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Biomedical subjects

P L Lu

Publications and source records attributed to P L Lu.

At least 19 recordsLinked to original sources
PubMed2001

Molecular epidemiology and mutations at gyrA and parC genes of ciprofloxacin-resistant Escherichia coli isolates from a Taiwan medical center.

Sixty-five ciprofloxacin-resistant clinical Escherichia coli isolates were collected from a Taiwan Medical Center from December 1998 to February 1999. All 65 clinical isolates were resistant (MICs > or = 4 microg/mL) to the following fluoroquinolones: ofloxacin, levofloxacin, sparfloxacin, and trovafloxacin. These isolates were cross-resistant to chloramphenicol (65 isolates, 100%), tetracycline (65 isolates, 100%), cefuroxime (64 isolates, 98.5%), ampicillin (57 isolates, 87.7%), gentamicin (53 isolates, 81.5%), and cephalothin (24 isolates, 36.9%). Pulsed-field gel electrophoresis (PFGE) revealed a high diversity among the genomes of these isolates and indicated that clonal spread was not responsible for the prevalence of ciprofloxacin resistance in the hospital. Sequencing of the polymerase chain reaction (PCR) amplified products of the quinolone resistance determining regions (QRDRs) of gyrA and parC showed that all isolates carrying double mutations in gyrA at codon 83 and 87 and at least one parC mutation at codon 80 and/or 84. The mutation at codon 83 of GyrA from serine to leucine (S83L) was present in all the clinical isolates. The most prevalent pattern was the S83L mutation and the mutation at codon 87 from an aspartate to an asparagine (D87N) of GyrA plus a mutation from a serine to an isoleucine (S80I) at codon 80 of ParC (63.2%). This indicated that the presence of high-level resistance to quinolones in clinical E. coli isolates were associated with mutations at hot spots, codon 83 and 87 in GyrA and followed by subsequent mutation in either codon 80 and/or 84 in ParC.

Anti-Infective Agents↗
PubMed2001

Emergence of reduced susceptibility and resistance to fluoroquinolones in Escherichia coli in Taiwan and contributions of distinct selective pressures.

A survey of 1,203 Escherichia coli isolates from 44 hospitals in Taiwan revealed that 136 (11.3%) isolates were resistant to fluoroquinolones and that another 261 (21.7%) isolates had reduced susceptibility. Resistance was more common in isolates responsible for hospital-acquired (mostly in intensive care units) infections (17.5%) than in other adult inpatient (11.4%; P = 0.08) and outpatient isolates (11.9%; P > 0.1). Similarly, reduced susceptibility was more common in isolates responsible for hospital-acquired infections (30.9%) than in other adult inpatient (21.0%; P = 0.04) and outpatient (21.4%; P = 0.06) isolates. Isolates from pediatric patients were less likely to be resistant (1.3 versus 12.0%; P < 0.01) but were nearly as likely to have reduced susceptibility (17.7 versus 21.9%; P > 0.1) as nonpediatric isolates. There was an inverse relationship in the proportion of isolates that were resistant versus the proportion that had reduced susceptibility among isolates from individual hospitals (R = 0.031; P < 0.05). In an analysis of isolates from two hospitals, all 9 resistant strains possessed double point mutations in gyrA and all 19 strains with reduced susceptibility strains had single point mutations; no mutations were found among fully susceptible strains. Risk factors for resistance included underlying cancer (odds ratio [OR], 83; 95% confidence interval [CI(95)], 7.3 to 2,241; P < 0.001), exposure to a quinolone (OR, undefined; P = 0.02), and exposure to a nonquinolone antibiotic (OR, 20; CI(95), 2.2 to 482; P < 0.001); underlying cancer was the only independent risk factor (OR, 83; CI(95), 8.6 to 807; P < 0.001). There were no significant associations between any of these factors and reduced susceptibility. Whereas acute and chronic quinolone use in cancer patients is a major selective pressure for resistance, other undetermined but distinct selective pressures appear to be more responsible for reduced susceptibility to fluoroquinolones in E. coli.

Adolescent↗
PubMed2000

Infective endocarditis complicated with progressive heart failure due to beta-lactamase-producing Cardiobacterium hominis.

