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Biomedical subjects

J E Stout

Publications and source records attributed to J E Stout.

At least 19 recordsLinked to original sources
PubMed2006

Effect of flow regimes on the presence of Legionella within the biofilm of a model plumbing system.

AIMS: Stagnation is widely believed to predispose water systems to colonization by Legionella. A model plumbing system was constructed to determine the effect of flow regimes on the presence of Legionella within microbial biofilms. METHODS AND RESULTS: The plumbing model contained three parallel pipes where turbulent, laminar and stagnant flow regimes were established. Four sets of experiments were carried out with Reynolds number from 10,000 to 40,000 and from 355 to 2,000 in turbulent and laminar pipes, respectively. Legionella counts recovered from biofilm and planktonic water samples of the three sampling pipes were compared with to determine the effect of flow regime on the presence of Legionella. Significantly higher colony counts of Legionella were recovered from the biofilm of the pipe with turbulent flow compared with the pipe with laminar flow. The lowest counts were in the pipe with stagnant flow. CONCLUSIONS: We were unable to demonstrate that stagnant conditions promoted Legionella colonization. SIGNIFICANCE AND IMPACT OF THE STUDY: Plumbing modifications to remove areas of stagnation including deadlegs are widely recommended, but these modifications are tedious and expensive to perform. Controlled studies in large buildings are needed to validate this unproved hypothesis.

Bacterial Adhesion↗
PubMed2006

Tuberculosis knowledge and attitudes among physicians who treat young children in North Carolina, USA.

SETTING: North Carolina, USA. OBJECTIVE: To understand physicians' knowledge and attitudes toward the treatment of young children with latent tuberculosis infection (LTBI) in a low-incidence region. DESIGN: Cross-sectional survey of 525 pediatricians and 525 family practitioners in North Carolina. RESULTS: Of 1050 surveys mailed, 149 (14%) were returned. In the previous year, 96% of responding physicians had treated children who had emigrated from a tuberculosis (TB) endemic country. During the last 2 years, 84% of physicians had not diagnosed any young children with TB disease, and 46% had not treated any young children with LTBI. Most (83%) physicians routinely placed tuberculin skin tests (TSTs), and 26% reported placing > 10 TSTs per month. Experience in treating children with LTBI was the only predictor of TB knowledge. Physicians were particularly confused about two issues: 1) TST among bacille Calmette-Guérin (BCG) vaccinated children and 2) treatment of young children with recent exposure to an adult with infectious TB. CONCLUSIONS: Knowledge of important issues related to management of LTBI in children aged < 5 years was limited among physicians in an area with relatively low TB incidence. Creative methods must be developed to help physicians in low-incidence areas to appropriately diagnose and treat LTBI among young children.

Child, Preschool↗
PubMed2004

Risk factors for infective endocarditis in patients with enterococcal bacteremia: a case-control study.

BACKGROUND: Based on previous studies, enterococcal infective endocarditis (IE) is considered a unimicrobial, community-acquired disease of older Caucasian men. PATIENTS AND METHODS: We evaluated the relationship between enterococcal bacteremia and IE by comparing clinical and demographic characteristics of all cases of enterococcal IE within an 8-year period (n = 41) with controls randomly chosen from patients with enterococcal bacteremia without IE. RESULTS: By univariate and multivariable analyses, the presence of a prosthetic valve (PV) and infection with Enterococcus faecalis were significantly associated with IE, while age, gender, race, polymicrobial infection and community-acquired infection were not. Almost an equal number of women and men had enterococcal IE. Cases of enterococcal IE were commonly nosocomial (39%) and polymicrobial (17%). CONCLUSIONS: Enterococcal endocarditis can no longer be considered exclusively a unimicrobial, community-acquired disease of Caucasian men. Instead, our data suggest that the presence of a PV and infection by E. faecalis are associated with an increased risk for IE.

Adult↗
PubMed2001

Mycobacterium bovis peritonitis mimicking ovarian cancer in a young woman.

We describe a 27-year-old woman with peritonitis due to Mycobacterium bovis that initially appeared to be ovarian cancer. Clinicians should include this disease in the differential diagnosis of ovarian cancer and should consider laparoscopic diagnosis in the appropriate epidemiologic setting.

Adult↗
PubMed2001

Persistently positive culture results in a patient with community-acquired pneumonia due to Legionella pneumophila.

