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V L Yu

Publications and source records attributed to V L Yu.

At least 55 records · Page 3Linked to original sources
PubMed1993

Growth of 28 Legionella species on selective culture media: a comparative study.

We compared the growth of 28 Legionella spp. on four manufacturers' buffered charcoal-yeast extract (BCYE) agar media and selective BCYE media that contained polymyxin B, anisomycin, and vancomycin or cefamandole. With BCYE as a "gold standard," growth for Legionella pneumophila was significantly better than for the nonpneumophila species on all media tested. L. pneumophila and 24 other Legionella spp. grew on vancomycin-containing media, while L. santicrucis, L. rubrilucens, and L. erythra grew poorly. In contrast, 11 of 28 species (notably L. micdadei and L. bozemanii) did not grow on cefamandole-containing media and 8 of 28 species only grew marginally. We demonstrated that selective BCYE media that contain vancomycin or cefamandole may not support the growth of all Legionella spp. One commercial manufacturer's media were consistently suboptimal. Laboratories should not rely on a manufacturer's quality control testing in lieu of their own.

Culture Media↗
PubMed1993

Roseomonas, a new genus associated with bacteremia and other human infections.

In the 1980s, a pink bacterium different from species of the genus Methylobacterium was implicated in human infection. Using biochemical tests and DNA hybridization, we examined 42 strains of pink-pigmented, gram-negative bacteria that were not members of the genus Methylobacterium. The isolates included 6 strains each of CDC "pink coccoid" groups I, II, III, and IV; 10 isolates from Gilardi's "unnamed taxon"; and 8 blood isolates from ill, debilitated, or immunosuppressed patients. The DNA hybridization studies supported the creation of six genomospecies encompassing the 42 strains. Reactions for esculin hydrolysis, glycerol oxidation, and D-mannose oxidation enabled separation of genomospecies 1 through 4. These tests, as well as motility, nitrate reduction, citrate utilization, and oxidation of L-arabinose, D-galactose, and D-xylose, differentiated genomospecies 5 and 6 from each other and from genomospecies 1 through 4. These organisms were susceptible in vitro to the aminoglycosides, tetracycline, and imipenem and generally susceptible to the quinolones. We propose the new genus, Roseomonas, for these bacteria to include three named species, Roseomonas gilardii sp. nov., Roseomonas cervicalis sp. nov., and Roseomonas fauriae sp. nov., and three unnamed genomospecies.

Bacteremia↗
PubMed1993

Aspects of lung transplantation that contribute to increased severity of pneumonia. An experimental study.

In lung or heart-lung transplant recipients, complications as a result of pulmonary infections continue to be the most frequent causes of morbidity and mortality. This study was undertaken to identify the contributions of (1) thoracotomy, (2) interruption of lymphatic vessels and bronchial arteries, (3) transplant procedure, (4) drug-induced immunosuppression, and (5) graft allogenicity to the increased risk of pneumonia in lung transplantation. Lewis rats were inoculated with 10(5) colony-forming units of Legionella pneumophila serogroup 1 by direct instillation into the trachea after one of the following: a general anesthetic with no operation; a left thoracotomy; a left thoracotomy with pulmonary hilar stripping; an isogeneic orthotopic left lung transplant with or without immunosuppression; or an allogeneic transplant with immunosuppression with Brown-Norway rats as donors. Immunosuppression was induced with an intramuscular injection of cyclosporine (25 mg/kg of body weight) from the inoculation day to day 3. All rats were killed on day 6, and severity of infection was determined by quantitative culture of Legionella organisms in the lungs and spleen, titer of Legionella urinary antigen, differential cell count in bronchoalveolar lavage fluid, body weight loss, and gross inspection of the lung. Significant increases in lung Legionella concentration occurred as a result of the addition of pulmonary hilar stripping (from 10(5.13 +/- 0.34) in the thoracotomy group to 10(5.66 +/- 0.25) in the thoracotomy with hilar stripping group, p = 0.013) and the addition of immunosuppression (from 10(5.47 +/- 0.47) in the isogeneic transplant group to 10(6.94 +/- 0.52) in the isogeneic transplant with immunosuppression group, p = 0.00016). Thoracotomy, transplant procedures, and allogenicity itself resulted in no significant increases. The results for all other indicators paralleled those for lung culture. We conclude that the combination of drug-induced immunosuppression with lung denervation and interruption of lymphatic vessels and bronchial arteries results in the early development and increased severity of pneumonia in lung transplantation.