We describe a 66-year-old woman with infective endocarditis due to Cardiobacterium hominis whose condition, complicated by severe aortic regurgitation and congestive heart failure, necessitated aortic valve replacement despite treatment with ceftriaxone followed by ciprofloxacin. The blood isolate of C. hominis produced beta-lactamase and exhibited high-level resistance to penicillin (MIC, >==256 microgram/ml) and reduced susceptibility to vancomycin (MIC, 8 microgram/ml).

Aged↗
PubMed2000

Application of pulsed-field gel electrophoresis to the investigation of a nosocomial outbreak of Vibrio parahaemolyticus.

The method of pulsed-field gel electrophoresis (PFGE) for Vibrio parahaemolyticus was first published in 1996. Since then, its application has been seldom reported in the literature. A food poisoning outbreak due to V. parahaemolyticus occurred in five wards of a hospital was investigated using this method. Twenty-five patients were involved and all of them had eaten food supplied by the hospital. Of the 15 cases whose stools were available for culture, only four cultures yielded V. parahaemolyticus. All four isolates were serotype K6 and were indistinguishable or closely related to each other based on PFGE patterns. Two isolates from food were recovered and they presented different characterizations from the patient isolates in both serotype and PFGE pattern. Successful typing by PFGE to identify the outbreak strain and differentiate V. parahaemolyticus strains between patient and food isolates in this study suggests the usefulness of PFGE for V. parahaemolyticus, the leading cause of food poisoning in Taiwan.

Cross Infection↗
PubMed2000

Bacteremia due to Campylobacter species: high rate of resistance to macrolide and quinolone antibiotics.

BACKGROUND AND PURPOSE: Although the rate of isolation of Campylobacter from stool specimens in Taiwan is similar to those in other developed countries, Campylobacter bacteremia has rarely been reported in Taiwan, and the patterns of antimicrobial susceptibility of blood isolates to various antimicrobial agents remain unknown in the Taiwanese population. The purpose of this study was to determine the clinical characteristics of patients with Campylobacter infection in a university hospital in Taiwan and the antimicrobial susceptibility patterns of the Campylobacter isolates. METHODS: We retrospectively reviewed medical records of all patients with Campylobacter bacteremia treated in a university hospital between January 1991 and March 1999. Minimum inhibitory concentrations of 13 antimicrobial agents to 10 stored blood isolates were determined using the E-test. RESULTS: Approximately half (52%) of the 21 patients had chronic liver disease and one-quarter had hepatobiliary or gastrointestinal malignancies. Thirteen (62%) patients had conditions that were associated with gastroenteritis. Other clinical manifestations associated with Campylobacter infection included cellulitis, perinatal sepsis, peritonitis, vascular catheter-related infection, and primary bacteremia. The duration of illness was generally short: approximately half (52%) of the 21 patients had fever lasting for only 1 day. Antimicrobial susceptibility testing of the 10 isolates revealed that most of the blood isolates were resistant to erythromycin and nalidixic acid (100% and 90%, respectively), while the rate of cross-resistance between erythromycin and azithromycin was 70%, and that between nalidixic acid and ciprofloxacin was 67%. CONCLUSIONS: Our observations suggest that Campylobacter bacteremia should be included in the differential diagnosis of patients with chronic liver disease or malignancies involving the hepatobiliary system or gastrointestinal tract who present with fever and gastroenteritis. Clinicians in Taiwan should be alert to the high rate of resistance of Campylobacter isolates to macrolide and quinolone antibiotics.

Adolescent↗
PubMed1999

Bacteremia due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a pediatric oncology ward: clinical features and identification of different plasmids carrying both SHV-5 and TEM-1 genes.

