out of 36 strains (22.2%) when ciprofloxacin was combined with amikacin.

Anti-Bacterial Agents↗
PubMed1997

The antimicrobial susceptibility of Mycobacterium chelonae isolated from corneal ulcer.

PURPOSE: To determine the in vitro susceptibility of Mycobacterium chelonae isolates from corneal ulcers to various traditional and newly-developed antimicrobial agents, alone or in combination. METHODS: Fifteen strains of M. chelonae isolated from corneal ulcers were collected at the National Taiwan University Hospital from 1989 to 1993. Susceptibility to antimicrobial agents was tested by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The antimicrobial effects of combinations of antimicrobial agents were assessed by the checkerboard titration method to determine the fractional inhibitory concentration (FIC) index. RESULTS: The MIC results showed that traditional antituberculous drugs had poor activity against M. chelonae. In the aminoglycoside group, tobramycin and amikacin had better activity than gentamicin. Among macrolides, clarithromycin was especially effective, with an MIC ranging from 0.125 to 1 microgram/ml. Among various beta-lactam antibiotics, imipenem was the only one to demonstrate good anti-mycobacterial activity. Of the quinolone group, ciprofloxacin was the most effective, with an MIC ranging from 0.5 to 16 micrograms/ml. Combination of an aminoglycoside with imipenem, ciprofloxacin or clarithromycin all showed antagonistic effect. CONCLUSIONS: The results suggested that amikacin, clarithromyicn, imipenem and ciprofloxacin had good in vitro antimicrobial activity against M. chelonae. However, no synergistic effect could be demonstrated for combinations of an aminoglycoside with other effective drugs.

Anti-Bacterial Agents↗
PubMed1997

Bacteremia due to Klebsiella oxytoca: clinical features of patients and antimicrobial susceptibilities of the isolates.

Forty-three patients with Klebsiella oxytoca bacteremia were seen between July 1980 and June 1996 at National Taiwan University Hospital (Taipei, Taiwan). We retrospectively analyzed the clinical features of these patients and the antimicrobial susceptibilities of the 43 isolates recovered from them. Twenty-seven patients (63%) had community-acquired bacteremia, and 16 patients (37%) had polymicrobial bacteremia. The clinical syndromes included hepatobiliary infections (58% of patients), primary bacteremia (23%), intravascular device-associated infections (7%), urinary tract infections (5%), skin and soft-tissue infections (5%), and peritonitis (2%). Most of these patients (93%) had underlying diseases including hepatobiliary diseases (53%), neoplastic diseases (42%), and diabetes mellitus (16%). Eight patients (19%) had septic shock, and two (5%) had disseminated intravascular coagulation. Four patients (9%) died of K. oxytoca bacteremia. All isolates were susceptible to ampicillin/sulbactam, cefmetazole, imipenem, aminoglycosides, and quinolones, and 86% of the isolates were susceptible to cefazolin.

Adolescent↗
PubMed1997

Secular trends in the epidemiology of nosocomial fungal infections at a teaching hospital in Taiwan, 1981 to 1993.

OBJECTIVE: To describe the incidence and patterns of nosocomial fungal infection in a large teaching hospital in Taiwan. DESIGN: Prospective, hospitalwide nosocomial surveillance data from 1981 through 1993 were analyzed to show the secular trend in nosocomial fungal infection rates and to identify the most common pathogens and sites of infection (other than skin) in this hospital. SETTING AND PATIENTS: The National Taiwan University Hospital is a medical school-affiliated hospital in the city of Taipei, Taiwan, with a 1200-bed capacity before 1991 and 1500 beds since 1992. It provides both primary and tertiary medical care. RESULTS: The overall nosocomial fungal infection rate rose from 0.9 infections per 1000 discharges in 1981 to 6.6 per 1000 discharges in 1993, with the highest rate at the medical intensive-care unit (26.5/1000 discharges in 1993). This increase in infection rate was found at four major anatomic sites of infection, particularly including the bloodstream (0.08-2.19/1000 discharges) and the urinary tract (0.36-2.95/1000 discharges). Of 256 pathogens causing nosocomial fungemia from 1981 through 1993, Candida albicans was the most commonly isolated (50.8%), followed by Candida tropicalis (17.6%). Candida parapsilosis (11.7%), and Candida glabrata (8.2%). As compared to isolates from 1981 through 1988, the proportion of C parapsilosis and C glabrata isolated between 1989 and 1993 increased more than sixfold and fourfold, respectively. The increasing importance of fungal infections was confirmed further by the increased use of amphotericin B and azoles in this hospital. CONCLUSIONS: Candida species and other yeasts have become a prominent cause of nosocomial infections in this hospital. These fungal pathogens accounted for a higher proportion of nosocomial bloodstream and urinary infections than any single bacterial species. Therefore, it is important to conduct a prospective epidemiological study and to establish in vitro antifungal susceptibility testing to enhance efforts to control nosocomial fungal infections and to minimize the risk of emergence of antifungal resistance.

Antifungal Agents↗
PubMed1997

Flavimonas oryzihabitans bacteremia: clinical features and microbiological characteristics of isolates.