We describe a patient with community-acquired pneumonia due to Legionella pneumophila serogroup 6. This patient was found to have bronchoalveolar carcinoma of the lung by means of cytologic testing in 1 of 2 bronchoalveolar lavage samples, but no lesions were visible on bronchoscopy. Despite intravenous administration of azithromycin to the patient, repeat culture and polymerase chain reaction showed persistence of Legionella; the isolates remained susceptible to azithromycin. The patient did not respond to 14 doses of daily intravenously administered azithromycin. The poor outcome may have been partially due to the suspected underlying lung malignancy, as shown by cytologic examination, and by a delay in seeking medical attention.

Aged↗
PubMed2001

Unexpected similarity of pulsed-field gel electrophoresis patterns of unrelated clinical isolates of Legionella pneumophila, serogroup 1.

Phenotypic and genotypic methods identify subtypes of Legionella pneumophila, serogroup 1, and match patient and environmental isolates from suspected sources. The strength of this association is limited by the lack of information regarding the frequency and distribution of isolates belonging to various subtypes. In this study, 62 clinical isolates of L. pneumophila, serogroup 1, were subtyped by using pulsed-field gel electrophoresis (PFGE), to determine the distribution and degree of diversity of PFGE patterns among monoclonal antibody (MAb) subtypes. Unexpectedly, 8 of 21 MAb Philadelphia 1 isolates had a common PFGE pattern, and, among 12 MAb OLDA isolates, only 2 PFGE patterns were seen. Our hypothesis was that PFGE patterns were distributed randomly; however, statistical analysis showed that the distribution of subtypes was not random (Fisher's exact test 0.13; P>.05). In light of these results, researchers who do epidemiological investigations should use caution when interpreting the significance of matching PFGE patterns of L. pneumophila, serogroup 1.

Antibodies, Monoclonal↗
PubMed2001

Hospital management of tuberculosis in a region with a low incidence of tuberculosis and a high prevalence of nontuberculous mycobacteria.

We prospectively assessed the management of patients with suspected tuberculosis (TB) in an area with a high prevalence of nontuberculous mycobacteria (NTM) and a low incidence of TB. Clinicians' assessments were sensitive for TB but had poor predictive value. The acid-fast smear was a weak predictor of TB, owing to a high rate of isolation of NTM.

Clinical Competence↗
PubMed2000

Thrombocytopenia in liver transplant recipients: predictors, impact on fungal infections, and role of endogenous thrombopoietin.

BACKGROUND: Thrombocytopenia is a frequent and potentially serious complication in liver transplant recipients. The role of endogenous thrombopoietin level in posttransplant thrombocytopenia, has not been fully defined in liver transplant recipients. Additionally, there is accumulating evidence to suggest that platelets play a important role in antimicrobial host defense. METHODS: There were 50 consecutive liver transplant recipients studied. Variables predictive of thrombocytopenia, its impact on infectious morbidity and outcome, and serial thrombopoietin (TPO) serum concentration were assessed. RESULTS: The median pretransplant platelet count was 67 x 10(3)/cmm. After the liver transplantation, the median nadir platelet count was 33 x 10(3)/cmm and was reached a mean of 6 days after the transplant. A lower pretransplant platelet count (r= +.068, P=.0001), lower serum albumin before the transplants (r=+0.39, P=.014), longer operation time (r=0.27, P=.05), higher intraoperative packed red cells (r=0.28, P=.049) and fresh frozen plasma transfusions (r=0.42, P=.004), higher bilirubin at Day 7 (r=-.386, P=.005), and higher serum creatinine at Day 7 after the transplants (r=-.031, P=.025) correlated significantly with a lower nadir in platelets after the transplant. Nadir in platelet count was significantly lower in nonsurvivors compared with survivors (16 vs. 36 x 10(3)/cmm, P=.0001). Forty-three percent (9 of 21) of the patients with nadir platelet counts of < or =30 x 10(3)/cmm had a major infection within 30 days of the transplant compared with 17% (5 of 29) with nadir platelet counts > 30 x 10(3)/cmm (P=.04). Fungal infections occurred in 14% of the patients with nadir platelet counts of < or =30 x 10(3)/cmm versus 0% in those with nadir platelet counts of > 30 x 10(3)/cmm (P=.06); all patients with fungal infections had nadir platelet counts of < or =30 x 10(3)/cmm before fungal infection. Nadir in platelet count preceded the first major infection by a median of 7 days. Pretransplant TPO level did not differ between survivors (mean 103 pg/ml) or nonsurvivors (mean 144 pg/ml). After the transplantation, TPO levels increased in both groups. TPO level peaked at Day 7 and subsequently declined in survivors. Nonsurvivors had persistent thrombocytopenia despite a progressive rise in TPO level; TPO level was significantly higher at Day 7 (P=.02), Day 9 (P=.0019), and Day 14 (P=.04) in nonsurvivors compared with survivors. CONCLUSION: Persistent thrombocytopenia portended a poor outcome in liver transplant recipients and was not related to low TPO levels. Thrombocytopenia preceded infections and identified a subgroup of liver transplant patients susceptible to early major infections; its precise role in fungal infections warrants validation in larger studies.