Thirteen patients who had 16 episodes of bacteremia were observed between 1993 and 1997 in a pediatric oncology ward with a high background isolation rate of cefotaxime- or aztreonam-resistant gram-negative bacteria. Four blood isolates were Escherichia coli and 12 were Klebsiella pneumoniae, and these isolates harbored extended-spectrum beta-lactamases (ESBLs). All episodes of bacteremia were nosocomial, all except one of the episodes occurred in neutropenic patients, and all patients were treated with piperacillin or ceftazidime with amikacin and cefazolin prior to the onset of bacteremia. Nine of 13 patients were receiving extended-spectrum beta-lactam treatment when the bacteremias caused by ESBL producers occurred. Molecular studies revealed that four K. pneumoniae SHV-2-producing isolates from 1994 were of the same clone. Other ESBL producers, including six that carried both TEM-1 and SHV-5, five that carried SHV-5, and one that carried SHV-2 alone, were unrelated. In conclusion, SHV-5 was present in 11 of the 16 isolates and coexisted with TEM-1 in 6 isolates. Acquisition of resistance genes probably occurred under antibiotic selection pressure. This study highlights the importance of routine checks for and detection of ESBL producers. Effective therapy against ESBL producers should be considered early for children who have malignancies and neutropenia and who are septic, despite treatment with a regimen that includes an extended-spectrum beta-lactam, in a clinical setting of an increased incidence of ESBL-producing bacteria.

Adolescent↗
PubMed1999

Epidemiological study of human salmonellosis during 1991-1996 in southern Taiwan.

Within a 6-year period from January 1991 to December 1996, 249 patients of salmonellosis admitted to Kaohsiung Medical College Hospital were enrolled for clinical and microbiological analysis. The number of patients increased by year from 1991 (14 patients) to 1996 (79 patients), especially in the case of nontyphoid salmonellosis. There were 57 different serotypes isolated during these period. Salmonella typhimurium was the most common clinical serotype of human origin in southern Taiwan, followed by S. choleraesuis, S. schwanzengrund, and S. derby. Fever (81.1%), diarrhea (68.9%), and anorexia (44.6%) were the most common manifestations of human salmonellosis. Relative bradycardia was a more important feature in S. typhi group (100%) than nontyphoid salmonellosis. Leukocytosis, especially lymphocytosis, was found especially in nontyphoid, but not in typhoid salmonellosis. Elevated liver function tests were found in the most severe patients, such as S. choleraesuis and S. typhi infections. Malignancy (8.8%), especially hematological malignancy (5.2%), gastrointestinal diseases (8.8%), and diabetes mellitus (6.4%) were the common underlying diseases. Case fatality rate of human salmonellosis was 8% (20/249), especially high in S. choleraesuis group. The severity of underlying diseases may be the major cause in S. choleraesuis group. There was no fatal case with typhoid fever. Very high resistance rate to commonly used antimicrobial agents in nontyphoid Salmonella was noted in southern Taiwan with overall rates of resistance to ampicillin, 67.9%, chloramphenicol, 66.7%, and TMP/SMZ, 42.2%. The emergence of ciprofloxacin-resistant and multiresistant strains was also a major therapeutic problem in this study.

Humans↗
PubMed1999

Salmonella choleraesuis bacteremia in southern Taiwan.

Within a 6-year period from January 1991 to December 1996, 19 patients with Salmonella choleraesuis bacteremia were enrolled for clinical and microbiological analysis. Young children, the elderly and patients with hematological malignancy (36.8%), liver cirrhosis (26.3%), systemic lupus erythematosus (10.5%), chronic renal impairment (10.5%), and peptic ulcer (10.5%) were at high risk of this infection. The ratio of male to female was 3:1. Three cases (15.8%) were nosocomially acquired. Fever (89.5%), chills (57.9%) and anorexia (52.6%) were the most common clinical manifestations. Seven patients (36.8%) presented no gastrointestinal manifestations. Normal white blood cell count was noted in seven patients (36.8%), and neutropenia caused by underlying diseases or severe infection was found in six cases (31.6%). Various types of metastatic focal infections were found, such as septic arthritis, cutaneous infection, spontaneous bacterial peritonitis, and pneumonia. The severe immunocompromised status of patients and the high virulence of this pathogen may contribute to the high case fatality rate (21%). Higher resistance rate to commonly used antimicrobial agents was noted in ampicillin (94.7%), chloramphenicol (89.5%), and TMP/SMZ (63.8%). All strains of S. choleraesuis were susceptible to third-generation cephalosporins and fluoroquinolones. Generally, S. choleraesuis bacteremia should be taken into account in the differential diagnosis of sepsis in immunocompromised patients, even without gastrointestinal manifestations. The third-generation cephalosporins and fluoroquinolones may be the first choice for treatment of this invasive infections.