Flavimonas oryzihabitans is rarely reported as a pathogen in humans. Twelve cases of F. oryzihabitans bacteremia were diagnosed at National Taiwan University Hospital over a 3-year period. The clinical features of these patients were analyzed, and antimicrobial susceptibilities and random amplified polymorphic DNA (RAPD) patterns of the 12 isolates were studied. Among these 12 patients, eight (67%) had underlying neoplastic diseases and all acquired F. oryzihabitans bacteremia while hospitalized. The clinical syndromes included primary bacteremia in 5 patients (42%), biliary tract infection in 3 (25%), and peritonitis, subdural empyema, infusion-related bacteremia, and pneumonia in 1 each. Polymicrobial bacteremia or concomitant fungemia was seen in three patients (25%). All the patients survived after antibiotic treatment. All isolates were susceptible to piperacillin, third-generation cephalosporins, aminoglycosides, and quinolones but resistant to cephalothin, cefuroxime, and trimethoprim. Susceptibility to aztreonam was variable (25%). The RAPD patterns differed among the isolates, indicating the epidemiological unrelatedness of these infections. F. oryzihabitans should be included as an etiology of severe nosocomial infection in patients with underlying debilitating diseases.

Adult↗
PubMed1997

Antimicrobial susceptibility of flavobacteria as determined by agar dilution and disk diffusion methods.

A total of 106 clinical isolates of flavobacteria, including 41 isolates of Flavobacterium meningosepticum, 59 of Flavobacterium indologenes, and 6 of Flavobacterium odoratum were collected from January 1992 to December 1995 from patients in Taiwan. The in vitro activities of antimicrobial agents were determined concomitantly by the standard agar dilution and disk diffusion methods. More than 90% of the flavobacterial isolates were resistant to cephalothin, cefotaxime, ceftriaxone, moxalactam, aztreonam, imipenem, aminoglycosides, erythromycin, and glycopeptides. The majority of F. meningosepticum isolates were susceptible to piperacillin and to minocycline but resistant to ceftazidime, with MICs at which 90% of the isolates are inhibited being 8, 4, and > 128 microg/ml, respectively. Approximately half of the F. indologenes isolates were susceptible to piperacillin, cefoperazone, ceftazidime, and minocycline, with MICs at which 50% of the isolates are inhibited being 4, 16, 8, and 4 microg/ml, respectively. The majority of F. odoratum isolates were resistant to all the antimicrobial agents tested except minocycline, to which five of six isolates were susceptible. With least-squares regression analysis and error rate-bounded analysis methods, the following resistant and susceptible zone diameter breakpoints were established: < or = 12 and > or = 17 mm, respectively, for piperacillin against F. meningosepticum and F. indologenes; < or = 13 and > or = 18 mm, respectively, for ceftazidime against F. meningosepticum and F. indologenes, < or = 17 and > or = 21 mm, respectively, for ofloxacin against F. indologenes; < or = 16 and > or = 20 mm, respectively, for ciprofloxacin against F. meningosepticum. Valid breakpoints for the disk diffusion method could not be established for cefoperazone and ofloxacin against F. meningosepticum and for minocycline against F. meningosepticum and F. indologenes due to a poor correlation coefficient for the regression line or for cefoperazone and ciprofloxacin against F. indologenes due to the presence of remarkable error rates.

Anti-Bacterial Agents↗
PubMed1997

Susceptibilities of Chryseobacterium indologenes and Chryseobacterium meningosepticum to cefepime and cefpirome.

In vitro activities of cefepime and cefpirome against 96 isolates of Chryseobacterium indologenes and 21 of C. meningosepticum were determined by the agar dilution method. Overall, cefepime was more active than cefpirome against C. indologenes (MIC at which 50% of the isolates were inhibited [MIC50] and MIC90, 4 and 16 microg/ml, respectively, for cefepime and 8 and 128 microg/ml, respectively, for cefpirome). Both agents had poor potency against C. meningosepticum (MIC50 and MIC90, 64 and >256 microg/ml, respectively, for cefepime and 128 and >256 microg/ml, respectively, for cefpirome).

Cefepime↗
PubMed1997

Bacteremia caused by Arcobacter cryaerophilus 1B.

Arcobacter cryaerophilus group 1B, a gram-negative, curved or helical bacillus primarily known as a bovine and porcine pathogen, was isolated from the blood of a uremic patient with hematogenous pneumonia. The patient was treated successfully with ceftizoxime and tobramycin.

Aged↗
PubMed1997

Comparison of Etest and agar dilution method for antimicrobial susceptibility testing of Flavobacterium isolates.

The Etest was evaluated as a possible alternative to the standard agar dilution method for susceptibility testing of nine antimicrobial agents against Flavobacterium species. In studies of 100 clinical isolates, the agreement between the MICs (+/-1 log2 dilution) obtained by the two methods was acceptable for cefotaxime, ceftazidime, amikacin, minocycline, ofloxacin, and ciprofloxacin (> 90%). Conversely, the agreement between the results obtained for piperacillin was limited (84%). The overall agreement was 92.5%.

Anti-Bacterial Agents↗
PubMed1997

Indwelling device-related bacteremia caused by serum-susceptible Campylobacter coli.

Two isolates of serum-susceptible Campylobacter coli were recovered in a 7-day interval from blood from a patient with hepatocellular carcinoma and liver cirrhosis whose peritoneal-caval (Denver's) shunt malfunctioned. Identical random amplified polymorphic DNA fingerprints, cellular fatty acid chromatograms, and antibiograms of the two isolates indicate that C. coli has the ability to cause catheter-related bacteremia following its colonization of the catheter.

Bacteremia↗