Adult↗
PubMed2000

Legionnaires' disease in a newly constructed long-term care facility.

OBJECTIVES: To determine whether a newly-constructed long-term care facility would become colonized with Legionella and whether Legionnaires' disease would occur in residents of this new facility. DESIGN: Prospective environmental surveillance of the hospital's water distribution system for the presence of Legionella pneumophila during construction. Utilization of diagnostic tests for Legionnaires' disease in cases of nosocomial pneumonia. SETTING: The Pittsburgh VA Health Care System, Aspinwall Division, a two-building 400-bed complex. PARTICIPANTS: Six patients who acquired Legionnaires' disease while in the facility. INTERVENTION: Installation of copper-silver ionization systems. MEASUREMENTS: Isolation of L. pneumophila from potable water and the occurrence of Legionnaires' disease. RESULTS: L. pneumophila serogroup 1 was recovered from the water distribution system within 1 month of operation; 74% (61/82) of distal sites were positive during construction. In the first 2 years of occupancy, six cases of legionellosis were diagnosed. Both clinical isolates of L. pneumophila were identical to environmental isolates by pulsed field gel electrophoresis (PFGE). Copper-silver ionization systems were installed to control Legionella in the water system. CONCLUSIONS: We conclude that long-term care residents are at risk for acquiring nosocomial Legionnaires' disease in the presence of a colonized water system, even in a newly constructed building.

Aged↗
PubMed2000

Simplified protocol for pulsed-field gel electrophoresis analysis of Streptococcus pneumoniae.

A variety of pulsed-field gel electrophoresis (PFGE) protocols for the molecular subtyping of Streptococcus pneumoniae have been reported; most are time-consuming and complex. We sought to modify reference PFGE protocols to reduce the time required while creating high-quality gels. Only protocol modifications that resulted in high-quality banding patterns were considered. The following protocol components were modified. Lysis enzymes (lysozyme, mutanolysin, and RNase A) were deleted in a stepwise fashion, and then the lysis buffer was deleted. Lysis and digestion were accomplished in a single step with EDTA and N-lauroyl sarcosine (ES; pH 8.5 to 9.3) incubation at 50 degrees C in the absence of proteinase K. All enzymes except the restriction enzyme were omitted. A minimum incubation time of 6 h was required to achieve high-quality gels. All of the reactions were performed within 9 h, and the total protocol time from lysis to gel completion was reduced from 3 days to only 36 h. Combining lysis and digestion into a single step resulted in a substantial reduction in the time required to perform PFGE for S. pneumoniae. The ES solution may have caused cell lysis by activating N-acetylmuramyl-L-alanine amidase, the pneumococcal autolysin.

Bacterial Typing Techniques↗
PubMed1999

Analysis of Minnesota Multiphasic Personality Inventory-2 profiles of prospective anonymous oocyte donors in relation to the outcome of the donor selection process.

OBJECTIVE: To examine the scores of prospective anonymous oocyte donors on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) in four outcome groups. DESIGN: Chart review. SETTING: Academic medical center. PATIENT(S): One hundred fifty prospective anonymous oocyte donors who underwent a preliminary screening and a 1-hour structured psychological interview and who completed the MMPI-2. INTERVENTION(S): Psychological evaluation prior to donation. MAIN OUTCOME MEASURE(S): Scores on the MMPI-2 and outcomes of the donor selection process. RESULT(S): Seventy (47%) women were accepted as donors and completed one donation cycle; 30 (20%) were accepted as donors but did not donate because of medical reasons or relocation; 18 (12%) were accepted as donors but were noncompliant; and 32 (21%) were rejected as donors because of psychological concerns. Statistically significant differences were found between outcome groups on scales F, K, 1, 2, 7, 8, and 0. Although these differences were statistically significant, all group subscale mean scores were in the average to low-average range and differences between group means were small. CONCLUSION(S): The MMPI-2 differentiates between prospective donor outcome groups, but psychologists need to interpret the results of the MMPI-2 carefully in the context of clinical interview information.

Female↗
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↗