Adolescent↗
PubMed1999

An indigenous melioidosis: a case report.

Melioidosis is a rare but potentially fatal infectious disease in Taiwan, although it has been endemic in Southeast Asia, especially northeast Thailand, and northern Australia. In this article, we report a male diabetes with fulminant pneumonia, and septicemia caused by Burkholderia pseudomallei without traveling abroad before this episode. Productive cough and intermittent chills, high fever for one week, followed by progressively deteriorating dyspnea, shock, disturbed consciousness status were the major presentations. Blood culture grew B. pseudomallei on the fifth admission day. Unfortunately, the patient died on the 9th admission day, despite intensive care and the broad-spectrum antimicrobial regimen used.

Adult↗
PubMed1999

Clones of Lactobacillus casei and Torulopsis glabrata associated with recurrent abdominal wall abscess.

Infectious disease caused by Lactobacillus sp has not been previously reported in Taiwan. We present a case of recurrent abdominal wall abscess in a chronically ill 36-year-old woman, and review the literature on Lactobacillus infection. Five isolates of L. casei were recovered from blood and pus samples, and two isolates of Torulopsis glabrata were isolated from two blood specimens 3 months apart. Two clones of L. casei and T. glabrata were identified by means of antibiotyping with the E test and molecular methods. The abscess was surgically removed because of poor response to 7 months of antimicrobial therapy for the second infectious episode. Recurrent Lactobacillus infection can occur in chronically ill or immunosuppressed patients. Treatment of these infections may require a longer duration of antibiotic therapy, or surgical intervention.

Abdominal Abscess↗
PubMed1998

Urinary 1-hydroxypyrene concentrations in coke oven workers.

OBJECTIVES: To investigate the relation of individual occupational exposure to total particulates benzene soluble fraction (BSF) of ambient air with urinary 1-hydroxypyrene (1-OHP) concentrations among coke oven workers in Taiwan. METHODS: 80 coke oven workers and 50 referents were monitored individually for the BSF of breathing zone air over three consecutive days. Exposures were categorised as high, medium, or low among coke oven workers based on exposure situations. The high exposure group (n = 18) worked over the oven. The medium and low exposure groups (n = 41 and n = 21) worked at the side of the oven for > 4 hours and < 4 hours a day, respectively. Urine was collected before the shift on the morning of day 1 and after the shift on the afternoon of day 3 to find the change of 1-OHP concentrations across the shift. RESULTS: The median (range) changes of urinary 1-OHP concentrations across the shift for various exposure situations (microgram/g creatinine) were as follows: high 182 (7 to 3168); medium 9 (-8 to 511); low 7 (-6 to 28); and referents 0.2 (-2 to 72). This change of urinary 1-OHP was highly associated with individual occupational exposure to the BSF in air (r = 0.74 and 0.64, p < 0.001). The regression model showed significant effects of individual exposures to the BSF and alcohol consumption on urinary postshift 1-OHP after adjusting for preshift 1-OHP in the total population (n = 130). More exposure to the BSF led to higher postshift 1-OHP (p < 0.001); current drinkers of > 120 g/week had lower urinary postshift 1-OHP than never and former drinkers (p = 0.01). A 10-fold increase in the average BSF in air resulted in about a 2.5-fold increase in postshift 1-OHP among the 80 coke oven workers. CONCLUSION: Urinary 1-OHP concentrations can be used as a good biomarker to assess individual exposure to the BSF in air. Alcohol drinking may modify the toxicokinetic pathway of the BSF; the effects of alcohol should be investigated further in occupational studies.

Adult↗
PubMed1998

Temporal changes in urinary 1-hydroxypyrene concentrations in coke-oven workers.

