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Biomedical subjects

V L Yu

Publications and source records attributed to V L Yu.

At least 37 records · Page 2Linked to original sources
PubMed2000

Antimicrobial resistance and clinical outcome of Bacteroides bacteremia: findings of a multicenter prospective observational trial.

There is debate regarding the correlation between in vitro susceptibility testing and clinical response to therapy for Bacteroides bacteremia. We conducted a prospective multicenter observational study of 128 patients with bacteroides bacteremia. Outcome was correlated with results of in vitro susceptibility testing of Bacteroides isolates recovered from blood and/or nonblood sites, determined with use of 3 end points: mortality at 30 days, clinical response (cure vs. failure), and microbiological response (eradication vs. persistence). The mortality rate among patients who received inactive therapy (45%) was higher than among patients who received active therapy (16%; P=.04). Clinical failure (82%) and microbiological persistence (42%) were higher for patients who received inactive therapy than for patients who received active therapy (22% and 12%, respectively; P=.0002 and.06, respectively). In vitro activity of agents directed at Bacteroides species reliably predicts outcome: the specificity was 97%, and positive predictive value was 82%. Antimicrobial susceptibility testing may be indicated for patients whose blood specimens yield Bacteroides species.

Adolescent↗
PubMed2000

Clinical manifestations and molecular epidemiology of late recurrent candidemia, and implications for management.

The aim of this study was to define the epidemiology and clinical manifestations of late recurrent candidemia. For this purpose, late recurrent candidemia was defined as an episode of candidemia occurring at least 1 month after the apparent complete resolution of an infectious episode caused by the same Candida sp. A total of five patients with recurrent candidemia were investigated. For all patients, isolates from the initial and recurrent episodes of candidemia were available for in vitro susceptibility testing and genetic characterization by DNA-based techniques. The results revealed the following salient features: prolonged duration between the initial and recurrent episodes (range, 1-8 months); recurrence of candidemia despite anti-fungal therapy; importance of retained intravascular catheters, neutropenia, and corticosteroids as factors predisposing to recurrence; high morbidity and mortality; no emergence of antifungal drug resistance between the initial and recurrent episodes; and relapse of infection due to the original infecting strain, rather than reinfection with a new strain. These findings raise several issues about the management and follow-up of patients with candidemia, which require assessment in future studies.

Aged↗
PubMed2000

Legionella as a cause of severe pneumonia.

Legionella pneumophila has been found to be a common cause of community-acquired pneumonia in patients who required intensive care unit (ICU) admission. In many studies, the clinical manifestations for Legionnaires' disease were more severe and the mortality was higher when compared with pneumonias of other etiology. However, this may be due to delay in diagnosis and suboptimal antibiotic therapy, rather than enhanced virulence of L. pneumophila. A syndromic approach using high fever, diarrhea, mental status changes, hyponatremia, etc., may be useful in suggesting the correct diagnosis in patients with severe pneumonia, but this remains to be validated. The availability of Legionella diagnostic microbiology testing in-house (rather than being sent to an outside reference laboratory) maximizes the ability to correctly diagnose Legionnaires' disease. All patients with community-acquired pneumonia admitted to an ICU should undergo Legionella testing using the urinary antigen and culture on selective media. Moreover, we recommend routine cultures of the hospital water supply once a year (regardless of whether a case of nosocomial Legionnaires' disease has ever been diagnosed). If Legionella is found in the water supply, all patients with nosocomial pneumonia should undergo diagnostic tests for Legionella; empiric anti-Legionella antibiotics should be administered pending definitive diagnosis.

Journal Article↗
PubMed2000

Epidemiology of ciprofloxacin resistance and its relationship to extended-spectrum beta-lactamase production in Klebsiella pneumoniae isolates causing bacteremia.