Animals↗
PubMed1992

Postoperative wound infection. A poor prognostic sign for patients with head and neck cancer.

BACKGROUND: The development of a wound infection has been identified as a favorable prognostic factor after oncologic surgical procedures. METHODS: The authors retrospectively studied the relationship between postoperative wound infection, local/regional tumor recurrence, and survival rates in 134 patients undergoing therapeutic surgical resection for squamous cell carcinoma of the head and neck (SCCHN). RESULTS: The median age was 61 years (range, 25-87 years) with most (75%) patients having advanced disease (Stage III or IV). Patients without evidence of recurrent disease were followed up for a median time of 34 months (range, 24-68 months). Twenty-nine (22%) had local or regional bacterial infections develop postoperatively. Recurrence rates were increased (P = 0.008) in patients with postoperative wound infections compared with patients who had distant infections, e.g., pneumonia or urinary tract infection, or no infection. Disease-free survival also was adversely affected (P = 0.04) in this group. Both advanced tumor stage and postoperative wound infections were independently associated with decreased survival, with odds ratios of 2:3 and 2:4, respectively. CONCLUSIONS: These data contrast with other reports in the literature of a beneficial effect of postoperative wound infection on outcome. These findings suggest a possible relationship between local/regional immune function and postoperative infection in patients with SCCHN:

Adult↗
PubMed1992

Potable water as a cause of sporadic cases of community-acquired legionnaires' disease.

BACKGROUND: The environmental sources of sporadic, community-acquired legionnaires' disease are largely unknown, and culturing of water sources after identification of a case is currently not recommended. We conducted a prospective study of sporadic cases of community-acquired legionnaires' disease to determine whether the environmental reservoirs could be identified. METHODS: We cultured samples of potable water obtained from sources to which each of 20 patients with culture-confirmed, community-acquired legionnaires' disease had been exposed during the two weeks before the onset of symptoms. Monoclonal-antibody subtyping and restriction-endonuclease analysis were performed on the legionella isolates recovered from both the patients and the associated environmental cultures. RESULTS: For 8 of the 20 patients, isolates of Legionella pneumophila with identical subtypes were identified in cultures from both the patient and the potable water to which the patient had been exposed. The environmental reservoirs linked to the infections were the water supplies of two private residences, two nursing homes, two hospital outpatient clinics, and an industrial plant. CONCLUSIONS: Potable-water supplies that harbor L. pneumophila are an important source of community-acquired legionnaires' disease. Future studies should include attempts to identify the environmental sources of this infection.

Adult↗
PubMed1992

Erythromycin ototoxicity: prospective assessment with serum concentrations and audiograms in a study of patients with pneumonia.

BACKGROUND AND METHODS: The incidence and risk factors for erythromycin-induced ototoxicity are unknown. We conducted a prospective, nested case-control study of assessment of auditory function in patients receiving erythromycin versus other antibiotics (control group) for community-acquired pneumonia. Sequential audiograms were performed during antibiotic therapy for both cases and controls by an audiologist unaware of the identity of the therapy administered. Erythromycin serum concentrations were obtained for all patients receiving erythromycin. RESULTS: Symptomatic ototoxicity (tinnitus or hearing loss) confirmed by audiograms was documented in five of 30 patients receiving erythromycin and none of 15 receiving other antibiotics. Ototoxicity was significantly related to high peak concentration and high AUC 0-infinity as a function of decreased total systemic clearance. Ototoxicity occurred only in those patients who received 4 g/day versus 2 g/day or no erythromycin (p = 0.05). Ototoxicity resolved in all patients within 6 to 14 days after discontinuation of therapy. CONCLUSIONS: Erythromycin ototoxicity is dose- and serum concentration-dependent. Patients receiving erythromycin, especially at a total daily dose of 4 g, should be monitored regularly for subjective evidence of sensorineural hearing dysfunction. Ototoxicity is reversible if the diagnosis is made early in the course.