Coke-oven workers are exposed to high concentrations of coke-oven emissions, which are comprised mainly of polycyclic aromatic hydrocarbons. We conducted a pilot study to determine the time changes in urinary 1-hydroxypyrene (1-OHP) concentrations, as a metabolite of pyrene, in coke-oven workers after exposure to a benzene-soluble fraction (BSF) of total particulates. Thirteen subjects, including 2 men (referents) from an administrative area, 6 workers who work at the sideoven, and 5 who work on the top of the oven in one coke-oven plant were studied. After 1.5 to 2 days off, subjects were monitored individually for breathing zone air BSF over 3 consecutive days in August 1995. Seven spot urine samples, including preshift and postshift urine over 3 days and preshift urine on a fourth-day morning, were collected to determine 1-OHP concentrations by fluorescent spectrophotometry. The mean ambient BSF concentrations in the sideoven and topside oven workers ranged from 18 to 159 microg/m3 and from 251 to 1362 microg/ m3, respectively, whereas the BSF concentrations in the referents were low but detectable (11 and 29 microg/m3). Urinary 1-OHP concentrations increased during the work period, from 10+/-3 and 41+/-9 microg/g creatinine (mean+/-SE) on the preshift first day to 57+/-26 and 334+/-63 microg/g creatinine on the postshift third day in the sideoven and topside oven workers, respectively. However, the urinary 1-OHP concentrations were relatively flat in the two referents. The across-shift change in urinary 1-OHP defined as postshift 1-OHP on the third day minus preshift 1-OHP on the first day was highly associated with individual mean occupational exposure to air BSF (r = 0.80, P = 0.001). Repeated-measures regression analyses revealed that daily postshift 1-OHP concentrations were marginally associated with daily air BSF. A 10-fold increase of daily air BSF resulted in a 1.67-fold increase of daily postshift 1-OHP levels (95% confidence interval = 0.99-2.83; P = 0.07). After adjusting for daily preshift 1-OHP concentrations, we found that a 10-fold increase of daily air BSF resulted in a 1.90-fold increase of daily postshift 1-OHP levels (95% confidence interval = 1.10-3.28; P = 0.03). Although the sample size is small in this study, these results indicate that daily postshift 1-OHP levels in urine are determined mainly by current occupational exposure to coke-oven emissions.

Air Pollutants, Occupational↗
PubMed1995

Ascertainment corrected prevalence rate (ACPR) of leukopenia in workers exposed to benzene in small-scale industries calculated with capture-recapture methods.

ACPRs of leukopenia in peripheral blood of workers exposed to benzene in small-scale industries are calculated using capture-recapture methods. The results from two figures with 6-month apart demonstrate that the ACPR in workers exposed to benzene is 36.81(29.14-44)%, significantly higher than that of control 12.71(7.20-18.22)% (P < 0.05), with a relative risk of 2.9. The prevalences of 4 cross-sectional investigations in exposure group calculated with routine method are 18.73%, 26.37%, 27.93%, and 36.76% respectively; in controls, 8.38%, 6.85%, 7.94%, and 15.00% respectively and all fall in the range of 95% CI of ACPR. It is suggested that the methods of calculating ACPR by capture-recapture methods is simple, feasible and efficient, with the results more precise than with traditional methods.

Adult↗
PubMed1994

Respiratory disease in cotton textile workers: epidemiologic assessment of small airway function.

We performed a cross-sectional study of 705 textile workers in two cotton mills and one silk mill in Shanghai, People's Republic of China, to assess small airway function among cotton textile workers and to compare the FEV1 to the FEF25-75 in detecting airflow obstruction in these workers. All workers had at least 2 years of work experience. Environmental sampling was performed with vertical elutriators and revealed that in the cotton mills mean elutriated dust levels were 1.07 +/- 0.23 mg/m3 in mill 1 and 1.01 mg/m3 +/- 0.24 mg/m3 in mill 2. Mean endotoxin levels were 332 +/- 83 ng/m3 in mill 1 and 101 +/- 46 ng/m3 in mill 2. No differences were found in preshift FEV1 or FEF25-75 between cotton and silk workers. Cotton workers had significantly greater declines than silk workers in FEV1 across a workshift, but not in FEF25-75. These acute changes in FEV1 were noted in both byssinotic and nonbyssinotic workers. Although cotton dust may affect both large and small airways, spirometric measures of small airway function (e.g., FEF25-75) add little to the FEV1 and FVC in detecting airflow limitation in cotton dust-exposed workers.