A prospective study of Klebsiella pneumoniae bacteremia was performed in 12 hospitals in 7 countries. Of 452 episodes of bacteremia, 25 (5.5%) were caused by K. pneumoniae that was resistant in vitro to ciprofloxacin. Extended-spectrum beta-lactamase (ESBL) production was detected in 15 (60%) of 25 ciprofloxacin-resistant isolates, compared with 68 (16%) of 427 ciprofloxacin-susceptible strains (P=.0001). Multivariate analysis revealed that risk factors for ciprofloxacin resistance in K. pneumoniae included prior receipt of a quinolone (P=.0065) and an ESBL-producing strain (P=.012). In all, 18% of ESBL-producing isolates were also ciprofloxacin-resistant. Pulsed-field gel electrophoresis showed that 11 of the 15 ciprofloxacin-resistant ESBL-producing strains belonged to just 4 genotypes, suggesting that patient-to-patient transmission of such strains occurred. The close relationship between ESBL production and ciprofloxacin resistance is particularly worrisome because the first reported instance of plasmid-mediated ciprofloxacin resistance has been in an isolate of K. pneumoniae also possessing an ESBL.

Anti-Infective Agents↗
PubMed2000

Short-course empiric antibiotic therapy for patients with pulmonary infiltrates in the intensive care unit. A proposed solution for indiscriminate antibiotic prescription.

Inappropriate antibiotic use for pulmonary infiltrates is common in the intensive care unit (ICU). We sought to devise an approach that would minimize unnecessary antibiotic use, recognizing that a gold standard for the diagnosis of nosocomial pneumonia does not exist. In a randomized trial, clinical pulmonary infection score (CPIS) (Pugin, J., R. Auckenthaler, N. Mili, J. P. Janssens, R. D. Lew, and P. M. Suter. Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid. Am. Rev. Respir. Dis. 1991;143: 1121-1129) was used as operational criteria for decision-making regarding antibiotic therapy. Patients with CPIS </= 6 (implying low likelihood of pneumonia) were randomized to receive either standard therapy (choice and duration of antibiotics at the discretion of physicians) or ciprofloxacin monotherapy with reevaluation at 3 d; ciprofloxacin was discontinued if CPIS remained </= 6 at 3 d. Antibiotics were continued beyond 3 d in 90% (38 of 42) of the patients in the standard as therapy compared with 28% (11 of 39) in the experimental therapy group (p = 0.0001). In patients in whom CPIS remained </= 6 at the 3 d evaluation point, antibiotics were still continued in 96% (24 of 25) in the standard therapy group but in 0% (0 of 25) of the patients in the experimental therapy group (p = 0.0001). Mortality and length of ICU stay did not differ despite a shorter duration (p = 0.0001) and lower cost (p = 0.003) of antimicrobial therapy in the experimental as compared with the standard therapy arm. Antimicrobial resistance, or superinfections, or both, developed in 15% (5 of 37) of the patients in the experimental versus 35% (14 of 37) of the patients in the standard therapy group (p = 0.017). Thus, overtreatment with antibiotics is widely prevalent, but unnecessary in most patients with pulmonary infiltrates in the ICU. The operational criteria used, regardless of the precise definition of pneumonia, accurately identified patients with pulmonary infiltrates for whom monotherapy with a short course of antibiotics was appropriate. Such an approach led to significantly lower antimicrobial therapy costs, antimicrobial resistance, and superinfections without adversely affecting the length of stay or mortality.

Aged↗
PubMed2000

Rational empiric antibiotic prescription in the ICU.

The prescribing of antibiotics in the ICU is usually empiric, given the critical nature of the conditions of patients hospitalized there. Appropriate antibiotic utilization in this setting is crucial not only in ensuring an optimal outcome, but in curtailing the emergence of resistance and containing costs. We propose that research in the ICUs is vitally important in guiding antibiotic prescription practices and, therefore, the achievement of above-stated goals. There is wide institutional diversity in the relative prevalence of predominant pathogens and their antimicrobial susceptibilities, and within individual ICUs there exist unique patient populations with varying risks for and susceptibilities to infections and specific pathogens. Appropriate antibiotic prescription practices should be formulated based on surveillance studies and research at individual ICUs; these goals can be accomplished utilizing existing resources.

Anti-Bacterial Agents↗
PubMed1999

Nasal carriage of and infection with Staphylococcus aureus in HIV-infected patients.