Adult↗
PubMed1992

Bacteremia in transplant recipients: a prospective study of demographics, etiologic agents, risk factors, and outcomes.

BACKGROUND: Bacteremic infections are a major cause of death among organ transplant recipients. We sought to identify the risk factors associated with death and examine the timing of the bacteremic episode after operation to recognize patients who may benefit from perioperative prophylactic antibiotic therapy. METHODS: A total of 125 episodes of bacteremia or fungemia in 16 heart, 26 kidney, and 70 liver recipients were monitored prospectively in 1 year. RESULTS: The urinary tract was the most frequent portal for kidney recipients, the gastrointestinal and biliary tracts were frequent for liver recipients, and the lung was frequent in heart recipients. Heart and liver recipients were more severely ill at the time of bacteremia and had bacteremia sooner after operation. Death at 14 days after onset of bacteremia was 33% in heart recipients, 24% in liver recipients, and 11% in kidney recipients. Risk of death was associated with the severity of the underlying condition of the transplant recipient, the source of the bacteremia, and the microbial agent. Pseudomonas aeruginosa and Enterobacter species had fatality rates of 47% and 63%, respectively. P. aeruginosa and Enterobacter were also most commonly associated with failures of perioperative antibiotic prophylaxis. CONCLUSIONS: There are distinct clinical patterns of bacteremia in transplant recipients. The emergence of P. aeruginosa and Enterobacter species in the immediate postoperative period appeared to be a significant cause of morbidity and death among transplant recipients.

Anti-Bacterial Agents↗
PubMed1992

Successful treatment of pulmonary infection due to Mycobacterium chelonae: case report and review.

During the past decade, Mycobacterium chelonae has been recognized with increasing frequency as a pulmonary pathogen. A review of previously reported cases reveals that most patients with pulmonary infections due to M. chelonae are nonimmunosuppressed but have underlying chronic lung disease. The infection is notably absent among blacks. M. chelonae organisms are characterized by a high degree of in vitro resistance to antituberculous drugs, and attempts at eradicating the organism through chemotherapy have been largely unsuccessful. The case of a 63-year-old previously healthy woman with progressive bilateral pulmonary disease due to M. chelonae is reported; she was treated successfully with a combination of cefoxitin and orally administered ciprofloxacin. Our experience supports the use of quinolones in combination with other active agents for the treatment of pulmonary infection due to M. chelonae.

Amikacin↗
PubMed1992

Osteomyelitis due to Veillonella parvula: case report and review.

Anaerobic gram-negative cocci of the genus Veillonella are generally normal flora of the oropharynx and upper respiratory tract. When isolated in clinical specimens, these bacteria are usually regarded as commensal organisms rather than as pathogens. We report a case of spinal osteomyelitis in which Veillonella parvula was isolated in pure culture from bone as well as blood. Osteomyelitis of the spine due to anaerobic bacteria may occur more frequently than has been recognized, and anaerobic cultures of biopsy specimens should be routinely performed.

Bacteremia↗
PubMed1992

Addition of rifampin to combination antibiotic therapy for Pseudomonas aeruginosa bacteremia: prospective trial using the Zelen protocol.