Adult↗
PubMed1994

Cotton dust exposure, across-shift drop in FEV1, and five-year change in lung function.

To evaluate chronic loss of lung function in cotton dust-exposed workers, a 5-yr follow-up study was performed in Shanghai, China from 1981 to 1986. Workers at a nearby silk thread manufacturing mill were used as a control population. There were 384 cotton textile workers restudied from an original group of 446, and 403 silk workers restudied from the original 468. The presence of byssinosis among retested cotton workers at the time of first survey was 7.3%. The prevalence of byssinosis was 9.7% at the initial survey among those lost to follow-up. No byssinosis was found among control subjects. The mean annual decline in FEV1 was 39.5 ml among cotton workers and 30.6 ml for silk workers (p < 0.05). The greatest annual decrements were found among smoking cotton workers, but nonsmoking cotton workers also lost lung function at a faster rate than silk nonsmokers (annual loss = 33.3 ml versus 24.4 ml, respectively). Autoregressive modeling revealed that after adjustments for age, sex, height, and smoking, cotton dust exposure was significantly associated with decline in FEV1. Moreover, across-shift drop of 5% or more at the time of first survey was predictive of 5-yr decline in FEV1. Cotton workers who had an acute response (5% or greater drop in FEV1 at the time of first survey) suffered a 57.0 ml/yr FEV1 drop compared with a 35.1-ml drop among cotton workers with less acute response at baseline (p < 0.01). Silk workers with or without 5% across-shift drops had similar annual rates of decline (-33.8 ml and -36.1 ml, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Pulmonary function among cotton textile workers. A study of variability in symptom reporting, across-shift drop in FEV1, and longitudinal change.

Longitudinal variability in respiratory responses, including symptom reporting and across-shift change in ventilatory function, were examined in relation to long-term loss of ventilatory function in a group of 447 cotton textile workers in Shanghai, China. The study used a standardized respiratory questionnaire and standardized spirometric testing before and after a work shift on the first day of the workweek. Prediction equations for FEV1 were generated from a group of silk textile workers from the same city. Environmental samples included both vertical elutriated cotton dust and endotoxin levels. There was considerable variability in symptom reporting between the baseline and 5-year follow-up survey for all symptoms. However, subjects who consistently reported symptoms had a significantly accelerated 5-year loss in FEV1 compared with those who never reported symptoms. Subjects with symptoms of chest tightness or dyspnea at one survey lost FEV1 at a rate intermediate between the never or both groups. Moreover, subjects with an across-shift change in FEV1 of more than 5 percent at both surveys had the greatest loss in FEV1 over 5 years (-267 ml) when compared with one-time responders (-224 ml), and nonresponders (-180 ml), though the differences were not significant. Workers with chest tightness and chronic bronchitis in both surveys were overrepresented in the high dust and endotoxin areas. Our results indicate that even with substantial survey-to-survey variability in responses, there is important information contained in both questionnaires and across-shift spirometry. Among cotton workers, consistent responders to either symptom questionnaire or across-shift FEV1 decrements of > or = 5 percent appear to be at increased risk for lung function impairment.

Adult↗
PubMed1994

[Air plethysmography in the diagnosis of primary venous insufficiency of lower extremities].

Through the assessment 101 limbs of 77 subjects by air plethysmography (AP), we studied the method of AP test and the values of various indices in diagnosis of primary venous insufficiency (PVI). Venous filling index (VFI) was found valuable to quantitate the venous reflux with its value beyond the threshold of 5 ml/sec. It has a potential value to assess the effect of operations on PVI, such as valvuloplasty aiming to abolish venous reflux. Ejection fraction (EF) was found to be abnormal with its value less than 40%. It may be used to evaluate the function of calf pump quantitatively, predict the ulcer formation, and help make a decision of surgery timely. The comprehensive analysis of VFI, EF, RVF (residual volume fraction) and AVP (ambulatory venous pressure) indicated that there seems to be different types of PVI: type 1, low ejection (low EF) high venous reflux (high VFI); type 2, high ejection low venous reflux; type 3, low ejection low venous reflux. This new classification may impose some on the selection of adequate therapies, which will be further investigated.

Air↗