BACKGROUND: Staphylococcus aureus is a common cause of serious infection in patients infected with HIV. OBJECTIVES: To evaluate risk factors for and quantitative effect of S. aureus infection in HIV-infected patients, with special attention to nasal carriage. DESIGN: Prospective, multihospital cohort study. SETTING: Three tertiary care Veterans Affairs Medical Centers. PARTICIPANTS: 231 ambulatory HIV-infected patients. RESULTS: Thirty-four percent of patients were nasal carriers of S. aureus. Of these patients, 38% were persistent carriers and 62% were intermittent carriers. Twenty-one episodes of infection occurred in 13 patients: Ten were bacteremias (including 2 cases of endocarditis), 1 was pneumonia, and 10 were cutaneous or subcutaneous infections. Seventeen (85%) of these episodes occurred in patients with CD4 counts less than 100 cells/mm3. Recurrent infections occurred in 3 of 7 patients who survived an initial S. aureus infection. The mortality rate was higher among patients with S. aureus infection than among those without infection (P = 0.03). Factors significantly associated with S. aureus infection were nasal carriage, presence of a vascular catheter, low CD4 count, and neutropenia. Molecular strain typing indicated that for 6 of 7 infected patients, the strain of S. aureus isolated from the infected sites was the same as that previously cultured from the nares. CONCLUSION: Nasal carriage is an important risk factor for S. aureus infection in HIV-infected patients. Controlled studies are indicated to determine whether eradication of nasal carriage in a selected subset of patients (for example, those with a low CD4 cell count) might prevent invasive S. aureus infection in patients with HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1999

Combination antibiotic therapy versus monotherapy for gram-negative bacteraemia: a commentary.

Whether combination antimicrobial therapy is more efficacious than monotherapy for gram-negative bacteraemia remains controversial. Although there are theoretical advantages to combination therapy that are buttressed by in vitro and animal studies, the data from studies of patients with gram-negative bacteraemias have been conflicting. A review of selected clinical studies suggests that combination therapy is associated with improved outcome typically only in severely ill patients and its efficacy may be further limited to those with Pseudomonas aeruginosa, Klebsiella spp. or Enterobacter spp. bacteraemia.

Anti-Bacterial Agents↗
PubMed1998

Treatment options for chronic prostatitis due to vancomycin-resistant Enterococcus faecium.

Prostatitis due to vancomycin-resistant enterococci has not been previously described. Reported here is a case of chronic prostatitis due to Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin and doxycycline, in a 42-year-old liver transplant recipient. Treatment with a combination of rifampin and nitrofurantoin for 6 weeks resulted in long-lasting cure. Other antimicrobial agents active in vitro against vancomycin-resistant enterococci, such as quinupristin/ dalfopristin and chloramphenicol, are unlikely to achieve sufficient prostatic tissue levels to be successfully utilized for treatment of this condition.

Adult↗
PubMed1998

Nosocomial legionnaires' disease discovered in community hospitals following cultures of the water system: seek and ye shall find.

BACKGROUND: The reservoir for hospital-acquired legionnaires' disease is the water distribution system. The Allegheny County (Pa.) Health Department recommended environmental cultures for all health care facilities for the prevention of hospital-acquired Legionella infection including facilities with no known cases of legionnaires' disease. METHODS: Environmental cultures of hot water tanks, faucets, and showerheads were performed in six health care facilities according to health department guidelines. If hot water tanks, faucets, or showerheads yielded Legionella, monitoring with Legionella culture and urinary antigen was performed for all cases of nosocomial pneumonia. RESULTS: Legionella was isolated from the water distribution system in 83% (five of six) of facilities. Three facilities dropped out of the study; two decided to disinfect the water and one had no Legionella in the water system. The other three facilities all discovered cases of legionnaires' disease during the 1-year study period after introduction of Legionella testing. L. pneumophilia, serogroups 1, 3, and 5, caused 12 cases of hospital-acquired legionnaires' disease. Positive diagnostic tests included: 10 of 12 (83%) urinary antigen, 6 of 8 (75%) respiratory cultures, and 2 of 5 (40%) serology. Molecular typing confirmed that the source of infection was the water supply in two hospitals. CONCLUSION: Routine environmental cultures for Legionella in the water distribution system are recommended even if the hospital had not previously recognized cases of hospital acquired legionnaires' disease. The Allegheny County Health Department guidelines were inexpensive to implement and resulted in the discovery of cases that would have otherwise been undiagnosed.

Cross Infection↗