A multicenter, prospective randomized trial was conducted to determine if the addition of rifampin to a combination therapy of an antipseudomonal beta-lactam agent and aminoglycoside improves the outcome of patients with Pseudomonas aeruginosa bacteremia. The Zelen protocol for randomized-consent design was used. Consent was sought only from patients randomized to the experimental therapy (rifampin+). If the experimental therapy was refused, the patient would then receive the standard combination therapy (control); however, when outcome was evaluated, all patients randomized to the rifampin+ group, including those that declined rifampin, were compared with the control group. One hundred twenty-one consecutive hospitalized patients with positive blood cultures for P. aeruginosa were enrolled. Entry was stratified for prior use of empiric antipseudomonal antibiotics, neutropenia, severity of illness, and presence of pneumonia. Fifty-eight patients were randomized to receive rifampin (600 mg orally every 8 h for the first 72 h and then every 12 h for a total of 10 days) plus a beta-lactam agent plus an aminoglycoside. Sixty-three received the standard therapy of a beta-lactam plus an aminoglycoside agent (control). Bacteriologic cure occurred significantly more frequently in patients randomized to the rifampin+ regimen. Breakthrough or relapsing bacteremias occurred in 2% of the three-drug (rifampin+) group, compared with 14% for the two-drug (standard therapy) group. Despite this favorable trend in bacteriological response, no significant differences in survival were seen for the two treatment groups. Rifamycin derivatives warrant further clinical study as antipseudomonal agents. The Zelen protocol appears well suited for comparative trials of antimicrobial agents.

Aged↗
PubMed1992

Clinical demonstration of isolation of Nocardia asteroides on buffered charcoal-yeast extract media.

Nocardia asteroides was isolated only from sputum samples, obtained from three patients with pulmonary nocardiosis, that had been cultured onto buffered charcoal-yeast extract (BCYE) and selective BCYE media as part of laboratory workups for Legionella species. A decontamination procedure with low-pH pretreatment (KCl-HCl solution) had been performed on the sputa prior to culture onto the BCYE media because direct cultures on the media were overgrown with commensal microflora. Chalky white colonies, 0.5 to 1.0 mm in diameter, that were subsequently identified as N. asteroides grew well on the BCYE media. Thus, the techniques and the selective media used for Legionella species were useful for isolating Nocardia species from sputum.

Agar↗
PubMed1992

Cefamandole-susceptible strains of Legionella pneumophila serogroup 1: implications for diagnosis and utility as an epidemiological marker.

The standard selective Legionella medium that contains cefamandole failed to grow legionella pneumophila serogroup 1, subtype Bellingham, from a sputum sample from a patient with nosocomial Legionnaires' disease; the isolate did grow on a similar selective medium that substitutes vancomycin for cefamandole. Two Bellingham isolates from this patient's hospital environment also failed to grow when tested on the cefamandole medium. We tested 106 additional L. pneumophila serogroup 1 isolates that belonged to nine different monoclonal antibody subtypes and demonstrated that susceptibility to cefamandole was rare (10%) and limited to the Bellingham subtype. The diagnosis of Legionnaires' disease may be missed unless the culture protocol includes both a nonselective medium and a selective medium that does not contain cefamandole. In vitro susceptibility to cefamandole also provided an epidemiologic marker that linked a water source for a patient to nosocomial Legionnaires' disease.

Cefamandole↗
PubMed1992

The efficacy of perioperative antibiotic therapy on recovery following tonsillectomy in adults: randomized double-blind placebo-controlled trial.

One hundred and one adult patients undergoing tonsillectomy for chronic/recurrent tonsillitis completed a prospective, randomized, double-blind, placebo-controlled study in which ticarcillin disodium and clavulanate potassium (Timentin) or placebo was administered intravenously at the time of surgery and for 12 hours postoperatively. The patients than received oral amoxicillin and clavulanate potassium (Augmentin) therapy or placebo for an additional seven days. Each patient kept a daily log to assess the incidence and severity of postoperative symptoms. Tonsillar core tissue at the time of surgery, as well as tonsillar fossa cultures after 7 days of treatment, were obtained. Those patients who received antibiotics fared consistently better in the immediate postoperative period compared with the placebo group. Specifically, patients in the antibiotic group experienced significantly less mouth odor, were able to tolerate a regular diet sooner, and resumed their normal activities earlier than did patients who received placebo. Patients who received antibiotics experienced fewer days with mouth odor (p = 0.004). In addition, on postoperative days 3 to 5, the antibiotic group was eating a regular diet (p = 0.05) and had returned to their routine activities earlier (p = 0.045) when compared with the placebo group. Perioperative antibiotic therapy was well tolerated and was effective in minimizing symptoms after tonsillectomy.

Adolescent↗